The associations of metabolic syndrome with incident hypertension, type 2 diabetes mellitus and chronic kidney disease: a cohort study

Metabolic syndrome (MetS) has been extensively studied for its long-term health effects, typically through conventional Cox proportional hazards regression modeling of the overall association of MetS with a single outcome. Such an approach neglects the inherent links between MetS-related disease outcomes and fails to provide sufficient insights into the impact of each component of MetS over time. We therefore conducted a retrospective cohort study of 63,680 individuals who received health check-ups at the MJ Health Screening Center in Taiwan from 1997-2005 to study the subsequent risks of hypertension, type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) simultaneously for MetS and its components. Multivariate-adjusted hazard ratios (HRs) were calculated using Cox models for multiple failure outcomes. At baseline, MetS was identified in 7835 participants. Over a median follow-up of 3 years, 8252, 1634, and 6714 participants developed hypertension, T2DM and CKD, respectively. The HR for MetS was 2.41 (95% CI 2.29-2.53) for hypertension, 5.17 (95% CI 4.68-5.71) for T2DM and 1.22 (95% CI 1.15-1.31) for CKD. Three MetS components showed the strongest association with each of the outcomes: elevated blood pressure with hypertension (HR = 3.62, 95% CI 3.46-3.79), raised fasting plasma glucose with T2DM (HR = 8.89, 95% CI 7.86-10.06) and elevated triglycerides with CKD (HR = 1.14, 95% CI 1.08-1.21). MetS may help identify individuals with metabolic profiles that confer incremental risks for multiple diseases. Additionally, several components of the syndrome should be considered by clinicians, as they show stronger associations with specific diseases than MetS.