Buxton OM, et al. – The authors aimed to examine the hypothesis that the effects of primary insomnia (PI) on glucose metabolism could be improved by 2 months of pharmacological treatment. In this preliminary study, compared with placebo, treatment with 3 mg eszopiclone for 2 months did not significantly influence either sleep or measures of diabetes risk.

• The authors conducted a randomized, double-blind, placebo-controlled clinical trial to study adult men and women meeting clinical criteria for PI (n=20, body mass index 25.1±2.7 kg/m², age 39.7±7.9).
• The study consisted of two 1-day inpatient admissions to a General Clinical Research Center separated by 2 months of at-home treatment with 3 mg eszopiclone or placebo.
• Each subject underwent two intravenous glucose tolerance tests (IVGTTs) pre- and post-treatment during inpatient admissions.
• They controlled diet for micro- and macro-nutrient content and calories on the day prior to pre- and post-treatment IVGTTs.
• They randomized subjects following completion of the initial IVGTT to take either placebo or eszopiclone 30 min prior to bedtime at home for 2 months.

• Compared with placebo, 2-month eszopiclone treatment did not change insulin sensitivity, glucose tolerance, or any of the sleep measures significantly.
• Changes in glycated hemoglobin (HbA1c, the clinical measure of glycemic control) were associated with changes in diary-reported total sleep time in the eszopiclone group (r=0.66, p=0.0360), and in the combined groups’ data (r=0.55, p=0.0125).
• Changes in polysomnography-measured wake after sleep onset, a hallmark of PI, were positively correlated with changes in IVGTT-derived glucose effectiveness, or non-insulin-mediated glucose uptake.