Objective: This study assesses the effect of the metabolic syndrome on all-cause and cardiovascular disease (CVD) mortality in healthy Chinese, Malays and Asian Indians in Singapore. The utility of the metabolic syndrome is also compared with the Framingham risk score for prediction of mortality.
Methods: Healthy participants (n = 5699) were grouped by the presence or absence of the metabolic syndrome, and followed up (mean 14.1 years) by data linkage with the National Death Register. Risk of mortality was obtained by Cox's proportional hazards model with adjusted hazard ratios (HRs). Area under receiver operating characteristic (ROC) curves were used to compare the metabolic syndrome and Framingham risk score for prediction of mortality.
Results: During a follow-up of 80,236 person-years, there were 382 deaths, of which 128 were due to CVD. Individuals with the metabolic syndrome had an increased risk of mortality for 'all-causes' (males: HR 1.4, 95% confidence intervals (95%CI) 1.1-1.8; and females: HR 1.8, 95%CI 1.3-2.6). There was also an increased risk of mortality due to CVD (males: HR 3.0, 95%CI 1.9-4.8; and females: HR 2.1, 95%CI 1.1-4.0). The area under ROC for Framingham risk score was higher for both all-cause and CVD mortality than metabolic syndrome.
Conclusions: Although an increased risk of 'all-cause' and CVD mortality due to the metabolic syndrome was found, the Framingham risk function still performed better than the metabolic syndrome in an Asian population. However, the metabolic syndrome should not be disregarded as it is a clinically useful entity for identifying individuals for management of its component CVD risk factors.