Metabolic Effects of Chronic Cannabis Smoking
- Ranganath Muniyappa, MD, PHD1,
- Sara Sable, BS1,
- Ronald Ouwerkerk, PHD2,
- Andrea Mari, PHD3,
- Ahmed M. Gharib, MD2,
- Mary Walter, PHD4,
- Amber Courville, PHD, RD5,
- Gail Hall, RN1,
- Kong Y. Chen, PHD1,
- Nora D. Volkow, MD6,
- George Kunos, MD, PHD7,
- Marilyn A. Huestis, PHD8 and
- Monica C. Skarulis, MD1⇑
- 1Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland
- 2Biomedical and Metabolic Imaging Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland
- 3Institute of Biomedical Engineering, National Research Council, Padova, Italy
- 4Clinical Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland
- 5Clinical Center, National Institutes of Health, Bethesda, Maryland
- 6Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland
- 7Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
- 8Intramural Program, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
- Corresponding author: Monica C. Skarulis, .
OBJECTIVE We examined if chronic cannabis smoking is associated with hepatic steatosis, insulin resistance, reduced β-cell function, or dyslipidemia in healthy individuals.
RESEARCH DESIGN AND METHODS In a cross-sectional, case-control study, we studied cannabis smokers (n = 30; women, 12; men, 18; 27 ± 8 years) and control subjects (n = 30) matched for age, sex, ethnicity, and BMI (27 ± 6). Abdominal fat depots and intrahepatic fat content were quantified by magnetic resonance imaging and proton magnetic resonance spectroscopy, respectively. Insulin-sensitivity indices and various aspects of β-cell function were derived from oral glucose tolerance tests (OGTT).
RESULTS Self-reported cannabis use was: 9.5 (2–38) years; joints/day: 6 (3–30) [median (range)]. Carbohydrate intake and percent calories from carbohydrates, but not total energy intake, were significantly higher in cannabis smokers. There were no group differences in percent total body fat, or hepatic fat, but cannabis smokers had a higher percent abdominal visceral fat (18 ± 9 vs. 12 ± 5%; P = 0.004). Cannabis smokers had lower plasma HDL cholesterol (49 ± 14 vs. 55 ± 13 mg/dL; P = 0.02), but fasting levels of glucose, insulin, total cholesterol, LDL cholesterol, triglycerides, or free fatty acids (FFA) were not different. Adipocyte insulin resistance index and percent FFA suppression during an OGTT was lower (P < 0.05) in cannabis smokers. However, oral glucose insulin sensitivity index, measures of β-cell function, or incretin concentrations did not differ between the groups.
CONCLUSIONS Chronic cannabis smoking was associated with visceral adiposity and adipose tissue insulin resistance but not with hepatic steatosis, insulin insensitivity, impaired pancreatic β-cell function, or glucose intolerance.
- Received November 6, 2012.
- Accepted February 5, 2013.
- © 2013 by the American Diabetes Association.
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