Digital Intervention Increasing Sleep Duration Among People With Type 2 Diabetes: Pilot Randomized Controlled Trial

Introduction and objective: Short sleep duration is associated with worse hemoglobin A 1c (HbA 1c ), and treatment guidelines recommend sufficient sleep duration. However, it is unclear whether extending sleep duration of short-sleeping people with type 2 diabetes causes improved HbA 1c . We aimed to assess the effect on HbA 1c of increasing sleep duration. Methods: We developed a personalized digital intervention based on the theory of planned behavior and conducted a single-blind, two-arm randomized controlled trial with 70 short-sleeping (≤6 hours) people with type 2 diabetes in Japan. Both arms measured sleep duration using an actigraph and a sleep diary. The intervention group received bedtime advancement support, including achievable bedtime goal setting and feedback. The primary outcome was between-arm difference in HbA 1c change after 12 weeks. Results: The baseline average sleep duration and HbA 1c were 5.96 ± 1.26 (hours) and 8.30 ± 0.91 (%) in the intervention group, and 5.94 ± 0.96 (hours) and 8.09 ± 0.51 (%) in the control group, respectively. Sleep duration improved with statistical significance (between-arm difference in change: 32.8 minutes, P = .0042). However, HbA 1c did not reduce significantly (between-arm difference in change: –0.11%, P = .51), and increases in sleep duration were not significantly associated with HbA 1c reduction ( P = .69). Conclusion: In this randomized trial, an average sleep extension of approximately 30 minutes over 12 weeks did not result in a significant improvement in HbA 1c among short-sleeping adults with type 2 diabetes. Further studies with larger sample sizes and greater sleep extension are warranted.