The Influence of Sex on Renal Function Decline in People with Type 2 Diabetes

Aims: Several reports have suggested a relationship between male sex and albuminuria in Type 2 diabetes, but impact on renal function decline has not been established. Our aim was to describe the influence of sex on renal function decline in Type 2 diabetes.

Methods: SURDIAGENE, an inception cohort, consisted in 1470 people with Type 2 diabetes. Patients without renal replacement therapy and with ≥ 3 serum creatinine determinations during follow-up prior to end-stage renal disease were included in the study. Estimated glomerular filtration rate was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. Primary outcome was steep estimated glomerular filtration rate (eGFR) decline, defined as a yearly slope value lower than -3.5 ml min(-1) 1.73 m(-2). Secondary outcomes were estimated glomerular filtration rate trajectories according to sex and occurrence of end-stage renal disease.

Results: A total of 22 914 serum creatinine determinations were considered in 1146 participants (60% men), aged 65 ± 11 years, with a median follow-up duration of 5.7 years (range 0.1-10.2). Median yearly estimated glomerular filtration rate slope was -1.31 ml min(-1) 1.73 m(-2) in women and -1.77 ml min(-1) 1.73 m(-2) in men (P < 0.001). Men were more likely than women to develop end-stage renal disease (22 men vs. 7 women; P(log-rank) = 0.03). Male sex was an independent risk factor of steep estimated glomerular filtration rate decline [adjusted odds ratio = 1.33 (1.02-1.76), P = 0.04] after adjustment for age, time from diagnosis of Type 2 diabetes, glycated haemoglobin, systolic blood pressure and urinary albumin:creatinine ratio. A multivariable linear mixed-effects model showed a significant difference of estimated glomerular filtration rate trajectories between men and women (P < 0.001).

Conclusion: Male sex is an important independent factor associated with renal function decline in Type 2 diabetes.