Lung Restriction From Childhood Is Associated With Obstructive Sleep Apnoea in Middle-Age.

BACKGROUND AND

OBJECTIVE

Whether lifetime lung function trajectories and spirometry patterns are associated with Obstructive Sleep Apnoea (OSA) is unknown. We aimed to investigate this association to widen the understanding of OSA pathophysiology.

METHODS

We previously identified six FEV1/FVC (forced expiratory volume in the first second/forced vital capacity) and five FVC trajectories within a population-based prospective cohort (n = 2422) using spirometry assessed at ages 7, 13, 18, 43, 50, and 53 years. These trajectories were combined into four lifetime spirometry patterns: restrictive-only, obstructive-only, mixed, and reference (normal), which were our exposure variables. Outcomes were medically-confirmed OSA in midlife and probable-OSA defined using the STOP-Bang questionnaire. Associations were assessed using logistic regression models.

RESULTS

The 'restrictive-only' spirometry pattern was associated with medically-confirmed OSA (OR = 2.5; 95% CI 1.5, 4.3). In addition, restriction-confirmatory low total lung capacity and reduced functional residual capacity were associated with increased odds of medically-confirmed OSA (OR = 1.4; 0.9, 2.1 and OR = 1.7; 1.1, 2.6, respectively, per one SD reduction in volume). The results were similar for probable OSA. These associations held when controlled for BMI and central obesity and were independent of childhood lung function. Neither transfer factor for carbon monoxide (TLco) nor transfer coefficient (Kco) was associated with OSA.

CONCLUSION

We provide first evidence that lifetime lung restriction is related to middle-age OSA. While this information may be used to incidentally flag middle-age OSA risk and vice versa, further research is encouraged to confirm the underlying pathophysiological mechanisms.