Sleep behaviours and associated habits and the progression of pre-diabetes to type 2 diabetes mellitus in adults: A systematic review and meta-analysis

Introduction Certain sleep behaviours increase risk of type 2 diabetes mellitus (T2DM) in the general population, but whether they contribute to the progression from pre-diabetes to T2DM is uncertain. We conducted a systematic review to assess this. Methods Structured searches were performed on bibliographic databases (MEDLINE, EMBASE and CINAHL) from inception to 26/04/2021 for longitudinal studies/trials consisting of adults⩾18 years with pre-diabetes and sleep behaviours (short or long sleep duration (SD), late chronotype, insomnia, obstructive sleep apnoea, daytime napping and/or night-shift employment) that reported on incident T2DM or glycaemic changes. The Newcastle-Ottawa Scale was used for quality assessment. Results Six studies were included. Meta-analysis of three studies (n = 20,139) demonstrated that short SD was associated with greater risk of progression to T2DM, hazard ratio (HR) 1.59 (95% CI 1.29-1.97), I2 heterogeneity score 0%, p < 0.0001, but not for long SD, HR 1.50 (0.86–2.62), I2 heterogeneity 77%, p = 0.15. The systematic review showed insomnia and night-shift duty were associated with higher progression to T2DM. Studies were rated as moderate-to-high quality. Conclusions Progression from pre-diabetes to T2DM increases with short SD, but only limited data exists for insomnia and night-shift duty. Whether manipulating sleep could reduce progression from pre-diabetes to T2DM needs to be examined.