PS-P03-8: INFLUENCE OF AVERAGE AIR TEMPERATURE, PRESSURE AND AIR RELATIVE HUMIDITY ON BLOOD PRESSURE

Abstract

Objective: To investigate the influence of average air temperature, pressure and air relative humidity on blood pressure (BP) and blood pressure variability in population. Methods: A total of 97,784 participants were included from the May Month Measurement 2020 in China. BP was measured three times consecutively in the sitting position with a 1-minute interval, using a validated electronic BP monitor. Trained volunteer investigators administered a questionnaire to collect information on medical history, lifestyle, and use of medications. Average air temperature, pressure, and air relative humidity of the day were recorded. The mean BP was taken as the mean of the second and third BP, and the systolic blood pressure variability (SBPV) was the standard deviation/mean of three systolic blood pressures (SBP). Statistical analysis was performed using SAS 9.4. Results: Linear regression analysis found that the average air temperature was negatively correlated with the mean SBP and SBPV in all participants and hypertensive subjects (P < 0.0001, P = 0.01). The average pressure was positively correlated with the mean SBP and SBPV in all participants and hypertensive subjects (P < 0.0001, P < 0.0001). The average air relative humidity was negatively correlated with SBPV in hypertensive subjects (P = 0.03). The relationship between average air relative humidity and SBP in all participants and hypertensive subjects, between average air relative humidity and SBPV in all participants was not found. After adjustment for age, sex, body mass index, taking antihypertensive medicine, smoking, alcohol consumption, diabetes, history of heart disease and previous stroke, the average air temperature and pressure remained associated with mean SBP in all participants and in hypertensive subjects. Logistic regression analysis showed that for every 1°C increase in air temperature, the risk of hypertension decreased by 1.8%, and for every 10hpa increase in pressure and 1% increase in air relative humidity, the risk of hypertension increased by 0.3% and 0.4%, respectively. When air temperature increased 1°C, the happen of hypertension control increased by 2.3%, and decreased by 0.2% for every 1% increase in air relative humidity. The relationship was not found between mean pressure and control of hypertension. Conclusion: The lower average air temperature and higher average pressure are possibly related with higher SBP, more likely to suffer hypertension, while the lower average air temperature and the higher average air relative humidity may resulted in more difficult hypertensive control.