Number of Cigarettes Smoked per Day Influences Stroke Risk in Young Men

A study of young men suggests that the number of cigarettes they smoke influences their risk of having a stroke. For the heaviest smokers—those puffing away on at least two packs a day—the risk of ischemic stroke was more than five times higher than that of someone who had never smoked.

“The clinical implications of our finding are that while complete cessation of smoking is the goal, even reducing the number of cigarettes smoked may have beneficial health effects,” write researchers led by Janina Markidan (University of Maryland School of Medicine, Baltimore).

The investigators say their findings of a dose-response relationship between the amount smoked and stroke risk is consistent with what has been seen in young women and in middle age and older adults, although it is less strong in the latter two groups than in younger people.

“The simple takeaway is ‘the more you smoke, the more you stroke,’” Markidan said in an email.

Andrew Russman, DO (Cleveland Clinic, Ohio), who commented on the study for TCTMD, said it “fills in some gaps” regarding the contribution of smoking to stroke in young people. While previous studies of young women have shown smoking to be a significant risk factor, he noted, extrapolating that to young men is complicated by additional risk factors for stroke that women have but men do not, such as use of oral contraception.

However, Russman said he disagrees with the conclusion reached by the investigators.

“I have to disagree with the idea that we should encourage people to just cut down on their smoking,” he said in an interview. One reason, Russman added, is that there is no evidence to support the idea that people who cut back on cigarettes but do not quit continue a long-term pattern of smoking less. Secondly, he said the study did not look at cutting back as a means of impacting risk.

“[This study] made an observation in the population that people who smoke less have lower risk than people who smoke more. That’s a different thing than saying if you just reduce your smoking, you’ll reduce your risk of having a stroke,” he observed.

“Of course, in an ideal world, people would never start smoking in the first place, and if they did start, they’d quit right away,” Markidan said. “However, if a patient isn’t ready or willing to quit today, they can still get benefits from just smoking less until they’re ready to drop cigarettes entirely.”

The study was published online April 19, 2018, in Stroke.

Risk Elevated With Smoking Volume

The researchers examined data from the Stroke Prevention in Young Men Study on 615 individuals under age 50 who had had a stroke in the previous 3 years, and 530 healthy men of the same age range. Study participants were classified as never smokers, former smokers, and current smokers. Current smokers were further divided into groups based on the number of cigarettes smoked daily: 1-10, 11-20, 21-39, or ≥ 40. Former smokers were those who had smoked > 100 cigarettes in their lifetime, but had not smoked in the previous 30 days. The method used for classifying smokers was similar to the one used in the Stroke Prevention in Young Women Study.

As a group, current smokers were much more likely to have had a stroke than men who had never smoked (OR 1.88; 95% CI 1.44-2.44). The number of cigarettes that people smoked per day affected that risk, ranging from OR 1.46 (95% CI 1.04-2.06) for those who smoked < 11 cigarettes per day to OR 5.66 (95% CI 2.14-14.95) for those in the two-pack-a-day or more group who smoked > 40 cigarettes per day.

The increased risk of stroke was not confined to current smokers, however. Among former smokers, the risk of ischemic stroke was lower than in the current-smoking group, but still significantly higher compared with never smokers (OR 1.42; 95% CI 1.01-1.99).

Young and Out of Touch

Russman said the study confirms the need for new or different approaches to educating young men about how smoking can affect them in the long term, stressing that damage caused by smoking cannot be undone. But the sense of “immortality” that often comes with youth can be a substantial barrier to this type of education, he noted.

If you ask women what stroke risk factors are, they do a better job telling you than men. Andrew Russman

“There’s really good evidence that men, especially young men, are less aware of their health or less likely to communicate issues about their health,” Russman said. “Women are much more in touch with their overall health, and they communicate much better about health concerns. If you ask women what stroke risk factors are, they do a better job telling you than men.” Making changes to health messages directed at young men should be a priority given that “what we’re doing now [obviously] hasn’t been very effective at changing this behavior because rates of stroke in younger people aren’t going down,” he added.

To TCTMD, Markidan said the findings may offer hope for quitters, since former smokers had a stroke risk that was closer to never smokers than to current smokers.