Subcutaneous and intraperitoneal insulin therapy in diabetic patients on CAPD

We evaluated in a cross-over manner the consequences of subcutaneously and intraperitoneally given insulin on glucose control, insulin sensitivity, and serum lipids in 8 type I diabetic patients on continuous ambulatory peritoneal dialysis (CAPD). The patients were treated with both subcutaneous and intraperitoneal insulin for at least three months. After each period, metabolic studies were performed. Despite significantly improved glycemic control (Hb A1c 10.00 +/- 0.38% after subcutaneous and 8.40 +/- 0.36% after intraperitoneal insulin, p = 0.01), serum lipids showed unfavorable changes. High-density lipoprotein (HDL)-cholesterol was significantly lower (1.28 +/- 0.18 mmol/L vs 0.88 +/- 0.06 mmol/L, p = 0.03) and low-density lipoprotein (LDL)/HDL-cholesterol ratio was higher (p = 0.025) during intraperitoneal insulin. Total cholesterol, LDL-cholesterol, and triglycerides were higher during intraperitoneal insulin administration. Severe hypoglycemic episodes were more common during subcutaneous than intraperitoneal insulin. It is concluded that, although intraperitoneal insulin administration offers significantly better glycemic control and insulin sensitivity than subcutaneous insulin, the effect of serum lipids is more disadvantageous possibly via a direct effect of insulin on the liver.