The influence of daily air temperature variability on arterial blood pressure: findings from a cross-sectional study in Kaunas city.

Several studies reported statistically significant associations of blood pressure (BP) with short-term air temperature variability (TV), but the effect of TV on BP was found to differ in different areas. This study aimed to detect the association between BP and TV in Kaunas, Lithuania. Data from the international Health, Alcohol, and Psychosocial Factors in Eastern Europe study was used to gather information on the participants' BP during 2006-2008. The TV variables were the diurnal temperature range (DTR), the standard deviation (SD) of hourly temperature during the 24 h (TSD) and the first 12 h of the day (TSDF), and the SD of daily minimum and maximum temperatures during the exposure days (DTV). Multiple linear regression was used after controlling for potential confounders. Among the participants, 45.5% were men, 30.9% were aged > 65 years, and 9.8% were normotensive. A positive association of systolic BP with TSD on the same day (TSD0), DTR with lags of 0-2 days, and DTV with lags of 0-1 day and of diastolic BP with TSD0 and TSDF was found, a stronger impact being observed in males and in physically active participants. The impact of TV was stronger at lower temperatures, and a statistically significant negative interaction between air temperature and TV variables was found. In May-June, a negative association of DTV with diastolic BP was observed. We found a positive association of BP with TV. Sex, the level of physical activity, and air temperature may modify the relationship between TV and BP.