Cannabis Use, Insulin Sensitivity, Obesity, Type 2 Diabetes
Conditions
Keywords
Diabetes, Obesity, Cannabis, Insulin Sensitivity
Brief summary
This study tests the effects of cannabinoid levels in blood on inflammation and insulin sensitivity both acutely and chronically in individuals across the weight spectrum. To that end, the study employs two observational designs: 1) A study of acute effects with intermittent cannabis users and 2) A study in which current cannabis users will select one of three cannabis strains for four weeks and are compared to a matched control group who do not use cannabis to study chronic effects. Blood levels of THC and CBD, inflammatory biomarkers, and insulin resistance will be measured in both studies.
Detailed description
According to the National Institute of Diabetes and Digestive and Kidney Diseases, over 30 million people in the US have diabetes, and just over 84 million people have pre-diabetes. Concurrently, 30 states and the District of Columbia have legalized cannabis for medical and/or recreational use and over the past decade, cannabis use among adults has more than doubled. Public perception and some scientific data suggest that cannabis causes acute over-eating, creating concern that public and legal acceptance of cannabis use will worsen the obesity epidemic in the United States, where more than two-thirds of US adults (68.8%) are currently overweight or obese. Paradoxically, cross sectional data demonstrate associations between chronic cannabis use and lower body mass index (BMI), prevalence of obesity, insulin resistance, waist circumference, and actual rates of type 2 diabetes despite data supporting higher caloric intake acutely. This study examines the effects of cannabinoid levels in blood on inflammation and insulin sensitivity both acutely and chronically in individuals across the weight spectrum. To that end, the study employs two observational designs: 1) A study of acute effects with intermittent cannabis users and 2) A study in which current cannabis users will select one of three cannabis strains for four weeks and are compared to a matched control group who do not use cannabis to study chronic effects.
Interventions
OTHERStudy A: Single use of cannabis flower product
Participants are asked to purchase and use one of three cannabis flower strains with differing levels of THC and CBD: 1) CBD (\~14% CBD/0% THC), 2) THC (\~14% THC/0% CBD), or 3) THC+CBD (\~7% THC/7% CBD).
OTHERStudy B: Ad libitum cannabis use for four weeks or no cannabis use
Participants choose whether to use a cannabis flower product ad libitum for four weeks or to not use cannabis for four weeks. Participants who choose to use cannabis are asked to purchase and use one of three cannabis flower strains with differing levels of THC and CBD: 1) CBD (\~14% CBD/0% THC), 2) THC (\~14% THC/0% CBD), or 3) THC+CBD (\~7% THC/7% CBD).
Sponsors
University of Colorado, Boulder
University of Colorado, Denver
Study design
Observational model
OTHER
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
21 Years to 40 Years
Inclusion criteria
* Able to provide informed consent * Cannabis users in Study A must have smoked or vaped cannabis at least once since January 1st 2014 with no negative effects but NOT used in the past three months * Cannabis users in Study B must have been a regular (at least weekly) user for at least a year * Non-users in Study B cannot have used any cannabis in the previous year * Weight stable (\<5 pound fluctuation in the past six months) * Planning to remain in the Boulder-Denver area for the next month * Fasting blood glucose greater than or equal to 55 mg/dl and less than or equal to 126 mg/dl * Cannabis users in Study A must endorse knowledge of the procedure(s) for smoking or vaping cannabis
Exclusion criteria
* Known auto-immune disease * Report of other drug use (cocaine, opiates, methamphetamine) in the past 90 days or fail urine screen for any of these drugs * Daily tobacco (cigarette, E-cigs, smokeless) user, given the impact of tobacco smoking on insulin function * Blood alcohol level greater than 0 at screening * Current use of medications for glucose lowering, immunosuppression, or anti-inflammation * Acute illness * Current use of psychotropic medications * Current diagnosis of diabetes * Heavy drinking as defined by an Alcohol Use Disorders Test (AUDIT) * Females can not be pregnant or trying to become pregnant * Females can not be nursing mothers * Have donated blood in the 8 weeks before the study or intend to donate blood in the 8 weeks after the study.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Markers of Inflammation | Study A: Difference between cytokines at baseline and cytokines one week later after acute use of cannabis product. Study B: Change from baseline to four weeks | Change in Circulating Levels of Cytokines (TNF-α, IL-6, IL-1β, IL-12, IFNG, and IL-4). Results are reported as a composite score of TNF-α, IL-6, IL-1β, IL-12, IFNG, and IL-4 |
| Change in Matsuda Index of Insulin Sensitivity | Study A: Baseline versus after acute use one week later of cannabis product. Study B: The two tests will be separated by four weeks | Calculation of Insulin Sensitivity using changes in fasting plasma glucose (FPG) and fasting plasma insulin (FPI). Measurements are collected on venous blood samples at 0, 30, 60, 90, and 120 minutes after ingestion of 75 grams oral glucose during oral glucose tolerance test (OGTT). Values across the timepoints were combined to create a Matsuda Index score as follows: 10000/sqrt ((FPG X FPI) X (Mean OGTT glucose concentration X Mean OGTT insulin concentration)). Higher scores mean higher sensitive to insulin and that your body more efficiently clears glucose from your bloodstream, thus higher scores are better. |
| Change in Plasma Glucose | Study A: Baseline versus one week later after acute use of cannabis product. Study B: The two tests will be separated by four weeks | Change in glucose over time after ingestion of 75 grams oral glucose measured during during oral glucose tolerance test (OGTT). Measurements are collected on venous blood samples at 0, 30, 60, 90, and 120 minutes and averaged across these timepoints for a mean score. |
| Change in Plasma Insulin | Study A: Baseline versus one week later after acute use of cannabis product. Study B: Baseline versus four weeks later | Change in insulin over time after ingestion of 75 grams oral glucose measured during OGTT. Measurements are collected on venous blood samples at 0, 30, 60, 90, and 120 minutes and averaged across these timepoints for a mean score. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Stanford Seven-Day Physical Activity Recall (PAR) | Study A: Baseline and one week following baseline Study B: Baseline and four weeks following baseline | Interviewer administered assessment of number of minutes of moderate to vigorous physical activity over the previous seven days. Scores are reported as total minutes in the last week summed across moderate, hard, and very hard activity levels. |
| Sleep Quality | Study A: Baseline only Study B: Baseline to four weeks following baseline | Pittsburgh Sleep Quality Index: Measurement of the quality and patterns of sleep from poor to good measuring seven domains (e.g., latency, duration, disturbances) over the last 2 weeks. Participants' scores are reported as a global score of the summed seven component scores together ranging from 0 to 21, where higher scores indicate worse sleep and a global score of 5 or above indicates poor sleep quality. |
| Marijuana Consumption Questionnaire | Study A: Baseline only. Study B: Baseline and four weeks following baseline | Times per day of cannabis flower use from 0 to 6. Includes all participants in Study A and only cannabis users in Study B. |
| Marijuana Dependence Scale | Study A: Baseline only. Study B: Baseline and four weeks following baseline | This is a self-report scale based on DSM-5 criteria to assess dependence and other problems related to the use of cannabis. Scores are reported as a sum across the 11 items with yes/no options, ranging from 0 to 11, with higher scores indicating more dependence symptoms. Includes all participants in Study A and only cannabis users in Study B. |
| Marijuana Withdrawal Checklist | Study A: Assessed at follow-up, one week following baseline. Study B: Assessed at follow-up, four weeks following baseline. | A 15-item scale used to collect information on withdrawal symptoms that participants may be experiencing due to the lack of use of marijuana. Options range from 0 (none) to 3 (severe) for each question and are summed to create a final score ranging from 0 to 45. Includes all participants in Study A and only cannabis users in Study B. |
| The Alcohol Use Disorder Identification Test (AUDIT) | Study A: Baseline only. Study B: Baseline and four weeks following baseline | Standardized assessment of the extent of alcohol use and problems related to alcohol use. Scores are summed and range from 0 to 40 with higher scores indicating more hazardous alcohol use. |
| Timeline Follow-Back of Substance Use | Study A: Baseline only. Study B: Baseline and four weeks following baseline | Calendar-based assessment of daily substance use for the 30 days prior to the baseline session for both studies. The average days of smoked cannabis use in the last 30 days are reported. |
| SF-12 Health Survey | Study A: Baseline only. Study B: Baseline and four weeks following baseline | The SF-12 Health Survey is a 12-item questionnaire used to assess general health and well-being and includes domains of physical functioning, role-physical, pain, general health, vitality, social functioning, role-emotional and mental health. Only the mental component was analyzed. Scores are calculated using a weighted algorithm with scores ranging from 0 to 100; scores greater than 50 meaning better than average health and scores worse than 50 meaning worse than average health. |
| Nutrition Data System for Research 24-Hour Dietary Recall | Study A: Baseline and one week following baseline Study B: Baseline and four weeks following baseline | Interviewer administered recall measure developed by the University of Minnesota Nutrition Coordinating Center (NCC), that facilitates the standardized collection of 24-hour dietary recall data. Healthy Eating Index (HEI) total scores are reported for each participant, which is a measure of healthy eating on a scale of 0 (poor eating) to 100 (very healthy eating). Scores above 80 indicate a good diet, and scores below 80 indicate a diet in need of improvement. |
| Stanford Leisure-Time Activity Categorical Item (L-Cat) | Study A: Baseline and one week following baseline Study B: Baseline and four weeks following baseline | Self-report measure of a single item comprising six descriptive categories ranging from inactive (1) to very active (6). |
Countries
United States
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Continuous | 29.7 Years STANDARD_DEVIATION 5.5 |
| Alcohol Use (Quantity x Frequency) | 16.90 Monthly total of avg drinks/drinking day STANDARD_DEVIATION 12.63 |
| Body Mass Index (BMI) | 23.71 kg/m2 STANDARD_DEVIATION 3 |
| Race (NIH/OMB) American Indian or Alaska Native | 1 Participants |
| Race (NIH/OMB) Asian | 4 Participants |
| Race (NIH/OMB) Black or African American | 3 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 10 Participants |
| Race (NIH/OMB) White | 203 Participants |
| Sex/Gender, Customized Sex Female | 16 Participants |
| Sex/Gender, Customized Sex Male | 13 Participants |
| Sex/Gender, Customized Sex Other | 1 Participants |
| Sleep Quality (Pittsburgh Sleep Quality Index Item 15) | 0.91 units on a scale STANDARD_DEVIATION 0.62 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk | EG004 affected / at risk | EG005 affected / at risk | EG006 affected / at risk |
|---|---|---|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 34 | 0 / 28 | 0 / 46 | 0 / 9 | 0 / 47 | 0 / 41 | 0 / 28 |
| other Total, other adverse events | 1 / 34 | 1 / 28 | 2 / 46 | 0 / 9 | 4 / 47 | 2 / 41 | 5 / 28 |
| serious Total, serious adverse events | 0 / 34 | 0 / 28 | 0 / 46 | 0 / 9 | 0 / 47 | 0 / 41 | 0 / 28 |
Outcome results
None listed