Smoking Combined With Obesity Creates Unique Health Risks
redOrbit Staff & Wire Reports – Your Universe Online
In addition to well-publicized tobacco-related health risks like cancer and cardiovascular disease, new research suggests that obese men and women exposed to smoke could experience issues with their prescription medication or other medical problems.
Speaking at the 246th National Meeting & Exposition of the American Chemical Society (ACS) in Indianapolis on Wednesday, Aaron Wright of the Pacific Northwest National Laboratory (PNNL) explained that those health threats might also apply to “passive” or “second-hand” smoke.
“Our research shows that smoking and obesity together may pose a triple health threat in addition to the increased risks for heart disease, cancer and diabetes,” Wright explained in a statement. “That dangerous combination impacts key mechanisms by which both the lung and liver perform metabolism.”
“For example, the body’s ability to metabolize prescription drugs may be altered in ways that could make standard dosages too high or too low to be effective in obese people who are exposed to tobacco smoke,” he added. “Tobacco smoke and obesity also intensifies the cancer-causing potential of cigarette smoke. We were surprised to find that in some instances, the substances in second-hand smoke seem to have a more dramatic effect than just smoking.”
According to Wright, he and his colleagues analyzed the activity of liver-and-lung-tissue enzymes obtained from both lean and obese mice that were exposed directly to cigarette smoke and second-hand smoke. These cytochrome P450 enzymes are responsible for metabolizing three-fourths of all prescription and over-the-counter drugs, as well as other ingested substances. The P450 enzymes make sure that substances such as insulin, beta-blockers and pain-relievers accomplish their mission and are then removed from the body.
Previous research had already established that cigarette smoke can make the enzymes, which also help metabolize fat, more active than usual. That could cause smokers to wind up with levels of medications in their blood that are too low to effectively treat a specific disease. Wright’s team studied how the enzymes work in liver and lung tissues from mice that were obese and normal weight, and had been exposed to cigarette smoke, second-hand smoke, or no smoke whatsoever.
“Exposure to cigarette smoke increased the activity of some of the P450 enzymes, and adding obesity had little or no change on that effect,” Wright said. “But for other enzymes, which usually are far more active when exposed to cigarette smoke, the addition of obesity had a dramatic, opposite effect. The enzymes were 100 times less active.”
These combined effects could have several potential consequences, including an increased risk of developing lung cancer, the PNNL scientist explained. Substances in cigarette smoke become carcinogenic when broken down by P450s, and the impact that obesity has on those enzymes could compound the cancer-causing effects of the smoke. In addition, the researchers said that second-hand smoke can make the effect even more pronounced.
“Wright said it will take additional research to establish the exact health implications for the millions of people who smoke and are obese. But the findings, he added, are another reason why people should maintain a normal body weight and avoid cigarette smoke,” the ACS said in a statement.
“And they may serve as an alert to pharmaceutical companies to consider both cigarette smoke exposure and obesity in drug research.”