Sleep profiles, including chronotype, sleep duration and sleep-wake time, may affect glycaemic outcomes. However, their associations with plasma glycaemic outcomes and 24-h interstitial glucose levels in individuals with prediabetes remains ambiguous. This study aimed to examine the association between sleep profiles and glycaemic outcomes in adults with prediabetes. Chronotype was assessed using the Malay-translated Munich Chronotype Questionnaire. Glycaemic outcomes, including fasting plasma glucose (FPG), 2-h postprandial glucose (2hPPG), glycated haemoglobin (HbA1c) levels and 24-h glucose profiles derived from seven-day continuous glucose monitoring (CGM). Generalised linear models and generalised estimating equations were used and adjusting for potential confounders. A total of 120 participants (mean age: 54 ± 15 years) were categorised as morning (18.4%), intermediate (60.8%) or evening (20.8%) chronotypes. Evening chronotypes demonstrated greater weekday-weekend discrepancy in awake time (0.7 h [±1.1 h]), indicating higher social jet lag. Each additional hour of jet lag in awake time was associated with a 0.28 mmol/L reduction in 2hPPG levels (95% CI: -0.49, -0.08), reflecting compensatory catch-up sleep on weekends. Longer sleep time was positively associated more time spent within the target glucose range (3.9-7.8 mmol/L) (β: 0.58, 95% CI: 0.06, 1.10), while evening chronotype showed higher 24-h mean glucose levels (β: 0.65 mmol/L, 95% CI: 0.22, 1.12). Evening chronotype and shorter sleep duration were associated with adverse glycaemic outcomes, while the unexpected inverse association between awake-time jet lag and 2hPPG may reflect short-term catch-up sleep rather than a protective effect. These findings highlight the importance of addressing sleep regularity in lifestyle interventions for prediabetes management.
