Discrepancies between adequacy goals in peritoneal dialysis: role of gender.
BACKGROUND
The National Kidney Foundation-Dialysis Outcome Quality Initiative (NKF-DOQI) recommends a weekly creatinine clearance (CrCl) of 60 L/wk/1.73 m2 or greater and a Kt/V of 2.0 or greater as peritoneal dialysis (PD) adequacy standards. It has been described that approximately one quarter of patients may have discrepancies between these goals. The purpose of this study is to identify associated factors in patients reaching both criteria, none, or only weekly Kt/V, where K is clearance, t is time, and V is volume.


METHODS
We studied 64 patients and their adequacy results in a cross-sectional analysis. Patients were divided in three groups. Group 1 reached both weekly Kt/V and CrCl criteria. Group 2 did not reach either criteria. Group 3 reached only the weekly Kt/V criterion. A new weekly Kt/V also was calculated, assigning to all patients a male V. One patient who met only the CrCl criterion was excluded.


RESULTS
Groups 2 and 3 had significantly less residual renal function (RRF) than group 1 (residual CrCl, 5.50 and 1.33 versus 37.3 L/wk/1.73 m2, respectively; P < 0.001). Other differences, such as age, weight, peritoneal membrane transport, nutritional parameters, or number of patients with diabetes, were not significantly different. Group 3 made up 19% of patients and was predominantly females. Conversely, group 2 was predominantly males. Using a male V, we obtained a weekly Kt/V below the NKF-DOQI recommendations for group 3 (1.9 versus 2.2; P < 0.05).


CONCLUSIONS
Conservation of RRF was the main factor in reaching both PD adequacy criteria. Discrepancies were frequent, accounting for 19% of our population. Female gender explained why patients reached weekly Kt/V only. This difference disappeared when we calculated Kt/V using a male V.
Castillo
Alvaro A
AA
Department of Medicine, Division of Renal Diseases and Hypertension, The George Washington University Medical Center, Washington, DC 20037, USA.
Lew
Susie Q
SQ
Smith
Amy M
AM
Whyte
Rachel L
RL
Bosch
Juan P
JP
D001810:Blood Volume / Q000502:physiology; D001834:Body Water / Q000378:metabolism; D003404:Creatinine / Q000097:blood / Q000378:metabolism / Q000652:urine; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000097:blood / Q000628:therapy / Q000652:urine; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000379:methods*; D012737:Sex Factors; D013997:Time Factors
D003404:Creatinine