This study, published in the Journal of Sleep Research, investigates the effects of sleep duration manipulation on serum brain-derived neurotrophic factor (BDNF) levels in adolescents at risk for type 2 diabetes (T2D). Conducted by Dutil et al., the research utilized a randomized crossover design involving 36 adolescent participants, with a mean age of 15.1 years, who were classified as severely obese (greater than the 99th BMI percentile).
The study aimed to experimentally manipulate sleep duration by increasing and decreasing time in bed by 1.5 hours per night over two separate weeks, with a one-week washout period of habitual sleep in between. The baseline sleep duration was determined from a week of habitual sleep data collected through actigraphy.
Results indicated that participants successfully adjusted their sleep duration, increasing it by an average of 1 hour and 2 minutes per night and decreasing it by 1 hour and 19 minutes per night. Notably, increasing sleep duration led to a significant decrease in serum BDNF levels by approximately 14% compared to both the habitual and decreased sleep conditions. However, no significant differences were found between the habitual and decreased sleep weeks.
This finding suggests that sleep duration has a measurable impact on serum BDNF levels in this specific population. The authors propose that the lower BDNF levels observed following sleep extension may be associated with reduced physiological stress or compensatory neurotrophic signaling, although the exact mechanisms remain to be elucidated. Conversely, the higher BDNF levels recorded during habitual and restricted sleep may indicate adaptive responses to insufficient sleep rather than improvements in metabolic function.
What this study does not show
This study does not establish a direct causal relationship between changes in sleep duration and metabolic health outcomes in adolescents at risk for type 2 diabetes.
Evidence scorecard
- Analytic validity: established
- Clinical validity: established
- Clinical utility: partial
The evidence is based on a randomized controlled trial involving human participants.