Association of ENOS polymorphism with basal peritoneal membrane function in uremic patients.
BACKGROUND
Basal peritoneal permeability has a major impact on the outcome of peritoneal dialysis (PD) patients, but the determinant of this is unknown. Early evidence suggests that peritoneal permeability is affected by nitric oxide (NO) activity. Recently, a gene polymorphism of the endothelial NO synthase (ENOS) gene was identified that is associated with circulating nitrate levels.


METHODS
We performed a cross-sectional study to examine the relationship between ENOS4(a/b) gene polymorphism and basal peritoneal function in 86 Chinese incident PD patients. ENOS genotypes for variable number tandem repeats in intron 4 (a/b) were identified by polymerase chain reaction. Patients were classified into 2 groups according to results of a basal peritoneal equilibration test (PET) performed within 2 months of dialysis therapy: group A consisted of patients with low (L)/L average (LA) PET results, and group B consisted of those with H and HA PET results.


RESULTS
Group A (L/LA) had a significantly greater prevalence of ENOS aa/ab genotype than group B (H/HA; 30% versus 12%; P < 0.05). Frequencies of the ENOS a allele also were greater in group A (L/LA) than group B (H/HA) (16% versus 6%; P = 0.03). ENOS genotype remained an independent predictor for peritoneal transport after adjustment for sex, body weight, and prevalence of diabetes by multivariate analysis (adjusted odds ratio, 3.3; confidence interval, 1.1 to 3.7; P = 0.03). Subjects with the aa/ab genotype had significantly lower mass transfer area coefficients (7.35 +/- 3.4 versus 9.48 +/- 5.21 mL/min; P = 0.023) and dialysate-plasma creatinine ratios at 4 hours (0.55 +/- 0.13 versus 0.62 +/- 0.14; P = 0.048) than those with the bb genotype.


CONCLUSIONS
ENOS4(a/b) gene polymorphism is associated with basal peritoneal permeability in uremic Chinese patients.
Wong
Teresa Yuk-Hwa
TY
Department of Medicine and Therapeutics, The Chinese University of Hong Kong, The Prince of Wales Hospital, Shatin, Hong Kong. wgteresa@alumni.cuhk.net
Szeto
Cheuk-Chun
CC
Szeto
Carol Yi-Ki
CY
Lai
Ka-Bik
KB
Chow
Kai-Ming
KM
Li
Philip Kam-Tao
PK
D001786:Blood Glucose / Q000032:analysis; D003404:Creatinine / Q000032:analysis; D003430:Cross-Sectional Studies; D005260:Female; D005787:Gene Frequency; D006801:Humans; D007676:Kidney Failure, Chronic / Q000201:enzymology* / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D019001:Nitric Oxide Synthase / Q000235:genetics*; D052250:Nitric Oxide Synthase Type III; D010530:Peritoneal Dialysis; D010537:Peritoneum / Q000502:physiology*; D010539:Permeability; D011110:Polymorphism, Genetic; D020080:Tandem Repeat Sequences
D001786:Blood Glucose; D003404:Creatinine; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III