TY - JOUR

T1 - Effects of cold and hot temperature on dehydration

T2 - a mechanism of cardiovascular burden

AU - Lim, Youn-Hee

AU - Park, Min-Seon

AU - Kim, Yoonhee

AU - Kim, Ho

AU - Hong, Yun-Chul

PY - 2015

Y1 - 2015

N2 - The association between temperature (cold or heat) and cardiovascular mortality has been well documented. However, few studies have investigated the underlying mechanism of the cold or heat effect. The main goal of this study was to examine the effect of temperature on dehydration markers and to explain the pathophysiological disturbances caused by changes of temperature. We investigated the relationship between outdoor temperature and dehydration markers (blood urea nitrogen (BUN)/creatinine ratio, urine specific gravity, plasma tonicity and haematocrit) in 43,549 adults from Seoul, South Korea, during 1995-2008. We used piece-wise linear regression to find the flexion point of apparent temperature and estimate the effects below or above the apparent temperature. Levels of dehydration markers decreased linearly with an increase in the apparent temperature until a point between 22 and 27 °C, which was regarded as the flexion point of apparent temperature, and then increased with apparent temperature. Because the associations between temperature and cardiovascular mortality are known to be U-shaped, our findings suggest that temperature-related changes in hydration status underlie the increased cardiovascular mortality and morbidity during high- or low-temperature conditions.

AB - The association between temperature (cold or heat) and cardiovascular mortality has been well documented. However, few studies have investigated the underlying mechanism of the cold or heat effect. The main goal of this study was to examine the effect of temperature on dehydration markers and to explain the pathophysiological disturbances caused by changes of temperature. We investigated the relationship between outdoor temperature and dehydration markers (blood urea nitrogen (BUN)/creatinine ratio, urine specific gravity, plasma tonicity and haematocrit) in 43,549 adults from Seoul, South Korea, during 1995-2008. We used piece-wise linear regression to find the flexion point of apparent temperature and estimate the effects below or above the apparent temperature. Levels of dehydration markers decreased linearly with an increase in the apparent temperature until a point between 22 and 27 °C, which was regarded as the flexion point of apparent temperature, and then increased with apparent temperature. Because the associations between temperature and cardiovascular mortality are known to be U-shaped, our findings suggest that temperature-related changes in hydration status underlie the increased cardiovascular mortality and morbidity during high- or low-temperature conditions.

KW - Blood Urea Nitrogen

KW - Cold Temperature

KW - Creatinine/analysis

KW - Dehydration/blood

KW - Female

KW - Hematocrit

KW - Hot Temperature

KW - Humans

KW - Male

KW - Middle Aged

KW - Republic of Korea/epidemiology

KW - Urinalysis

U2 - 10.1007/s00484-014-0917-2

DO - 10.1007/s00484-014-0917-2

M3 - Journal article

C2 - 25344017

VL - 59

SP - 1035

EP - 1043

JO - International Journal of Biometeorology

JF - International Journal of Biometeorology

SN - 0020-7128

IS - 8

ER -