High iron exposure has been associated with colorectal neoplasia in several studies. The authors investigated plasma ferritin, an indicator of iron stores, and iron intake as risk factors for ...adenomatous polyps, intermediate markers for colorectal cancer. During 1991–1993, they collected fasting blood samples from and administered questionnaires to men and women 50–75 years old who visited free sigmoidoscopy clinics at a health maintenance organization. Data from 965 subjects (467 cases, 498 controls) were analyzed. Compared with those who had low-normal plasma ferritin concentrations (73–141 μg/liter), those with elevated concentrations (>289 μg/liter) had a multivariate-adjusted odds ratio of 1.5 (95% confidence interval (Cl) 1.0–2.3) after excluding subjects with possible non-iron-related elevations in ferritin. Compared with subjects consuming an adequate amount of iron (11.6–13.6 mg/day), multivariate-adjusted odds ratios were 1.6 (95% Cl 1.1–2.4) for <11.6 mg/day and 1.4 (95% Cl 0.9–2.0) for >27.3 mg/day. These results provide further support for a weak positive association between iron exposure and colorectal polyps. Am J Epidemiol 1996; 144: 34–41.
Depressed serum somatomedin C levels have been suggested by others as an early indicator of selenium (Se) toxicity. In both human and animal studies, somatomedin C levels were lower in Se ...supplemented as compared to control subjects. The present study examined Se and somatomedin C levels in 44 adult long-term residents of seleniferous areas in South Dakota. Serum Se (SSe) and whole blood Se (WBSe) levels were analyzed by GC/MS. Toenail Se (TSe) was measured by neutron activation analysis. Somatomedin C was analyzed by RIA assay. Subjects were divided into 3 groups based on the following criteria: group I, SSe 200, WBSe 320 ng/ml; group II, SSe 201-240, WBSe 321-400 ng/ml; group III, SSe 240, WBSe 400 ng/ml. Data were pooled across gender (20 males, 24 females). Somatomedin C levels were not different despite greater than 50% differences in SSe, WBSe, and TSe levels among the groups. In these subjects, somatomedin C was not a sensitive index of elevated Se exposure
After lung cancer, cancers of the breast and large bowel are the most common fatal cancers in the US. Epidemiologic data strongly support a subtle dose-response association of alcoholic beverage ...consumption with increased risk of cancer of the breast and large bowel.
To identify the determinants of p,p'-dichlorodiphenyldichloroethane (p,p'-DDE) in adipose tissue in subjects who participated in a cross-sectional study, we analyzed fatty acids, antioxidants, and ...p,p'-DDE in aspirates of adipose tissue of 328 postmenopausal women from 5 European countries. The overall mean of p,p'-DDE concentration was 1.66 μg/g of fatty acids (95% confidence interval = 1.46, 1.88). In a multiple-regression analysis, the main predictors of log
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(p,p'-DDE) were center of recruitment (p < .0001), adipose arachidic acid (p = .001), and adipose retinol (p = .04). These factors explained 14.9% of the overall variability of log
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(p,p'-DDE). In our subjects, adipose tissue p,p'-DDE concentrations were only weakly related with biomarkers reflecting intake of fish and other foods. This result is consistent with the notion that p,p'-DDE exists in different foods and, given the widespread contamination of the food chain, is relatively evenly distributed among foods.
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background: Prenatal exposure to perfluoroalkyl substances (PFAS) has been associated with lower birth weight in epidemiologic studies. This association could be attributable to glomerular filtration ...rate (GFR), which is related to PFAS concentration and birth weight.
Objectives: We used a physiologically based pharmacokinetic (PBPK) model of pregnancy to assess how much of the PFAS–birth weight association observed in epidemiologic studies might be attributable to GFR.
Methods: We modified a PBPK model to reflect the association of GFR with birth weight (estimated from three studies of GFR and birth weight) and used it to simulate PFAS concentrations in maternal and cord plasma. The model was run 250,000 times, with variation in parameters, to simulate a population. Simulated data were analyzed to evaluate the association between PFAS levels and birth weight due to GFR. We compared simulated estimates with those from a meta-analysis of epidemiologic data.
Results: The reduction in birth weight for each 1-ng/mL increase in simulated cord plasma for perfluorooctane sulfonate (PFOS) was 2.72 g (95% CI: –3.40, –2.04), and for perfluorooctanoic acid (PFOA) was 7.13 g (95% CI: –8.46, –5.80); results based on maternal plasma at term were similar. Results were sensitive to variations in PFAS level distributions and the strength of the GFR–birth weight association. In comparison, our meta-analysis of epidemiologic studies suggested that each 1-ng/mL increase in prenatal PFOS and PFOA levels was associated with 5.00 g (95% CI: –21.66, –7.78) and 14.72 g (95% CI: –8.92, –1.09) reductions in birth weight, respectively.
Conclusion: Results of our simulations suggest that a substantial proportion of the association between prenatal PFAS and birth weight may be attributable to confounding by GFR and that confounding by GFR may be more important in studies with sample collection later in pregnancy.
The relation between ethnicity, alcohol use, & mortality is investigated, using county-level statistics from Pa; these include 1960 & 1970 census records, 1972-1976 Liquor Control Board records, 1977 ...marketing statistics, & National Center for Health Statistics mortality records for 1971-1975. Persons born in a foreign country, or with at least one parent born in a foreign country, drank relatively large amounts of distilled spirits, & also had relatively high death rates from alcoholic liver cirrhosis & stomach cancer. 3 Tables. Modified HA.
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