Smoking effects may differ among races Black people may be more susceptible to the damaging effects of cigarette smoke than white people, says the lead author of a recent study. While studying racial differences in smoking patterns and lung function in patients with advanced COPD, Wissam Chatila, MD, found that blacks with COPD began smoking later in life, smoked fewer cigarettes, and yet presented with similar disease severity at an earlier age compared to white patients in the study. “We’ve long known that there is a higher rate of disease and mortality of COPD in whites compared to African Americans,” says Chatila, a pulmonologist at Temple University Hospital and assistant professor of medicine at the Temple University School of Medicine, Philadelphia. “To our knowledge, however, this is the first study to look at racial differences in cigarette smoking exposure while characterizing the severity of the pulmonary disease in a group of susceptible smokers.” Chatila says that more research is needed to confirm the findings, which appeared in the January 2004 issue of Chest. “The challenge will be to discern reasons for these observed differences, which may be biological, physiologic, or environmental,” he says. Study finds Chronic Cough Gender Discrepancy All that hacking appears to be keeping her up longer at night than him. In a cough-specific quality of life questionnaire, significantly more female than male chronic coughers reported physical complaints, such as headache, painful breathing, nausea, and urinary incontinence. Women in that group also reported more psychosocial issues, such as embarrassment. The researchers from the departments of medicine and psychiatry, University of Massachusetts Medical School, Worcester, concluded that these physical and psychosocial issues indicate why more women than men seek medical treatment for the condition. The study appeared in the February issue of Chest, the peer-reviewed journal of the American College of Chest Physicians.

Scientists Identify Diesel Fume Allergy Genes
The risk of developing respiratory allergies from exposure to diesel emissions depends largely on genetics, according to a study funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH).

Researchers examined a group of volunteers who are allergic to ragweed. Study participants who lacked the antioxidant-producing form of the GSTM1 gene had significantly greater allergic responses when exposed to a mix of ragweed and diesel exhaust. Within the group that lacked GSTM1, those who had a particular variant of the GSTP1 gene experienced even greater allergic reactions.

Given their findings, researchers estimate that up to 50% of the US population could be in jeopardy of experiencing health problems related to air pollution.

“The knowledge provided by this work will help us identify people who are susceptible to the deleterious effects of diesel emissions on the clinical course of asthma and hay fever,” says Kenneth Adams, PhD, who oversees asthma research funded by NIAID. “It will also help accelerate development of drugs to treat and prevent these diseases.”

Published in the January 10 issue of the Lancet, the study also received support from the National Institute of Environmental Health Sciences, another NIH component.

Study links fatty acid defect to cystic fibrosis
Confirming evidence from earlier research performed on mice, researchers have discovered an imbalance of fatty acids in the tissues of those with cystic fibrosis (CF). This finding may help scientists focus treatment efforts, says the research team at Beth Israel Deaconess Medical Center (BIDMC), Boston; UMass Memorial Health Care (UMMHC), Worcester, Mass; and Massachusetts General Hospital (MGH), Boston.

The 38 CF patients involved in the study had abnormally high levels of arachidonic acid and abnormally low levels of docosahexaenoic acid (DHA)—a condition that predisposes to inflammation, according to senior author Steven D. Freedman, MD, PhD, of the gastroenterology division at BIDMC and associate professor of medicine at Harvard Medical School. The study also revealed that this fatty acid abnormality was unique to cystic fibrosis and not simply a reflection of the disease state.

CF patients are typically treated with antibiotics, and the researchers say that up until now, new treatments efforts had focused on symptomatic therapies and methods to improve CFTR gene function.

This study found that large doses of DHA corrected the fatty acid imbalance and reversed signs of the disease in CF mice. However, Freedman cautions that exceptionally high doses of DHA were required to treat the CF mice and says over-the-counter supplements would not be beneficial for humans and could be harmful at the high doses required to achieve clinical effectiveness.

This study was funded by grants from the Cystic Fibrosis Foundation and Genzyme Corp, Cambridge, Mass, and supported in part by a grant to the BIDMC General Clinical Research Center from the National Institutes of Health. BIDMC owns issued and pending patents on novel methods for treating disorders in which DHA levels are affected and has an exclusive licensing agreement with Genzyme Corp for the development of therapies for CF.

The findings appear in the February 5 issue of The New England Journal of Medicine.