Volume control in diabetic and nondiabetic peritoneal dialysis patients

Diabetic patients especially the elderly have higher mortality on peritoneal dialysis treatment as compared to nondiabetic patients. As fluid overload is an important contributor for the high dropout rate in peritoneal dialysis therapy, the present study tried to compare the fluid status in diabetic and non-diabetic peritoneal dialysis patients and to investigate the effect of salt and water restriction on fluid status in diabetic peritoneal dialysis patients.

A cross sectional study was performed in 58 peritoneal dialysis patients who had been treated for at least 3 months. Among them, 20 patients were diabetics and the others were nondiabetics. We reviewed their dialysis prescription, peritoneal ultrafiltration, urine volume and fluid status. Then the 20 diabetic patients were advised to restrict their salt and water intake and were followed for 3 months.

During the cross sectional study there were no significant differences in age, gender, height and urine volume between the diabetic and nondiabetic patients. However, body weight, normalized extracellular water (nECW), dialysis dose, dialysate glucose load, peritoneal ultrafiltration, total fluid removal and the prevalence and extent of edema were all significantly higher in diabetics as compared to nondiabetics. After restricting salt and water intake, body weight, nECW, edema, fasting blood glucose, dialysate dose, dialysate glucose load, peritoneal ultrafiltration and total fluid removal were all significantly decreased, whereas the urine volume did not change significantly.

The present study suggests that diabetic patients were more fluid overloaded as compared to nondiabetics despite use of more hypertonic glucose solutions and, as a consequence, higher peritoneal ultrafiltration and higher total fluid removal; this indicates that our diabetic patients must have had significantly higher salt and fluid intakes. It also suggests that restricting salt and water intake can effectively treat fluid overload in diabetic peritoneal dialysis patients. Dietary salt and fluid restriction may help reduce the use of hypertonic glucose solution and thus facilitate the blood glucose control in diabetic patients undergoing peritoneal dialysis.