Cardiometabolic Burden of Irritable Bowel Syndrome: A Case-Control Analysis of Metabolic Syndrome Clustering

Irritable bowel syndrome (IBS) is a common functional gastrointestinal (GI) disorder, which is more frequently associated with some extra-intestinal comorbidities, particularly cardiometabolic comorbidities. Metabolic syndrome (MetS) comprises a constellation of risk factors for cardiovascular diseases, including central obesity, dyslipidemia, hypertension, and insulin resistance. Therefore, the purpose of this study was to assess the prevalence and factors associated with MetS in IBS patients.

A hospital-based cross-sectional case-control study was conducted, enrolling 140 IBS patients diagnosed according to Rome IV criteria and 140 non-IBS controls from a healthcare center in Dakahlia, Egypt. Metabolic syndrome was defined using International Diabetes Federation criteria. Demographic information was collected together with anthropometric measurements and clinical and biochemical data. Binary logistic regression analysis was conducted with sequential models that adjusted for age, sex, and lifestyle factors (body mass index, smoking status, and residence). Model discrimination was evaluated using the area under the receiver operating characteristic (ROC) curve (AUC).

IBS patients showed a significant increase in metabolic syndrome rates at 49.3% compared to 17.1% in controls, p-value < 0.001. The metabolic components of IBS cases showed significant elevation in the following measures: abdominal obesity occurred in 71.4% of cases compared to 44.3% in controls and fasting blood glucose levels ≥ 100 mg/dL occurred in 42.9% of cases compared to 19.3% in controls and blood pressure levels ≥ 130/85 mmHg occurred in 57.9% of cases compared to 17.9% in controls and triglyceride levels ≥ 150 mg/dL occurred in 25.7% of cases compared to 15.7% in controls. Low-density lipoprotein cholesterol levels (median values) were 115 mg/dL in cases versus 102 mg/dL in controls (p = 0.01). When age, sex, BMI, smoking status, and residence were considered in the multivariate logistic regression model, IBS status remained an independent predictor of metabolic syndrome (AOR: 7.818; 95% CI: 3.913-15.620; p < 0.001). This model demonstrated excellent discriminatory performance (AUC: 0.852; 95% CI: 0.806-0.898) and adequate calibration (Hosmer-Lemeshow: 0.442). Within the IBS cohort, BMI functioned as the only independent predictor for metabolic syndrome co-occurrence (AOR: 1.18 per unit increase; 95% CI: 1.08-1.30; p < 0.001), with the model correctly classifying 75.7% of cases (sensitivity: 73.9%; specificity: 77.5%).

Our findings suggest that IBS may identify a subgroup of patients with elevated cardiometabolic burden, warranting routine cardiometabolic evaluation in clinical practice. However, causal relationships and temporal sequence cannot be inferred from this cross‑sectional case-control design.