Metabolic syndrome as a precursor of cardiovascular disease and type 2 diabetes mellitus

Background - The incidence of cardiovascular disease ( CVD), coronary heart disease ( CHD), and type 2 diabetes mellitus ( T2DM) has not been well defined in persons with the metabolic syndrome ( at least 3 of the following: abdominal adiposity, low HDL cholesterol, high triglycerides, hypertension, and impaired fasting glucose). The objective was to investigate risk for CVD, CHD, and T2DM according to metabolic syndrome traits. Methods and Results - The study followed a cohort of 3323 middle-aged adults for the development of new CVD, CHD, and T2DM over an 8-year period. In persons without CVD or T2DM at baseline, the prevalence of the metabolic syndrome ( >= 3 of 5 traits) was 26.8% in men and 16.6% in women. There were 174 incident cases of CVD, 107 of CHD, and 178 of T2DM. In men, the metabolic syndrome age-adjusted relative risk ( RR) and 95% CIs were RR = 2.88 ( 95% CI 1.99 to 4.16) for CVD, RR = 2.54 ( 95% CI 1.62 to 3.98) for CHD, and RR = 6.92 ( 95% CI 4.47 to 10.81) for T2DM. Event rates and RRs were lower in women for CVD ( RR = 2.25, 95% CI 1.31 to 3.88) and CHD ( RR = 1.54, 95% CI 0.68 to 3.53), but they were similar for T2DM ( RR = 6.90, 95% CI 4.34 to 10.94). Population-attributable risk estimates associated with metabolic syndrome for CVD, CHD, and T2DM were 34%, 29%, and 62% in men and 16%, 8%, 47% in women. Conclusions - Metabolic syndrome is common and is associated with an increased risk for CVD and T2DM in both sexes. The metabolic syndrome accounts for up to one third of CVD in men and approximately half of new T2DM over 8 years of follow-up.