Cannabis use does not impact on type 2 diabetes: A two‐sample Mendelian randomization study

• Published in: Addiction biology Vol. 26; no. 6; pp. e13020 - n/a
• Main Authors: Baumeister, Sebastian‐Edgar, Nolde, Michael, Alayash, Zoheir, Leitzmann, Michael, Baurecht, Hansjörg, Meisinger, Christa
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01-11-2021
• Subjects: Cannabis; Databases, Genetic; Diabetes; Diabetes mellitus (non-insulin dependent); Diabetes Mellitus, Type 2 - epidemiology; Diabetes Mellitus, Type 2 - genetics; Genome-wide association studies; Genomes; Glucose metabolism; Humans; Insulin; Marijuana; Marijuana Abuse - epidemiology; Marijuana Abuse - genetics; Mendelian Randomization Analysis; Odds Ratio; Pleiotropy; Polymorphism, Single Nucleotide; Risk Factors; Sensitivity analysis; Single-nucleotide polymorphism; cannabis; diabetes
• ISSN: 1355-6215; 1369-1600
• DOI: 10.1111/adb.13020

Cannabis has effects on the insulin/glucose metabolism. As the use of cannabis and the prevalence of type 2 diabetes increase worldwide, it is important to examine the effect of cannabis on the risk of diabetes. We conducted a Mendelian randomization (MR) study by using 19 single‐nucleotide polymorphisms (SNPs) as instrumental variables for lifetime cannabis use and 14 SNPs to instrument cannabis use disorder and linking these to type 2 diabetes risk using genome‐wide association study data (lifetime cannabis use [N = 184,765]; cannabis use disorder [2387 cases/48,985 controls], type 2 diabetes [74,124 cases/824,006 controls]). The MR analysis suggested no effect of lifetime cannabis use (inverse‐variance weighted odds ratio [95% confidence interval] = 1.00 [0.93–1.09], P value = 0.935) and cannabis use disorder (OR = 1.03 [0.99–1.08]) on type 2 diabetes. Sensitivity analysis to assess potential pleiotropy led to no substantive change in the estimates. This study adds to the evidence base that cannabis use does not play a causal role in type 2 diabetes.
The causal relevance of cannabis use as a risk factor for diabetes is unclear based on traditional observational studies. By considering the relationships between genetically predicted values of lifetime cannabis use and cannabis use disorder and type 2 diabetes within a two‐sample instrumental variable framework that is less influenced by environmental confounding, we found that cannabis use does not affect diabetes.