Influence of lung function and sleep-disordered breathing on stroke: a community-based study.

BACKGROUND AND PURPOSE: Impaired lung function is regarded as a risk factor for stroke in patients with chronic obstructive pulmonary disease. However, the association between reduced lung function and incident stroke in a community-based population with sleep-disordered breathing (SDB) remains unknown.

METHODS: A prospective study was performed within the Sleep Heart Health Study cohort. Full montage home sleep testing and spirometry data on 2082 and 2072 individuals with and without SDB, respectively, were analysed. Cox proportional hazards regression models were used to estimate the association between lung function and incident stroke.

RESULTS: Over 11.7 years, 183 cases of stroke were identified in participants without pre-existing cardiovascular diseases, including 71 and 112 with an apnoea-hypopnoea index <5 events/h and ≥5 events/h, respectively. In the entire population, lung function was inversely associated with incident stroke [hazard ratio (HR) 0.913 (95% confidence interval 0.839-0.994) for every 10% increase in percentage of predicted forced vital capacity]. When the population was divided according to the presence/absence of SDB, the association of lung function with incident stroke became stronger in individuals with SDB [HR 0.899 (0.822-0.984) for every 10% increase in percentage of predicted forced expiratory volume in 1 s; HR 0.881 (0.787-0.987) for every 10% increase in percentage of predicted forced vital capacity] but not in individuals without SDB.

CONCLUSIONS: Lung function may serve as a risk factor for incident stroke in a community-based population, especially in those with SDB. Spirometry may help improve the risk management for primary care in community-based populations.