The authors report the results of a dietary survey of 38,121 Iowa women, 55-69 years of age in 1986, based on a semiquantitative food frequency questionnaire previously tested among Boston-area women aged 34-59 years. The Iowa women, compared with the younger Boston-area women, consumed a similar amount of calories (1,767 vs. 1,844 kcal) and a similar amount of total calories from fat (35 vs. 37%) but had markedly greater intake of the following micronutrients after including supplement use: iron (+18%), calcium (+33%), vitamin A (+43%), riboflavin (+46%), thiamine (+50%), and pyridoxine (+122%). The reproducibility of the questionnaire was examined in two more administrations to 44 of the Iowa women in January and June of 1988. Reproducibility was highest for alcohol (Pearson's r = 0.99), caffeine (r = 0.95), and vitamin E (r = 0.90) and lowest for sucrose (r = 0.53), polyunsaturated fat (r = 0.56), and iron (r = 0.59). Micronutrient intakes were generally more reproducible than macronutrient intakes. The agreement between the June 1988 questionnaire and the average of five 24-hour dietary recalls was also assessed in the 44 subjects. The median correlations of energy-adjusted intake were as follows: for macronutrients, r = 0.45; for micronutrients without supplements, r = 0.33; and for micronutrients with supplements, r = 0.64. This food frequency questionnaire appears to be reasonably reproducible and accurate, so that its use may be extended to epidemiologic studies of older women with a broad range of socioeconomic backgrounds.

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Epidemiologic studies have established that increased body weight is associated with a greater incidence of breast cancer in postmenopausal women. The authors hypothesized that abdominal adiposity further increases risk of postmenopausal breast cancer. They therefore investigated the waist-to-hip circumference ratio in relation to breast cancer incidence in a nested case-control study of 41,837 postmenopausal Iowa women aged 55-69 years. Women were recruited through a mail survey in January 1986 and were asked to have someone measure their body circumferences using a paper tape measure and written instructions. Cancer incidence was ascertained using a statewide cancer registry. A total of 229 incident breast cancers occurred among at-risk women during the first 2 years of follow-up (1986-1987). Compared with randomly selected controls (n = 1,839), women with incident breast cancer had a higher age-adjusted mean waist-to-hip ratio (by 0.013 units, p = 0.030), as well as greater mean weight (by 1.7 kg, p = 0.07), body mass index (by 0.6 kg/m2, p = 0.08), and weight gain since age 18 (by 2.7 kg, p less than 0.01). In multiple logistic regression models, age and current body mass index were significant effect modifiers of the association between the waist-to-hip ratio and breast cancer. A two-standard deviation increase in the waist-to-hip ratio (0.168 units) was associated with no increase in the relative risk of breast cancer in younger and lighter postmenopausal women. However, in older, heavier postmenopausal women, the same increase in the waist-to-hip ratio carried greater than a twofold excess relative risk. Adjustment for other breast cancer risk factors did not materially alter this finding. Two plausible explanations for elevated breast cancer incidence in women with abdominal adiposity include 1) increased concentrations of non-protein-bound estrogens due to reduced sex hormone binding globulin, or 2) increased conversion of adrenal androgens to estrone with abdominal adiposity.

The lasR gene ofPseudomonas aeruginosa is required for transcription of the genes for elastase (1asB) and LasA protease (lasA), two proteases associated with virlence. We report here that the alkaline protease gene (apr) also requires the lasR gene for transcription. Alkaline protease mRNA was absent in the lasR mutant PAO-R1 and present when an intact lasR gene was supplied in trans as determined by Northern (RNA) analysis. The lasR gene also enhances exotoxin A production. Exotoxin A activity in supernatants of PAO-R1 were 30%o less than in supernatants of the parental strain, PAO-SR. Multiple copies of lasR in trans in PAO-R1 increased toxin A activity to twice the parental levels. Analysis of PAO-R1 containing the tox4 promoter fused to 13-galactosidase suggests that LasR acts at the tQX4 promoter or at upstream tox4 mRNA sequences. 13-Galactosidase activity was approximately 40%o lower in PAO-R1 than in the parental strain, PAO-SR. Furthermore, the effect of LasR on the toxA promoter is not due to the stimulation of transcription of regA, a transcriptional activator of tox4. No difference in chloramphenicol acetyltransferase (CAT) activity was noted between PAO-SR and PAO-R1 containing transcriptional regA promoter-CAT gene fusions. These results broaden the regulatory dominion of lasR and suggest that the lasR gene plays a global role in P. aeruginosa pathogenesis.

Waist/hip circumference ratio is a better marker than body mass index of risk of death in older women. Waist/hip circumference ratio should be measured as part of routine surveillance and risk monitoring in medical practice.