RESUMO
BACKGROUND: With increasing use of cannabis, we need to know if cannabis use and Body Mass Index (BMI) are associated. METHODS: The Coronary Artery Risk Development in Young Adults Study followed Black and White adults over 30 years with assessments every 2 to 5 years in four centers in the USA. We assessed self-reported current and computed cumulative cannabis exposure at every visit, and studied associations with BMI, adjusted for relevant covariables in mixed longitudinal models. We also applied marginal structural models (MSM) accounting for the probability of having stopped cannabis over the last 5 years. RESULTS: At the Year 30 visit, 1,912 (58 %) identified as women and 1,600 (48 %) as Black, mean age was 56 (SD 2) years. While 2,849 (85 %) had ever used cannabis, 479 (14 %) currently used cannabis. Overall, participants contributed to 35,882 individual visits over 30 years. In multivariable adjusted models, mean BMI was significantly lower in daily cannabis users (26.6 kg/m2, 95 %CI 26.3 to 27.0) than in participants without current use (27.7 kg/m2, 95 %CI 27.5 to 27.9, p < 0.001). Cumulative cannabis use was not associated with BMI. The MSM showed no change in BMI when stopping cannabis use over a 5-year period (ß=0.2 kg/m2 total, 95 %CI -0.2 to 0.6). CONCLUSIONS: Current cannabis use was associated with lower BMI, but cumulative cannabis use and cessation were not. This suggests that recreational cannabis use may not lead to clinically relevant changes in BMI and that the association between current cannabis use and lower BMI is likely due to residual confounding.
RESUMO
BACKGROUND: Electronic nicotine-delivery systems - also called e-cigarettes - are used by some tobacco smokers to assist with quitting. Evidence regarding the efficacy and safety of these systems is needed. METHODS: In this open-label, controlled trial, we randomly assigned adults who were smoking at least five tobacco cigarettes per day and who wanted to set a quit date to an intervention group, which received free e-cigarettes and e-liquids, standard-of-care smoking-cessation counseling, and optional (not free) nicotine-replacement therapy, or to a control group, which received standard counseling and a voucher, which they could use for any purpose, including nicotine-replacement therapy. The primary outcome was biochemically validated, continuous abstinence from smoking at 6 months. Secondary outcomes included participant-reported abstinence from tobacco and from any nicotine (including smoking, e-cigarettes, and nicotine-replacement therapy) at 6 months, respiratory symptoms, and serious adverse events. RESULTS: A total of 1246 participants underwent randomization; 622 participants were assigned to the intervention group, and 624 to the control group. The percentage of participants with validated continuous abstinence from tobacco smoking was 28.9% in the intervention group and 16.3% in the control group (relative risk, 1.77; 95% confidence interval, 1.43 to 2.20). The percentage of participants who abstained from smoking in the 7 days before the 6-month visit was 59.6% in the intervention group and 38.5% in the control group, but the percentage who abstained from any nicotine use was 20.1% in the intervention group and 33.7% in the control group. Serious adverse events occurred in 25 participants (4.0%) in the intervention group and in 31 (5.0%) in the control group; adverse events occurred in 272 participants (43.7%) and 229 participants (36.7%), respectively. CONCLUSIONS: The addition of e-cigarettes to standard smoking-cessation counseling resulted in greater abstinence from tobacco use among smokers than smoking-cessation counseling alone. (Funded by the Swiss National Science Foundation and others; ESTxENDS ClinicalTrials.gov number, NCT03589989.).