Diabetes Mellitus, Type 2, Glucose Intolerance, Prediabetic State
Conditions
Keywords
Circadian Rhythm
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.
Interventions
BEHAVIORALExposure 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.
BEHAVIORALExposure 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.
Sponsors
Maastricht University Medical Center
Maastricht University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Crossover Assignment
Eligibility
Sex/Gender
ALL
Age
40 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
* 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%.
Exclusion criteria
* 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).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Postprandial glucose (mg/dL) | Study Day 1-3 | Assessed with a continuous glucose monitor (CGM) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 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 |
| 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 |
| 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 |
| Energy expenditure | Study Day 1-3 | continuous measurement with whole room indirect calorimetry |
| 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 |
| Continuous interstitial glucose (mg/dL) | Study Day 1-3 | Assessed with continuous glucose monitor (CGM) |
Countries
Netherlands
Outcome results
None listed