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Urinary potassium excretion, renal ammoniagenesis, and risk of graft failure and mortality in renal transplant recipients.
- Source :
- American Journal of Clinical Nutrition; 12/1/2016, Vol. 104 Issue 6, p1703-1711, 9p
- Publication Year :
- 2016
-
Abstract
- Background: Renal transplant recipients (RTRs) have commonly been urged to limit their potassium intake during renal insufficiency and may adhere to this principle after transplantation. Importantly, in experimental animal models, low dietary potassium intake induces kidney injury through stimulation of ammoniagenesis. In humans, low potassium intake is an established risk factor for high blood pressure. Objective: We hypothesized that low 24-h urinary potassium excretion [UKV; urinary potassium concentration x volume], the gold standard for assessment of dietary potassium intake, represents a risk factor for graft failure and mortality in RTRs. In secondary analyses, we aimed to investigate whether these associations could be explained by ammoniagenesis, plasma potassium, or blood pressure. Design: In a prospective cohort of 705 RTRs, we assessed dietary potassium intake by a single 24-h UKV and food-frequency questionnaires. Cox regression analyses were used to investigate prospective associations with outcome. Results: We included 705 stable RTRs (mean ± SD age: 53 ± 13 y; 57% men) at 5.4 y (IQR: 1.9-12.0 y) after transplantation and 253 kidney donors. Mean ± SD UKV was 73 ± 24 mmol/24 h in RTRs compared with 85 ± 25 mmol/24 h in kidney donors. During follow-up for 3.1 y (IQR: 2.7-3.9 y), 45 RTRs developed graft failure and 83 died. RTRs in the lowest sex-specific tertile of UKV (women, <55 mmol/24 h; men, <65 mmol/24 h) had an increased risk of graft failure (HR: 3.70; 95% CI: 1.64, 8.34) and risk of mortality (HR; 2.66; 95% CI: 1.53, 4.61), independent of potential confounders. In causal path analyses, 24-h urinary ammonia excretion, plasma potassium, and blood pressure did not affect these associations. Conclusions: Our results indicate that low UKV is associated with a higher risk of graft failure and mortality in RTRs. Specific attention for adequate potassium intake after transplantation seems warranted. [ABSTRACT FROM AUTHOR]
- Subjects :
- AMMONIA metabolism
ANALYSIS of variance
BLOOD pressure
CHI-squared test
CONFIDENCE intervals
KIDNEY function tests
KIDNEY transplantation
LONGITUDINAL method
MULTIVARIATE analysis
NUTRITIONAL assessment
PATH analysis (Statistics)
POTASSIUM
PROBABILITY theory
QUESTIONNAIRES
RESEARCH funding
STATISTICAL hypothesis testing
T-test (Statistics)
MULTIPLE regression analysis
BODY mass index
TREATMENT effectiveness
PROPORTIONAL hazards models
DATA analysis software
DESCRIPTIVE statistics
ODDS ratio
MANN Whitney U Test
KRUSKAL-Wallis Test
Subjects
Details
- Language :
- English
- ISSN :
- 00029165
- Volume :
- 104
- Issue :
- 6
- Database :
- Complementary Index
- Journal :
- American Journal of Clinical Nutrition
- Publication Type :
- Academic Journal
- Accession number :
- 119931181
- Full Text :
- https://doi.org/10.3945/ajcn.116.134056