The metabolic syndrome defined by modified International Diabetes Federation criteria and mortality: a 9-year follow-up of the aged in Finland

Abstract

Aim: The aim of this study was to investigate the relationship between the metabolic syndrome (MetS) and mortality in the aged population.

Methods: In this prospective population-based study with a 9-year follow-up, the participants were all residents of the municipality of Lieto, Finland, aged 64 and over in 1998-99 (n=1529). Altogether, 1260 (82%) were included in the study. Cox proportional-hazard models were used to estimate hazard ratios (HRs) for all-cause, cardiovascular (CVD), coronary heart disease (CHD) and cerebrovascular (CV) mortality as predicted by MetS (defined by modified International Diabetes Federation criteria).

Results: At baseline, 17% of the men and 21% of the women had MetS. During the 9-year follow-up, 422 deaths occurred. After multivariable adjustment, no significant differences were found between subjects with and without MetS for all-cause, CVD, CHD or CV mortality in all study participants or by gender. On evaluating MetS components separately, elevated blood pressure was found to predict lower all-cause mortality in all participants [HR: 0.65; 95% confidence interval (CI): 0.47-0.89], and lower CHD mortality in men (HR: 0.42; 95% CI: 0.18-0.97). In women, high triglyceride levels predicted lower all-cause mortality (HR: 0.67; 95% CI: 0.47-0.95), whereas low HDL cholesterol predicted higher all-cause (HR: 1.61; 95% CI: 1.15-2.24) and CV (HR: 2.44; 95% CI: 1.05-5.67) mortality.

Conclusion: These findings suggest that MetS does not predict mortality later in life and, of the separate components of MetS, only low HDL cholesterol is predictive of mortality in women. Also, even markedly higher blood pressure values than those included in the criteria for MetS fail to predict mortality in this age group.