Sleep Apnea Treatment and Insulin Resistance in Patients with Acromegaly
What effects do sleep apnea and treatment for the condition have on insulin resistance in patients with acromegaly? A team led by researchers in the Division of Endocrinology and Metabolism at The University of São Paulo Medical School in Brazil set out to answer this question in a recent study.
The study is titled “The impact of sleep apnea treatment on carbohydrate metabolism in patients with acromegaly.” It was published online ahead of print in September 2012 in the journal Pituitary.
According to the researchers, sleep apnea is a common problem in people with acromegaly, and it may lead to insulin resistance in many of these patients. The study authors were interested in how sleep apnea that was treated with a continuous positive air pressure (CPAP) device might affect insulin resistance in people with acromegaly. Insulin resistance was measured and assessed using the hyperinsulinemic euglycemic clamp (HEC) technique.
The small, prospective, randomized, placebo-controlled study included 12 patients with
acromegaly. The study was performed at an outpatient pituitary center. All participants were being treated for acromegaly with somatostatin analogs (SA). Additionally, all of the patients were recently diagnosed with sleep apnea (cases ranging from moderate to severe). The 12 participants were randomly separated into groups: some received CPAP therapy, and others received a nasal dilator adhesive (NDA).
The results of the study showed a reduction in insulin resistance (as evidenced by HEC) in patients in the CPAP group. The same reduction was not seen in the NDA group. Additionally, the study showed no significant differences in patients’ HbA1c levels or their peripheral insulin resistance indexes, regardless of the treatment group. However, an association was seen between CPAP treatment and peripheral insulin sensitivity in the study participants.
The researchers conclude that their study demonstrates the important role that sleep apnea plays in patients’ glucose metabolism.