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-dependent diabetic (IDDM) and nondiabetic patients.


METHODS
One to two 24-hour dialysate and urine collections were obtained in 20 diabetic patients and 42 nondiabetic patients. The protein equivalent of nitrogen appearance (PNA) was calculated by the Randerson formula. KT/V was determined using V obtained by the Watson formula. PNA was normalized using three different methods to determine body weight: first, by normal or ideal body weight according to the Metropolitan Table (nPNA); second, by standard body weight according to the NHANES Table (sPNA); and third, by V/0.58 (vPNA).


RESULTS
The mean PNA was not different in diabetics and nondiabetics (53 +/- 21 g/day vs 60 +/- 14 g/day), nor was weekly 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 = 0.0009). KT/V also correlated with sPNA in IDDM (r = 0.57, p = 0.001), but not in non-DM (r = 0.25, p = 0.08). The slope for normalized PNA versus KT/V was steeper for IDDM than for non-DM.


CONCLUSIONS
KT/V and PNA are more closely correlated in IDDM patients than in non-DM patients. Thus it is extremely important that IDDM patients receive an adequate level of dialysis.
Bernardini
J Y
JY
University of Pittsburgh, Pennsylvania, USA.
Kelman
B
B
Piraino
B
B
D001835:Body Weight; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000378:metabolism* / Q000652:urine; D015314:Dialysis Solutions / Q000032:analysis / Q000493:pharmacokinetics; D004044:Dietary Proteins / Q000008:administration & dosage / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007668:Kidney / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009584:Nitrogen / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D009752:Nutritional Status; D010530:Peritoneal Dialysis; D012044:Regression Analysis; D012709:Serum Albumin / Q000032:analysis; D014508:Urea / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine
D015314:Dialysis Solutions; D004044:Dietary Proteins; D012709:Serum Albumin; D014508:Urea; D009584:Nitrogen