Effects of Outdoor Temperature on Blood Pressure in a Prospective Cohort of Northwest China

Shan Zheng; Min Zhen Wang; Zhi Yuan Cheng; Feng Kang; Yong Hong Nie; Xiu Ying Mi; Hai Yan Li; Lan Jin; Ya Wei Zhang; Ya Na Bai

doi:10.3967/bes2021.014

Effects of Outdoor Temperature on Blood Pressure in a Prospective Cohort of Northwest China

Biomed Environ Sci. 2021 Feb 20;34(2):89-100. doi: 10.3967/bes2021.014.

Authors

Shan Zheng¹, Min Zhen Wang¹, Zhi Yuan Cheng², Feng Kang³, Yong Hong Nie⁴, Xiu Ying Mi⁵, Hai Yan Li³, Lan Jin⁶, Ya Wei Zhang⁷, Ya Na Bai¹

Affiliations

¹ Institute of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou 73000, Gansu, China.
² Department of Epidemiology, School of Public Health, Brown University, Providence, Rhode Island 02903, USA.
³ Workers' Hospital of Jinchuan Group Co., Ltd., Jinchang 737103, Gansu, China.
⁴ Jinchang Center for Disease Prevention and Control, Jinchang 737100, Gansu, China.
⁵ Jinchang Meteorological Service, Jinchang 737100, Gansu, China.
⁶ Department of Surgery, Yale School of Medicine, New Haven 06511, USA.
⁷ Department of Surgery, Yale School of Medicine, New Haven 06511, USA;Department of Environmental Health Sciences, Yale School of Public Health, New Haven 06511, USA.

PMID: 33685567
DOI: 10.3967/bes2021.014

Abstract

Objective: The relationship between outdoor temperature and blood pressure (BP) has been inconclusive. We analyzed data from a prospective cohort study in northwestern China to investigate the effect of outdoor temperature on BP and effect modification by season.

Methods: A total of 32,710 individuals who participated in both the baseline survey and the first follow-up in 2011-2015 were included in the study. A linear mixed-effect model and generalized additive mixed model (GAMM) were applied to estimate the association between outdoor temperature and BP after adjusting for confounding variables.

Results: The mean differences in systolic blood pressure (SBP) and diastolic blood pressure (DBP) between summer and winter were 3.5 mmHg and 2.75 mmHg, respectively. After adjusting for individual characteristics, meteorological factors and air pollutants, a significant increase in SBP and DBP was observed for lag 06 day and lag 04 day, a 0.28 mmHg (95% CI: 0.27-0.30) per 1 °C decrease in average temperature for SBP and a 0.16 mmHg (95% CI: 0.15-0.17) per 1 °C decrease in average temperature for DBP, respectively. The effects of the average temperature on both SBP and DBP were stronger in summer than in other seasons. The effects of the average temperature on BP were also greater if individuals were older, male, overweight or obese, a smoker or drinker, or had cardiovascular diseases (CVDs), hypertension, and diabetes.

Conclusions: This study demonstrated a significant negative association between outdoor temperature and BP in a high-altitude environment of northwest China. Moreover, BP showed a significant seasonal variation. The association between BP and temperature differed by season and individuals' demographic characteristics (age, gender, BMI), unhealthy behaviors (smoking and alcohol consumption), and chronic disease status (CVDs, hypertension, and diabetes).

Keywords: Blood pressure; Jinchang cohort; Outdoor temperature; Season.

MeSH terms

Adult
Blood Pressure / physiology*
China / epidemiology
Environmental Exposure / adverse effects
Environmental Exposure / statistics & numerical data*
Female
Humans
Male
Middle Aged
Prospective Studies
Risk Factors
Seasons
Temperature