Data were reviewed from 69 studies of 2,152 cannabis users (mean age, 20.6 years) and 6,575 comparison participants (mean age, 20.8 years) with minimal cannabis exposure.
The researchers found that, compared with never smoking, current smoking was associated with higher mean left ventricular (LV) mass index and lower mean LV circumferential strain after adjustment for confounding factors
Compared with men in the top income group, men in the bottom income group (poorest 20% of the population) would gain 6.7 times more life years (155 versus 23 million). For each smoker in the bottom income group, the average life years gained from cessation was 5.1 times that of the top group (1.46 versus 0.23 years).
The researchers found that delta-9-tetrahydrocannabinol was detected at low concentrations at all the time points beyond time 0, but no metabolites were detected at any time point.
The researchers found that receptivity to any advertising was high at wave 1 for those aged 12 to 14 years (44%) and highest for those aged 18 to 21 years (68.7%).
From 2005 to 2017, the subset of marijuana searches on Google indicative of shopping increased 199%: During June 2017 there were 1.4 to 2.4 million marijuana shopping searches.
The more chemicals in an e-liquid, the more toxic it was likely to be; in addition, vanillin was associated with elevated toxicity values. There was a correlation for the concentration of cinnamaldehyde and vanillin, but not triacetin, with toxicity.
In a study of hospitalized smokers who planned to quit smoking post-discharge, users of e-cigarettes were not as likely as nonusers to refrain from using tobacco at 6 months.
"This study has shown that the iQOS system may not be as harm-free as claimed and also emphasizes the urgent need for further safety testing as the popularity and user base of this product is growing rapidly," the authors write.
Serum cotinine level was not significantly associated with airflow obstruction in the multivariate analysis with both exposures included as covariates (adjusted odds ratio, 1.07; 95% confidence interval, 0.94 to 1.21); there was no correlation in children with asthma or those without asthma.
The researchers found that before the ban, 59.7% of menthol smokers said that they would switch to or only use nonmenthol cigarettes; at follow-up, only 28.2% had done so.
The researchers found that, compared with e-cigarette-only users, dual users had significantly higher urine excretion of metabolites of benzene, ethylene oxide, acrylonitrile, acrolein, and acrylamide (all P<0.05).
The researchers found that 7.2% of women who gave birth in 2016 smoked cigarettes during pregnancy. The prevalence of smoking was highest for women aged 20 to 24 years, followed by those aged 15 to 19 and 25 to 29 years.
The researchers found that none of the 11 studies included in the meta-analysis found significant estimates of pre-post MML changes in marijuana use prevalence among adolescents compared with changes in non-MML states over the same time period.
The researchers found that median metal concentrations were higher in samples from the aerosol and tank, compared to the dispenser (all P<0:001), for aluminum, chromium, nickel, lead, and zinc.
For current non-daily cigarette smokers, there were statistically significant associations with death from lung cancer, oral cancer, circulatory death, cardiovascular death, cerebrovascular death (stroke), and chronic obstructive pulmonary disease.
Perceived harm from secondhand e-cigarette vapor showed similar patterns. Adolescents who use e-cigarettes are more likely to initiate using tobacco products than those who do not use e-cigarettes.
"These results indicate that nicotine nitrosation occurs in vivo in mice and that e-cigarette smoke is carcinogenic to the murine lung and bladder and harmful to the murine heart," the authors write.
For both smokers and nonsmokers, the onset time estimates for mild conditions were associated with self-perceptions of risk and fear level of developing smoking-related conditions.
The researchers found that the pooled relative risk for coronary heart disease was 1.48 and 2.04, respectively, for smoking 1 and 20 cigarettes per day for men.
The researchers found that the prevalence of current cigarette smoking was 15.5% among adults in 2016, which marked a significant decline from 20.9% in 2005.
Never-cigarette-smoking youths who initiated tobacco use with noncigarette products including e-cigarettes, hookahs, noncigarette combustible tobacco, or smokeless tobacco were more likely to smoke cigarettes in the following year than those who did not use noncigarette tobacco.