Current and former marijuana users are more likely to have prediabetes than those who have never used marijuana, a study published in Diabetologia has found. The study, however, has not determined a direct link between marijuana use and type 2 diabetes.

Prior studies have suggested marijuana use can lower the risk of diabetes, while some have shown an association with increased calorie consumption. Researchers conducted a study to assess the link between self-reported use of marijuana and concurrent and incident prediabetes and full blown type 2 diabetes, taking into account both quantity and status of current use. The roles of body mass index (BMI), waist circumference, sex, and race were also examined.

Study authors used data from the Coronary Artery Risk Development in Young Adults (CARDIA) study to determine marijuana use and prediabetes and diabetes at exam Year 25 in 3,034 study patients (currently on Year 30 of observation). Also, incidence of prediabetes and diabetes according to previous marijuana use was established in 3,151 individuals free from prediabetes and diabetes at Year 7 who returned for at least one of four ubsequent follow-up exams over the next 18 years.

Compared to individuals who never used marijuana, there was a 65% increased chance of currently having prediabetes in individuals who reported current use of marijuana, and a 49% increased chance in those who reported lifetime use of ≥100 times. Researchers did not find an association between marijuana use and full blown type 2 diabetes at CARDIA exam Year 25. They noted it was not possible to account for changes in marijuana use due to the users’ health status concerns.