Early-to-midlife body mass index trajectories and obstructive sleep apnoea.

Abstract

Background: While short-term weight changes are known to influence obstructive sleep apnoea (OSA), the impact of changes in body mass index (BMI) over the life-course was poorly documented. Our aim was to examine the association between BMI trajectories from childhood to middle age and adult OSA. Method(s): Five BMI trajectories were previously identified in the population-based Tasmanian Longitudinal Health Study (TAHS), using eight time points from age 5 to 43 years. The primary outcome was probable OSA at 53 years, defined mainly using STOP-Bang questionnaire. Clinically significant diagnosed OSA at 53 years was defined as having self-reported medical diagnosis or mild OSA with symptoms or moderate-to-severe OSA, using type-4 sleep studies. Associations were examined using multivariable logistic regression. Result(s): Compared with the average BMI trajectory, the child average-increasing (aOR=5.26, 95% 3.36-8.23) and persistently high trajectories (aOR=3.71, 2.06-6.71) were associated with increased risk of probable OSA defined using STOP-Bang. These associations were consistent when using clinically significant diagnosed OSA (child average-increasing trajectory: aOR=2.95, 1.52-5.70; high trajectory: aOR=2.45, 1.14-5.27, separately). Individuals belonging to the low were less likely than the average trajectory to have OSA. Notably, the child highdecreasing trajectory was not associated with OSA. Conclusion(s): Physicians and the public should be aware of the potential for OSA in middleaged adults when BMI is high or increasing from childhood to middle age. Importantly, obese children who subsequently lose weight are not at higher risk of OSA in middle age-a novel finding and key message.