Sleep apnea occurs when breathing during sleep either stops for a period or becomes reduced or labored. Though sometimes caused by neurological problems (central sleep apnea) or prescription drugs, the much more common variety is called obstructive sleep apnea (OSA). The breathing passage becomes blocked; oxygen levels drop because attempts to breathe are unsuccessful, and the subject may gasp for air, disrupting normal sleep. Sleep apnea can introduce or worsen conditions such as high blood pressure, congestive heart failure, and mood disorders.
Obesity and Obstructive Sleep Apnea
In obese patients, though other factors are believed to contribute, OSAS is often blamed on fat deposition around the throat. One treatment for OSA is to keep the airways open using machines that control air pressure; the most well known is the continuous positive airway pressure machine, or CPAP.
The prevalence of OSA among the severely obese ranges from 50% to 90%, leading to the assumption that effective treatment of obesity could help treat OSA. Indeed, studies have shown that a 15% reduction of baseline body weight can substantially increase the pharyngeal cross-sectional area and dramatically reduce the severity of OSAS in morbidly obese patients.
Bariatric surgery and sleep apnea
If changes in diet and exercise are unsuccessful in bringing about significant and lasting weight loss, bariatric surgery can be considered. These treatments significantly improve and in some cases completely cure sleep apnea. It is recommended that CPAP therapy be continued for about six months after the surgery. After 12 months, the situation can be reassessed to determine whether CPAP is still necessary.