Elevated Ambient Temperature Associated With Increased Cardiovascular Disease–Risk Among Patients on Hemodialysis

Abstract

IntroductionAmbient temperatures have increased due to climate change in many parts of the world. Due to loss of renal function which impacts regulation of thermoregulatory mechanisms the ability to adapt and resilient to changing conditionals is particularly concerning among individuals with kidney failure. The aim of this study is to assess the effect of heat on mortality and health care utilization among US hemodialysis patients. MethodsWe conducted a retrospective analysis 2011-2016 in contiguous United States during warmer months among eligible dialysis patients identified in the United States Renal Data system. Daily ambient temperature was estimated on a 1 km grid and assigned to ZIP-code. Case-crossover design with conditional Poisson models were used to assess the risk of developing adverse health outcomes associated with temperature exposure. ResultsOverall, exposure to high temperature is associated with elevated risk for both mortality and health care utilization among hemodialysis patients. The risk ratios for all-cause mortality and daily temperature were 1.07 (95% CI: 1.03-1.11), 1.17 (1.14-1.21) for fluid disorder-related hospital admissions, and 1.19 (1.16-1.22) for cardiovascular event-related emergency department visits, comparing 99th percentile vs. 50th percentile daily temperatures. Larger effects were observed for cumulative lagged exposure three-days prior to the outcome and for Southwest and Northwest climate regions. ConclusionHeat exposure is associated with elevated risk for CVD-related mortality and health care utilization among this vulnerable population. Furthermore, the effect appears to be potentially cumulative in the short-term, and varies geographically.