Frailty and muscle weakness in elderly patients with asthma and their association with cumulative lifetime oral corticosteroid exposure

BackgroundFrailty is a geriatric syndrome of age-related physiological decline, which is associated with higher mortality and decreased healthy life expectancy, and muscle weakness is one of the presentations of frailty. We investigated an association between lifetime oral corticosteroid (OCS) exposure with frailty and muscle weakness among elderly patients with asthma.MethodsWe studied 203 consecutive elderly outpatients with asthma aged ≥60 years old. They were classified into three groups according to their cumulative lifetime OCS dose (lifetime non-users, lower-dose users, and higher-dose users), which was retrospectively estimated from the response to a structured questionnaire. The prevalence of frailty determined by the Kihon Checklist was compared between the three groups. Hand-grip strength, and lean mass index were also measured as markers of muscle strength.ResultsThirty-seven percent of the patients studied were considered frail. Higher cumulative lifetime OCS exposure was associated with a significantly higher prevalence of frailty (33% in lifetime non-users, 59% in lower-dose users, and 68% in higher-dose users; P for trend <0.005). This was also associated with lower hand-grip strength in both sexes (P for trend; 0.012 in men, and 0.020 in women), and lower lean mass index in men (P for trend 0.002). However, current doses of OCS were not significantly associated with these outcomes.ConclusionsCumulative lifetime OCS exposure was associated with a higher prevalence of frailty and muscle weakness. These findings emphasize the importance of minimizing lifetime OCS exposure for the prolongation of healthy life expectancy in patients with asthma.