Smokers in Milwaukee and Madison who quit gained about 10 pounds over a year but had a beneficial increase in their HDL cholesterol that likely reduced their risk of having a heart attack or stroke, according to a University of Wisconsin School of Medicine and Public Health study. The research, released Sunday, was one of several new studies on smoking Hilton presented here, including one that found that the number of adult smokers in the Minneapolis-St. Paul area declined by more than half over the last 30 years.
It has been known for decades that smoking lowered HDL cholesterol, but much of that research was done in the 1980s when American smokers were thinner. It also was known that gaining weight lowered HDL.
What was not known is what would happen when the overweight smokers of today quit and gained weight.
The answer: Their HDL still went up by an average of 2.4 points. LDL cholesterol (the bad kind), which normally goes up with weight gain, remained unchanged.
For women, an HDL level of less than 50 is considered a risk factor for heart disease. For men, the number is less than 40.
While the HDL change is not a huge improvement, it is enough to lower the risk of a heart attack or stroke by up to 6%, said Adam Gepner, a UW physician and the study’s lead author.
Quitting smoking also reduces cardiovascular risk for other reasons, such as reducing inflammation in blood vessels.
“Even small changes in HDL are important,” said Ralph Sacco, president of the American Heart Association.
The study, which involved 1,504 smokers from Milwaukee and Madison, was presented at the Heart Association’s annual meeting.
The smokers in the study all were part of a smoking cessation program. At the end of one year, 923 had returned for a follow-up visit and 334 of them had quit smoking.
Those who did not quit had gained about 1.5 pounds and had virtually no change in the HDL.
Other than moderate alcohol consumption and exercise, there are not a lot of ways to boost HDL, Sacco said.
Gepner noted that one of the biggest excuses for not quitting is concern about weight gain.
Being able to tell smokers their HDL will improve even if they gain weight provides them with more incentive to quit, he said.
He said that may be especially true of weekend smokers, who got the same kind of improvement as heavier smokers.
“It doesn’t matter how much you were smoking,” he said.
The improvement in HDL was the strongest in women, a group for whom HDL is especially important, said Sharonne Hayes, a cardiologist at the Mayo Clinic in Rochester, Minn., and director of its Women’s Heart Clinic. Women also tend to be more concerned about quitting causing weight gain than men, she said.
“You can gain weight but other great things happen,” Hayes said.
Why smoking lowers HDL is not known, said UW cardiologist James Stein, senior author of the study.
One possibility, he said, is that smoking inhibits an enzyme that is involved in processing and stabilizing HDL.
In an earlier study involving the same group of smokers, UW researchers found that quitting smoking also improved blood vessel health.
In a related matter, researchers found that between 1980 and 2009 smoking among adults in the Minneapolis-St. Paul area dropped from 33% to 16% in men and 33% to 12% in women.
“The prevalence of smoking has been decreasing, but it remains a public health issue,” lead author Kristian Filion, a University of Minnesota researcher, said in a statement.