Effect of the seasons on the peak expiratory flow in institutionalized and noninstitutionalized elderly

ABSTRACT Respiratory diseases affect millions of people, especially the elderly, and climate change is among the predisposing factors interfering with the health of this population. This study aimed to evaluate the peak expiratory flow in institutionalized and noninstitutionalized elderly during the four seasons of the year. A prospective cohort study with 67 elderly men and women living in the city of Maringá, Paraná, Brazil, divided into two groups: institutionalized elderly (n=37) and noninstitutionalized elderly (n=30). The data were collected for one month, once a week in the four seasons of the year, totaling 16 evaluations. The peak expiratory flow was evaluated using the Peak-Flow Meter equipment. The two groups of elderly were compared by two-way analysis of variance using the Bonferroni post-hoc. The lowest mean peak expiratory flow for institutionalized and noninstitutionalized elderly was observed in the summer (176.2±60.2 and 263.2±116.2), followed by fall (193.4±59.5 and 287.5±118), winter (215.3±82.5 and 291.5±08.4), and spring (221.7±83.5 and 291.5±08.4). The conclusion was that the peak of expiratory flow of the elderly varies according to the seasons, but the institutionalized ones have lower values. The highest values are found in the spring, although below the value predicted for the elderly of both groups.

摘要 呼吸系统疾病影响数百万人群，尤以老年人为甚，而气候变化亦是影响该人群健康的易感因素之一。本研究旨在评估一年四个季节中机构养老老年人与居家养老老年人的峰呼气流量（peak expiratory flow）水平。本研究为前瞻性队列研究（prospective cohort study），共纳入巴西巴拉那州马林加市的67名老年男女受试者，分为两组：机构养老老年人组（n=37）与居家养老老年人组（n=30）。研究于一年四个季节中各开展为期一月、每周一次的数据采集，累计完成16次评估。采用峰流速仪（Peak-Flow Meter）对受试者的峰呼气流量进行检测。采用双向方差分析（two-way analysis of variance）结合Bonferroni事后检验（Bonferroni post-hoc）对两组老年人的相关指标进行比较。机构养老与居家养老老年人的平均峰呼气流量最低值均出现在夏季（分别为176.2±60.2与263.2±116.2），其次为秋季（193.4±59.5与287.5±118）、冬季（215.3±82.5与291.5±08.4）及春季（221.7±83.5与291.5±08.4）。研究结果显示，老年人的峰呼气流量随季节变化，且机构养老老年人的峰呼气流量水平更低；两组老年人的峰呼气流量最高值均出现在春季，但仍低于两组老年人群的预测参考值。