All-Cause Mortality Associated With Specific Combinations of the Metabolic Syndrome According to Recent Definitions

Abstract

The aim was to evaluate the impact of specific component combinations of the metabolic syndrome on all-cause mortality risk in a large French cohort. The population was composed of 39,998 men (aged 52.6 +/- 8.3 years) and 20,756 women (aged 54.7 +/- 9.2 years) who were examined at the Investigations Préventives et Cliniques Center from 1999 to 2002. Mean follow-up was 3.57 +/- 1.12 years. Metabolic syndrome was defined according to three definitions: the National Cholesterol Educational Program (NCEP 2001), the revised NCEP (NCEP-R; American Heart Association/National Heart, Lung, and Blood Institute 2005), and the International Diabetes Federation (IDF 2005). Subjects with metabolic syndrome were compared with subjects without metabolic syndrome and with subjects with no metabolic syndrome components using Cox regression models. The prevalence of metabolic syndrome increased from 10.3% (NCEP) to 17.7% (NCEP-R) and 23.4% (IDF). After adjustment for age, sex, classical risk factors, and socioprofessional categories, and compared with subjects without metabolic syndrome, the risk of all-cause mortality was 1.79 (95% CI 1.35-2.38), 1.46 (1.14-1.88), and 1.32 (1.04-1.67) with the NCEP, NCEP-R, and IDF definitions, respectively. Among the combinations significantly associated with all-cause mortality, the following three-component combinations and the four-component combination were more highly significant than other combinations (P < 0.05): elevated waist circumference plus elevated glucose, plus either elevated blood pressure or elevated triglycerides, and the combination of all four of these. In a large middle-aged French population, four specific components of metabolic syndrome are associated with a much higher mortality risk. These results may have a significant impact on detecting high-risk subjects suffering from metabolic disorders and underline the fact that metabolic syndrome is a nonhomogeneous syndrome.