A LARGE-SCALE community-based study has revealed that the majority of people with obstructive sleep apnoea (OSA) do not have obesity, challenging the widespread belief that OSA is primarily a condition of individuals with excess body weight. Drawing on data from over 12,800 middle-aged and older adults across four cohorts in the United States and Switzerland, the researchers found that 68.5% of people with OSA did not meet criteria for obesity, with 23.5% falling within the normal or underweight BMI range.
OSA is a disorder caused by repeated obstruction of the upper airway during sleep, which leads to disrupted breathing patterns. Although obesity is a well-established risk factor, due to fat accumulation around the airway and reduced lung volumes, this study emphasises that a wide range of anatomical and physiological factors also contribute to the condition. These include airway structure, ventilatory control instability, low muscle responsiveness, and arousal threshold abnormalities, which may all lead to OSA independently of weight status.
The findings persisted even among those with more severe forms of OSA. In moderate-to-severe cases, over 60% were not obese; in severe OSA, more than half of participants were still non-obese. Conversely, the study confirmed that individuals with obesity remain at significantly higher risk for OSA, with those affected having over four times greater odds of the condition compared to individuals with a BMI below 25 kg/m².
These findings carry important clinical and public health implications. Many individuals with OSA who fall within normal weight categories may go undiagnosed due to the misconception that obesity is a necessary indicator. As untreated OSA is associated with cardiovascular disease, cognitive decline, and reduced quality of life, this diagnostic gap could have serious health consequences. The study calls for a broader, individualised approach to OSA screening and treatment, one that accounts for diverse physiological contributors beyond body weight alone.
Reference
Esmaeili N et al. The relationship between obesity and obstructive sleep apnea in four community-based cohorts: an individual participant data meta-analysis of 12,860 adults. eClinicalMedicine. 2024;83:103221.
