A letter was recently published in JAMA Internal Medicine (Association Between Cannabis Use and Risk for Diabetic Ketoacidosis in Adults With Type 1 Diabetes), stating that the risk of hospitalization for DKA (diabetic ketoacidosis) was higher in people with type 1 diabetes who used marijuana than in people with T1D who were non-users.
The reseachers, who work in Colorado where marijuana is legal for both medical and recreational use, asked 450 adults with type 1 diabetes (mean age, 35; mean duration of diabetes, 19 years) about marijuana use and hospitalization for DKA in the previous year; 30% of these patients were marijuana users, half used the substance at least twice weekly, and half had used for longer than 3 years. About 40% were considered to have possibly hazardous levels of use or associated disorders. (There's no mention whether urinary or other screening tests for THC or other metabolites were performed to confirm use or non-use.)
Based on patients' self-reports, marijuana use was associated with greater likelihood of hospitalization for DKA than was nonuse. Over 20% of these patients with type 1 diabetes who used marijuana — either recreationally or for medical purposes — were hospitalized for diabetic ketoacidosis within the previous year compared with only 8.2% of nonusers.
But the users were distinctly different from the non-users in several important ways. Users had higher A1C levels (mean 8.4%) than non-users (mean 7.6%) (P<0.01). Even after adjustment for the method of insulin delivery, age, and income level, people who reported marijuana use still had higher HbA1c levels. And users of marijuana included in the study tended to be younger with a shorter duration of diabetes, along with lower education and income levels, Additionally, use of diabetes technology also tended to be lower among patients who used marijuana. This included lower rates of continuous glucose monitoring (45.5% vs 55.1%), as well as lower rates of using an insulin pump (50.7% vs 66.5%) compared with nonusers, which also may have influenced the findings.
So, the question remains: is the use of marijuana a risk factor for developing DKA? It's unclear based on this survey, but the findings are sufficiently intriguing to encourage further research to clarify if there's a relationship. A larger, multi-center, prospective study should be undertaken to confirm the present findings and evaluate what the mechanism might be. And, since marijuana is now completely legal in Canada, perhaps Canadian research centers would be appropriate to participate.