Serum RBP4 positively correlates with triglyceride level but not with BMI, fat mass and insulin resistance in healthy obese and non-obese individuals.

ABSTRACT

PURPOSE: Retinol binding protein 4 (RBP4) has recently been identified as an adipokine possibly involved in the development of impaired glucose metabolism. We aimed to test serum RBP4 in healthy non-obese individuals and in patients with well-characterized phenotype obesity without confounding effects of diabetes, metabolic syndrome or dyslipidaemia. Additionally, we examined whether serum RBP4 is associated with anthropometric parameters, insulin resistance and blood lipid parameters. PATIENTS AND METHODS: Twenty-eight patients with obesity and no co-morbidities and twenty-five age-matched lean controls were recruited. Anthropometric parameters, body composition, fasting blood lipid profile, RBP4, glucose and insulin were assessed and HOMA-IR was calculated. RESULTS: Mean concentration of RBP4 did not differ between studied groups (in obese patients was 33.93 ± 4.46 µg/ml and 32.53 ± 2.53 µg/ml in non-obese controls). RBP4 positively correlated with serum triglycerides in obese and non-obese individuals (r = 0.74, p = 0.03 and r = 0.62, p = 0.02, respectively) and did not show any significant associations with HOMA-IR, anthropometric and body composition parameters. CONCLUSIONS: Excessive adiposity without co-morbidities is not associated with higher levels of circulating RBP4. Serum RBP4 cannot be considered as a direct predictive marker for impaired glucose metabolism. RBP4 possibly contributes to lipid metabolism.