June 9, 2014
Obstructive Sleep Apnea Linked To Diabetes In Large Cohort Study
Gerard LeBlond for redOrbit.com - Your Universe Online
A new study with more than 8,500 Canadian patients revealed a link between obstructive sleep apnea (OSA) and the onset of diabetes. The study was the largest one of its kind to date and the results confirmed what earlier studies revealed with smaller and shorter follow-up periods.
“Our study, with a larger sample size and a median follow-up of 67 months was able to address some of the limitations of earlier studies on the connection between OSA and diabetes. We found that among patients with OSA, the initial severity of the disease predicted the subsequent risk for incident diabetes.” said lead author Tetyana Kendzerska, MD, PhD, from the University of Toronto.
The findings are published in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.
Between 1994 and 2010, 8,678 adults with suspected OSA and without diabetes were used in a diagnostic sleep study and were followed-up on through May of 2011 by using provincial health data to examine the occurrence of diabetes. The severity of the sleep apnea was determined by the apnea-hypopnea index (AHI) which uses the complete cessation of airflow and partial cessation of airflow per hours of sleep.
The AHI classifications in the patients were AHI under 5 had no OSA, AHI 5 to 14.9 had mild OSA, AHI 15 to 30 had moderate OSA and AHI over 30 had severe OSA. The follow-up of the patients revealed that 1,017 or 11.7 percent developed diabetes. The analysis added in risk factors like age, sex, body mass index, neck circumference, smoking, income status and comorbidities at the beginning of the study.
The findings showed that the patients with an AHI over 30 had a 30 percent higher risk of diabetes than the patients with an AHI under 5. The patients with mild or moderate OSA were 23 percent more likely to develop diabetes. Oxygen destruction, sleep deprivation and a sympathetic nervous during sleep, are other risk factors for diabetes.
The study was limited by lack of some data, including family history of diabetes, race, and the possible misclassification of some individuals due to limits of the administrative health data used.
“After adjusting for other potential causes, we were able to demonstrate a significant association between OSA severity and the risk of developing diabetes. Our findings that prolonged oxygen desaturation, shorter sleep time and higher heart rate were associated with diabetes are consistent with the pathophysiological mechanisms thought to underlie the relationship between OSA and diabetes,” said Dr. Kendzerska. “The OSA-related predictors of increased diabetes risk that we found in our study may allow for early preventative interventions in these patients,” he added.