Trends in the Incidence of Coronary Disease and Changes in Diet and Lifestyle in Women This study of nearly 86,000 nurses found that the incidence of coronary heart disease declined by 31 percent between 1980 and 1994. Two thirds of the decline could be explained by a reduction in smoking, improvements in diet, and an increase in the use of postmenopausal hormone-replacement therapy. An increase in obesity, however, slowed the trend.

Siblings, Day Care, and the Risk of Asthma in Children Among children followed from birth to 13 years of age, the incidence of asthma and frequent wheezing episodes between the ages of 6 and 13 years was lower among those who attended day care during the first 6 months of life and those who had one or more older siblings at home than among those without such exposure. A possible explanation for these findings is that children with more exposure to other children may have more infections, which in some way protect against asthma.

Hemoglobin H Disease in Hong Kong In hemoglobin H disease, a common hemoglobinopathy in China and Southeast Asia, two of the four a-globin genes are deleted and a third is deleted or mutated. In this study, most patients in Hong Kong who had hemoglobin H disease had deletions of three of the four a-globin genes. They had milder disease than patients in whom the third a-globin gene was mutated. Iron overload, a frequent and potentially serious complication of hemoglobin H disease, was independent of the type of genetic abnormality. Hence, the types of abnormalities of a-globin genes in hemoglobin H disease cannot account for all of its clinical variations.