Seasonal Changes in Blood Pressure and Frequency of Related Complications in Elderly Israeli Patients with Essential Hypertension

Abstract

Background: Earlier studies on hypertension demonstrated seasonal variations in different age groups. However, slightly greater fluctuations were found in the hypertensive elderly. Objective: We conducted a prospective 5-year study from January 1997 to December 2001 to evaluate the seasonal variation in blood pressure and the variables of age, gender, body mass index and related complications in elderly Israeli patients with essential hypertension. Methods: Blood pressure was measured in four seasons in 182 patients (98 men and 84 women; age range 65–91 years) treated for hypertension in our outpatient clinic. Results: Both systolic and diastolic mean blood pressures were higher during winter compared to summer (165 ± 11.6 and 90 ± 13.7 and 134 ± 47.3 and 74 ± 8.5 mm Hg, respectively; p < 0.001). There were no significant seasonal differences between spring and autumn or any correlation between the seasonal winter-summer difference in blood pressure and other studied parameters. Patients aged 65–75 years were unexpectedly more sensitive to winter-summer changes than older patients. There was a correlation between a large winter-summer difference in systolic blood pressure and a body mass index between 20 and 30, but there was none in lower or higher ranges. Supplementary antihypertension treatment was required during winter in 38% of these selected patients. Complications such as myocardial infarctions and strokes occurred twice as frequently in winter than in any other season (p < 0.0001). Conclusions: Both systolic and diastolic blood pressures were highest during winter. Hypertension complications were more frequent in winter. Our results refute those of earlier studies that failed to find significant seasonal variations in blood pressure among the elderly.

Whether Atmospheric Pressure Changes Predict Variations in Blood Pressure

“…Previous report [6] had shown greater seasonal BP fluctuations among elderly patients with HTN whose mean SBPs and DBPs were higher during the winter compared to the summer.…”

“…Theories on climate changes and their impact on organisms originated in the period of Enlightenmentbut continuous recordings of weather conditions and their relationship with life parameters was not possible until the development of physics and technology, specifically, the invention of the thermometer and barometer, AP is the most objective meteorological factor that has the same influence on humans both indoors and outdoors. Several studies have confirmed that the flow of specific air masses is correlated with changes in wellbeing and the accompanying changes in BP [2][3][4][5][8][9][10], and that patients with chronic diseases are reportedly more liable to be affected by weather changes compared to healthy individuals [6]. In patients with hypertension (HTN), even small fluctuations in BP influenced by weather can potentially result in serious neurological and cardiovascular complications.…”

“…There is a tendency for both systolic (SBP) and diastolic blood pressure (DBP) to rise in the winter [1][2][3][4][5][6]. Atmospheric pressure (AP) is the most objective weather factor because, regardless of being indoors or outdoors, it affects all objects in the same way.…”

“…Their mean winter-summer difference was 31±19.1 mmHg for SBP and 15±14.3 for DBP (p<0.001) [6]. The specific cause of seasonal variation is not clear: one possibility that has been put forward is an inverse relationship between BP and the ambient temperature [1].…”

Summertime dosage-dependent hypersensitivity to an angiotensin II receptor blocker

“…5-10 mm Hg) have long been known, both in normotensive and hypertensive subjects. Nevertheless, perhaps because adverse cardiovascular events are more frequent in winter, it is the practice in some quarters to decrease antihypertensive medication in summer, and/or increase in winter (Charach, Rabinovich & Weintraub, 2004). However, this is controversial.…”