The effects of weight loss on FABP4 and RBP4 in obese women with metabolic syndrome.

Fat accumulation is associated with the release of many novel adipokines such as retinol-binding protein 4 and fatty acid-binding protein 4. These adipokines have been linked to insulin resistance, metabolic syndrome, type 2 diabetes and cardiovascular disease. Since weight loss is the first step for the treatment of metabolic syndrome, which increases the risks for both type 2 diabetes and cardiovascular disease, we have investigated the effects of weight loss on serum retinol-binding protein 4 and fatty acid-binding protein 4 in obese individuals with this syndrome. Twenty-nine obese female subjects with metabolic syndrome, aged 18-62 years completed a 2-month weight loss diet plan. Data were collected from dual-energy X-ray absorptiometry and indirect calorimetry. Blood was taken at baseline and at 2 months and assayed for adipokines, lipids, and insulin resistance parameters. The change in circulating fatty acid-binding protein 4 levels were inversely correlated with total weight loss (p<0.02) and lean mass loss (p<0.01), but not with fat mass loss. Retinol-binding protein 4 levels did not track with any measure of body composition. Changes in leptin levels were found to correlate with weight loss (p<0.02), fat loss (p<0.03), and lean mass loss (p<0.05). Fatty acid-binding protein 4 levels increased and retinol-binding protein 4 levels did not change during moderate weight loss in obese women with metabolic syndrome; however, several other risk factors for type 2 diabetes and cardiovascular disease did improve with weight loss.