Glycemic control predicts diabetic extrarenal microvascular complications but not renal survival in patients with moderate to severe chronic kidney disease.

ABSTRACT

BACKGROUND: Control of blood pressure (BP) and blood glucose can slow the development of diabetic nephropathy (DN). However, BP control may be of relatively more importance than glycemic control on the progression of DN. OBJECTIVE: To determine the effects of glycemic control on renal survival in a predominantly African American diabetic population with moderate-to-severe renal disease. DESIGN: This was a retrospective chart review of all diabetic patients seen in an academic nephrology clinic in 2001 and 2002 for renal survival and its predictors and micro/macrovascular disease. The weighted mean glycosylated hemoglobin (GHb) over followup was determined. Mean GHb < or = 9 was defined as low, and GHb >9 was high. The effect of glycemic control on endpoints was determined by Cox proportional hazards and logistic regression. RESULTS: One hundred fifty-five diabetic patients (87.7% African American, mean creatinine =2.2 mg/dL) had sufficient GHb measurements. Compared to the high group (n=81), the low group (n=74) was significantly younger, had a shorter duration of diabetes, and worse renal function. No significant association of glycemic control with renal survival (ESRD) was seen. Glycemic control and the presence of DN were significantly related to extrarenal microvascular complications, independent of other factors. CONCLUSION: Glycosylated hemoglobin (GHb) is not a significant predictor of renal survival in patients with diabetes and moderate renal disease. However, glycemic control does predict extrarenal microvascular complications in this population. Therefore, good metabolic control remains important in patients with diabetes and renal disease.