Gender differences in the association between HDL cholesterol and the progression of diabetic kidney disease in type 2 diabetic patients

Background. The impact of serum lipid abnormalities on the progression of diabetic kidney disease (DIG)) remains conflicting. Furthermore, gender differences in the association between dyslipidaemia and outcome of DKD are largely unknown. We therefore conducted this single-centre observational cohort study to clarify gender differences in the association between serum lipid profiles and the progression of DKD. Methods. Seven hundred and twenty-three Japanese type 2 diabetes mellitus (T2DM) patients with normoalbuminuria or microalbuminuria, 280 women and 443 men, with a mean (+/- SD) age of 63 +/- 11 years were studied. The endpoint was the progression to a more advanced stage of albuminuria. For statistical analyses, Cox proportional hazard model analyses were conducted. Results. During the mean follow-up period of 4.3 years, 62 of 477 patients with normoalbuminuria and 69 of 246 patients with microalbuminuria reached the endpoint. A significant interaction between high-density lipoprotein (HDL) cholesterol and gender was detected (P-interaction = 0.04); therefore, separate analyses were conducted for men and women. Overall, in men, the univariate Cox proportional hazard model revealed that higher triglycerides and lower HDL cholesterol levels were significantly associated with higher risk of reaching the endpoint. In the multivariate Cox proportional hazard model, only HDL cholesterol levels remained as an independent predictor of the endpoint (hazard ratio 0.391, P = 0.01). In women, no serum lipid parameters were associated with the endpoint. Conclusions. Lower HDL cholesterol levels seem to be associated with the progression of DKD in men but not in women.