Glomerular filtration rate in patients with Cushing’s disease: a matched case–control study

Abstract

Background: Patients with Cushing’s disease have a high prevalence of atherosclerosis and maintain an increased cardiovascular risk even after cure of the disease. However, the impact of Cushing’s disease on renal function remains to be quantified. Objectives: To evaluate glomerular filtration rate (GFR) and to identify predictors of GFR in patients with Cushing’s disease. Design and methods: We conducted a matched case–control study: 18 patients with active or cured Cushing’s disease were compared with healthy population controls matched for age and sex. The main outcome measures were GFR and micro-albuminuria. Results: Patients with Cushing’s disease had a lower GFR, as measured by 24-h creatinine clearance (79 versus 95 ml/min per 1.73 m2, P = 0.005) and estimated by the MDRD2 formula (75 versus 88 ml/min per 1.73 m2, P = 0.008). Multiple regression analyses indicated that disease duration was the strongest predictor for a worse GFR. The prevalence of micro-albuminuria was low (5.5% in both groups). Conclusions: Patients with Cushing’s disease have a decreased GFR. Even if they are cured, close follow-up with strict control of cardiovascular risk factors and monitoring of GFR seems mandatory. Furthermore, the dosage of certain drugs should be adapted to the individual GFR.