Glycemic control in diabetic CAPD patients assessed by continuous glucose monitoring system (CGMS)

From 20% to 40% of all patients commencing dialysis are diabetic. The quality of glycemic control is an important determinant of outcome. The aims of this study were to investigate the use of the continuous glucose monitoring system (CGMS) to assess overall 24-hour glycemic control and the effects of both nonglucose containing and more biocompatible alternative peritoneal dialysis solutions in insulin-treated continuous ambulatory peritoneal dialysis (CAPD) patients.

We studied 8 insulin treated diabetic CAPD patients. A CGMS probe was inserted [allowing automatic measurement of interstitial fluid (ISF) glucose every 5 minutes, for a 72-hour period]. The patients were then allowed home with CGMS monitoring to assess the effect on glycemic control of three differing peritoneal dialysis regimes. Phase 1 consisted of three exchanges of 1.36% glucose and one of 3.86% glucose, utilizing a lactate/bicarbonate buffer. Phase 2 was identical but used lactate-buffered fluid alone. Phase 3 utilized a minimally glycemic combination of one amino acid, one icodextrin, and two 1.36% glucose lactate/bicarbonate-containing exchanges.

ISF glucose measured by CGMS correlated well with venous glucose measurements (r2 = 0.82, P < 0.0001). There was a statistically significant difference in the mean ISF glucose between all three phases (P < 0.0001). The variation in glycemic control was tighter during phase 3 [mean coefficient of variation (CV) 0.21 +/- 0.03].

CGMS appears to be a clinically useful tool to gain additional insights into the glycemic control of diabetic CAPD patients. More biocompatible and nonglucose-containing dialysis fluids seem to be associated with improvements in glycemic control in this group of patients.