Effect of improved metabolic control on loss of kidney function in Type 1 (insulin-dependent) diabetic patients: an update of the Steno studies

Abstract

We re-examined 69 of the 70 patients entering the two independent Steno Studies of effects of improved metabolic control on progression of late diabetic complications. They were analysed according to an intent to treat after follow-up for 8 years (Steno Study 1) and 5 years (Steno Study 2). The glycaemic control had improved in the insulin infusion group compared with the conventional treatment group (mean HbA_1c) by 2.0±0.6% vs 0.7±1.2 in Steno Study 1 and by 1.8±1.2% vs 0.4±1.3 (p−1·1.73 m⁻² vs −1.0 (−2.1 to −0.1) (conventional vs insulin infusion group, mean (95% confidence interval, pn=69, r=0.49, pn=10) vs insulin infusion (n=9): Clinical nephropathy (10 of 10 vs 2 of 9, pp−1·1.73 m⁻² (p<0.05) but not during insulin infusion (−13 (−31 to 5) NS). These results suggest that patients at risk of nephropathy should be offered near normal glycaemic control in order to preserve their kidney function.