
Individuals with high or continuously increasing BMI from childhood to middle age are at greater risk of developing obstructive sleep apnoea (OSA) later in life, reveals a study.
However, “being obese in childhood does not necessarily increase the risk of adulthood OSA if weight is subsequently reduced,” according to the investigators.
In this analysis, the investigators previously identified five BMI trajectories in the population-based cohort Tasmanian Longitudinal Health Study. They used eight time-point BMI from age 5 to 43 years.
Probable OSA at 53 years, defined using the STOP-Bang questionnaire, was the primary outcome. To make sure that the findings were consistent, the investigators used the Berlin and OSA-50 questionnaires. Moreover, clinically significant diagnosed OSA was defined as self-reported medical diagnosis or mild OSA with symptoms or moderate-to-severe OSA, using type-4 sleep studies.
Finally, the associations between BMI trajectory and the risk of OSA in adulthood were explored using multivariable logistic regression.
Compared with the average BMI trajectory, the “child average-increasing" (adjusted odds ratio [aOR], 5.28, 95 percent confidence interval [CI], 3.38–8.27) and persistently high trajectories (aOR, 3.73, 95 percent CI, 2.06–6.74) significantly correlated to a higher risk of probably OSA. [Respirology 2025;30:435-445]
Such associations persisted in clinically significant diagnosed OSA (“child average-increasing" trajectory: aOR, 2.95, 95 percent CI, 1.30–6.72; high trajectory: aOR, 2.23, 95 percent CI, 0.82–6.09).
On the other hand, the low BMI trajectory was associated with a lower risk of OSA compared with the average trajectory. Furthermore, the “child high-decreasing" trajectory showed no significant association with OSA, indicating the importance of weight reduction.
“Physicians and the public should be aware of the potential risk of OSA in middle-aged adults when BMI is high or continuously increasing from childhood to mid-40s,” the investigators said. “Obese children who subsequently lose weight were not at higher risk of OSA in middle age.”
Potential mechanisms
The association between obesity and OSA can be possibly explained by some factors. For instance, fat buildup in the tongue or around the pharynx can narrow the upper airway, which leads to the decrease or restriction of airflow. [Am J Respir Crit Care Med 1995;152:1673-1689]
Previous studies have also shown the independent association of OSA with abdominal visceral adipose tissue deposition, which potentially reduces lung volumes. [Front Endocrinol 2022;13:847324; J Appl Physiol 2010;108:430-435]
Leptin resistance is also common in people with obesity. This condition may “destabilize respiratory control” while sleeping, leading to OSA in some individuals. [Respir Physiol 2000;119:163-170; Sleep 2016;39:1097-1106]
In addition, hormonal imbalances and metabolic dysfunction, along with increased fat accumulation and inflammation, could increase the odds of developing OSA in some individuals. [Chest 2005;127:1074-1075]
“On the other hand, weight loss may improve OSA by reducing the abdominal fat and then improving airway traction or by reducing several upper airway soft tissues, both of which could prevent upper airway collapse during sleep,” the investigators said. [Am J Respir Crit Care Med 2020;201:718-727]