Aniqa Azim1, Jennifer Murray2, Srinivasan Beddhu3, Kalani L Raphael1,4. 1. Department of Medicine, Oregon Health and Science University, Portland, Oregon. 2. The Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, New Hampshire. 3. Department of Internal Medicine, University of Utah Health, Salt Lake City, Utah. 4. Division of Hospital and Specialty Medicine, VA Portland Health Care System, Portland, Oregon.
Abstract
Background: Sulfur is an important mineral element whose principal source is animal protein. Animal protein contributes to the daily acid load, which is associated with poor outcomes in individuals with chronic kidney disease (CKD). We hypothesized that higher urinary sulfate, as a reflection of the daily acid load, is associated with a greater risk of death and CKD progression. Methods: Urinary sulfate was measured in 1057 African American Study of Kidney Disease and Hypertension (AASK) participants at baseline. Participants were categorized by tertiles of daily sulfate excretion. The longitudinal outcome of interest was the composite of death, dialysis, or 50% reduction in measured glomerular filtration rate (GFR). Multivariable adjusted Cox regression models were fit to relate the composite outcome to daily sulfate excretion using the lowest tertile as the reference. Results: Participants in the highest urinary sulfate tertile were more likely to be men and have a higher body mass index, protein intake, measured GFR, and urinary ammonium and phosphate excretion, and lower urinary protein/creatinine. Compared with those in the lowest tertile of sulfate, those in the highest tertile had a 44% lower hazard (95% CI, 0.37 to 0.84), and those in the middle tertile had a 27% lower hazard (95% CI, 0.55 to 0.96) of death, dialysis, or 50% reduction in measured GFR during follow-up after adjusting for demographics, GFR, protein intake, and other potential confounders. Protein intake was not associated with risk of these events. Conclusions: Higher urinary sulfate excretion is associated with more favorable outcomes in Blacks who have CKD attributed to hypertension.
Background: Sulfur is an important mineral element whose principal source is animal protein. Animal protein contributes to the daily acid load, which is associated with poor outcomes in individuals with chronic kidney disease (CKD). We hypothesized that higher urinary sulfate, as a reflection of the daily acid load, is associated with a greater risk of death and CKD progression. Methods: Urinary sulfate was measured in 1057 African American Study of Kidney Disease and Hypertension (AASK) participants at baseline. Participants were categorized by tertiles of daily sulfate excretion. The longitudinal outcome of interest was the composite of death, dialysis, or 50% reduction in measured glomerular filtration rate (GFR). Multivariable adjusted Cox regression models were fit to relate the composite outcome to daily sulfate excretion using the lowest tertile as the reference. Results: Participants in the highest urinary sulfate tertile were more likely to be men and have a higher body mass index, protein intake, measured GFR, and urinary ammonium and phosphate excretion, and lower urinary protein/creatinine. Compared with those in the lowest tertile of sulfate, those in the highest tertile had a 44% lower hazard (95% CI, 0.37 to 0.84), and those in the middle tertile had a 27% lower hazard (95% CI, 0.55 to 0.96) of death, dialysis, or 50% reduction in measured GFR during follow-up after adjusting for demographics, GFR, protein intake, and other potential confounders. Protein intake was not associated with risk of these events. Conclusions: Higher urinary sulfate excretion is associated with more favorable outcomes in Blacks who have CKD attributed to hypertension.
Authors: Bruno Cianciaruso; Andrea Pota; Vincenzo Bellizzi; Daniela Di Giuseppe; Lucia Di Micco; Roberto Minutolo; Antonio Pisani; Massimo Sabbatini; Pietro Ravani Journal: Am J Kidney Dis Date: 2009-10-02 Impact factor: 8.860
Authors: Tanushree Banerjee; Deidra C Crews; Donald E Wesson; Anca Tilea; Rajiv Saran; Nilka Rios Burrows; Desmond E Williams; Neil R Powe Journal: BMC Nephrol Date: 2014-08-24 Impact factor: 2.388