The Influence of Seasonal Temperature Variation on Blood Pressure Behavior

Abstract

Background: Hypertension in Brazil affects 32.5% of the population, accounting for 50% of deaths due to cardiovascular disease. The correct measurement and interpretation of blood pressure are essential for attaining an adequate disease diagnosis and management.Objective: To verify the correlation between the seasonal temperature variation during 2016 and blood pressure variation in 902 patients of a private Cardiology Service in the city of Porto Alegre/RS. Method: A total of 902 ambulatory blood pressure monitoring (ABPM) results were analyzed in 2016. Pearson's Correlation Coefficient was used to correlate blood pressure levels with the values of temperature and relative air humidity; the Kolmogorov-Smirnov and Shapiro-Wilk tests were adopted for significance values, assuming an alpha error < 0.05 and a 95% confidence interval. The Analysis of Variance compared the 902 ABPM results with the continuous variables obtained for this study. Results:No statistically significant differences were found when the blood pressure values obtained from the 902 ABPM results were correlated with the minimum, mean and maximum values of temperature and relative air humidity, and also when each of the continuous variables obtained for this study were compared with these same pressure measurements. Conclusion:Despite the great variation in temperature and relative air humidity throughout the year in the region, there was no significant influence on the systemic arterial pressure in the study population. New comparative studies in the same population with different thermal variations may provide further clarification on this subject.

Casual and inaccurate measurements of a continuous fluctuating variable: the original sin of the concept of arterial hypertension?

“…Seasonal BP variability is not well understood. Some studies have shown that there may be a slightly high BP during the fall and winter months [7], whereas other studies have not found any significant seasonal variations [8]; there are also reports of an inverse seasonal variation: higher BP levels in summer than in winter [9].…”