J Neurogastroenterol Motil 2024; 30(2): 208-219  https://doi.org/10.5056/jnm23090
Factors Associated With the Prevalence of Irritable Bowel Syndrome: The Miyagi Part of the Tohoku Medical Megabank Project Community-based Cohort Study
Kumi Nakaya,1,2* Naoki Nakaya,1,2 Mana Kogure,1,2 Rieko Hatanaka,1,2 Ippei Chiba,1,2 Ikumi Kanno,1,2 Satoshi Nagaie,1,2 Tomohiro Nakamura,1,2,3 Motoyori Kanazawa,2 Soichi Ogishima,1,2 Nobuo Fuse,1,2 Shin Fukudo,2 and Atsushi Hozawa1,2
1Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan; 2Graduate School of Medicine, Tohoku University, Sendai, Japan; and 3Faculty of Data Science, Kyoto Women’s University, Kyoto, Japan
Correspondence to: *Kumi Nakaya, PhD
Tohoku Medical Megabank Organization, Tohoku University, 2-1 Seiryo, Sendai, Miyagi 980-8573, Japan
Tel: +81-22-273-6212, E-mail: kumi.nakaya.b3@tohoku.ac.jp
Received: June 16, 2023; Revised: August 28, 2023; Accepted: October 16, 2023; Published online: April 30, 2024
© The Korean Society of Neurogastroenterology and Motility. All rights reserved.

cc This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Background/Aims
The objective of this research is to examine factors related to irritable bowel syndrome (IBS) prevalence in a large population-based study.
Methods
A cross-sectional study was conducted with participants in the Miyagi part of the Tohoku Medical Megabank Project Community-Based cohort study who completed the Rome II Modular Questionnaire. Multivariate odds ratios (ORs) for the presence of IBS and 95% confidence intervals (95% CIs) for the reference group were calculated for each factor. Additionally, a stratified analysis was performed by sex and age group (20-49 years, 50-64 years, and ≥ 65 years).
Results
Among 16 252 participants, 3025 (18.6%) had IBS, comprising 750 men (15.5%) and 2275 women (19.9%). Multivariate ORs for the presence of IBS decreased significantly with each year of age (OR, 0.98; 95% CI, 0.98-0.99). Moreover, compared with the reference group, ORs for the presence of IBS were significantly higher in individuals whose home was partially damaged by the Great East Japan Earthquake, those with < 16 years of education, those who spent less time walking, those with high perceived stress (1.77, 1.57-2.01), those with high psychological distress (1.58, 1.36-1.82), and those with high symptoms of depression (1.76, 1.60-1.94). In stratified analyses, a significant relationship was found between psychological factors and IBS prevalence in all sex and age groups.
Conclusions
This large cross-sectional population-based cohort study identified several factors associated with IBS prevalence. Psychological factors were significantly associated with IBS prevalence across all age groups and sexes.
Keywords: Cross-sectional studies; Irritable bowel syndrome; Prevalence; Tohoku Medical Megabank Project Community-based cohort study
Introduction

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder in which the gut-brain interaction has been implicated but the pathology is yet to be revealed.1 The prevalence varies depending on the study and region but is high, ranging from a few percent to 10% or more,2,3 and the deterioration of quality of life4,5 and high medical costs are issues worldwide.6

An elevated risk of IBS has been linked to sex, age, and psychological factors such as anxiety and depression, physical issues such as gastrointestinal infections, and social conditions.1,3,7 In a systematic review, 67 of 79 studies identified female sex as a risk factor for abdominal pain-related disorders of the gut–brain interaction, including IBS.7 A meta-analysis of 56 studies found that the odds ratio (OR) for IBS in women was 1.67 (95% confidence interval [95% CI], 1.53-1.82) compared with men.8 Younger people may also be more susceptible to IBS.2,9-11 According to the Rome IV criteria, applied in a global epidemiological study of 33 countries, the prevalence was 4.9% among those aged 18-39 years, 3.3% among those aged 40-64 years, and 1.9% among those aged ≥ 65 years.2 According to the Rome II or III criteria, the prevalence tended to be higher in younger age groups and decrease as age increased.2 There are many uncertainties about the mechanism underlying the high prevalence of IBS in women and/or younger age groups. On the other hand, sex differences are believed to be a consequence of sex hormones, as well as differences in central sensitivity to sensory stimuli.12,13 Furthermore, lifestyle habits and psychosocial backgrounds may differ depending on sex and age, which may influence the difference in IBS prevalence.14 The examination of risk factors stratified by sex and age would yield more detailed results on the pathogenesis of IBS.

The Miyagi part of the Tohoku Medical Megabank Project Community-based cohort study (TMM CommCohort Study), a large-scale genomic cohort research project, was conducted from May 2013 to March 2016, about 2 years after the Great East Japan Earthquake.15 Various health effects of large-scale disasters have been reported,16-18 and the prevalence of IBS might show disaster-related increases in stress and infections.3

The objective of this study is to cross-sectionally examine factors related to IBS prevalence using the Miyagi part of the TMM CommCohort Study, which has collected a variety of data such as psychological factors, physical issues, social conditions, earthquake impact, and lifestyle factors. Furthermore, we stratified by sex and age to examine the differences in the characteristics of each group.

Materials and Methods

Participants

The design of this cohort study has been described in detail elsewhere.15 The Miyagi part of the TMM CommCohort Study was a large-scale community-based cohort study containing information on a natural disaster, genomes, and metabolomes that was conducted from May 2013 to March 2016 and that targeted residents of Miyagi Prefecture aged ≥ 20 years.15 Miyagi Prefecture is one of the areas that suffered considerable damage in the Great East Japan Earthquake of March 11, 2011. The survey was performed at specific municipal health check-up sites or at community support centers, which were established by Tohoku Medical Megabank Organization (ToMMo) in 7 areas in Miyagi Prefecture. Participants visited the community support center voluntarily, which allowed them to undergo detailed physiological functional tests that cannot be measured at specific municipal health check-up sites. The presence of IBS was assessed in this study using the Rome II Modular Questionnaire19,20 at the community support center, which began in October 2013. The Rome II Modular Questionnaire was used in this survey because it was the only validated questionnaire for IBS in Japanese in 2013. The Japanese versions of the Rome III and Rome IV Diagnostic Questionnaires became available in 2015 and 2017,21,22 respectively. The Rome II Modular Questionnaire was administered using a tablet survey at the community support center and those who visited the center were included in this survey. The TMM CommCohort Study was approved by the Ethics Committee of ToMMo (first approval, 2012-4-617; latest approval, 2022-4-160) and the Medical Ethics Committee of Iwate Medical University (HG H25-2).

Of the 17 822 individuals who participated in additional testing at the community support center, we excluded 247 who withdrew their consent and 1323 who did not complete the Rome II Modular Questionnaire. As a result, our final analysis included 16 252 participants (Fig. 1).

Figure 1. Study flowchart.

Measurements

The questionnaire requested the following information from all participants: degree of damage to their home due to the disaster, educational history, marital status, underlying diseases, social networks (the Lubben Social Network Scale-6 [LSNS-6]),23,24 smoking status, drinking status, time spent walking, perceived stress, psychological distress (the Kessler 6-item psychological distress scale [K6]),25,26 and depressive symptoms (the Center for Epidemiological Studies Depression scale [CES-D]).27

The presence of IBS was evaluated using the Rome II Modular Questionnaire.19,20 Participants were considered to have IBS if they had experienced abdominal pain or discomfort at least once per week for at least 3 weeks in the previous 3 months and at least 2 of the following 3 symptoms: (1) pain or discomfort that improved or stopped after a bowel movement, (2) a change in the number of bowel movements when the pain or discomfort started, and (3) either softer or harder stools than usual when the pain or discomfort started.

Statistical Methods

The background characteristics were aggregated for the entire period and for each year separately. Each fiscal year corresponds to approximately 2 to 5 years after the Great East Japan Earthquake, and the aggregation for each fiscal year shows changes over time following the earthquake. Age and sex adjusted, and multivariate logistic regression analysis was used for the analysis. Prevalence of IBS was used as the dependent variable, and related factors included age, sex, degree of disaster damage, social factors (educational history, marital status, social isolation [LSNS-6]), lifestyle factors (smoking history, drinking history, and daily walking hours), and psychological factors (perceived stress, psychological distress [K6], and depression [CES-D]). ORs and 95% CIs for the reference group for each factor were calculated. In addition, a stratified analysis was performed by sex and age group (20-49 years, 50-64 years, and ≥ 65 years). The participants were divided into 3 age groups such that the number of participants did not differ significantly.

Results

A cross-sectional study was conducted on 16 252 individuals (4843 men and 11 409 women) who participated in the TMM CommCohort Study and completed the Rome II Modular Questionnaire. The characteristics of the whole period and of each fiscal year are shown in Table 1, and age-sex distribution of participants are shown in Figure 2. Over the whole period, 3025 participants had the presence of IBS (18.6%). Participants with IBS comprised 1031 (19.2%), 1213 (18.1%), and 781 (18.7%) in the first, second, and third fiscal years, respectively. Over the entire study period, the average ages of participants without IBS and with IBS were 58.5 (SD, 12.8) years and 54.4 (14.1) years, respectively. In all age groups, there were more female participants than male participants, with the greatest number of individuals aged 60 to 69 (Fig. 2). Furthermore, 69.1% of those without IBS and 75.2% of those with IBS were female, 16.4% of those without IBS and 14.5% of those with IBS had an educational background of 16 years or more, and 35.0% of those without IBS and 30.5% of those with IBS had a past history of hypertension. Regarding damage to the home as a result of the disaster, people whose home had considerable damage or was completely destroyed comprised 14.1% of those without IBS and 15.7% of those with IBS. Furthermore, the prevalence of IBS increased with the degree of disaster damage to the home in each year and in the whole period, in the order of not living in the disaster area or no damage, partial damage or moderate destruction, and considerable damage or complete destruction (Fig. 3). Over the entire period, the prevalence of IBS was 17.6% for those who did not live in the disaster area or had no damage, 18.8% for those who had partial damage or moderate destruction, and 20.3% for those who had considerable damage or complete destruction.

Figure 2. Age-sex distribution of participants (N = 16 252).

Figure 3. Prevalence of irritable bowel syndrome by year and degree of damage to the home due to the disaster.

Table 1 . Characteristics of Participants by Fiscal Year

CharacteristicsFirst fiscal yearSecond fiscal yearThird fiscal yearWhole period
2013.10-2014.32014.4-2015.32015.4-2016.32013.10-2016.3
All subjectsIBSAll subjectsIBSAll subjectsIBSAll subjectsIBS
AbsencePresenceAbsencePresenceAbsencePresenceAbsencePresence
Number of participants53674336 (80.8)1031 (19.2)67155502 (81.9)1213 (18.1)41703389 (81.3)781 (18.7)16 25213 227 (81.4)3025 (18.6)
Age (yr)57.9 ± 12.758.5 ± 12.555.4 ± 13.258.1 ± 13.159.0 ± 12.654.1 ± 14.457.1 ± 13.857.8 ± 13.453.7 ± 14.957.8 ± 13.258.5 ± 12.854.4 ± 14.1
Female sex3687 (68.7)2907 (67.0)780 (75.7)4753 (70.8)3854 (70.0)899 (74.1)2969 (71.2)2373 (70.0)596 (76.3)11 409 (70.2)9134 (69.1)2275 (75.2)
Education
≤ 12 yr3095 (57.7)2504 (57.7)591 (57.3)3848 (57.3)3168 (57.6)680 (56.1)2213 (53.1)1808 (53.3)405 (51.9)9156 (56.3)7480 (56.6)1676 (55.4)
13-15 yr1366 (25.5)1070 (24.7)296 (28.7)1784 (26.6)1431 (26.0)353 (29.1)1151 (27.6)913 (26.9)238 (30.5)4301 (26.5)3414 (25.8)887 (29.3)
≥ 16 yr805 (15.0)673 (15.5)132 (12.8)1022 (15.2)852 (15.5)170 (14.0)774 (18.6)639 (18.9)135 (17.3)2601 (16.0)2164 (16.4)437 (14.5)
Unknown101 (1.9)89 (2.1)12 (1.2)61 (0.9)51 (0.9)10 (0.8)32 (0.8)29 (0.9)3 (0.4)194 (1.2)169 (1.3)25 (0.8)
Damage to home due to the disaster
Not living in the disaster area or no damage1445 (26.9)1187 (27.4)258 (25.0)1933 (28.8)1606 (29.2)327 (27.0)1216 (29.2)998 (29.4)218 (27.9)4594 (28.3)3791 (28.7)803 (26.5)
Partial damage or moderate destruction2755 (51.3)2213 (51.0)542 (52.6)3687 (54.9)3015 (54.8)672 (55.4)2291 (54.9)1863 (55.0)428 (54.8)8733 (53.7)7091 (53.6)1642 (54.3)
Considerable damage or complete destruction950 (17.7)755 (17.4)195 (18.9)872 (13.0)696 (12.6)176 (14.5)520 (12.5)416 (12.3)104 (13.3)2342 (14.4)1867 (14.1)475 (15.7)
Unknown217 (4.0)181 (4.2)36 (3.5)223 (3.3)185 (3.4)38 (3.1)143 (3.4)112 (3.3)31 (4.0)583 (3.6)478 (3.6)105 (3.5)
Underlying diseases
Hypertension1714 (35.5)1422 (36.4)292 (31.5)2031 (34.0)1689 (34.7)342 (31.0)1241 (32.7)1038 (33.6)203 (28.5)4986 (34.1)4149 (35.0)837 (30.5)
Diabetes mellites671 (15.0)555 (15.4)116 (13.3)897 (16.3)746 (16.6)151 (15.0)597 (16.7)494 (17.0)103 (15.3)2165 (16.0)1795 (16.3)370 (14.5)
Hyperlipidemia1445 (31.3)1183 (31.9)262 (29.1)1833 (31.7)1512 (32.1)321 (30.1)1112 (30.2)921 (30.7)191 (27.8)4390 (31.2)3616 (31.6)774 (29.2)
Cancera408 (2.5)316 (2.4)92 (3.0)504 (3.1)417 (3.2)87 (2.9)306 (1.9)249 (1.9)57 (1.9)1218 (7.5)982 (7.4)236 (7.8)
Stroke120 (0.7)99 (0.7)21 (0.7)131 (0.8)112 (0.8)19 (0.6)77 (0.5)64 (0.5)13 (0.4)328 (2.0)275 (2.1)53 (1.8)
Myocardial infarction154 (0.9)123 (0.9)31 (1.0)192 (1.2)165 (1.2)27 (0.9)97 (0.6)81 (0.6)16 (0.5)443 (2.7)369 (2.8)74 (2.4)

aCancer includes gastric cancer, colorectal cancer, lung cancer, liver cancer, kidney cancer, pancreatic cancer, skin cancer, breast cancer, testis cancer, prostate cancer, brain tumor, leukemia, malignant lymphoma, multiple myeloma, ovarian cancer, uterine cervical cancer, and endometrial cancer.

IBS, irritable bowel syndrome.

Data are presented as n (%) or mean ± SD.



The association between the presence of IBS and basic characteristics, social factors, lifestyle factors, and psychological factors is shown in Table 2. The multivariate OR for IBS prevalence decreased significantly with each year of age (OR, 0.98; 95% CI, 0.98-0.99). In addition, the odds ratio of IBS was significantly higher among those whose home was partially damaged by the earthquake compared with no damage (OR, 1.12; 95% CI, 1.02-1.23), with less than 12 years of education compared with 16 years or more (OR, 1.20; 95% CI, 1.06-1.36), with 13 to 15 years of education compared with 16 years or more (OR, 1.21; 95% CI, 1.06-1.39), with less time spent walking compared with walking for 1 hour or more (OR, 1.10; 95% CI, 1.01-1.19), with high perceived stress compared with low perceived stress (OR, 1.77; 95% CI, 1.57-2.01), with high psychological distress compared with a K6 score less than 13 points (OR, 1.58; 95% CI, 1.36-1.82), and with high symptoms of depression compared with a CES-D score less than 16 points (OR, 1.76; 95% CI, 1.60-1.94).

Table 2 . Odds Ratios and 95% Confidence Intervals for the Presence of Irritable Bowel Syndrome

VariableIBSAge- and sex-adjusted odds ratioMultivariate adjusted odds ratio
AbsencePresenceOR (95% CI)P-valueOR (95% CI)P-value
Age (yr)58.5 ± 12.854.4 ± 14.10.98 (0.98-0.98)< 0.0010.98 (0.98-0.99)< 0.001
Sex
Male4093 (30.9)750 (24.8)1.0 (ref.)1.0 (ref.)
Female9134 (69.1)2275 (75.2)1.25 (1.14-1.37)< 0.0011.07 (0.96-1.21)0.220
Fiscal year
Third fiscal year3389 (25.6)781 (25.8)1.0 (ref.)1.0 (ref.)
Second fiscal year5502 (41.6)1213 (40.1)0.98 (0.89-1.08)0.6970.97 (0.87-1.07)0.508
First fiscal year4336 (32.8)1031 (34.1)1.06 (0.96-1.18)0.2721.03 (0.93-1.15)0.602
Damage to the home due to the disaster
Not living in the disaster area or no damage3791 (28.7)803 (26.5)1.0 (ref.)1.0 (ref.)
Partial damage or moderate destruction7091 (53.6)1642 (54.3)1.17 (1.06-1.28)0.0011.12 (1.02-1.23)0.022
Considerable damage or complete destruction1867 (14.1)475 (15.7)1.27 (1.12-1.45)< 0.0011.11 (0.98-1.27)0.111
Unknown478 (3.6)105 (3.5)1.14 (0.91-1.43)0.2451.05 (0.82-1.32)0.704
Social factors
Education
≥ 16 yr7480 (56.6)1676 (55.4)1.0 (ref.)1.0 (ref.)
13-15 yr3414 (25.8)887 (29.3)1.24 (1.08-1.41)0.0021.21 (1.06-1.39)0.006
≤ 12 yr2164 (16.4)437 (14.4)1.24 (1.10-1.40)< 0.0011.20 (1.06-1.36)0.004
Unknown169 (1.3)25 (0.8)0.85 (0.54-1.29)0.470.76 (0.47-1.19)0.249
Marital status
Married10 374 (78.4)2258 (74.6)1.0 (ref.)1.0 (ref.)
Single1039 (7.9)362 (12.0)1.12 (0.97-1.29)0.1161.03 (0.89-1.19)0.657
Separate689 (5.2)174 (5.8)1.06 (0.88-1.25)0.5440.95 (0.79-1.13)0.562
Widowed1001 (7.6)198 (6.5)1.07 (0.91-1.26)0.4121.02 (0.86-1.20)0.834
Unknown124 (0.9)33 (1.1)1.25 (0.83-1.83)0.2601.31 (0.85-1.96)0.207
Social isolation (LSNS-6 score)
Socially integrated (≥ 12)10 059 (76.0)2161 (71.4)1.0 (ref.)1.0 (ref.)
Socially isolated (< 12)2744 (20.7)777 (25.7)1.32 (1.20-1.45)< 0.0011.06 (0.96-1.17)0.218
Unknown424 (3.2)87 (2.9)1.04 (0.82-1.31)0.7540.94 (0.73-1.20)0.635
Lifestyle factors
Smoking
Never smoker8484 (64.1)1967 (65.0)1.0 (ref.)1.0 (ref.)
Ex-smoker3298 (24.9)668 (22.1)0.98 (0.88-1.09)0.6930.95 (0.85-1.07)0.398
Current smoker1379 (10.4)372 (12.3)1.10 (0.96-1.25)0.1871.00 (0.87-1.15)0.960
Unknown66 (0.5)18 (0.6)1.31 (0.75-2.16)0.3211.36 (0.76-2.32)0.284
Drinking
Non-drinker5658 (42.8)1289 (42.6)1.0 (ref.)1.0 (ref.)
Ex-drinker316 (2.4)78 (2.6)1.17 (0.89-1.50)0.2461.06 (0.81-1.37)0.671
Current drinker7235 (54.7)1656 (54.7)1.03 (0.95-1.12)0.5081.07 (0.98-1.17)0.134
Unknown18 (0.1)2 (0.1)0.63 (0.10-2.21)0.5420.55 (0.08-2.03)0.433
Time spent walking
≥ 1 hr6843 (51.7)1456 (48.1)1.0 (ref.)1.0 (ref.)
< 1 hr6197 (46.9)1513 (50.0)1.13 (1.04-1.22)0.0041.10 (1.01-1.19)0.029
Unknown187 (1.4)56 (1.9)1.56 (1.14-2.10)0.0051.44 (1.04-1.95)0.024
Psychological factors
Perceived stress
Not felt much or not at all3341 (25.3)363 (12.0)1.0 (ref.)1.0 (ref.)
A lot or moderate9839 (74.4)2657 (87.8)2.13 (1.89-2.41)< 0.0011.77 (1.57-2.01)< 0.001
Unknown47 (0.4)5 (0.2)0.95 (0.33-2.20)0.9140.75 (0.25-1.84)0.563
Psychological distress (K6 score)
Absence (< 13)12 460 (94.2)2599 (85.9)1.0 (ref.)1.0 (ref.)
Presence (≥ 13)669 (5.1)407 (13.5)2.49 (2.17-2.84)< 0.0011.58 (1.36-1.82)< 0.001
Unknown98 (0.7)19 (0.6)1.05 (0.62-1.68)0.8620.96 (0.55-1.61)0.885
Depressive symptoms (CES-D score)
Absence (< 16)10 099 (76.4)1770 (58.5)1.0 (ref.)1.0 (ref.)
Presence (≥ 16)2766 (20.9)1164 (38.5)2.21 (2.03-2.41)< 0.0011.76 (1.60-1.94)< 0.001
Unknown362 (2.7)91 (3.0)1.52 (1.19-1.91)< 0.0011.43 (1.11-1.82)0.005

IBS, irritable bowel syndrome; LSNS-6, the Lubben Social Network Scale-6; K6, the Kessler 6-item psychological distress scale; CES-D, the Center for Epidemiological Studies Depression scale.

Multivariate adjusted ORs are adjusted for all listed variables.

Data are presented as mean ± SD or n (%).

P < 0.05 was considered statistically significant.



Table 3 shows the results of a stratified analysis of factors associated with the presence of IBS by sex. In addition to significantly lower ORs for IBS with increasing age (OR, 0.98; 95% CI, 0.97-0.99), psychological factors were associated with significantly higher ORs for IBS in male participants. Similar to men, women had significantly higher ORs for psychological factors and significantly lower ORs for aging. Additionally, the OR for IBS was significantly higher among those whose home was partially damaged by the earthquake (OR, 1.20; 95% CI, 1.08-1.35) or who experienced considerable damage or complete destruction (OR, 1.18; 95% CI, 1.01-1.37) compared with no damage, those with 13 to 15 years of education (OR, 1.29; 95% CI, 1.08-1.53) or less than 12 years of education (OR, 1.27; 95% CI, 1.08-1.51) compared with 16 years or more, and those with less time spent walking compared with walking for 1 h or more (OR, 1.14; 95% CI, 1.04-1.26).

Table 3 . Multivariate Adjusted Odds Ratios and 95% Confidence Intervals for the Presence of Irritable Bowel Syndrome According to Sex

VariableMaleFemale
Number of participants484311 409
Prevalence of IBS (%)750 (15.5)2275 (19.9)
OR (95% CI)P-valueOR (95% CI)P-value
Age (numeric)0.98 (0.97-0.99)< 0.0010.99 (0.98-0.99)< 0.001
Fiscal year
Third fiscal year1.0 (ref.)1.0 (ref.)
Second fiscal year1.10 (0.90-1.35)0.3770.92 (0.82-1.04)0.187
First fiscal year1.04 (0.84-1.29)0.7131.03 (0.91-1.16)0.670
Damage to the home due to the disaster
Not living in the disaster area or no damage1.0 (ref.)1.0 (ref.)
Partial damage or moderate destruction0.92 (0.76-1.11)0.3591.20 (1.08-1.35)0.001
Considerable damage or complete destruction0.93 (0.71-1.20)0.5781.18 (1.01-1.37)0.034
Unknown0.93 (0.57-1.49)0.7791.08 (0.82-1.41)0.588
Social factors
Education
≥ 16 years1.0 (ref.)1.0 (ref.)
13-15 years1.09 (0.83-1.42)0.5431.29 (1.08-1.53)0.004
≤ 12 years1.11 (0.92-1.35)0.2811.27 (1.08-1.51)0.005
Unknown0.71 (0.31-1.48)0.3900.77 (0.41-1.34)0.372
Marital status
Married1.0 (ref.)1.0 (ref.)
Single1.01 (0.74-1.35)0.9741.04 (0.88-1.23)0.640
Separate0.74 (0.44-1.19)0.2410.98 (0.80-1.19)0.830
Widowed1.18 (0.67-1.95)0.5510.99 (0.83-1.18)0.900
Unknown1.20 (0.50-2.58)0.6671.29 (0.77-2.07)0.316
Social isolation (LSNS-6 score)
Socially integrated (≥ 12)1.0 (ref.)1.0 (ref.)
Socially isolated (< 12)0.94 (0.78-1.13)0.5001.12 (1.00-1.26)0.052
Unknown1.07 (0.66-1.68)0.7890.89 (0.66-1.18)0.425
Lifestyle factors
Smoking
Never smoker1.0 (ref.)1.0 (ref.)
Ex-smoker0.94 (0.78-1.14)0.5340.96 (0.84-1.11)0.614
Current smoker0.89 (0.71-1.13)0.3451.09 (0.91-1.30)0.339
Unknown1.46 (0.30-5.49)0.6031.30 (0.68-2.34)0.398
Drinking
Non-drinker1.0 (ref.)1.0 (ref.)
Ex-drinker1.49 (0.94-2.31)0.0780.91 (0.64-1.27)0.598
Current drinker1.23 (0.99-1.54)0.0601.04 (0.95-1.15)0.404
Unknown-0.76 (0.12-3.01)0.735
Time spent walking
≥ 1 hr1.0 (ref.)1.0 (ref.)
< 1 hr0.98 (0.83-1.16)0.8241.14 (1.04-1.26)0.007
Unknown1.55 (0.83-2.73)0.1471.41 (0.96-2.02)0.075
Psychological factors
Perceived stress
Not felt much or not at all1.0 (ref.)1.0 (ref.)
A lot or moderate1.92 (1.57-2.36)< 0.0011.68 (1.44-1.97)< 0.001
Unknown1.03 (0.19-4.23)0.9670.47 (0.07-1.66)0.322
Psychological distress (K6 score)
Absence (< 13)1.0 (ref.)1.0 (ref.)
Presence (≥ 13)1.56 (1.13-2.14)0.0071.57 (1.33-1.85)< 0.001
Unknown1.53 (0.56-3.81)0.3820.75 (0.36-1.42)0.405
Depressive symptoms (CES-D score)
Absence (< 16)1.0 (ref.)1.0 (ref.)
Presence (≥ 16)1.93 (1.57-2.36)< 0.0011.72 (1.53-1.92)< 0.001
Unknown1.56 (0.91-2.57)0.0931.39 (1.04-1.84)0.025

IBS, irritable bowel syndrome; LSNS-6, the Lubben Social Network Scale-6; K6, the Kessler 6-item psychological distress scale; CES-D, the Center for Epidemiological Studies Depression scale.

Multivariate adjusted ORs are adjusted for all listed variables.



Table 4 shows the results of a stratified analysis of factors associated with the presence of IBS by age group. Significantly lower ORs for IBS were confirmed with increasing age in the 20-49-year group (OR, 0.98; 95% CI, 0.97-0.99) and the 50-64-year group (OR, 0.98; 95% CI, 0.96-0.99). Women had significantly higher ORs for IBS than men in the 50-year to 64-year (OR, 1.32; 95% CI, 1.07-1.62) and ≥ 65-year (OR, 1.26; 95% CI, 1.01-1.58) age groups. Damage to the home as a result of the disaster had a significantly higher OR for IBS in the 20-49-year group than in the no damage group. For social factors, those with lower educational attainment had significantly higher ORs in the 20-49-year and ≥ 65-year groups. In terms of lifestyle factors, the OR for IBS among ex-drinkers was significantly higher in the ≥ 65-year group (OR, 1.81; 95% CI, 1.22-2.65), and the OR for IBS was significantly higher among those who walked less than 1 hour per day in the 20-49-year group (OR, 1.23; 95% CI, 1.06-1.43). In all age groups, the ORs for IBS were significantly higher in the groups with subjective stress, mental distress, and depressive symptoms. For perceived stress, the ORs for IBS were 1.63 (95% CI, 1.24-2.17), 1.89 (95% CI, 1.53-2.36), and 1.75 (95% CI, 1.46-2.10) for the 20-49-year, 50-64-year, and ≥ 65-year groups, respectively. Similarly, for psychological distress, the ORs for IBS were 1.60 (95% CI, 1.28-2.00), 1.47 (95% CI, 1.14-1.88), and 1.69 (95% CI, 1.21-2.35) for the 20-49-year, 50-64-year, and ≥ 65-year groups, respectively. For depressive symptoms, the ORs for IBS were 1.75 (95% CI, 1.47-2.08), 1.74 (95% CI, 1.48-2.03), and 1.82 (95% CI, 1.52-2.18) for the 20-49-year, 50-64-year, and ≥ 65 year groups, respectively. When subjects with self-reported cancer history were excluded from the logistic analysis, the results were essentially unchanged (data not shown).

Table 4 . Multivariate Adjusted Odds Eatios and 95% Confidence Intervals for the Presence of Irritable Bowel Syndrome According to Age

Variable20-49 yr50-64 yr≥ 65 yr
Number of participants410660866060
Prevalence of IBS (%)1039 (25.3)1103 (18.1)883 (14.6)
OR (95% CI)P-value OR (95% CI)P-valueOR (95% CI)P-value
Age (numeric)0.98 (0.97-0.99)< 0.0010.98 (0.96-0.99)0.0020.99 (0.98-1.02)0.733
Sex
Male1.0 (ref.)1.0 (ref.)1.0 (ref.)
Female0.88 (0.73-1.07)0.1981.32 (1.07-1.62)0.0101.26 (1.01-1.58)0.044
Fiscal year
Third fiscal year1.0 (ref.)1.0 (ref.)1.0 (ref.)
Second fiscal year1.03 (0.86-1.23)0.7611.02 (0.86-1.22)0.8210.86 (0.72-1.03)0.098
First fiscal year0.97 (0.80-1.18)0.7641.18 (0.99-1.41)0.0740.97 (0.80-1.17)0.751
Damage to the home due to the disaster
Not living in the disaster area or no damage1.0 (ref.)1.0 (ref.)1.0 (ref.)
Partial damage or moderate destruction1.21 (1.03-1.43)0.0221.06 (0.90-1.25)0.4771.09 (0.91-1.30)0.353
Considerable damage or complete destruction1.30 (1.03-1.63)0.0251.06 (0.85-1.32)0.6131.00 (0.79-1.28)0.973
Unknown1.24 (0.77-1.96)0.3660.98 (0.65-1.44)0.9140.94 (0.63-1.37)0.744
Social factors
Education
≥ 16 yr1.0 (ref.)1.0 (ref.)1.0 (ref.)
13-15 yr1.39 (1.13-1.71)0.0020.95 (0.76-1.20)0.6731.36 (1.02-1.84)0.042
≤ 12 yr1.30 (1.06-1.60)0.0130.96 (0.78-1.19)0.7171.38 (1.08-1.79)0.013
Unknown0.97 (0.36-2.31)0.9410.90 (0.41-1.80)0.7820.50 (0.20-1.10)0.111
Marital status
Married1.0 (ref.)1.0 (ref.)1.0 (ref.)
Single1.04 (0.85-1.26)0.7170.99 (0.72-1.35)0.9650.61 (0.35-0.996)0.062
Separate1.11 (0.82-1.48)0.4940.90 (0.67-1.19)0.4510.75 (0.50-1.09)0.145
Widowed1.82 (0.73-4.32)0.1830.96 (0.70-1.28)0.7680.94 (0.76-1.17)0.604
Unknown0.98 (0.37-2.30)0.9561.11 (0.51-2.24)0.7761.62 (0.85-2.93)0.124
Social isolation (LSNS-6 score)
Socially integrated (≥ 12)1.0 (ref.)1.0 (ref.)1.0 (ref.)
Socially isolated (< 12)1.15 (0.97-1.37)0.1151.07 (0.91-1.26)0.3871.00 (0.82-1.20)0.964
Unknown1.24 (0.72-2.08)0.4290.99 (0.65-1.46)0.9610.79 (0.52-1.16)0.243
Lifestyle factors
Smoking
Never smoker1.0 (ref.)1.0 (ref.)1.0 (ref.)
Ex-smoker0.90 (0.74-1.08)0.2520.96 (0.79-1.15)0.6331.14 (0.92-1.42)0.245
Current smoker0.93 (0.76-1.15)0.5111.13 (0.89-1.43)0.3180.99 (0.68-1.39)0.937
Unknown4.14 (1.31-13.51)0.0151.59 (0.55-4.00)0.3510.61 (0.20-1.54)0.343
Drinking
Non-drinker1.0 (ref.)1.0 (ref.)1.0 (ref.)
Ex-drinker0.77 (0.45-1.26)0.3130.67 (0.38-1.12)0.1421.81 (1.22-2.65)0.003
Current drinker1.03 (0.89-1.21)0.6741.11 (0.96-1.28)0.1501.09 (0.92-1.29)0.307
Unknown--1.10 (0.16-4.69)0.909
Time spent walking
≥ 1 hr1.0 (ref.)1.0 (ref.)1.0 (ref.)
< 1 hr1.23 (1.06-1.43)0.0050.95 (0.83-1.09)0.5011.15 (0.99-1.33)0.074
Unknown1.29 (0.55-2.80)0.5421.56 (0.94-2.52)0.0771.46 (0.88-2.33)0.123
Psychological factors
Perceived stress
Not felt much or not at all1.0 (ref.)1.0 (ref.)1.0 (ref.)
A lot or moderate1.63 (1.24-2.17)< 0.0011.89 (1.53-2.36)< 0.0011.75 (1.46-2.10)< 0.001
Unknown0.23 (0.01-2.18)0.267--1.30 (0.36-3.64)0.651
Psychological distress (K6 score)
Absence (< 13)1.0 (ref.)1.0 (ref.)1.0 (ref.)
Presence (≥ 13)1.60 (1.28-2.00)< 0.0011.47 (1.14-1.88)0.0031.69 (1.21-2.35)0.002
Unknown1.51 (0.34-5.81)0.5591.05 (0.38-2.53)0.9230.78 (0.34-1.61)0.527
Depressive symptoms (CES-D score)
Absence (< 16)1.0 (ref.)1.0 (ref.)1.0 (ref.)
Presence (≥ 16)1.75 (1.47-2.08)< 0.0011.74 (1.48-2.03)< 0.0011.82 (1.52-2.18)< 0.001
Unknown1.54 (0.88-2.60)0.1151.09 (0.69-1.67)0.7051.72 (1.17-2.48)0.005

IBS, irritable bowel syndrome; LSNS-6, the Lubben Social Network Scale-6; K6, the Kessler 6-item psychological distress scale; CES-D, the Center for Epidemiological Studies Depression scale.

Multivariate adjusted ORs are adjusted for all listed variables.


Discussion

Approximately 2 to 5 years after the Great East Japan Earthquake, and almost no year-to-year difference was observed. Overall, age, damage to the home due to the disaster, educational history, time spent walking, perceived stress, emotional distress, and symptoms of depression were associated with the prevalence of IBS. Regarding sex, there was a significant association between psychological factors and the presence of IBS in men. On the other hand, in women, not only psychological factors, but also other factors, such as damage to the home due to the disaster, education, and time spent walking were associated with the prevalence of IBS. In the 20-49-year and ≥ 65-year age groups, not only psychological factors, but also other factors were associated with IBS prevalence. In people aged 50 to 64 years, only psychological factors and female sex were associated with IBS prevalence. Thus, psychological factors were found to be significantly associated with IBS prevalence across all age groups and sexes.

In a meta-analysis, Lovell et al9 reported a pooled prevalence of 9.4% (95% CI, 7.8-11.1) for IBS from 36 studies conducted using the Rome II criteria, and our findings showed a higher prevalence. In Japan, Kanazawa et al5 reported that the prevalence of IBS using the Rome II criteria was 14.2% in a study of 417 participants recruited for an annual health examination at their workplace. Similarly, using the Japanese version of the Rome II criteria, Kumano et al11 reported an IBS prevalence of 6.1% in 4000 participants while Miwa28 reported a prevalence of 9.8% in 10 000 participants.11 Despite differences among studies, all of these studies on Japanese individuals reported a lower IBS prevalence than the present study. Our study was conducted in the area affected by the Great East Japan Earthquake from about 2 to 5 years after the disaster. It is reasonable to assume an increased prevalence of IBS due to the earthquake. Indeed, the prevalence of IBS increased with the degree of disaster damage to the home in each year and in the whole period, in the order of not living in the disaster area or no damage, partial damage or moderate destruction, and considerable damage or complete destruction. Various health effects of large-scale disasters have been reported.16-18 Victims of large-scale disasters have been found to be highly stressed and to have many health effects, such as infectious diseases,29,30 post-traumatic stress disorders, depression, anxiety, and psychosocial distress,17,18,31,32 cerebrovascular disease,33 hypertension,34,35 and diabetes.35 In a large-scale flood-affected area, Yusof et al36 reported that 36 of 211 residents (17%; average age, 54.5 years; female, 71%) had IBS 6 months after the flood. Because there have been few previous studies of IBS following a major disaster, there are many uncertainties. It is important to track the transition of the IBS prevalence rate in the participants of this study.

Here, we examined factors related to IBS prevalence based on sex and age. We found associations between IBS prevalence and psychological factors in all sex and age groups studied, indicating the significance of the associations. A meta-analysis of 10 case-control studies reported that IBS patients had significantly higher anxiety and depression levels than healthy controls.37 Similarly, a meta-analysis of 73 articles on the prevalence of anxiety and depression in people with IBS found that people with IBS had ORs of 3.11 (95% CI, 2.43-3.98) for anxiety symptoms and of 3.04 (95% CI, 2.37-3.91) for depression symptoms.38 A meta-analysis of IBS onset reported that anxiety and depression provide a two-fold risk for IBS as well.39 Because this is a cross-sectional study, it is not possible to extrapolate the causality of IBS and psychological factors. However, bidirectional effects are possible based on the gut-brain interaction.1,7,40-42

In addition to psychological factors, we also found that age, damage to the home due to the disaster, education, drinking, and time spent walking were all associated with IBS. In terms of age, the odds of IBS prevalence significantly decreased with increasing age, which is consistent with previous studies.2,9-11,22 Furthermore, a significant association between earthquake damage to the home and the prevalence of IBS was found in women and the relatively young age group of 20-49 years. Environmental changes, stress, and infectious diseases caused by large-scale disasters are believed to be factors in the onset of IBS, but there have been few studies and the details remain to be explored.36 In comparison to the group with more than 16 years of education, the group with less than 16 years of education had a significantly higher OR for IBS in women, as well as in the 20-49 and ≥ 65 age groups. A previous study reported no difference in the educational level between males with and without IBS but that females with IBS had a lower level of education.43 However, another study determined that IBS patients, both male and female, had lower educational levels than healthy individuals.44 Possible mechanisms for the association between educational attainment and health status include the influence of educational attainment on other health-related risk factors, a direct influence through brain structure or brain function,45 or indirect influences such as access to medical services, neighborhood environment, occupation, income, and marital status.46 Less than an hour of walking each day was associated with a higher prevalence of IBS in females and the relatively young age group of 20-49 years. Wu et al47 found significant interactions between sex and frailty status in relation to frailty and IBS risk, with females having a higher risk in both the general population and middle-aged adults. According to a randomized controlled trial, exercise reduces IBS symptoms.48 However, the sex and age differences in the association between IBS and physical activity are largely unknown. In our recent study of female-dominant samples, less physical activity was related to negative emotion in IBS individuals but not in those without IBS.49 As noted previously, women had more factors associated with IBS prevalence than men, and those aged 20-49 years and ≥ 65 years had more factors associated with IBS prevalence than those aged 50-64. Overall, our results suggest that the pathology and effects of IBS may differ depending on sex and age, and they warrant more studies.

This study has some limitations. First, because the study is cross-sectional, the causal relationship between the items shown to be related and IBS cannot be determined. Other than the effects of the earthquake disaster, it is difficult to determine whether the factors found to be related to IBS prevalence in this study are a cause or an effect or have a bidirectional relationship. It is possible that the causality can also be clarified by prospectively examining the factors found to be related in this study and the onset of IBS. The TMM CommCohort Study is undergoing a second period survey approximately 4 years after the baseline survey and will be examined prospectively in the future. Second, IBS was identified using a self-administered questionnaire. Previous research has shown that self-completed questionnaires find a higher prevalence of IBS than interviews.2,9 It is also possible that other disorders of gut-brain interactions were included in the IBS diagnosis because physicians did not rule out other disorders. However, we used the validated Rome II Modular Questionnaire,19,20 which is a suitable method for broadly evaluating the prevalence of long-duration IBS in general community residents. The final limitation concerns selection bias. It is possible that the prevalence rate was low because the participants were typically healthy people willing to take part in the survey. However, because the study was conducted in a disaster-affected area, it may not be representative of general residents in other areas, and the prevalence rate may be high due to the effect of the disaster on infection and psychosocial stress. Despite these limitations, this study is important because it is the largest study in Japan to examine IBS and its related factors in detail using the Rome criteria for approximately 16 000 general community residents. The TMM CommCohort Study, which includes questionnaire surveys, blood and urine test, physiological function tests, and genomic and metabolomics data, is a valuable database with high expectations for future research.

In conclusion, this large cross-sectional cohort study of the general population identified factors associated with IBS prevalence. Although these associations differed by age and sex, a significant relationship was found between psychological factors such as subjective stress, psychological distress, and depressive symptoms and the prevalence of IBS in all sex and age groups, indicating the specificity of the relationship.

Acknowledgements

This research is based on the Tohoku Medical Megabank Organization (ToMMo) study. We are grateful to everyone who participated in or worked for the cohort to make the studies possible.

Financial support:

ToMMo is supported by grants from the Reconstruction Agency, from the Ministry of Education, Culture, Sports, Science and Technology, from the Intramural Research Grant (2-2) for Neurological and Psychiatric Disorders, and from the Japan Agency for Medical Research and Development (AMED) (JP17km0105001 and JP21tm0124005). The supercomputer resource (powered by AMED research grant JP22tm0424601) and an integrated database dbTMM were provided by Tohoku Medical Megabank Organization, Tohoku University. This work was supported by AMED (Grant No. JP21zf0127001).

Conflicts of interest

None.

Author contributions

Kumi Nakaya, Naoki Nakaya, Mana Kogure, Rieko Hatanaka, Ippei Chiba, Ikumi Kanno, Satoshi Nagaie, Tomohiro Nakamura, Motoyori Kanazawa, Soichi Ogishima, Nobuo Fuse, Shin Fukudo, and Atsushi Hozawa contributed to the study conception and design, commented on previous versions of the manuscript, and read and approved the final manuscript; Kumi Nakaya performed data analysis and wrote the first draft of the manuscript; and Atsushi Hozawa managed the study.

References
  1. Enck P, Aziz Q, Barbara G, et al. Irritable bowel syndrome. Nat Rev Dis Primers 2016;2:16014.
    Pubmed KoreaMed CrossRef
  2. Sperber AD, Bangdiwala SI, Drossman DA, et al. Worldwide prevalence and burden of functional gastrointestinal disorders, results of rome foundation global study. Gastroenterology 2021;160:99-114, e3.
    CrossRef
  3. Black CJ, Ford AC. Global burden of irritable bowel syndrome: trends, predictions and risk factors. Nat Rev Gastroenterol Hepatol 2020;17:473-486.
    Pubmed CrossRef
  4. Gralnek IM, Hays RD, Kilbourne A, Naliboff B, Mayer EA. The impact of irritable bowel syndrome on health-related quality of life. Gastroenterology 2000;119:654-660.
    Pubmed CrossRef
  5. Kanazawa M, Endo Y, Whitehead WE, Kano M, Hongo M, Fukudo S. Patients and nonconsulters with irritable bowel syndrome reporting a parental history of bowel problems have more impaired psychological distress. Dig Dis Sci 2004;49:1046-1053.
    Pubmed CrossRef
  6. Nellesen D, Yee K, Chawla A, Lewis BE, Carson RT. A systematic review of the economic and humanistic burden of illness in irritable bowel syndrome and chronic constipation. J Manag Care Pharm 2013;19:755-764.
    Pubmed KoreaMed CrossRef
  7. Zia JK, Lenhart A, Yang PL, et al. Risk factors for abdominal pain-related disorders of gut-brain interaction in adults and children: a systematic review. Gastroenterology 2022;163:995-1023, e3.
    Pubmed KoreaMed CrossRef
  8. Lovell RM, Ford AC. Effect of gender on prevalence of irritable bowel syndrome in the community: systematic review and meta-analysis. Am J Gastroenterol 2012;107:991-1000.
    Pubmed CrossRef
  9. Lovell RM, Ford AC. Global prevalence of and risk factors for irritable bowel syndrome: a meta-analysis. Clin Gastroenterol Hepatol 2012;10:712-721, e4.
    Pubmed CrossRef
  10. Johansen SG, Ness-Jensen E. The changes in prevalence and risk of irritable bowel syndrome over time in a population-based cohort, the HUNT study, Norway. Scand J Gastroenterol 2022;4:1-7.
    Pubmed CrossRef
  11. Kumano H, Kaiya H, Yoshiuchi K, Yamanaka G, Sasaki T, Kuboki T. Comorbidity of irritable bowel syndrome, panic disorder, and agoraphobia in a Japanese representative sample. Am J Gastroenterol 2004;99:370-376.
    Pubmed CrossRef
  12. Meleine M, Matricon J. Gender-related differences in irritable bowel syndrome: potential mechanisms of sex hormones. World J Gastroenterol 2014;20:6725-6743.
    Pubmed KoreaMed CrossRef
  13. Labus JS, Wang C, Mayer EA, et al. Sex-specific brain microstructural reorganization in irritable bowel syndrome. Pain 2023;164:292-304.
    Pubmed KoreaMed CrossRef
  14. Kuriyama S, Nakaya N, Ohmori-Matsuda K, et al. The Ohsaki cohort 2006 study: design of study and profile of participants at baseline. J Epidemiol 2010;20:253-258.
    Pubmed KoreaMed CrossRef
  15. Hozawa A, Tanno K, Nakaya N, et al. Study profile of the Tohoku medical megabank community-based cohort study. J Epidemiol 2021;31:65-76.
    Pubmed KoreaMed CrossRef
  16. Bell SA, Horowitz J, Iwashyna TJ. Health outcomes after disaster for older adults with chronic disease: a systematic review. Gerontologist 2020;60:e535-e547.
    Pubmed KoreaMed CrossRef
  17. Palinkas LA, Wong M. Global climate change and mental health. Curr Opin Psychol 2020;32:12-16.
    Pubmed CrossRef
  18. Satcher D, Friel S, Bell R. Natural and manmade disasters and mental health. JAMA 2007;298:2540-2542.
    Pubmed CrossRef
  19. Drossman DA. Research diagnostic questions for functional gastrointestinal disorders: Rome II modular questionnaire: investigations and respondent forms. In: Drossman DA, Corazziari E, Talley NJ, Thompson WG, eds. Rome II: the functional gastrointestinal disorders. 2nd ed. McLean, VA: Degnon Associates 2000:669-714.
  20. Shinozaki M, Kanazawa M, Sagami Y, et al. Validation of the Japanese version of the rome II modular questionnaire and irritable bowel syndrome severity index. J Gastroenterol 2006;41:491-494.
    Pubmed CrossRef
  21. Kanazawa M, Nakajima S, Oshima T, et al. Validity and reliability of the Japanese version of the rome III diagnostic questionnaire for irritable bowel syndrome and functional dyspepsia. J Neurogastroenterol Motil 2015;21:537-544.
    Pubmed KoreaMed CrossRef
  22. Fukudo S, Nakaya K, Muratsubaki T, et al. Characteristics of disorders of gut-brain interaction in the Japanese population in the rome foundation global epidemiological study. Neurogastroenterol Motil 2023;35:e14581.
    Pubmed CrossRef
  23. Kurimoto A, Awata S, Ohkubo T, et al. [Reliability and validity of the Japanese version of the abbreviated lubben social network scale]. Nihon Ronen Igakkai Zasshi 2011;48:149-157. [Japanese].
    Pubmed CrossRef
  24. Lubben J, Blozik E, Gillmann G, et al. Performance of an abbreviated version of the lubben social network scale among three European community-dwelling older adult populations. Gerontologist 2006;46:503-513.
    Pubmed CrossRef
  25. Furukawa TA, Kawakami N, Saitoh M, et al. The performance of the Japanese version of the K6 and K10 in the world mental health survey Japan. Int J Methods Psychiatr Res 2008;17:152-158.
    Pubmed KoreaMed CrossRef
  26. Kessler RC, Andrews G, Colpe LJ, et al. Short screening scales to monitor population prevalences and trends in non-specific psychological distress. Psychol Med 2002;32:959-976.
    Pubmed CrossRef
  27. Radloff LS. The CES-D scale: a self-report depression scale for research in the general population. Appl Psychol Meas 1977;1:385-401.
    CrossRef
  28. Miwa H. Prevalence of irritable bowel syndrome in Japan: internet survey using rome III criteria. Patient Prefer Adherence 2008;2:143-147.
  29. Charnley GEC, Kelman I, Gaythorpe KAM, Murray KA. Traits and risk factors of post-disaster infectious disease outbreaks: a systematic review. Sci Rep 2021;11:5616.
    Pubmed KoreaMed CrossRef
  30. Kouadio IK, Aljunid S, Kamigaki T, Hammad K, Oshitani H. Infectious diseases following natural disasters: prevention and control measures. Expert Rev Anti Infect Ther 2012;10:95-104.
    Pubmed CrossRef
  31. Fernandez A, Black J, Jones M, et al. Flooding and mental health: a systematic mapping review. PLoS One 2015;10:e0119929.
    Pubmed KoreaMed CrossRef
  32. Kawakami N, Fukasawa M, Sakata K, et al. Onset and remission of common mental disorders among adults living in temporary housing for three years after the triple disaster in Northeast Japan: comparisons with the general population. BMC Public Health 2020;20:1271.
    Pubmed KoreaMed CrossRef
  33. Omama S, Yoshida Y, Ogasawara K, et al. Influence of the great East Japan earthquake and tsunami 2011 on occurrence of cerebrovascular diseases in Iwate, Japan. Stroke 2013;44:1518-1524.
    Pubmed CrossRef
  34. Kario K. Disaster hypertension - its characteristics, mechanism, and management -. Circ J 2012;76:553-562.
    Pubmed CrossRef
  35. Gohardehi F, Seyedin H, Moslehi S. Prevalence rate of diabetes and hypertension in disaster-exposed populations: a systematic review and meta-analysis. Ethiop J Health Sci 2020;30:439-448.
    Pubmed KoreaMed CrossRef
  36. Yusof N, Hamid N, Ma ZF, et al. Exposure to environmental microbiota explains persistent abdominal pain and irritable bowel syndrome after a major flood. Gut Pathog 2017;9:75.
    Pubmed KoreaMed CrossRef
  37. Fond G, Loundou A, Hamdani N, et al. Anxiety and depression comorbidities in irritable bowel syndrome (IBS): a systematic review and meta-analysis. Eur Arch Psychiatry Clin Neurosci 2014;264:651260.
    Pubmed CrossRef
  38. Zamani M, Alizadeh-Tabari S, Zamani V. Systematic review with meta-analysis: the prevalence of anxiety and depression in patients with irritable bowel syndrome. Aliment Pharmacol Ther 2019;50:132-143.
    Pubmed CrossRef
  39. Sibelli A, Chalder T, Everitt H, Workman P, Windgassen S, Moss-Morris R. A systematic review with meta-analysis of the role of anxiety and depression in irritable bowel syndrome onset. Psychol Med 2016;46:3065-3080.
    Pubmed CrossRef
  40. Ford AC, Lacy BE, Talley NJ. Irritable bowel syndrome. N Engl J Med 2017;376:2566-2578.
    Pubmed CrossRef
  41. Saito K, Kanazawa M, Fukudo S. Colorectal distention induces hippocampal noradrenaline release in rats: an in vivo microdialysis study. Brain Res 2002;947:146-149.
    Pubmed CrossRef
  42. Saito K, Kasai T, Nagura Y, Ito H, Kanazawa M, Fukudo S. Corticotropin-releasing hormone receptor 1 antagonist blocks brain-gut activation induced by colonic distention in rats. Gastroenterology 2005;129:1533-1543.
    Pubmed CrossRef
  43. Andrews EB, Eaton SC, Hollis KA, et al. Prevalence and demographics of irritable bowel syndrome: results from a large web-based survey. Aliment Pharmacol Ther 2005;22:935-942.
    Pubmed CrossRef
  44. Farzaneh N, Ghobaklou M, Moghimi-Dehkordi B, Naderi N, Fadai F. Effects of demographic factors, body mass index, alcohol drinking and smoking habits on irritable bowel syndrome: a case control study. Ann Med Health Sci Res 2013;3:391-396.
    Pubmed KoreaMed CrossRef
  45. Aizawa E, Sato Y, Kochiyama T, et al. Altered cognitive function of prefrontal cortex during error feedback in patients with irritable bowel syndrome, based on FMRI and dynamic causal modeling. Gastroenterology 2012;143:1188-1198.
    Pubmed CrossRef
  46. Yuan S, Xiong Y, Michaëlsson M, Michaëlsson K, Larsson SC. Genetically predicted education attainment in relation to somatic and mental health. Sci Rep 2021;11:4296.
    Pubmed KoreaMed CrossRef
  47. Wu S, Yang Z, Liu S, Zhang Q, Zhang S, Zhu S. Frailty status and risk of irritable bowel syndrome in middle-aged and older adults: a large-scale prospective cohort study. EClinicalMedicine 2022;56:101807.
    Pubmed KoreaMed CrossRef
  48. Johannesson E, Simrén M, Strid H, Bajor A, Sadik R. Physical activity improves symptoms in irritable bowel syndrome: a randomized controlled trial. Am J Gastroenterol 2011;106:915-922.
    Pubmed CrossRef
  49. Koseki T, Muratsubaki T, Tsushima H, et al. Impact of mindfulness tendency and physical activity on brain-gut interactions. J Gastroenterol 2023;58:158-170.
    Pubmed KoreaMed CrossRef


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