The United States Food and Drug Administration (FDA) has approved the weight-loss drug Tirzepatide — sold by the brand name Zepbound — for the treatment of Obstructive Sleep Apnoea (OSA), a condition in which the throat muscles sag and block air passages, resulting in difficulty breathing during sleep. The drug has been approved for use in combination with a low-calorie diet and increased physical activity in those with moderate to severe OSA. This shows that the weight-loss drug has multifarious uses other than controlling type-2 diabetes and obesity. Fat accumulation around the neck region is the reason for the laxity of throat muscle. What is OSA? OSA is a condition where the muscles in the throat relax when a person is sleeping, resulting in a choking sensation and the person waking up. Those with the condition usually do not feel rested even after a complete night’s sleep and are likely to feel sleepy during the day. Obesity is one of the major risk factors for OSA. “More than 50 per cent of people with OSA are obese and another 25 per cent are overweight. The fat around the abdomen actually puts pressure on the lungs, making them smaller. Those with smaller lungs are likely to have a floppy tongue that can block their airway at night. Fat around the neck as well as fat deposition on the back part of the tongue can block the airway during sleep, causing OSA,” said Dr JC Suri, consultant at Sitaram Bhartia and former head of pulmonology, critical care, and sleep medicine at Safdarjung Hospital. How does the drug help? Significant weight loss, which can be achieved using drugs such as Tirzepatide, relieves the pressure around the neck. “Excess body fat contributes to several diseases, including OSA. This is just a new indication where the medicine helps by reducing weight in obese individuals. This is largely meant for insurers — so that the treatment and its cost can be justified. Right now, we are seeing the impact of the drug in more and more diseases, mainly because of its weight loss properties. Although, some other mechanism of action is also being studied,” said Dr Ambrish Mithal, chairman and head of endocrinology and diabetes at Max Healthcare. What did the trial for OSA show? Zepbound was approved for OSA based on two studies — one with participants using machines for positive airway pressure and one with those who were unwilling to use it. In both studies, the participants were given 10 or 15 milligrams of Zepbound or placebo. After 52 weeks, there was a significant reduction in the apnoea hypopnea index for patients on Zepbound as compared to the placebo. How is OSA treated now? Patients use a positive airway pressure machine while they sleep. It blows pressurised room air into the respiratory tract that keeps the airway open through the night. Patients may also be prescribed medicines to improve their sleep at night. But so far, there has been no drug for the treatment of OSA. Can OSA happen in non-obese people as well? Yes. And, drugs such as Zepbound are unlikely to help in these cases. “Although, it is more frequently diagnosed in obese and overweight people, OSA can happen even in leaner people. In them, OSA results mainly from bony abnormalities such as smaller jaws resulting in smaller air passage,” said Dr Suri.
