Combined impact of adiponectin and retinol-binding protein 4 on metabolic syndrome in elderly people: the Korean Longitudinal Study on Health and Aging.

The prevalence of metabolic syndrome (MS) increases with progressing and is potentially associated with changes in adipose-derived cytokines, including adiponectin and retinol-binding protein 4 (RBP4). We aimed to determine the prevalence of MS, and the relationships between these factors and MS in elderly people. A population-based cohort study, the Korean Longitudinal Study on Health and Aging (KLoSHA), was performed on subjects aged > or =65 years by random stratified sampling in 2005-2006 (439 men and 561 women). Anthropometrics, biochemical factors including adiponectin and RBP4 levels, body composition, and abdominal fat by computed tomography (CT) were measured. The prevalence of MS was 61.0% in women and 39.9% in men. After adjustment for age, gender, smoking, alcohol, and exercise status and muscle mass, participants with the lowest quartile of adiponectin had a higher risk for having MS than those with the highest quartile (odds ratio (OR) = 4.12, P < 0.01). Similarly, subjects with the highest quartile of RBP4 showed an increased risk for having MS (OR = 1.73, P < 0.01). When both the lowest adiponectin and the highest RBP4 quartiles were combined, the OR increased to 6.22 compared with the opposite quartiles (i.e., highest adiponectin and lowest RBP4 concentrations). Furthermore, circulating levels of adiponectin and RBP4 were significantly correlated with visceral fat and insulin resistance index. In this study, the increased prevalence of MS in elderly but relatively lean population was associated with low adiponectin and high RBP4 levels. The combination of these factors might predict older subjects at high risk for having MS.