RESUMO
Objective To investigate the effect of seasonal variation of blood pressure (BP) on the incidence of cardiovascular and cerebrovascular events in the elderly aged 80 years and over.Methods The 67 patients (aged 80-86 years) with essential hypertension were enrolled, the BP were measured at home, in consulting room, and by 24-h ambulatory BP monitor in every season for 2 years. The incidences of cardiovascular and cerebrovascular events were recorded in the meantime.Results Both systolic BP (SBP) and diastolic BP (DBP) were lower in summer than in any other season (P＜0. 01 ). SBP was higher in winter than in any other season. (P＜0.01), DBP was higher in winter than in summer(P＜0. 01). There were no significant differences in SBP and DBP between spring and autumn. The incidence of cardiovascular and cerebrovascular events were higher in winter and summer than in spring and autumn (P＜0.05). The season (OR= 1. 525, P=0. 001), BMI (OR =1.145, P=0.018) and heart function (OR= 2. 037, P=0.01) were related to the incidence of cardiovascular events. And the season (OR = 1. 604, P= 0. 001 ), history of cerebrovascular disease (OR= 1. 598, P=0. 034), office-measured SBP (OR=0.960, P=0.013) and ambulatory DBP (OR =0. 936, P = 0. 008) were related to the incidence of cerebrovascular events.Conclusions The blood pressure measured by three methods in the elderly aged 80 and over shows that both SBP and DBP are at the lowest in summer; SBP is at the highest in winter, DBP is higher in winter than in summer. There are no significant differences in BP between spring and autumn. The incidences of cardiovascular and cerebrovascular events are significantly higher in winter and summer than in spring and autumn.