All-cause mortality risk predictors in a preventive cardiology clinic cohort-examining diabetes and individual metabolic syndrome criteria: a PRECIS database study

Aim:  It is unclear if metabolic syndrome (MS) is equal to type 2 diabetes mellitus (DM) in predicting cardiovascular disease (CVD) risk and mortality, and its prognostic value compared to Framingham risk model is controversial. We assessed mortality, CVD risk and prevalence in patients with DM and those without DM who met National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) MS criteria compared to patients without DM or MS. We analysed which component(s) of NCEP MS criteria had greatest predictive value for mortality.
Methods:  Retrospective cohort analysis of 1189 DM, 1241 MS (fasting glucose < 126 mg/dl and ≥3 components NCEP-ATP III criteria) and 3023 non-DM/non-MS patients presented for baseline visit to Preventive Cardiology clinic between 1995 and 2006, whose subsequent vital status was determined for a median of 5.2 years. The association with mortality was determined by Cox proportional hazards models. The incremental predictive value of MS components was performed by concordance indexes.
Results and conclusion:  DM group had highest mortality and CVD prevalence vs. MS and non-DM/non-MS groups respectively (all p ≤ 0.001). Patients with MS criteria had increased CVD prevalence and 1.5-fold increased mortality vs. non-DM/non-MS group (all p < 0.02). In NCEP MS criteria, only fasting glucose significantly predicted mortality in MS group (p = 0.05). MS criteria predicted CVD prevalence in a parallel manner to Framingham risk score assessment. In a cohort of patients at high risk for CVD whose risk factors are being treated, presence of diabetes in addition to plasma glucose within NCEP MS criteria strongly predicts all-cause mortality.