Associations between sex and incident chronic kidney disease in a prospective diabetic cohort

AIM: Women with diabetes have a higher prevalence of chronic kidney disease (CKD) risk factors compared with men, but whether they are at higher risk for incident CKD remains uncertain. METHODS: This was a prospective, observational cohort study of 1464 patients with diabetes and normal renal function, recruited from primary care clinics at a vertically integrated healthcare system in Seattle, WA, USA. The primary predictor was sex. Incident CKD was defined by an estimated glomerular filtration rate (eGFR) <60 mL/min per 1.73 m(2) by Chronic Kidney Disease‐Epidemiology equations or sex‐specific microalbuminuria (urine albumin/creatinine ratio ≥25 mg/g for women or ≥17 mg/g for men). RESULTS: Of the 1464 patients (52.0% women), CKD incidence rates were 154.0 and 144.3 cases per 1000 patient‐years for women and men, respectively. In the competing risks regression, women had an increased risk of incident CKD (sub‐hazard ratio 1.37, 95% confidence interval (CI) 1.17, 1.60) compared with men after adjustment for demographics, baseline eGFR and duration of diabetes, which persisted after additional adjustment for CKD risk factors, depressive symptoms and diabetes self‐care (sub‐hazard ratio 1.35, 95% CI 1.15, 1.59). Sex differences in incident CKD were consistent across age groups and appeared to be driven by differences in the development of low eGFR rather than microalbuminuria. CONCLUSION: Women with diabetes had a higher risk of incident CKD compared with men, which could not be entirely explained by differences in biologic CKD risk factors, depression or diabetes self‐care. Additional work is needed determine if these sex differences contribute to worse outcomes in women with diabetes.