Sleep disordered breathing and obesity: Independent effec...( Sleep Apnea Linked to Insulin Resis...),Health

In a study that addressed the issue of insulin sensitivity with respect to sleep disordered breathing (SDB), Naresh Punjabi, M.D., Ph.D. sought to examine the relationship between SDB and insulin resistance using the best tools at his disposal to do so.

The results definitively link SDB to pre-diabetic changes in insulin production and glucose metabolism. It was published in the first issue for February of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.

"In the past researchers have used body mass index, or BMI, as a proxy measure for body fat, but we know this to be a variable and crude tool to assess the true percentage of body fat," said Dr. Punjabi. "In addition, previous studies have used surrogate measurements to assess the body's response to insulin without investigating the interaction that occurs between reduced insulin sensitivity and increased insulin production in the body."

To address the shortcomings of previous studies, Dr. Punjabi and colleagues used two tools in their investigation into the link between SDB and insulin resistance: 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, rather than a simple snapshot at a specific moment.

They recruited 118 subjects, 39 who had no SDB, and 79 who were newly diagnosed with SDB but who had not been treated. Each subject underwent a sleep study to assess their level of SDB, and then underwent a FSIVGGT to determine their glucose metabolism and insulin sensitivity/production the following day.

"Our major finding was that, as we suspected, SDB was strongly associated with a decrease in the three major metabolic pathways that the
'/>"/>