Chrononutrition, Chronotype and Glucose Tolerance among Prediabetic Adults in Malaysia: Prospective Longitudinal Study Chrono-DM™

Chong, Guey Yong (2025) Chrononutrition, Chronotype and Glucose Tolerance among Prediabetic Adults in Malaysia: Prospective Longitudinal Study Chrono-DM™. Doctoral thesis, Tunku Abdul Rahman University of Management and Technology.

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Abstract

Chrononutrition and chronotype, concerning dietary timings and sleep-wake preference patterns, are pivotal in metabolic health. However, their associations with glucose tolerance, particularly in prediabetic adults, remain unexplored. This study aimed to examine the associations of chrononutrition, chronotype and glucose tolerance in Malaysian prediabetic adults. The present study comprises three phases: Phase I involved a scoping review exploring the association between chrononutrition characteristics and glycaemic outcomes; Phase II was the translation, validation and tested the reliability of instrument measures chrononutrition; and Phase III consisted of a prospective longitudinal observational study. In Phase I, a total of 49 relevant studies has been identified to reveal the associations between delayed night eating times, night snacking and reduced overnight fasting durations with adverse glycaemic outcomes. Subsequently, Phase II validated the Malay Chrononutrition Profile Questionnaire (CPQ-M) in 202 Malaysian adults. Exploratory factor analysis revealed a strong correlation with the original English version and high reliability (ICC: 0.82–0.97). The CPQ-M demonstrated good internal consistency (Cronbach’s alpha: 0.75), indicating its suitability for assessing chrononutrition. Phase III enrolled 120 individuals diagnosed with prediabetes from healthcare clinics in Malacca, with mean age of 54 ± 18 years. The findings revealed that 83% of the subjects were non-daytime eaters (defined as eating time before 7.00am or after 7.00pm), while 17% were daytime eaters (eating within solar time range of 7.00am and 7.00pm). Non-daytime eaters showed a significant association with higher mean glucose levels (β:0.61 mmol/L, 95% CI: 0.27, 0.94), greater glucose management index (β: 2.46 mmol/mol, 95% CI: 1.02, 3.91) and higher 24-hour interstitial glucose levels over consecutive 7 days (β: 0.44 mmol/L, 95% CI: 0.11, 0.76) after adjusted for controlled variables. For chronotype, the evening chronotype was significantly associated with lower fasting plasma glucose (FPG) (β: -0.45 mmol/L, 95% CI: -0.72, -0.18), elevated glycated haemoglobin (HbA1c) (β: 1.39%, 95% CI: 1.20, 1.57) and greater 24-hour mean interstitial glucose levels over consecutive 7 days (β: 0.65 mmol/L, 95% CI: 0.22, 1.12) after adjusted for controlled factors. A later last meal was significantly associated with increased weight (β: 0.68 mmol/mol, 95% CI: 0.31, 1.04) and higher total body fat (β: 0.44 The National Health Morbidity Survey (NHMS), conducted by the Ministry of Health, has mmol/mol, 95% CI: 0.14, 0.74). These findings suggest that individuals with an evening chronotype may experience metabolic disruptions, potentially due to circadian misalignment and irregular eating patterns, which could influence glucose regulation. In conclusion, late eating, and an evening chronotype are associated with unfavourable glycaemic outcomes. These findings highlight the importance of integrating circadian eating patterns and sleep-wake activities into clinical management of prediabetes