Login to Access Video or Poster Abstract: MP01-17
Sources of Funding: NIH K23DK106428

Introduction

Prior studies have demonstrated that high daily temperatures increase the risk of kidney stone presentation, men produce more sweat than women, and people with public insurance have greater exposure to ambient temperatures than those with private insurance. The objective of this study was to determine differences in the temperature dependence of kidney stone presentation by sex, age, race, climate, and insurance type.

Methods

We performed a time series study of 132,597 patients who presented with kidney stones to Emergency Departments in South Carolina from 1996-2015. Conditional Poisson regression and distributed lag non-linear models were used to assess the association and lagged response between daily temperature and kidney stone presentation stratified by sex, age, insurance type, race, and climate zone.

Results

The relative risk for a daily temperature at the 99th percentile versus 10°C was 1.72 (95% CI 1.55, 1.91) for men and 1.15 (95% CI 1.01, 1.31) for women. This difference was greatest among patients 20-65 years old. The risk of kidney stone presentation following moderately high daily temperatures was less among patients living in warmer climates. The temperature-dependence of stone presentation did not differ by race or insurance type.

Conclusions

The risk of kidney stone presentation following high daily temperatures was substantially greater among men than women and similar between patients with public and private insurance, which suggests that the higher risk among men is due to the sexually dimorphic effect of heat on evaporative water loss rather than greater exposure to ambient temperature. The lower risk among patients living in warmer climates suggests that prolonged heat exposure may lead to adaptive responses that mitigate the effect of high temperatures on kidney stone presentation. These differences should be considered in secondary prevention strategies to increase fluid intake and projections of the effect of climate change on nephrolithiasis prevalence.

Funding

NIH K23DK106428