Irritable Bowel Syndrome Is Positively Related to Metabolic Syndrome: A Population-Based Cross-Sectional Study

<div><p>Irritable bowel syndrome is a common gastrointestinal disorder that may affect dietary pattern, food digestion, and nutrient absorption. The nutrition-related factors are closely related to metabolic syndrome, implying that irritable bowel syndrome may be a potential risk factor for metabolic syndrome. However, few epidemiological studies are available which are related to this potential link. The purpose of this study is to determine whether irritable bowel syndrome is related to metabolic syndrome among middle-aged people. We designed a cross-sectional study of 1,096 subjects to evaluate the relationship between irritable bowel syndrome and metabolic syndrome and its components. Diagnosis of irritable bowel syndrome was based on the Japanese version of the Rome III Questionnaire. Metabolic syndrome was defined according to the criteria of the American Heart Association scientific statements of 2009. Dietary consumption was assessed via a validated food frequency questionnaire. Principal-components analysis was used to derive 3 major dietary patterns: “Japanese”, “sweets-fruits”, and “Izakaya (Japanese Pub) “from 39 food groups. The prevalence of irritable bowel syndrome and metabolic syndrome were 19.4% and 14.6%, respectively. No significant relationship was found between the dietary pattern factor score tertiles and irritable bowel syndrome. After adjustment for potential confounders (including dietary pattern), the odds ratio (95% confidence interval) of having metabolic syndrome and elevated triglycerides for subjects with irritable bowel syndrome as compared with non-irritable bowel syndrome are 2.01(1.13–3.55) and 1.50(1.03–2.18), respectively. Irritable bowel syndrome is significantly related to metabolic syndrome and it components. This study is the first to show that irritable bowel syndrome was significantly related to a higher prevalence of metabolic syndrome and elevated triglycerides among an adult population. The findings suggest that the treatment of irritable bowel syndrome may be a potentially beneficial factor for the prevention of metabolic syndrome. Further study is needed to clarify this association.</p></div

Age- and sex-adjusted characteristics of the subjects in relation to irritable bowel syndrome (n = 1,096)^†

†<p>BMI, body mass index; PA, physical activity; METs, metabolic equivalents; SDS, Self-rating Depression Scale; SBP, systolic blood pressure; DBP, diastolic blood pressure; TG, triglyceride; FBG, fasting blood glucose; HDL, high-density lipoprotein-cholesterol; LDL, low-density lipoprotein; hsCRP, high-sensitivity C-reactive protein.</p>‡<p>Analysis of covariance or logistic regression analysis adjusted for age and sex where appropriate.</p>§<p>Adjusted least squares mean (95% confidence interval) (all such values).</p>¶<p>Adjusted geometric mean (95% confidence interval).</p><p>Age- and sex-adjusted characteristics of the subjects in relation to irritable bowel syndrome (n = 1,096)^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0112289#nt101" target="_blank">†</a>}</p

Odds ratios (95% confidence interval) of IBS prevalence in staple foods consumption.^a

<p><i>Notes</i>: Model 1, adjusted for age (continuous variable), sex, and body mass index (continuous variable); Model 2, adjusted for Model 1 + smoking status (never, former, current), drinking frequency (never, sometimes, every day), occupation (desk work), educational levels (≥college), sleep duration (6–8 hours/day), physical activity (≥23 metabolic equivalent hours/week), and depressive symptoms (self-rating depression scale ≥45 points); Model 3, adjusted for Model 2 + fat intake (continuous variable); Model 4, adjusted for Model 2 + carbohydrate intake (continuous variable); Model 5, adjusted for Model 2 + plant protein intake (continuous variable); Model 6, adjusted for Model 2 + soluble fiber intake (continuous variable); Model 7, adjusted for Model 2 + insoluble fiber intake (continuous variable).</p><p>^a Analyzed by logistic regression analysis.</p><p>Odds ratios (95% confidence interval) of IBS prevalence in staple foods consumption.<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0119097#t003fn002" target="_blank">^a</a></p

Adjusted odds ratios and 95% confidence interval for the relationship between MS and IBS (n = 1,096) ^†

†<p>MS, metabolic syndrome; IBS, irritable bowel syndrome; HDL, high-density lipoprotein cholesterol; SBP, systolic blood pressure; DBP, diastolic blood pressure.</p>‡<p>Adjusted for age, sex and body mass index.</p>§<p>Additionally adjusted for smoking and drinking status, educational level, and physical activity.</p>¶<p>Additionally adjusted for dietary patterns, and total energy intake.</p><p>Additionally adjusted for depressive symptoms.</p>|<p>Additionally adjusted for mutual metabolic syndrome components.</p><p>Adjusted odds ratios and 95% confidence interval for the relationship between MS and IBS (n = 1,096) ^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0112289#nt105" target="_blank">†</a>}</p

Location of the epicenter of the Great East Japan Earthquake and Oroshi-machi.

<p>(a) The epicenter of the East Japan Earthquake (cross) was under the Pacific Ocean about 150 km east of the Miyagi Prefecture. (b) The Sendai Oroshisho Center is located in Oroshi-machi in Eastern Sendai, where the tsunami approached within 2–3 km distance.</p

Participants characteristics and pre-disaster factors associated with the total score of IES-R-J in men (n = 399)^a.

a<p>IES-R-J, the Japanese version of the Impact of Event Scale-Revised; PA, physical activity; METs, metabolic equivalent of tasks; SDS, Self-rating Depression Scale.</p>b<p>Data are summarized by median (interquartile range) for continuous variables and by percentage for category variables.</p>c<p>All continuous variables have been log-transformed.</p>d<p>Data was measured in 2011 only.</p

Analysis of Covariance on Association between Staple Foods Consumption and Irritable Bowel Syndrome (IBS) Prevalence.

<p>Confounding factors include age (continuous variable), sex, body mass index (continuous variable), smoking status (never, former, current), drinking frequency (never, sometimes, every day), occupation (desk work), educational levels (≥college), sleep duration (6–8 hours/day), physical activity (≥23 metabolic equivalent hours/week), and depressive symptoms (self-rating depression scale ≥45 points). Data on the consumption of staple foods were log-transformed prior to multivariate statistical analyses due to their abnormal distribution and back-transformed for data presentation. Data were shown as means and 95% confidence interval. Of the 1 082 subjects, 212 had IBS.</p

Flow chart of the sample selection process.

<p>Flow chart of the sample selection process.</p

Relationship of leg extension power with each subscale scores of IES-R-J among men and women^a.

a<p>Adjusted for physical activiy (<1 METs·hours/week, 1–22 METs·hours/week, or≥23 METs·hours/week), smoking status (never, former, or current), drinking status (never, 1–6 day(s)/week, or 7 days/week), sleep duration (6–8 hours/day or not), tooth brushing (≥3 times/day or <3 times/day), eating breakfast (<4 times/week or ≥4 times/week), diabetes (no or yes), hypertension (no or yes), dyslipidemia (no or yes), depressive symptoms (SDS≥45), age (log-transformed), education (≥ college or < college), occupation (deskwork or non-desk work), marital status (unmarried or married), family loss (no or yes), property damage (other, partially damaged, or completely damaged), and work volume (unchanged, increased, or decreased).</p>b<p>All continuous variables have been log-transformed.</p

Additional file 1 of Association of physiological factors with grip and leg extension strength: tohoku medical megabank community-based cohort study

Supplementary Material 1: Supplementary Table 1. Grip strength and physiological data by age groups. Supplementary Table 2. Leg extension strength and physiological data by age groups