title: Longitudinal Study of Serum Uric Acid, Nutritional Status, and Mortality in Maintenance Hemodialysis Patients.
abstract: We hypothesized that longitudinal changes in uric acid (UA) may have independent associations with changes in nutritional parameters over time and consequently, long-term survival of patients on maintenance hemodialysis.
  
  
  
  We conducted a retrospective, longitudinal cohort study of a clinical database containing the medical records of patients on maintenance hemodialysis receiving dialysis between June of 1999 and December of 2012 in a single center; 200 patients (130 men and 70 women) with a median age of 69.0 (interquartile range, 59.3-77.0) years old were included in the study. Dietary intake, biochemical markers of nutrition, anthropometric measurements, and UA levels were recorded at 0, 6, 12, 18, 24, 30, and 36 months followed by 15 additional months of clinical observations. The patients were followed until January 31, 2015 (median follow-up was 38.0 [interquartile range, 30.0-46.8] months).
  
  
  
  In a linear mixed effects model adjusted for baseline demographics and clinical parameters, each 1.0-mg/dl longitudinal increase in UA was associated with a 13.4% slower rate of decline in geriatric nutritional risk index (GNRI) levels over 3 years of observation (95% confidence interval [95% CI], 0.11 to 0.39; P<0.001 for UA × time interaction). UA remained associated with the rate of change in GNRI, even after controlling for C-reactive protein. During the follow-up, 87 (43.5%) all-cause and 38 (19.0%) cardiovascular deaths were reported. For each 1.0-mg/dl increase in serum UA over time, the multivariate adjusted all-cause mortality hazard ratio using Cox models with the effect of time-varying risk was 0.83 (95% CI, 0.74 to 0.95; P<0.01), which continued to be significant, even after including the baseline GNRI levels in this model: 0.89 (95% CI, 0.79 to 0.98; P=0.02).
  
  
  
  Longitudinal changes in serum UA seem to track with changes in nutritional status over time, and these changes are associated with survival of patients on maintenance hemodialysis. An increase in serum UA levels over time is accompanied by improvement of nutritional status and lower mortality rate.
authors.affiliation: Nephrology Division.
authors.forename: Ilia
authors.initials: I
authors.lastname: Beberashvili
authors.affiliation: Internal Department B.
authors.forename: Anatoli
authors.initials: A
authors.lastname: Erlich
authors.affiliation: Nutrition.
authors.forename: Ada
authors.initials: A
authors.lastname: Azar
authors.affiliation: Pathology, and.
authors.forename: Inna
authors.initials: I
authors.lastname: Sinuani
authors.affiliation: Nephrology Division.
authors.forename: Leonid
authors.initials: L
authors.lastname: Feldman
authors.affiliation: Internal Department F, Assaf Harofeh Medical Center, Tel Aviv University, Zerifin, Israel.
authors.forename: Oleg
authors.initials: O
authors.lastname: Gorelik
authors.affiliation: Urology Departments, and.
authors.forename: Kobi
authors.initials: K
authors.lastname: Stav
authors.affiliation: Nephrology Division.
authors.forename: Shai
authors.initials: S
authors.lastname: Efrati
mesh_terms: D000368:Aged; D000886:Anthropometry; D002318:Cardiovascular Diseases / Q000401:mortality; D002423:Cause of Death; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000401:mortality / Q000628:therapy*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D016016:Proportional Hazards Models; D006435:Renal Dialysis; D012189:Retrospective Studies; D015996:Survival Rate; D014527:Uric Acid / Q000097:blood*
chemical_list: D014527:Uric Acid
keywords: Cohort Studies; Humans; Longitudinal Studies; Nutritional Status; geriatric nutritional risk index; hemodialysis; inflammation; mortality; nutrition; uric acid