The relationship between adiponectin, ageing and renal function in a bi-ethnic sample

Ageing is associated with elevated adiponectin levels. Our aim was to assess whether age-related increase in adiponectin is associated with a decrease in renal function. The study comprised African (N=277) and Caucasian (N=326) men and women. Adiponectin levels, estimated creatinine clearance rate and obesity indices were determined. African men revealed significantly higher adiponectin levels compared to Caucasian men (p<0.01), reflecting the lower adiposity levels of the African men. No difference in obesity measures (p=0.92) and adiponectin levels (p=0.27) was observed between African and Caucasian women. A significant increase in adiponectin levels with ageing was observed in both African men and women (p<0.01). To the contrary, progressive ageing seems not to be significantly related to elevated adiponectin levels within Caucasians. Renal impairment decreased significantly within all of the groups (p<0.01). Single regression analyses performed in all specified groups revealed significant associations between adiponectin and estimated creatinine clearance, however a multiple regression model revealed that insulin resistance had the strongest association with adiponectin within all the groups. In conclusion, age-related rise in adiponectin levels observed in Africans may not be due to renal impairment.