UREA KINETICS AND NITROGEN APPEARANCE RATES IN DIABETIC-PATIENTS ON PERITONEAL-DIALYSIS

Objective: We compared the relationship of protein intake (as measured by protein nitrogen appearance) and dialysis delivery in insulin-depe ndent diabetic (IDDM) and nondiabetic patients. Design: One to two 24- hour dialysate and urine collections were obtained in 20 diabetic pati ents and 42 nondiabetic patients. The protein equivalent of nitrogen a ppearance (PNA) was calculated by the Randerson formula. KT/V was dete rmined using V obtained by the Watson formula. PNA was normalized usin g three different methods to determine body weight: first, by normal o r ideal body weight according to the Metropolitan Table (nPNA); second , by standard body weight according to the NHANES Table (sPNA); and th ird, by V/0.58 (vPNA). Results: The mean PNA was not different in diab etics and nondiabetics (53+/-21 g/day vs 60+/-14 g/day), nor was weekl y KT/V (2.1+/-0.6 vs 2.1+/-0.6). Mean normalized PNA was not different in IDDM versus non-DM regardless of the method. KT/V correlated with nPNA in IDDM (r = 0.54, p = 0.002 and non-DM, r = 0.31, p = 0.03), and with vPNA in IDDM (r = 0.73, p < 0.00001, and non-DM, r = 0.45, p 0.0 009). KT/V also correlated with sPNA in IDDM (r = 0.57, p = 0.001), bu t not in non-DM (r = 0.25, p = 0.08). The slope for normalized PNA ver sus KT/V was steeper for IDDM than for non-DM. Conclusion: KT/V and PN A are more closely correlated in IDDM patients than in non-DM patients . Thus it is extremely important that IDDM patients receive an adequat e level of dialysis.