[Characteristics of peak expiratory flow and analysis of risk factors for its decline in stroke patients]

Objective: To analyze the characteristics of peak expiratory flow (PEF) and the risk factor for its decline in stroke patients. Methods: This was a case-control study. A total of 809 stroke patients hospitalized in the Department of Rehabilitation of the First Affiliated Hospital of Wenzhou Medical University from January 2020 to December 2022 were prospectively enrolled as the stroke group, and 801 age-and sex-matched healthy subjects from the hospital's Physical Examination Center during the same period served as the control group. The measured PEF was detected using an adult peak flow meter. The predicted PEF and PEF% (measured/predicted PEF×100%) were calculated based on age, sex, and height. The stroke group was further divided into a normal PEF group (PEF%≥80%) and a decreased PEF group (PEF%<80%). PEF metrics were compared within and between the stroke and control groups. A multivariate logistic regression was used to analyze risk factors for PEF decline in the stroke group. Results: The stroke group (539 males, 270 females) aged (63.2±11.9) years and the control group (498 males, 303 females) aged (63.5±12.1) years. The measured PEF in the stroke group was lower than its predicted value [(243.89±139.38) vs (390.45±94.30) L/min, P<0.001], while no significant difference was found between the measured and predicted PEF values in the control group (P>0.05). Compared with the control group, the stroke group had lower measured PEF [(243.89±139.38) vs (371.52±114.78) L/min] and PEF% [(61.80±30.79)% vs (98.14±22.48)%], but higher predicted PEF [(390.45±94.30) vs (379.21±84.78) L/min] and a higher proportion of severe PEF% decline [48.6% (393/809) vs 4.5% (36/801)] (all P<0.05). Within the stroke group, the decreased PEF group had higher proportions of smoking, alcohol drinking, atrial fibrillation, total anterior circulation infarction, higher NIHSS and mRS scores and a higher proportion of dysphagia compared with the normal PEF group (all P<0.05). The decreased PEF group had a lower proportion of partial anterior circulation infarction, Barthel index score, and independent standing (all P<0.05). Multivariate logistic regression identified smoking (OR=1.466, 95%CI: 1.014-2.118), increased NIHSS score (OR=1.072, 95%CI: 1.003-1.145), dysphagia (OR=1.691, 95%CI: 1.161-2.463), and increased mRS score (OR=2.286, 95%CI: 1.263-4.137) as risk factors for PEF decline in stroke patients. Conclusions: Stroke patients exhibit decreased measured PEF and PEF%, along with higher predicted PEF and a higher proportion of severe PEF% decline. Smoking, neurological dysfunction, impaired mobility, and dysphagia are risk factors for PEF decline in stroke patients.