Sleep Disordered Breathing and Obesity

Sleep disordered breathing (SDB), more commonly known as sleep apnea, has been linked to insulin resistance, a condition that may not necessarily be tied to obesity.

Dr. Naresh Punjabi recruited 118 subjects for a sleep study. While 39 had no history of SDB, 79 of the participants were newly diagnosed but had yet to receive treatment for the disorder. In addition to the sleep study, the participants were also evaluated using a dual-energy x-ray absorptiometry (DEXA), a highly precise technique for assessing body fat, and frequently sampled intravenous glucose tolerance test (FSIVGTT), which provides a detailed picture of the subject’s insulin sensitivity over time. The FSIVGTT was performed the day after the initial sleep study.

Researchers found that SDB was strongly associated with a decrease in insulin sensitivity, glucose effectiveness, and pancreatic cell function. Researchers found this to be true regardless of how much body fat the participants had. Dr. Punjabi also noted that, “What our research tells us is that SDB is characterized by multiple physiological deficits that increase the predisposition for type 2 diabetes mellitus.”

Additional testing conducted by researchers from the Johns Hopkins Bayview Medical Center Bariatric Surgery Clinic has confirmed that SDB is linked to insulin resistance, and may also be linked to the progression of liver disease. Sleep apnea has also been tied to a sedentary lifestyle, even if there are no current signs of obesity.

These findings may help explain why as many as 40% of people who suffer from obstructive sleep apnea (OSA) are not obese. It also gives researchers insight into why many patients who begin exercise programs find relief from OSA, even if they do not lose weight.