Relationship of Cough Strength to Respiratory Function, Physical Performance, and Physical Activity in Older Adults.

Abstract

Age- and lifestyle-related changes in respiratory and physical function affect cough strength. However, in older adults, the main factors that relate to cough strength remain unclear. This study was a preliminary investigation of factors that contribute to cough strength and the relationships between cough strength and respiratory function, physical performance, physical activity, and sedentary behavior in community-dwelling older adults. By using accelerometers and other tools, we assessed cough peak flow (CPF), FVC, maximum inspiratory pressure (PImax), maximum expiratory pressure (PEmax), chest and abdominal wall mobility (breathing movement scale), physical performance (Timed Up and Go test and 30-s chair stand test), physical activity (steps, and locomotive and non-locomotive moderate-to-vigorous physical activity), and sedentary behavior (sedentary time) in 65 community-dwelling older adults (25 males and 40 females) without air-flow limitation. Twenty-six percent of the subjects (17/65) had reduced CPF (<240 L/min). The subjects with reduced CPF had significantly lower FVC, PImax, PEmax, chest and abdominal wall mobility, physical performance, and locomotive moderate-to-vigorous physical activity compared with those with non-reduced CPF. Significant correlations between CPF and variables of respiratory function (FVC, PImax, PEmax, and breathing movement scale) and physical performance were weak to moderate. FVC and PImax were independently associated with CPF during the multiple regression analysis adjusted for sex, age, and height. The receiver operating characteristic analysis showed that FVC and PImax had fair-to-good sensitivity for detecting reduced CPF. Analysis of our results indicated that FVC and PImax were related to CPF and provided preliminary evidence that supported strategies for preserving and improving cough strength in community-dwelling older adults.