Peak expiratory flow, but not tongue pressure, can predict pneumonia development in older adults

Pneumonia is the leading cause of mortality and morbidity in aging populations. Major causes of pneumonia in older adults are swallowing dysfunction and decreased airway clearance capacity, including an impaired cough reflex. Maximal tongue pressure is useful for evaluating swallowing function, and peak expiratory flow indirectly reflects cough strength. However, it is unclear whether they can predict pneumonia development in older adults. In this study, we investigated whether tongue pressure and peak expiratory flow could predict pneumonia development in older adults.

This two-center prospective observational study included older adults aged 65 years or older without respiratory disease or head and neck cancer. We enrolled 383 consenting participants, many of whom had a history of stroke, and followed them for 2 years. The association between time to pneumonia development and tongue pressure or peak expiratory flow at enrollment was examined in a Cox proportional hazards model.

The mean age of the participants was 77.1 ± 6.2 years, and 36.0% of them were women. The mean tongue pressure was 35.4 ± 10.5 kPa and median peak expiratory flow was 218 L/min at enrollment. Six patients developed pneumonia during the study period. A low peak expiratory flow at enrollment was significantly associated with pneumonia development in the multivariate Cox proportional hazards model, but this association was not observed for tongue pressure.

Decreased peak expiratory flow may predict pneumonia development in older adults. Future studies should investigate interventions for peak expiratory flow improvement.