Longitudinal Study of Serum Uric Acid, Nutritional Status, and Mortality in Maintenance Hemodialysis Patients

Abstract

Background and objectives 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.Design, setting, participants, & measurements 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).Results 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 3 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).Conclusions 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.

Serum uric acid, protein intake and mortality in hemodialysis patients

“…the HD population is reversed compared with the general population [17][18][19][20]. We acknowledge that these studies including ours did not examine the effect of intervention and thus may not indicate a causal relationship.…”

Pre- and Postdialysis Uric Acid Difference and Risk of Long-Term All-Cause and Cardiovascular Mortalities in Japanese Hemodialysis Patients; Miyazaki Dialysis Cohort Study

“…Few studies have examined UA as a predictor of outcomes in HD patients, and controversy surrounds whether SUA is an independent risk factor for mortality in patients receiving HD [4,10,11]. Furthermore, SUA was recently identified as a nutritional marker in patients receiving HD [12][13][14].…”

Variação do índice tornozelo-braquial pré e pós-hemodiálise: correlação com água corporal, cálcio do dialisato e sistema nervoso autônomo

“…Indeed, changes in HRV have been used to predict hemodynamic instability, [3] and 69 it is also associated with left ventricular hypertrophy [6]. 70 Ankle brachial index (ABI), another marker of mortality in patients on 71 hemodialysis [7] correlated with measurement of HRV in both, normal subjects [8] [9] 72 and in patients with high cardiovascular risk [10]. The ABI, which is the higher systolic 73 BP at the ankle, divided by the higher systolic BP at the arm, is usually calculated pre 74 dialysis.…”

“…A lower ABI usually indicates peripheral 76 artery disease, whereas an elevated ABI indicates arterial sclerosis due to a more 77 pronounced calcification of the vessel wall. Both low and high ABI are associated with 78 increased mortality in patients on hemodialysis [7,12]. Since there is an interaction 79 4 between the autonomic nervous system and the vascular response [13], acute changes in 80 ABI during hemodialysis may be a result of the sympathetic response to ultrafiltration.…”

“…Study population 89 This was a prospective study that included consecutive incident patients on 90 hemodialysis, defined as less than 30 days since the first hemodialysis session, at the Tokyo, Japan) simultaneously to measure the blood pressure in the upper and lower 115 extremities, as previously described by our group [7,11]. Cuffs were comfortably set in 116 place, adjusted to the arm above the cubital malleolus with the cuff directed towards the 117 brachial artery trajectory, and directed toward the trajectory of the posterior tibial artery.…”