Aim: The aim was to evaluate the impact of metabolic syndrome (MS), MS individual components and 32 kinds of MS specific component combinations on all-cause mortality risk in a fixed cohort of MJ check-up population.
Methods: We observed the events of death in a fixed cohort, where the population was composed of 45,542 individuals aged 35-74 who were examined at MJ Health check-up Center in 1997 as baseline examination, and were followed up to 2005. Median duration of follow-up was 7.44 years. MS was defined according to the National Cholesterol Educational Program (the revised NCEP-ATPIII for Asian in 2004), the prevalence of MS was standardized according to China's fifth census data. We constructed common Cox regression model, simultaneously adjusting the classic risk factors (such as age, sex, smoking, alcohol drinking, physical activity, family history, etc.) to examine the relationship between MS, MS individual components and 32 kinds of MS specific component combinations on the occurrence of death with the fixed cohort.
Results: The standardized prevalence of MS was 29.75% (male: 30.36%, female: 29.51%). There were 1,749 persons who died during the median 7.44-years follow-up, the mortality rate was 46 per 10,000 person years. The mortality rates were 71 and 35 per 10,000 person years for those with and without MS, respectively. After adjustment for age, sex and classical risk factors, compared with subjects without MS, the hazard ratio of all-cause mortality was 1.26 (95% CI: 1.14-1.40). The all-cause mortality were more highly significant than other combinations (P <0.05) when the following combinations exist: "elevated blood pressure", "elevated fasting plasma glucose + low high-density lipoprotein cholesterol", "elevated blood pressure + elevated triglyceride + elevated fasting plasma glucose", "elevated fasting plasma glucose + low high-density lipoprotein cholesterol + elevated blood pressure + elevated triglyceride". After adjusting age, sex and classical risk factors, the HRs for those with 0 to 5 components were 1, 1.22, 1.25, 1.33, 1.66, and 1.92, respectively. There was a significant dose-response relationship (P for liner trend <0.001) between the number of MS components and the risk of all-cause mortality in the overall fixed cohort sample.
Conclusion: In a large scale middle-aged Taiwan check-up population, MS may be associated with a much higher risk for all-cause mortality. These results may underline the fact that MS is a non-homogeneous syndrome and have a significant impact on detecting high-risk individuals suffering from metabolic disorders for preventing and controlling death.