In 2013, The Impact of Marijuana Use on Glucose, Insulin, and Insulin Resistance among US Adults.

BACKGROUND: We included 4657 adult men and women from the National Health and Nutrition Examination
Survey from 2005 to 2010. Marijuana use was assessed by self-report in a private room. Fasting insulin and
glucose were measured via blood samples after a 9-hour fast, and homeostasis model assessment of insulin
resistance (HOMA-IR) was calculated to evaluate insulin resistance

You can read the full article here => http://www.amjmed.com/article/S0002-9343(13)00200-3/pdf