Obesity
Conditions
Brief summary
This study examines the relationship between sleep timing and insulin resistance in adolescents with obesity. The investigators also aim to develop a physiologically-based mathematical model of adolescent sleep/wake and circadian interactions.
Interventions
None listed
Sponsors
University of Colorado, Denver
Study design
Observational model
CASE_ONLY
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
15 Years to 19 Years
Healthy volunteers
Yes
Inclusion criteria
* High school students between the ages of 15-19 * BMI \> 90th percentile * Tanner stage 2 or greater
Exclusion criteria
* Any medications that affect insulin resistance or sleep (e.g., metformin, hormonal contraception, stimulants, atypical antipsychotics) * Regular use of melatonin or sleep aids * A prior diagnosis of obstructive sleep apnea, diabetes (HbA1c \> 6.5), liver disease other than non-alcoholic fatty liver disease, pregnancy or breastfeeding * IQ \< 70 or severe mental illness that may impact sleep (e.g., schizophrenia, psychotic episodes) * Not enrolled in a traditional high school academic program (e.g., home school students) * Night shift employment * Travel across more than 2 time zones in the month prior to the study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Insulin Sensitivity | 3 hours | After an overnight fast, participants completed an oral glucose tolerance test (OGTT) in the morning. Participants consumed a 75g dextrose drink and serum for glucose and insulin concentrations were collected at baseline and every 30 minutes for 3 hours. The homeostatic model assessment for insulin resistance (HOMA-IR) was calculated as \[fasting insulin (μU/ml) x fasting glucose (mmol/l)\] / 22.5); lower HOMA-IR indicates better insulin sensitivity. The Matsuda Index was calculated as √10,000 / \[\[fasting insulin (μU/ml) x fasting glucose (mmol/l)\] x \[mean OSTT insulin (μU/ml) x mean OSTT glucose (mmol/l)\]\]; high Matsuda Index indicates better insulin sensitivity. |
| Dim Light Melatonin Onset and Offset | 1 day | \ 1mL saliva was collected at 30- to 60- minute intervals in dim light (\<5 lux in the angle of gaze, approximately the light level of candlelight or civil twilight) from approximately 5pm until noon the next day. Dim light melatonin onset (DLMOn) was defined as the linear interpolated clock time at which evening salivary melatonin concentrations increased and remained above a threshold of 3pg/mL. Melatonin offset (DLMOff) was the linear interpolated clock time at which salivary melatonin concentrations fell below this threshold. Later DLMOn and DLMOff are indicative of a later circadian rhythm. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Observation Home and in-lab observation | 25 |
| Total | 25 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Withdrawal by Subject | 3 |
Baseline characteristics
| Characteristic | Observation |
|---|---|
| Age, Continuous | 16.48 years STANDARD_DEVIATION 1.09 |
| BMI | 97.04 percentile STANDARD_DEVIATION 2.39 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 18 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 7 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 6 Participants |
| Race (NIH/OMB) More than one race | 6 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 1 Participants |
| Race (NIH/OMB) White | 12 Participants |
| Region of Enrollment United States | 25 participants |
| Sex: Female, Male Female | 15 Participants |
| Sex: Female, Male Male | 10 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 25 |
| other Total, other adverse events | 0 / 25 |
| serious Total, serious adverse events | 0 / 25 |
Outcome results
Primary
Dim Light Melatonin Onset and Offset
\ 1mL saliva was collected at 30- to 60- minute intervals in dim light (\<5 lux in the angle of gaze, approximately the light level of candlelight or civil twilight) from approximately 5pm until noon the next day. Dim light melatonin onset (DLMOn) was defined as the linear interpolated clock time at which evening salivary melatonin concentrations increased and remained above a threshold of 3pg/mL. Melatonin offset (DLMOff) was the linear interpolated clock time at which salivary melatonin concentrations fell below this threshold. Later DLMOn and DLMOff are indicative of a later circadian rhythm.
Time frame: 1 day
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Observation | Dim Light Melatonin Onset and Offset | Dim Light Melatonin Onset | 21.33 decimal hours | Standard Deviation 1.47 |
| Observation | Dim Light Melatonin Onset and Offset | Dim Light Melatonin Offset | 8.32 decimal hours | Standard Deviation 1.09 |
Primary
Insulin Sensitivity
After an overnight fast, participants completed an oral glucose tolerance test (OGTT) in the morning. Participants consumed a 75g dextrose drink and serum for glucose and insulin concentrations were collected at baseline and every 30 minutes for 3 hours. The homeostatic model assessment for insulin resistance (HOMA-IR) was calculated as \[fasting insulin (μU/ml) x fasting glucose (mmol/l)\] / 22.5); lower HOMA-IR indicates better insulin sensitivity. The Matsuda Index was calculated as √10,000 / \[\[fasting insulin (μU/ml) x fasting glucose (mmol/l)\] x \[mean OSTT insulin (μU/ml) x mean OSTT glucose (mmol/l)\]\]; high Matsuda Index indicates better insulin sensitivity.
Time frame: 3 hours
Population: 1 participant with missing data
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Observation | Insulin Sensitivity | Homeostatic Model Assessment (HOMA-IR) | 2.9 units on a scale | Standard Deviation 2.01 |
| Observation | Insulin Sensitivity | Matsuda Index | 4.93 units on a scale | Standard Deviation 2.75 |