Seasonal blood pressure variation assessed by different measurement methods: systematic review and meta-analysis

Abstract

Objective: The current study reviewed the published evidence on the seasonal changes in blood pressure (BP) assessed using different measurement methods. Methods: A systematic PubMed/EMBASE search was performed for studies assessing seasonal BP changes. Prospective and cross-sectional studies were included fulfilling the following criteria: (i) report of ambulatory and/or home BP data; (ii) cross-sectional studies reporting only office BP measurements and including 1000 or more participants. Results: Forty-seven studies fulfilled the selection criteria and were included (856 539 participants, weighted age 49.7 ± 4.8 years, 38.8% treated hypertensive patients). The pooled summer minus winter SBP/DBP difference (95% confidence intervals) was office BP (29 studies) −5.6 (−7.1, −4.0)/−3.3 (−4.0, −2.7) mmHg; daytime ambulatory BP (15 studies) −3.4 (−4.4, −2.4)/−2.1 (−2.8, −1.4) mmHg; night-time ambulatory BP (13 studies) 1.3 (0.2, 2.3)/0.5 (−0.2, 1.2) mmHg; home BP (9 studies) −6.1 (−7.0, −5.1)/−3.1 (−3.5, −2.6) mmHg. Meta-analysis of 28 prospective studies (N = 5278) which examined the same individuals during different seasons showed pooled seasonal SBP/DBP difference: office BP −5.8/−4.0 mmHg; daytime ambulatory BP −3.9/−2.7 mmHg; night-time ambulatory BP 0.5/−0.5 mmHg; home BP −6.4 /−3.3 mmHg. In meta-regression analysis seasonal systolic daytime ambulatory BP difference was related to the percentage of treated hypertensive patients across studies (P = 0.02) and borderline to age (P = 0.07). Conclusion: Seasonal BP changes are evident using all daytime BP measurement methods, but not with night-time ambulatory BP. The average BP decline in hot season is at about 5/3 (SBP/DBP) mmHg and appears to be larger in treated hypertensive patients and in older individuals.

World Heart Federation Roadmap for Hypertension – A 2021 Update

“…For instance, there is significant seasonal variation in BP levels as well the risk of cardiovascular events, with the peak in winter. Data in general show higher BP levels in winter [59,60,61], especially in the elderly [62][63][64][65].…”

“…For instance, there is significant seasonal variation in BP levels as well the risk of cardiovascular events, with the peak in winter. Data in general show higher BP levels in winter [ 59 60 61 ], especially in the elderly [ 62 63 64 65 ]. Recently, evidence for the association between air pollution and CVD has been comprehensively reviewed [ 66 ], and fine particulate matter <2.5 µg (PM2.5) was identified as a significant contributor to the incidence of hypertension [ 67 ].…”

Dependence of seasonal dynamics of hemorrhagic and ischemic strokes on the climate of a region: A meta-analysis

“…This is probably due to the fact that HS is mainly associated with an increase in blood pressure, which shows seasonal dynamics with the maximum in the cold season and the nadir in summer in regions with different types of climate. 42,43 Most authors associate the blood pressure rise in the cold season mainly with low air temperature. 43 It has been found that in people, circannual fluctuations in daytime systolic blood pressure averaged at 3–6 mmHg.…”

The Effects of Two Intervention Strategies to Reduce the Intake of Salt and the Sodium-To-Potassium Ratio on Cardiovascular Risk Factors. A 4-Month Randomised Controlled Study among Healthy Families

“…Systolic and diastolic blood pressure was reduced from baseline to follow-up both in the intervention groups and the control group. The reduced blood pressure in the control group can probably be explained both by the natural seasonal variation from winter to summer [33] but also by the fact that the salt content in the control bread was lower than the salt content in the usual bread sold by the baker [22]. Due to ethical considerations, we chose that the control bread should meet the criteria for healthy products (the keyhole label [22]) set by the health authorities.…”