ABSTRACT
Objective To explore the influence of seasonal variations on acute cerebral infarction outcome. Meth-ods We collected data from acute cerebral infarction patients in the Second Hospital of Tianjin Medical University from January 2009 to February 2012. All cases were classified by months and seasons into different groups to analyze the season-al variations retrospectively. Results (1) The percentage of good outcome of acute cerebral infarction show significant dif-ference between each month(P<0.01). The percentage of good outcome was highest in August(92.1%), lowest in Decem-ber(78.1%), second lowest in April(81.9%). The percentage of good outcome in summer(91.6%)was higher than spring (87.2%), autumn(86.4%)and winter(83.9%)(P<0.05). (2) Among those patients converted to bad outcome more pa-tients was attacked by cerebrovascular accident in winter(68.3%)than in summer(43.2%), and more patients was combined with a pulmonary infection in winter(69.5%)than in summer(48.6%)and in autumn(49.3%)(P<0.05). (3) Seasonal effect in acute cerebral infarction outcome was obvious in those≥65 years of age(P<0.05). Conclusion Seasonal changes are associated with the outcome and severity of acute cerebral infarction.
ABSTRACT
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.
ABSTRACT
Objective To investigate the circadian and seasonal distribution of cardiovascular events (CVE) and the relationship between average monthly temperature and the incidence of CVE. Methods A total of 5837 emergency patients with CVE were enrolled from 1997 to 2007. The exact admission time of each patient was registered. The average monthly temperature data from a regional weather station for this time period was supplied by the meteorological office of the city. The relationship between the average monthly temperature and the incidence of CVE was explored and the corresponding curves were plotted. Results The occurrence of CVE has obvious seasonal variation, and its a higher tendency of episodes was found in spring and winter periods. High incidence of acute myocardial infarction, angina pectoris, acute left-sided heart failure, hypertensive crisis, and sudden death occurred in spring and winter as wee as the time for a change of season, that is, January, February, March, April, October, November, and December. There was a significant negative correlation between the incidence and the average monthly temperature (P<0.005-0.001). Circadian rhythm of CVE was present, with a peak in the early morning and forenoon. Conclusion There are circadian and circannian rhythms of the incidence of CVE. Cold weather condition is a risk factor for the occurrence of CVE, which usually peaks in the early morning and forenoon.