PURPOSE: Recent studies have revealed close relationships between hepatic injury, metabolic pathways, and gut microbiota. The microorganisms in the intestine also cause irritable bowel syndrome (IBS). The aim of this study was to examine whether IBS was associated with elevated hepatic enzyme [alanine aminotransferase (ALT) and aspartate aminotransferase (AST)], gamma-glutamyl transferase (gamma-GT) levels, and metabolic syndrome (MS). MATERIALS AND METHODS: This was a retrospective, cross-sectional, case-control study. The case and control groups comprised subjects who visited our health promotion center for general check-ups from June 2010 to December 2010. Of the 1127 initially screened subjects, 83 had IBS according to the Rome III criteria. The control group consisted of 260 age- and sex-matched subjects without IBS who visited our health promotion center during the same period. RESULTS: Compared to control subjects, patients with IBS showed significantly higher values of anthropometric parameters (body mass index, waist circumference), liver enzymes, gamma-GT, and lipid levels. The prevalences of elevated ALT (16.9% vs. 7.7%; p=0.015) and gamma-GT (24.1% vs. 11.5%; p=0.037) levels were significantly higher in patients with IBS than in control subjects. A statistically significant difference was observed in the prevalence of MS between controls and IBS patients (12.7% vs. 32.5%; p<0.001). The relationships between elevated ALT levels, MS, and IBS remained statistically significant after controlling for potential confounding factors. CONCLUSION: On the basis of our study results, IBS may be an important condition in certain patients with elevated ALT levels and MS.
Adult ; Alanine Transaminase/analysis/*metabolism ; Aspartate Aminotransferases/analysis/*metabolism ; Body Mass Index ; Case-Control Studies ; Cross-Sectional Studies ; Female ; Humans ; Irritable Bowel Syndrome/diagnosis/*enzymology/epidemiology ; Liver/metabolism ; Male ; Metabolic Syndrome X/complications/diagnosis/*enzymology/epidemiology ; Middle Aged ; Obesity/epidemiology ; Prevalence ; Retrospective Studies ; Waist Circumference ; gamma-Glutamyltransferase/analysis/*metabolism

PURPOSE: Elevation in serum alanine aminotransferase (ALT) levels is a biomarker for metabolic syndrome (MS); however, the relationship has not been fully investigated within the reference interval of ALT levels. Our objective was to explore the relationship between serum ALT levels within the reference interval and MS in Chinese adults. MATERIALS AND METHODS: This cross-sectional study included 16028 adults, who attended routine health check-ups at Shengli Oilfield Central Hospital from January 2006 to March 2012. The reference interval of serum ALT level was defined as less than 40 U/L. Logistic regression models and restricted cubic spline were used to evaluate the association of ALT with MS. RESULTS: The prevalence of MS in the total population was 13.7% (6.4% for females and 18.4% for males). Multiple logistic regression showed that ALT levels were positively associated with MS after adjustment for potential confounding factors. The odds ratio of MS in the top quartile was 4.830 [95% confidence interval (CI): 2.980–7.829] in females and 3.168 (95% CI: 2.649–3.790) in males, compared with the ALT levels in the bottom quartile. The restricted cubic spline models revealed a positive non-linear dose-response relationship between ALT levels and the risk of MS in women (p for nonlinearity was 0.0327), but a positive linear dose-response relationship in men (p for nonlinearity was 0.0659). CONCLUSION: Serum ALT levels within the reference interval are positively associated with MS in a dose-response manner. Elevated ALT levels, even within the reference interval, may reflect early dysmetabolic changes.
Adult ; Aged ; Alanine Transaminase/*blood ; Asian Continental Ancestry Group ; Biomarkers/blood ; Confidence Intervals ; Cross-Sectional Studies ; Dose-Response Relationship, Drug ; Female ; Humans ; Logistic Models ; Male ; Metabolic Syndrome X/*enzymology/epidemiology ; Middle Aged ; Odds Ratio ; Prevalence ; Reference Values