Perirenal fat and chronic kidney disease in type 2 diabetes: The mediation role of afferent arteriolar resistance

Aim: Perirenal fat (PRF) is an independent predictor for chronic kidney disease (CKD) in type 2 diabetes mellitus (T2DM) patients. Previous studies speculated that PRF may promote renal dysfunction through affecting renal hemodynamics. To verify this hypothesis, we studied the relationship between PRF and renal hemodynamics in T2DM. Methods: 91 T2DM patients were included. PRF thickness (PRFT) was measured by magnetic resonance imaging. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were determined by renal dynamic imaging. Renal vascular resistance (RVR), glomerular hydrostatic pressure (PGLO), afferent (RA) and efferent (RE) arteriolar resistance were calculated by Gomez equations. Multiple linear regression was used to determine the relationship between PRFT and renal hemodynamics. Mediation analysis was conducted to estimate the mediation effects of renal hemodynamics on the relationship between PRF and CKD. Results: All patients were divided into three groups according to the tertiles of PRFT. Compared with patients in tertile 1, GFR and ERPF were significantly decreased in patients in tertile 3, while RVR and RA were significantly increased. PRFT was negatively correlated with GFR, ERPF and PGLO, and positively correlated with RVR and RA after adjustment for sex, age, visceral adipose tissue and treatments with ACE inhibitors/angiotensin receptor blockers and sodium-glucose cotransporter protein-2 inhibitors. Moreover, RVR and RA mediated the effect of PRF on GFR, with a mediated proportion of 29.1 % and 41.4 % respectively. Conclusion: In T2DM patients, PRF was negatively correlated with GFR, and positively correlated with RA. RA mediated the relationship between PRF and CKD.