The Effects of Light on Glucose Metabolism
- Conditions
- Diabetes Mellitus, Type 2Glucose IntolerancePrediabetic State
- Interventions
- Behavioral: Exposure to bright light during the dayBehavioral: Exposure to dim light during the day
- Registration Number
- NCT03829982
- Lead Sponsor
- Maastricht University
- Brief Summary
This study evaluates the effect of bright light on postprandial blood glucose metabolism in obese subjects with impaired fasting glucose and/or impaired glucose tolerance.
- Detailed Description
Light has a major influence on the biological clock and several studies suggest that bright light during the day and dim light in the evening are beneficial for the circadian timing system. Nowadays, large parts of the population spend 90% of their time indoors and are thereby exposed to artificial lighting instead of daylight. The artificial light levels are relatively low during the day and continue relatively late in the evening. The lack of a clear natural light-dark cycle could results in delayed timing of the biological clock relative to the behaviour. Optimizing the lighting conditions under controlled laboratory settings might lead to better alignment of the biological clock, which in turn could improve metabolic parameters such as glucose control.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 14
-
Caucasian
-
BMI 25-35 kg/m2
-
Stable weight (+/- 3 kg in the last 3 months)
-
One of the four criteria for prediabetes:
- Impaired fasting glucose (6.1 mM to 6.9 mM)
- Blood glucose values 7.8 - 11.1 mM 2h after glucose drink consumption during the oral glucose tolerance test (OGTT) in screening
- Insulin Resistance: glucose clearance rate ≤ 360 ml/kg/min, as determined using the oral glucose insulin sensitivity (OGIS120) index
- HbA1c of 5.7 - 6.4%.
- Fasting plasma glucose ≥7.0 mM
- Blood donation one month prior to study and three months after finishing study.
- Participants with extreme chronotypes (going to bed extremely late/early).
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description bright light during the day Exposure to bright light during the day Participants will be exposed to bright light (1250 lux) between 8:00 and 18:00 and to dim light (5 lux) between 18:00 and 23:00. dim light during the day Exposure to dim light during the day Participants will be exposed to dim light (10 lux) between 8:00 and 18:00 and to dim light (1250 lux) between 18:00 and 23:00.
- Primary Outcome Measures
Name Time Method Postprandial glucose (mg/dL) Study Day 1-3 Assessed with a continuous glucose monitor (CGM)
- Secondary Outcome Measures
Name Time Method Glucose levels (mmol/L) in the postprandial state Study Day 2-3 venous blood draw every 30 min for 4 hours after breakfast and after dinner
Insulin levels (µU/mL) in the postprandial state Study Day 2-3 venous blood draw every 30 min for 4 hours after breakfast and after dinner
Energy expenditure Study Day 1-3 continuous measurement with whole room indirect calorimetry
Continuous interstitial glucose (mg/dL) Study Day 1-3 Assessed with continuous glucose monitor (CGM)
Free fatty acid levels (µmol/L) in the postprandial state Study Day 2-3 venous blood draw every 30 min for 4 hours after breakfast and after dinner
Triglycerides levels (mmol/L) in the postprandial state Study Day 2-3 venous blood draw every 30 min for 4 hours after breakfast and after dinner
Core body temperature (CBT) and skin temperature Study Day 1-3 Measured with a telemetric pill (CBT) and 14 temperature sensors (iButtons) in degrees celsius
Trial Locations
- Locations (1)
Maastricht University
🇳🇱Maastricht, Limburg, Netherlands