Melatonin Use in Patients with Type 2 Diabetes and Insomnia

Study Shows Melatonin Improves Sleep and A1c Levels

A small pile of melatonin tablets on a marble tile.Type 2 diabetes is a major co-morbidity in many people who have insomnia. In a study, Israeli researchers examined the safety and effectiveness of prolonged-release melatonin (2 mg) in the treatment of glucose, lipid metabolism, and sleep in 36 patients who have type 2 diabetes and insomnia.

A total of 11 men and 25 women participated in this randomized, double-blind, crossover study. Participants were between 46 and 77 years old.

Results of the study appeared in the November 2011 issue of Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy in the article “Efficacy and safety of prolonged-release melatonin in insomnia patients with diabetes: a randomized, double-blind, crossover study.”

Study participants were given prolonged-release melatonin or a placebo for 3 weeks (period 1), followed by a 1-week washout period, and then crossed over for another 3 weeks of treatment with the other preparation (period 2). All tablets were taken 2 hours prior to bedtime for 3 weeks.

In an extension period of 5 months, all study participants were given prolonged-release melatonin nightly. This was done in an open-label design. Sleep was monitored objectively in a sub-group that included 22 study participants. Wrist actigraphy was used.

The following levels were measured at baseline and at the end of the study:

  • C-peptide
  • fasting glucose
  • fructosamine
  • glycosylated hemoglobin (A1c)
  • high-density and low-density lipoprotein cholesterol
  • insulin
  • some antioxidants
  • total cholesterol
  • triglycerides

Patients continued to take concomitant medications throughout the duration of the study.

Researchers found that there were no significant changes after 3 weeks of taking prolonged-release melatonin in the following levels:

  • antioxidants
  • blood chemistry
  • C-peptide
  • fructosamine
  • insulin
  • serum glucose

The researchers also found that sleep efficiency, wake time after sleep onset, and number of awakenings improved significantly when taking prolonged-release melatonin as compared with a placebo.

Following 5 months of prolonged-release melatonin use, it was noted that mean A1c (±standard deviation) was significantly lower than at baseline (9.13%±1.55% vs 8.47%±1.67%, respectively; p=0.005).

The research team concluded that short-term use of prolonged-release melatonin improves sleep maintenance in people who have type 2 diabetes and insomnia without affecting blood glucose and lipid metabolism. However, long-term prolonged-release melatonin has a beneficial effect on A1c levels, suggesting improved glycemic control.

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