Cockcroft's formula underestimates glomerular filtration rate in diabetic subjects treated by lipid-lowering drugs.

Diabetic subjects are often dyslipemic and have to be treated by fibrates or statins. These drugs must be cautiously used (and sometimes withdrawn) when chronic renal failure is present. Accurate evaluation of glomerular filtration rate (GFR) is thus of crucial importance in diabetic patients to detect early renal impairment. The Cockroft-Gault formula estimates glomerular function as a function of age, body weight, and serum creatinine, and is recommended by the American Diabetes Association (1). We evaluated the accuracy of Cockroft’s formula (CF) for predicting GFR, by reference to 51Cr-EDTA clearance, in 48 diabetic subjects without important renal failure (GFR >60 ml/min). Diabetic subjects were divided into two groups: 22 were not treated by lipid-lowering drugs (TTT−) and 26 were treated (TTT+; 22 with statin, 4 with fibrates). Results of plasma …