吸烟者点燃香烟即增加风险

The health risks of cigarette smoking are well known, such as cancer, emphysema and cardiovascular disease. But new research shows that when you smoke can make it even more risky.

Tobacco remains the leading cause of preventable death, according to the World Health Organization. It estimates six million people die every year from smoking-related illnesses, most in low and middle income countries.

A new study looks at smokers, who light-up right after waking up each morning. Penn State University researchers say those smokers are more likely to develop lung or oral cancer.

Steven Branstetter, an assistant professor of biobehavioral health, “For a lot of years, one of the ways people had been assessing nicotine dependence was through a measure called the Fagerstrom Test of Nicotine Dependence. It was about eight to ten items and one of those items was how soon after waking you smoke your first cigarette -- one of the very best indicators of dependence. Even more so interestingly than the actual number of cigarettes somebody smokes per day.”

He and his colleague, Professor Joshua Muscat, think they know why.

“What we theorize is happening is that it’s really an indicator of how people go about smoking their cigarettes. And what I mean by that is people who are smoking first thing in the morning inhale deeper. They probably have more puffs per cigarette. So, it’s really an indicator of how people go about smoking, probably moreso than anything else that we’re looking at,” he said.

Inhaling more deeply, holding smoke within the lungs longer and taking more puffs, greatly increases exposure to all toxins.

“But most importantly,” said Branstetter, “what we found is they’re getting exposure to a nicotine-specific nitrosamine or carcinogen.

That’s something that can cause cancer. Branstetter says the carcinogen in question is called NNK. As the body metabolizes it a substance called NNAL is produced. That’s found in high-levels in people who smoke immediately after waking up.

“Having a reasonably high presence of it increases the risk. How much? We’re not sure yet. [Are] there things that people do that modify that risk? We’re not sure about that yet either. We’re still relatively early in that phase of our research. But we do know that when we find it there in the urine it does indicate some increased risk of lung cancer,” he said.

The study’s findings are based on data from nearly 2000 adult smokers. More than 30 percent said they smoked their first cigarette within five minutes of waking. Nearly the same amount said they took their first puff within 6 to 30 minutes of waking up.

Branstetter said, “Some people have asked should I just smoke later in the day. Would that help it? And the answer is I don’t think it’s going to help anything right now. People are never really aware of how dependent they themselves are. The recommendation might be if you’re a smoker, notice how soon after you wake up that you smoke your first cigarette. That is going to be a pretty good indicator of your level of not only potential, later on risk for lung cancer, but it’s a pretty good indicator of how dependent on nicotine you actually are.”

The Penn State University researchers say the next step is to give smokers devices that scientifically measure how deeply they inhale when they smoke throughout the day.

The findings appear in the March 29th issue of the journal Cancer, Epidemiology, Biomarkers and Prevention.