Changes and relations of circulating visfatin, apelin, and resistin levels in normal, impaired glucose tolerance, and type 2 diabetic subjects

Visfatin and apelin are two novel adipocyte-secreted hormone proposed to link obesity with insulin resistance. In this study we investigated whether plasma visfatin and apelin levels were altered in normal, impaired glucose tolerance, and type 2 diabetic subjects. We also assessed the association between plasma visfatin, or apelin and body composition, metabolic parameters, and resistin concentrations in these subjects. The visfatin levels of fasting and 2-h post-glucose load were found to be significantly decreased in diabetics compared with the controls (P < 0.05). In contrast, basal apelin levels were significantly increased in the IGT and diabetic subjects compared with the controls (P < 0.05 and P < 0.01). The apelin levels of 2-h post-glucose load were significantly higher than the basal levels in every group (all P < 0.05). Fasting plasma visfatin was found to correlate positively and significantly with BMI, WHR, and fasting plasma resistin, but negatively with HbA1c and 2h OGTT glucose. Multiple regression analysis showed that WHR, HbA1c, 2 h OGTT glucose were independent related factors influencing plasma visfatin levels. Fasting plasma apelin levels correlated positively with HOMA-IR, BMI, TC, LDL-C, FBG and Fasting plasma insulin. Multiple regression analysis also showed that HOMA-IR, BMI, and TC were independent related factors influencing plasma apelin levels. The present work indicates the potential link of visfatin and apelin with the pathogenesis of insulin resistance and T2DM.