Type 2 diabetes mellitus (T2DM), marked by insulin resistance and impaired blood glucose regulation, can lead to serious complications when poorly controlled. Recent studies highlight interactions between diet, sleep, and metabolic disorders, showing that elevated nighttime glucose levels are associated with a higher risk of cardiometabolic disorders. Time-restricted eating (TRE) is a lifestyle strategy that aligns dietary intake with the circadian system with a consistent 8- to 10-hour eating window during the day. TRE is a safe and effective lifestyle intervention that improves cardiovascular health and glycemic control, and may provide additional benefits beyond stable use of a glucagon-like peptide-1 receptor agonist (GLP-1RA). The three patients presented here participated in a clinical trial for adults with T2DM in which they were instructed to follow a consistent 8 to 10-hour TRE intervention for 3 months (NCT05365529). Assessments, including fasted blood draws, 10-day continuous glucose monitor (CGM) use, and 14-day actigraphy to measure sleep-wake cycles, were conducted at baseline and 3 months. At baseline, all 3 patients were on stable GLP-1RA and exhibited high mean glucose levels (>130mg/dL) during their nightly sleep. Following the 3-month TRE intervention, all 3 patients experienced reductions in hemoglobin A1c (HbA1c) and nighttime glucose, along with improved time in range (TIR) during sleep. This case series highlights the potential benefits of TRE, alongside GLP-1RA use, on nighttime glucose levels, while also underscoring the potential of CGM to identify glycemic phenotypes that may predict specific responses to TRE, demonstrating the importance of a personalized approach.
