In a study of 2,950 Southern California 4th, 7th, and 10th grade children, researchers found that the adverse effects of in utero exposure to maternal smoking were associated with asthma and wheezing in a number of young persons, almost exclusively affecting those who had a genetic susceptibility found in over 45 percent of the study participants. After investigating the effects of maternal smoking during pregnancy in children from 12 Southern California communities, the researchers found that the lack of a common genotype called glutathione S-transferase (GST)M1 in the children appeared to play a significant role in the development of asthma and wheezing among those exposed to smoking as fetuses. For those children who did not have the GSTM1 genotype, the investigators found that in utero smoke exposure was associated with increased prevalence of early onset asthma, asthma without current symptoms, persistent asthma, lifetime history of wheezing, wheezing with exercise, wheezing requiring medication, and emergency rooms visits for the problems during the past year. According to the authors, GST constitutes an important superfamily of metabolizing enzymes that play a central role in the elimination of foreign chemicals, as well as in antioxidant defenses. The GSTM1 null genotype was not associated with asthma outcome unless there had been fetal exposure to smoke. The research appears in the second issue for August 2002 of the American Thoracic Society's peer- reviewed American Journal of Respiratory and Critical Care Medicine.
LOW BODY WEIGHT IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE PATIENTS ASSOCIATED WITH GREATER MUSCLE ATROPHY/POORER EXERCISE TOLERANCE
Despite similar degrees of lung function impairment, low weight patients with chronic obstructive pulmonary disease (COPD) showed more muscle atrophy and worse exercise capacity than did similar patients with a normal body mass index, according to Spanish investigators. The investigators showed that skeletal muscle cell death and atrophy were increased in seven COPD patients with low body mass index (BMI), as contrasted to three other groups of subjects, including eight normal weight COPD patients, eight healthy volunteers, and six sedentary volunteers. The researchers also discovered that exercise capacity in the underweight patients was better correlated with their BMI than with the degree of their airflow restriction. COPD is a slowly progressive airway disease that produces a serious decrease in lung function. This loss is associated with an abnormal inflammatory response of the lungs to noxious particles and gasses associated with long-term cigarette use. The characteristics of COPD include symptoms such as cough, sputum production, and shortness of breath on exertion. Unexplained weight loss due to skeletal muscle atrophy occurs frequently in these patients. The research appears in the second issue for August 2002 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.
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