Adiponectin and leptin in chronic kidney disease: causal factors or mere risk markers?

Experimental and clinical evidence implicates the 2 major adipose tissue cytokines, adiponectin (ADPN) and leptin (LEP), in renal damage. The interpretation of the link between these cytokines and renal outcomes is strictly context-sensitive. Albuminuria is a feature of renal disease in the ADPN null mouse and this alteration can be reversed by supplementing ADPN. Accordingly, in young normoalbuminuric obese individuals low ADPN is associated with higher albumin excretion rate. Conversely, high ADPN is associated with more severe proteinuria in chronic kidney disease patients, possibly underlying a protective response aimed at countering the high renal and cardiovascular risk of high proteinuria. LEP administration ameliorates insulin resistance in insulin-resistant patients with hereditary lipodystrophy--a disease characterized by severe LEP deficiency and renal disease--and the same intervention reverses both, insulin resistance and renal damage in a mouse model of LEP deficiency. However, LEP may exert noxious effects on the kidney (particularly renal fibrosis) if administered in conditions of LEP sufficiency or excess.