Are obese people
at higher risk of having sleep apnea?
Dr Raymond Tso
Specialist in Respiratory Medicine
Obstructive Sleep Apnea (OSA) is caused by the narrowing of the airway during sleep, which prevents air from entering the lungs, resulting in a decrease in oxygen in the body. Among obese people, we noticed that 40% of them have significant sleep apnea; and among patients with sleep apnea, 70% are obese. Many people wonder why obese people are more likely to suffer from sleep apnea. In fact, the main reason is that the obese people have excessive fat and tissue in the upper airway. When they lie down and sleep, the fat and the tissue will relax and fall due to gravity, blocking part of the airway, making the airway narrow, air cannot enter the body smoothly, and the blood oxygen level will also be decreased. As a result, they are more likely to have the symptoms of sleep apnea.
Can losing weight cure sleep apnea?
A study pointed out that 10% weight loss can reduce 26% of the AHI, which proves that losing weight can effectively improve sleep apnea. However, sleep apnea is always caused by different factors, it cannot be cured by weight loss alone. If the patient suffers from OSA, after the patient has successfully lost weight, even if the weight has dropped significantly, we will still recommend the patient to continue to use CPAP and retake the sleep test, because the severity of your sleep apnea may change due to weight loss. Moreover, the CPAP you are using may also need to be reset to the air pressure you currently need, especially for the patients who are using a fixed CPAP, it is recommended to retake the sleep test every 2 years. Last but not least, sleep apnea is a long-term disease, you must always use the CPAP to reduce the related symptoms. When you stop using CPAP, the related symptoms will slowly reappear after a period of time, such as drowsiness, high blood pressure or other more serious health problems.
 “Obesity, Sleep Apnea, and Hypertension”- American Heart Association https://www.ahajournals. org/doi/pdf/10.1161/01.HYP.0000101686.98973.A3
 “Longitudinal Study of Moderate Weight Change and Sleep-Disordered Breathing” https://jamanetwork.com/journals/jama/fullarticle/193382