The relationship between adipokines and the onset of type 2 diabetes in middle-aged men: The PRIME study.

AIMS:Epidemiological evidence suggests that adipokines may be associated with the onset of type 2 diabetes, but the evidence to date is limited and inconclusive. This study examined the association between adiponectin and leptin and the subsequent diagnosis of type 2 diabetes in a UK population based cohort of non-diabetic middle-aged men. METHODS:Baseline serum levels of leptin and adiponectin were measured in 1839 non-diabetic men aged 50-60years who were participating in the prospective population-based PRIME study. Over a mean follow-up of 14.7years, new cases of type 2 diabetes were determined from self-reported clinical information with subsequent validation by general practitioners. RESULTS:151 Participants developed type 2 diabetes during follow-up. In Cox regression models adjusted for age, men in the top third of the leptin distribution were at increased risk (hazard ratio (HR) 4.27, 95% CI 2.67-6.83) and men in the top third of the adiponectin distribution at reduced risk (HR 0.24, 95% CI 0.14-0.42) relative to men in the bottom third. However, significance was lost for leptin after additional adjustment for BMI, waist to hip ratio, lifestyle factors and biological risk factors, including C-reactive protein (CRP). Further adjustment for HOMA-IR also resulted in loss of significance for adiponectin. CONCLUSIONS:This study provides evidence that adipokines are associated with men's future type 2 diabetes risk but not independently of other risk factors.