Blue Light Exposure During Sleep in Type 1 Diabetes: Impacts on Glycemic Control and Psychosocial Health.

Light exposure at night is linked to increased risk for obesity and insulin resistance in the general population. While sleep health is recognized as a key component of diabetes management, there has been less emphasis on nighttime light exposure. This study aimed to investigate the effects of blue and white light exposure immediately prior to (1 h) and during sleep (LEDS) on glycemic control and psychosocial wellbeing in adults with type 1 diabetes (T1D). Using baseline data from a randomized controlled trial testing a sleep intervention (NCT04506151), we analysed the following data from 170 adults with T1D: light exposure pattern and sleep from one week of wrist-worn actigraphy, glucose levels from one week of continuous glucose monitoring (CGM), and A1C and self-reported psychosocial measures. Generalized linear models, adjusting for covariates, were employed to examine the relationship between log-transformed light variables and glycemic/psychosocial outcomes. The results revealed that greater blue LEDS was significantly associated with higher glucose levels from CGM including less % time spent in glucose range 70-180 mg/dL (B = -7.30; p = 0.022) and greater % time spent above glucose range 180 mg/dL (B = 6.95; p = 0.041), along with greater depressive (B = 4.41; p = 0.016) and anxiety symptoms (B = 2.25; p = 0.008), and worse diabetes quality of life (B = -5.81; p = 0.031). Light exposure one hour prior to sleep was related to increased fatigue. In conclusion, increased blue LEDS is linked to hyperglycemia and worse psychosocial outcomes in T1D. Thus, blue LEDS warrants further investigation as a modifiable risk factor. Trial Registration: NCT04506151, www.clinicaltrial.gov.