Smoking marijuana increases risk of emphysema, study suggests

In a small retrospective case-control study, emphysema and airway inflammation were more common in marijuana smokers compared with tobacco-only smokers.

In a sex- and age-matched analysis, most marijuana smokers also smoked cigarettes, but had a significantly higher incidence of emphysema compared with cigarette-only smokers (93% vs. 67%, P.=0.009) and a higher incidence of paraseptal emphysema (57% vs. 24%, respectively; P.=0.09), reported by Luke Murtha, MD, and colleagues from Ottawa Hospital, Ontario, Canada.

Overall, emphysema was also slightly more common in marijuana smokers in the peer-to-peer analysis (75% vs. 67%), although the difference here was not significant. Radiology.

Marijuana smokers also had significantly higher rates of bronchial thickening (83% vs. 42%, P.<0.001), bronchiectasis (33% vs 6%, P.=0.006), mucoid impaction (67% vs 15%, P.<0.001) in concordant (shown here) and discordant analyses.

“It was surprising to find that more patients who smoked marijuana actually had emphysema than heavy smokers…and more patients had airway inflammation than smokers.” , Said MedPage Today.

She noted that because the larger group of tobacco-only smokers were older than both marijuana smokers and heavy smokers, it was estimated that they had more exposure to smoking and therefore more serious adverse events. Stated.

“There is public perception that marijuana is safe, and many people consider it safer than tobacco,” Revah said. “And this study raises concerns that it may not be true.”

and Editorial accompanying the studyJeffrey Galvin, M.D., Ph.D., of the University of Maryland School of Medicine, Baltimore, and Teri Franks, M.D., Ph.D., of the Joint Center for Pathology, Silver Spring, Md., said, “The presence of paraseptal emphysema, especially in young people, is associated with increased lung tone. We have informed our radiologists about possible use of marijuana and other inhaled drugs.”

Revah explained that she and her colleagues would like to learn how to identify marijuana smokers from CT images the way it is done for heavy cigarette smokers. “I was surprised at how little information was available,” she said. “And that’s probably because [marijuana] It was illegal in Canada, and still illegal in many places in the United States, and no one could ethically study it.

With this information, she added, it may be easier to identify symptoms associated with marijuana use as opposed to tobacco-only use. 2 Previous the study A potential association between marijuana and emphysema was investigated in lung imaging, but a strong association could not be established.

The current study also supports the known link between marijuana smoking and gynecomastia (increase of breast tissue in men), with 11% of marijuana smokers seen in 38% (P.=0.04), 16% of nonsmokers (P.= 0.039).

age-matched marijuana smokers (70%) and tobacco-only smokers (85%; P.=0.16).

“Patients in our … group are very heavy smokers, so we’re not comparing marijuana. [use] “But the question is, is it just marijuana, or is it a synergistic effect of marijuana and tobacco?”

She added that many questions remain about the effects of smoking marijuana and that she is currently working on a prospective study that will completely separate marijuana-only and tobacco-only users.

The authors hypothesized that higher rates of bronchial wall thickening and inflammation in marijuana users may be related to the use of cigarette filters. Long inhalation times and keeping the smoke in the mouth longer may also be linked to higher incidences of emphysema, but Revah said more research is needed. emphasized.

The study included 56 marijuana smokers (mean age 49 years, 34 men), 50 of whom also smoked cigarettes. The study also included 57 nonsmokers (mean age 49, 32 men).

Marijuana smokers who also smoked cigarettes had an average smoking history of 25 pack years, and cigarette-only smokers had an average smoking history of 40 pack years. Age- and sex-matched subgroups included 30 marijuana smokers, 33 tobacco-only smokers, and 23 controls.

Not surprisingly, marijuana smokers had higher emphysema rates compared to nonsmokers (75% vs. 5%, P.<0.001). The incidence of bronchial thickening, bronchiectasis, and mucous stones was also significantly higher in marijuana smokers compared with nonsmokers.

Limitations of the study included a small sample size and an inability to quantify marijuana use: only 28 of 56 marijuana smokers specified amounts, and users They often share joints, smoke in different ways, and use different strains of marijuana. There was a difference.