The Association of Parathyroid Hormone with ESRD and Pre-ESRD Mortality in the Kidney Early Evaluation Program

Abstract

Studies have suggested that PTH may influence mortality and progression of chronic kidney disease. However, the development of either event may influence the development of the other as a competing risk. The objective of the study was to examine the association of PTH with end-stage renal disease (ESRD) and pre-ESRD death using a competing risk survival model. A total of 10,823 participants in the Kidney Early Evaluation Program with chronic kidney disease (estimated glomerular filtration rate < 60 ml/min per 1.73 m(2)) were examined from 2005 to 2010. The association of PTH levels with ESRD and pre-ESRD mortality was ascertained by linking Kidney Early Evaluation Program data to the Social Security Administration Death Master File and the U.S. Renal Data System. Among the cohort, the incidence of ESRD and pre-ESRD mortality was 6.4 and 20.1 events per 1000 person-years. Higher PTH levels were associated with increasing age, black race, lack of a high school education, cardiovascular disease, hypertension, and lower glomerular filtration rate. The incidence of ESRD and pre-ESRD mortality was lowest among participants in the second PTH quintile. After multivariate adjustment, as compared with the second quintile, the risk of pre-ESRD mortality was higher in the third [subhazard ratio (SHR) 1.52 (95% confidence interval 1.04-2.22)], fourth [SHR 1.73 (95% confidence interval 1.19-2.52)], and fifth [SHR 1.86 (1.28-2.52)] quintiles, respectively. Conversely, PTH was not associated with ESRD after multivariate adjustment. The association was not modified by diabetic status, gender, race, or glomerular filtration rate status. Elevated PTH levels are associated with increased pre-ESRD mortality but not with ESRD.