Pulmonary Function as a Predictor of Frailty Syndrome in Community-Dwelling Older Adults

Background and Purpose: Diminished pulmonary function is associated with negative health outcomes and pulmonary impairment, and can be associated with frailty. The objectives of this study were to compare pulmonary function between frail, prefrail, and nonfrail older adults; to verify the association between pulmonary function and frailty syndrome; and to establish cut-off points for pulmonary function variables for predicting frailty. Methods: A cross-sectional study was conducted with 379 community-dwelling older adults of both sexes. Spirometry was used to measure pulmonary function criteria (forced vital capacity, FVC; forced expiratory volume in 1 second, FEV1; and FEV1/FVC ratio). The presence of frailty was evaluated with Fried's frailty phenotype. Statistical analysis included a multinomial logistic regression model. Pulmonary function cut-off points for discriminating frailty syndrome were established through analysis of the receiver operating characteristic curves. Results and Discussion: The study participants were a median of 69.0 (64.0-74.0) years old, and 12.4% presented frailty while 58% presented prefrailty. Frail and prefrail older adults presented significantly lower median FVC and FEV1 values-FVC = 1.89 L (1.45-2.31) and FEV1 = 1.60 L (1.24-1.91); FVC = 2.07 L (1.62-2.67) and FEV1 = 1.66 L (1.32-2.09), respectively-than nonfrail participants-FVC = 2.53 L (1.96-3.16) and FEV1 = 2.01 L (1.54-2.43). The adjusted analysis indicated that FEV1 (odds ratio [OR] = 0.63; 95% confidence interval [CI], 0.39-0.99) and the FVC (OR = 0.68; 95% CI, 0.48-0.96) were inversely associated with prefrailty and that FVC (OR = 0.52; 95% CI, 0.29-0.94) was associated with frailty. Cut-off points for prefrailty (FVC <= 2.3 L and FEV1 <= 1.86 L) and frailty (FVC <= 2.07 L and FEV1 <= 1.76 L) were established. Conclusions: Pulmonary function was lower in frail and prefrail older adults than in their nonfrail peers. Frailty and prefrailty were inversely associated with pulmonary function. Cut-off points for FEV1 and FVC for discriminating frailty were established and may allow pulmonary function to serve as an indicator of frailty in older adults.