Circulating retinol-binding protein 4, cardiovascular risk factors and prevalent cardiovascular disease in elderly

Our aim was to examine relations of serum retinol-binding protein 4 (RBP4) to cardiovascular risk factors, and prevalent metabolic syndrome (MetS) and cardiovascular disease (CVD) in a large community-based sample of elderly.

We evaluated cross-sectional relations of serum RBP4 to cardiovascular risk factors including anthropometrical measures, blood pressure, lipid measures, fasting glucose and insulin, body fat distribution including truncal fat by dual-energy x-ray absorptiometry (DXA), homeostasis model assessment insulin resistance (HOMA-IR) and prevalent MetS in one thousand eight 70-year old participants (50% women) of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS), and in five hundred seven 82-year old men from Uppsala Longitudinal Study of Adult Men (ULSAM). In ULSAM, we also examined associations with prevalent CVD.

RBP4 concentrations were positively correlated with serum triglycerides (r=0.30; P<0.0001 in both samples), whereas correlations with body mass index (BMI), waist circumference, sagittal abdominal diameter, total and truncal fat mass, total cholesterol, fasting glucose and HOMA-IR were weak. In multivariable-adjusted models, RBP-4 was associated with MetS (odds ratio (OR), 1.16 and 1.33; 95% confidence interval (CI), 0.99-1.37 and 1.05-1.67 per 1-standard deviation (SD) increase in PIVUS and ULSAM, respectively), and prior cerebrovascular disease (OR, 1.37; 95% CI, 1.00-1.88 per 1-SD increase in ULSAM), but not with prior myocardial infarction.

In elderly, RBP4 concentrations were associated with MetS and its components in both sexes, and prior cerebrovascular disease in men. These findings are consistent with the hypothesis that circulating RBP4 could be a marker of metabolic complications and possibly also atherosclerosis and overt CVD.