Thyroid Status and Mortality in a Prospective Hemodialysis Cohort.
Compared with the general population, hemodialysis patients have a substantially higher risk of hypothyroidism, as defined by an elevated serum thyrotropin (TSH) level, and cardiovascular mortality. Whereas an elevated TSH is associated with cardiovascular disease and death in the general population, associations among dialysis patients have been inconsistent.



We examined 541 hemodialysis patients from 17 southern California dialysis centers in the prospective Hypothyroidism, Cardiovascular Health, and Survival study who underwent protocolized measurement of repeated serum TSH levels every 6 months from 2013 to 2015. Associations between TSH tertiles (<1.28, 1.28 to <2.14, and 2.14 to 86.7 mIU/L) and mortality were estimated using time-dependent Cox models with four adjustment levels. In sensitivity analyses, we excluded patients receiving thyroid hormone supplementation.



Compared with the lowest TSH tertile, the highest TSH tertile was associated with a 2.2- to 2.5-fold higher mortality risk in unadjusted, case-mix, expanded case-mix+laboratory, and expanded case-mix+laboratory+medication models [hazard ratios (95% confidence interval), 2.54 (1.32 to 4.89), 2.53 (1.30 to 4.93), 2.19 (1.11 to 4.32), and 2.28 (1.45 to 3.58), respectively]. We observed a consistent trend between higher TSH tertiles and numerically higher mortality risk across all models. Similar findings were observed in analyses excluding patients receiving thyroid hormone supplementation.



In time-dependent analyses, TSH levels in the high-normal to high range were independently associated with higher death risk in hemodialysis patients. Further studies are indicated to determine whether normalization of TSH levels with thyroid hormone supplementation improves survival in this population.
Harold Simmons Center for Chronic Disease Research and Epidemiology, University of California Irvine, Orange, California 92868.
Connie M
CM
Rhee
Harold Simmons Center for Chronic Disease Research and Epidemiology, University of California Irvine, Orange, California 92868.
Amy S
AS
You
Division of General Internal Medicine, University of California Irvine, Orange, California 92868.
Danh V
DV
Nguyen
DaVita Clinical Research, Minneapolis, Minnesota 55404.
Steven M
SM
Brunelli
Los Angeles BioMedical Research Institute, Torrance, California 90502.
Matthew J
MJ
Budoff
Harold Simmons Center for Chronic Disease Research and Epidemiology, University of California Irvine, Orange, California 92868.|Veterans Affairs Long Beach Healthcare System, Long Beach, California 90822.
Elani
E
Streja
Harold Simmons Center for Chronic Disease Research and Epidemiology, University of California Irvine, Orange, California 92868.
Tracy
T
Nakata
Division of Nephrology, University of Tennessee Health Science Center, Memphis, Tennessee 38163.|Nephrology Section, Memphis Veterans Affairs Medical Center, Memphis, Tennessee 38104.
Csaba P
CP
Kovesdy
Department of Medicine, VA Greater Los Angeles Healthcare System 90073.|Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California 90095.|Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095.
Gregory A
GA
Brent
Harold Simmons Center for Chronic Disease Research and Epidemiology, University of California Irvine, Orange, California 92868.|Los Angeles BioMedical Research Institute, Torrance, California 90502.|Veterans Affairs Long Beach Healthcare System, Long Beach, California 90822.
Kamyar
K
Kalantar-Zadeh
D000328:Adult; D000368:Aged; D002140:California / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000453:epidemiology*; D007676:Kidney Failure, Chronic / Q000453:epidemiology* / Q000628:therapy; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009026:Mortality; D016016:Proportional Hazards Models; D011446:Prospective Studies; D006435:Renal Dialysis; D012307:Risk Factors; D013972:Thyrotropin / Q000097:blood
D013972:Thyrotropin