Predicting Weight Gain in Ex-Smokers
Quit Smoking, Gain Weight? It Ain't Necessarily So
Nov. 24, 2003 -- Markers that predict heart disease and diabetes may also predict weight gain in people who quit smoking.
A person's energy balance depends on the number of calories burned and the number of calories consumed. Energy balance is so important to health that many different body functions help regulate it. Sure signs it's out of whack: Obesity, diabetes, and heart disease.
Recent studies show that an early sign of heart disease is inflammation -- with chemical markers that are increased in the blood. More recently, these inflammatory markers have been seen as a person develops the early signs of type 2 diabetes. Weight gain in adulthood has also been associated with elevated markers of inflammation. But this doesn't seem to happen as much to smokers, notes Bruce B. Duncan, MD, PhD, of the Federal University of Rio Grande do Sul in Porto Alegre, Brazil.
Why? Duncan led a research team that analyzed data from nearly 12,000 U.S. men and women -- with a focus on 2,664 smokers and 493 people who quit smoking. They found that if a person with inflammation quits smoking, that person is 50% more likely to have a large weight gain than a quitter without inflammation.
"This is interesting. It suggests there is something going on with inflammation -- something we don't understand -- that has importance for how, when people quit smoking, they gain more weight," Duncan tells WebMD. "When we understand this better, we may be able to help people not gain so much weight when they quit."
Metabolism and Fat Cells
Fat cells help regulate inflammation, says Laurence S. Sperling, MD, director of the risk reduction program at the Emory University Heart Center. He says the Duncan team's finding is interesting. It suggests that when people with inflammation quit smoking, they are more likely to have an out-of-whack metabolism -- and thus are more likely to gain weight.
"Smoking revs up the inflammatory cascade," Sperling notes. "It makes sense that those who have high levels of inflammation when they stop smoking are those most likely to gain more weight."