Impact of age on leptin and adiponectin independent of adiposity

AbstractAge-related changes in leptin and adiponectin levels remain controversial, being affected by inconsistent normalisation for adiposityand body fat distribution in the literature. In a cross-sectional study on 210 Caucasians (127 women, eighty-three men, 18–78 years,BMI 16·8–46·8kg/m 2 ), we investigated the effect of age on adipokine levels independent of fat mass (FM measured by densitometry), vis-ceral and subcutaneous adipose tissue volumes (VAT and SAT assessed by whole-body MRI). Adiponectin levels increased with age in bothsexes, whereas leptin levels decreased with age in women only. There was an age-related increase in VAT (as a percentage of total adiposetissue, VAT%TAT), associated with a decrease in SAT legs %TAT. Adiposity was the main predictor of leptin levels, with 75·1% of the varianceexplained by %FM in women and 76·6% in men. Independent of adiposity, age had a minor contribution to the variance in leptinlevels (5·2% in women only). The variance in adiponectin levels explained by age was 14·1% in women and 5·1% in men. In addition,independent and inverse contributions to the variance in adiponectin levels were found for truncal SAT (explaining additional 3·0%in women and 9·1% in men) and VAT%TAT (explaining additional 13·0% in men). In conclusion, age-related changes in leptin andadiponectin levels are opposite to each other and partly independent of adiposity and body fat distribution. Normalisation for adipositybut not for body fat distribution is required for leptin. Adiponectin levels are adversely affected by subcutaneous and visceral trunk fat.Key words: Body fat distribution: Fat mass: Ageing: Leptin: Adiponectin