Author(s): Hu G
BACKGROUND: Few studies have evaluated the associations between the metabolic syndrome (by any definition) and mortality. This study examined the age- and sex-specific prevalence of the metabolic syndrome and its association with all-cause and cardiovascular mortality in nondiabetic European men and women.
METHODS: The study was based on 11 prospective European cohort studies comprising 6156 men and 5356 women without diabetes and aged from 30 to 89 years, and had a median follow-up of 8.8 years. A modification of the World Health Organization definition of the metabolic syndrome was used. The subjects were considered to have the metabolic syndrome if they had hyperinsulinemia and 2 or more of the following: obesity, hypertension, dyslipidemia, or impaired glucose regulation; however, other definitions were also studied. Hazard ratios for all-cause and cardiovascular mortality were estimated with Cox models in each cohort. Meta-analyses were performed to assess the overall association of the metabolic syndrome with mortality risk.
RESULTS: The age-standardized prevalence of the metabolic syndrome was slightly higher in men (15.7%) than in women (14.2%). Of the 1119 deaths recorded during follow-up, 432 were caused by cardiovascular disease. The overall hazard ratios for all-cause and cardiovascular mortality in persons with the metabolic syndrome compared with persons without it were 1.44 (95% confidence interval [CI], 1.17-1.84) and 2.26 (95% CI, 1.61-3.17) in men and 1.38 (95% CI, 1.02-1.87) and 2.78 (95% CI, 1.57-4.94) in women after adjustment for age, blood cholesterol levels, and smoking.
CONCLUSIONS: The overall prevalence of the metabolic syndrome in nondiabetic adult Europeans is 15%. Nondiabetic persons with the metabolic syndrome have an increased risk of death from all causes as well as cardiovascular disease.