Risk of metabolic syndrome raised even by secondhand smoke

Aug 4 2005

A new study has shown that even secondhand smoke can raise the risk of metabolic syndrome, a condition marked by obesity, high blood pressure, unhealthy cholesterol levels and pre-diabetes.

According to the American Heart Association, 47 million U.S. adults have metabolic syndrome, which markedly raises the odds of heart disease, stroke and diabetes, and is associated with obesity and smoking in adults.

This new study also shows that teenagers who smoke, and those who are around people who smoke, also have a higher risk of this condition.

Study leader Dr. Michael Weitzman of the University of Rochester in New York, says this is the first study to link this syndrome, which most people associate with obesity, to secondhand smoke.

Weitzman adds that being exposed to secondhand smoke, increases the risk of developing the metabolic syndrome almost five times more likely, while smoking increases the risk to at least six times that of a non-exposed individual.

Weitzman and his team looked at interviews of 2,273 adolescents aged 12 to 19 which were done as part of the U.S. Center for Disease Control and Prevention's National Health and Nutrition Examination Survey.

They found that overall 5.6 percent of adolescents had metabolic syndrome, including 1.2 percent of those with no exposure to smoke, as defined by their own reports and by measuring levels of a chemical byproduct of nicotine called cotinine in their blood.

Over 5 percent of those whose cotinine levels suggested smoke exposure, had metabolic syndrome, and 8.7 percent of those who actively smoked had metabolic syndrome.

The situation was even worse for overweight teens, as the researchers found that 23.6 percent of overweight teen smokers had metabolic syndrome, and two-thirds of the teens who did not smoke had cotinine levels of between .05 and 15 nanograms per milliliter, indicating they were exposed to secondhand smoke.

Weitzman views this is an insidious factor as people are unaware they are developing these complications, and as it is, the average 17-year-old has trouble understanding the implications for 30 years later.

Weitzman says what is clear is that teens who associate with smokers are also in danger, a message that may get through to teen smokers, because they are not just harming themselves by smoking, they are also harming their friends.

According to the American Heart Association, about 16 percent of all children and teens in the United States are overweight, and Weitzman says this is the group in which it is profoundly important to reduce secondhand smoke exposure and active smoking.

Many believe that smoking may also be a marker for unhealthy behavior, meaning that people who smoke are also less likely to exercise or eat healthily, but Weitzman believes that further research will show that smoking affects the body in ways that may in turn impact metabolism.

The study is published in the journal Circulation.