Survival benefits of metabolic syndrome among older men aged 75 years and over in Taiwan

Abstract

Background: Metabolic syndrome (MetS) was common in the elderly, but its prognostic significance in older old population remained unclear. The main purpose of this study was to evaluate the survival impact of MetS among older men aged 75 and over in Taiwan.

Methods: From 2008, residents aged 75 years and older of Banciao Veterans Home were invited for study and were followed for 3 years. All participants received history taking, physical examinations, and laboratory tests. Mortality was determined by Veteran Affairs Death Registry, which was linked to the National Death Registry.

Results: Overall, 680 men (mean age: 82.5±4.7 years) were enrolled for study and the prevalence of MetS was 31.6%. During the follow-up period, 140 (20.6%) participants died, and the causes of death included infectious diseases (62, 9.1%), cardiovascular disease (37, 5.4%), cancer (20, 2.9%), and others (21, 3.1%). MetS subjects had a significantly higher prevalence of hypertension, diabetes mellitus, and having higher body mass index, waist circumferences, systolic blood pressure, fasting blood glucose, serum triglyceride and lower HDL-C level than non-MetS subjects. However, MetS subjects were less likely to die during study period (16.3% vs. 22.6%, P=0.059). Multivariate logistic regression showed that older age (OR:1.04, 95% C.I.: 1.00-1.08, P=0.04), diabetes mellitus (OR: 2.10, 95% CI: 1.34-3.30, P=0.001) were independent risk factors for mortality; and serum total cholesterol and triglyceride were protective factors (OR: 0.99, 95% CI: 0.99-1.00, P=0.037 for cholesterol; OR: 0.99, 95% CI: 0.99-1.00, P=0.013 for triglyceride). Adjusted for age, diabetes mellitus, serum levels of total cholesterol, and triglyceride, MetS played a potential trend of survival benefits among study subjects (HR: 0.71, 95% CI: 0.45-1.12, P=0.144).

Conclusions: The prevalence of MetS among men aged 75 years and over was 31.6%, and the 3-year mortality rate was 20.6%. Older age, diabetes mellitus, lower serum cholesterol and lower serum triglyceride were independent risk factors for mortality. Further investigation is needed to clarify the prognostic impact of MetS in older adults.