Circulation weather types and hospital admissions for cardiovascular disease in Changchun, China

Epidemiological studies have reported significant associations between weather situations and health. Cardiovascular disease is a serious chronic non-communicable disease which causes mortality and morbidity, bringing large economic burden to patients' families. This study explored the relationship between cardiovascular disease (CVD) and weather conditions in Changchun, northeast China. The frequency distributions of 13 main circulation weather types (CWTs) were analyzed, and a comparison between air mass classification and hospital admissions was performed for various groups using an admission index (AI). The results indicated that women had a lower risk of CVD than men did. The risk of CVD for older people (aged >= 65 years) was lower than that for young people (aged < 65 years). Younger men had the highest risk. The risks of CVD were higher in all groups (i.e., men, women, older, and younger) under southwesterly (SW) and northerly (N) CWTs and were lowest under the anticyclone (A) CWT. The risk of CVD among men was higher than that for women under these CWTs. N type circulation is characterized by cold, dry weather and was most closely associated with an increased incidence of CVD. The most significant effect of N type circulation on AI was observed with a delay of 2 days. SW type circulation is characterized by humid, hot weather and was the CWT that was second most closely associated with an increased incidence of CVD, with a peak in AI on the day that SW type circulation occurred. The results of this study could be provided to local health authorities as scientific guidelines for controlling and preventing CVD in Changchun, China.