Related Experiment Videos
[Seasonal variations in arterial pressure in hypertensive patients]
Insights
Blood pressure is lower in summer, especially when standing, increasing orthostatic hypotension risk in some patients. Beta-blockers may mitigate this risk.
Area of Science:
- Cardiology
- Gerontology
- Pharmacology
Context:
- Hypertensive outpatients (aged 65±13 years) with comorbidities like diabetes and cardiovascular insufficiency were studied.
- Patients were on various antihypertensive medications, including diuretics, beta-blockers, ACE inhibitors, and calcium channel blockers.
Purpose:
- To investigate seasonal variations in blood pressure and orthostatic responses in hypertensive patients.
- To assess the impact of summer conditions on blood pressure control and the incidence of orthostatic hypotension.
Summary:
- Blood pressure was significantly lower in summer compared to winter (144.1/79.4 vs 150.8/82.9 mmHg).
- The reduction in blood pressure was position-dependent, with a greater fall in standing and lying positions during summer.
- Orthostatic testing revealed a more pronounced systolic BP drop (-14.4 vs -9.6 mmHg) and increased orthostatic hypotension episodes (34% vs 20%) in summer.
- Diabetic patients and those on diuretics/vasodilators were more susceptible to summer-induced orthostatic hypotension.
Impact:
- Seasonal monitoring of blood pressure is crucial for hypertensive patients, particularly the elderly and those with comorbidities.
- Understanding positional blood pressure changes in summer can help prevent adverse events like falls and reduced cerebral perfusion.
- Beta-blocker therapy may offer a protective effect against summer-related orthostatic hypotension.
Abstract:
Blood pressure (BP) was measured once every month during one year in 80 hypertensive outpatients. An orthostatic test was performed in winter and another during summer. The collective was aged 65 +/- 13 years (m +/- SD) and presented an elevated prevalence of diabetes mellitus, cardiac failure, and coronary, cerebral and arterial insufficiency. Diuretics, betablockers, converting enzyme inhibitors and calcium channel blockers were used by 31 patients as monotherapy and by 49 patients in association. During summer a significantly lower seated BP was found (144.1/79.4 mm Hg vs 150.8/82.9 mm Hg in winter, p < 0.001). One fourth of the patients did not show this diminution. On the basis of the WHO criteria of BP definition, 31% of the patients could be considered hypertensive in winter vs 16% in summer and 28% as normotensive in winter vs 43% in summer (p < 0.05). The summer reduction in BP depended on position. It was less marked in seated position (-5.3/-2.7 mm Hg) than in lying (-6/-5.1 mm Hg) or even in standing position (-10.8/-5.1 mm Hg). The orthostatic test induced a greater immediate fall in systolic BP in summer than in winter (-14.4 vs -9.6 mm Hg, p < 0.001), more orthostatic hypotensive episodes defined as a systolic BP fall of 20 mm Hg or more (34% of patients vs 20% in winter, p = 0.05) and more signs of reduced cerebral perfusion (14% vs 7.5% in winter, NS). Diabetic patients and patients treated by diuretic and vasodilator drugs are particularly exposed to orthostatic hypotension in summer. Betablockers can minimize this risk.(ABSTRACT TRUNCATED AT 250 WORDS)