The influence of the North Atlantic Oscillation index on arterial blood pressure.

to detect the complex association between arterial blood pressure (BP) and air temperature, atmospheric pressure, relative humidity, wind speed, and North Atlantic oscillation (NAO) indices. Data were obtained from the survey performed in the framework of the international Health, Alcohol and Psychosocial Factors in Eastern Europe study. The number of individuals used in the models or other analysed groups was 7077. The association between environmental variables and SBP and DBP were evaluated by applying the multiple regression analysis, adjusting for health-related and weather variables. More than one-half (58.7%) of the respondents had high BP, and 39.4% of the respondents had taken drugs for high BP during the last 2 weeks. Among the respondents, the mean SBP and DBP were 141.6 ± 22.2 and 90.4 ± 12.5 mmHg, respectively. An increase in SBP was associated with the presence of a lower relative humidity, and a higher wind speed and extreme atmospheric pressure with a lag of 2 days. During the period of spring-autumn, continuous NAO indices on the same day and a positive NAO on the same and on 2 previous days were negatively associated with the SBP value. A positive NAO was associated (P = 0.001) with a decrease in SBP by 1.7 mmHg in all participants, by 2.30 mmHg in physically active participants, and by 3.62 mmHg in the elderly, as compared with a negative NAO. These results provided new evidence that the NAO index may be affect the value of SBP and DBP in the elderly during the period of spring-autumn.