August 23, 2014

Sleep Apnea May Be Tied to Diabetes

Prior to this study, most studies included few patients and were too short in length. Now we have a larger study and a suggested link between sleep apnea and diabetes.  Unfortunately, the study had some critical limitations. The limitations included lack of family history of diabetes, the race of the participants, and the possible misclassification of some subjects due to the limitations of the administrative health data used.

This is a severe fault of the study and that is the reason I only used the words 'may be tied' in the title. I don't care that they used the word “tied” in their title with claims of a link between obstructive sleep apnea and diabetes. Yes, there are some similarities between the two and being overweight is very common. As to one causing the other, this is still unproven. I will continue so that you can make up your own mind.

Lead author, Tetyana Kendzerska, MD, PhD, of the University of Toronto says, "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."

The study included 8,678 adults with suspected OSA without diabetes at baseline who underwent a diagnostic sleep study between 1994 and 2010 and were followed through May 2011 using provincial health administrative data to examine the occurrence of diabetes. The apnea-hypopnea index (AHI) was used to assess sleep apnea severity. The AHI indicates severity based on the number of apneas per hour of sleep. Patients were classified as not having OSA (AHI < 5), or having mild (AHI 5-14.9), moderate (AHI 15-30) or severe (AHI>30) OSA.

During the follow-up, 1017 (11.7%) patients developed diabetes. In analyses, adjusting for known risk factors for diabetes, including age, sex, body mass index, neck circumference, smoking, income status and comorbidities at baseline, patients with an AHI>30 had a 30% higher risk of developing diabetes than those with an AHI <5 .="" 23="" a="" developing="" diabetes.="" had="" increased="" mild="" moderate="" of="" or="" osa="" p="" patients="" risk="" with="">

"After adjusting for other potential causes, we were able to demonstrate a significant association between OSA severity and the risk of developing diabetes, said Dr. Kendzerska. 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."

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