Cross sectional assessment of weekly urea and creatinine clearances and indices of nutrition in continuous ambulatory peritoneal dialysis patients.

OBJECTIVE

To perform a cross sectional analysis in 71 patients on continuous ambulatory peritoneal dialysis (CAPD) to identify significant correlations of weekly small solute clearances and indices of nutritional status with each other and with patient demographics and other commonly monitored clinical and laboratory parameters.

DESIGN

This was a retrospective, cross sectional analysis in 71 patients on CAPD from less than 1 to 105 patient-months (average, 20 months).

SETTING

An outpatient CAPD program.

PATIENTS

All patients on CAPD in our program at the time of the study willing to undergo the clearance and nutritional status measurements.

INTERVENTIONS

No interventions other than the monitoring of their status.

MAIN OUTCOME MEASURES

Weekly small solute clearances, dietary protein intake, serum albumin, lean body mass, net protein catabolic rate, and urinary and dialysate nitrogen.

RESULTS

Weekly Kt/V urea (weekly urea clearance normalized to total body water) of at least 1.7 and weekly total creatinine clearances (liter/week/1.7 m2) of at least 50 are associated with net protein catabolic rates (PCR) greater than 0.9 g/kg of normalized body weight in average CAPD patients. Kt/V urea and net PCR correlate significantly with serum albumin. High transporters identified by the peritoneal equilibration test have greater albumin losses and lower serum albumin concentrations. Estimates of lean body mass correlate significantly with serum albumin and net PCR; lean body mass correlates significantly and inversely with age.

CONCLUSIONS

Greater small solute clearances are associated with better nutritional status.