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Helicobacter pyloriinfection may decrease serum ghrelin and increase gastric leptin levels, which may, in turn, decrease body mass index.To determine whetherH. pyloriseropositivity is associated with body mass index.SerumH. pyloriand cytotoxin-associated gene product A (CagA) antibody levels were measured on 6724 adult participants of the third National Health and Nutrition Examination Survey (1988–91). We evaluated the association betweenH. pylori/CagA antibody status [both negative (−/−),H. pylori-positive/CagA-negative (+/−), or both positive (+/+)] and body mass index, adjusting for sociodemographic factors. We also investigated whetherH. pylori/cytotoxin-associated gene product A antibody status was associated with fasting serum leptin levels.H. pylori/CagA antibody status was not associated with obesity (body mass index ≥ 30 kg/m2) [adjusted odds ratio (OR) 1.2, 95% CI: 0.9–1.6 comparing (+/+) to (−/−) and adjusted OR 1.1, 95% CI: 0.8–1.5 comparing (+/−) to (−/−)], overweight (body mass index 25 to<30 kg/m2) [adjusted OR 1.0, 95% CI: 0.7–1.2 comparing (+/+) to (−/−) and adjusted OR 1.0, 95% CI: 0.8–1.3 comparing (+/−) to (−/−)], or fasting serum leptin level in the USA population.H. pyloriseropositivity and CagA antibody status are not associated with body mass index or fasting serum leptin level. [ABSTRACT FROM AUTHOR]

Background: An analysis combining data from several clinical trials has raised concern that tamoxifen therapy may increase the risk of a subsequent colorectal malignancy. We conducted a nested case-control study to test this hypothesis.Methods: A cohort of women diagnosed with breast cancer in 1978-1992 was identified from the western Washington population-based cancer registry. Cases included women who subsequently developed colorectal cancer prior to 1995. Controls were a random sample of the cohort who did not develop a second primary malignancy, matched to cases on age, stage, and year of initial cancer diagnosis. Tamoxifen use was ascertained by medical record abstraction and physician questionnaires.Results: Thirty-six percent of the 122 cases for whom information could be obtained received tamoxifen versus 38% of 194 controls. Relative to non-users and adjusted for receipt of other therapies, there was no increased risk of colorectal cancer associated with tamoxifen use in general (matched odds ratio [mOR] = 0.9, 95% CI 0.6-1.6), longer durations of use (for > or =37 months, mOR = 0.8, 95% CI 0.4-1.9), higher cumulative doses of therapy (for > or =15 g, mOR = 0.8, 95% CI 0.4-1.6), or use that started at least 5 years prior to the end of study follow-up (mOR = 1.1, 95% CI 0.3-3.7).Conclusions: We found no overall increased risk for colorectal cancer among tamoxifen users. [ABSTRACT FROM AUTHOR]

Objective: This case-cohort study was designed to examine whether total hip bone mineral density (BMD) is independently associated with breast cancer over and above its association with other determinants, including levels of total and bioavailable estradiol and testosterone and sex-hormone binding globulin.Methods: Our study population was selected from a cohort of 8,203 postmenopausal women who were screened for the Fracture Intervention Trial in 1992, at which time BMD was assessed, and blood samples were obtained. A total of 109 women developed breast cancer during four years of follow-up; 173 other randomly selected women from the larger cohort were also selected. Cox proportional hazards with robust variance adjustment was used for these analyses.Results: Relative to women in the lower fourth of the BMD distribution, the risk associated with being in the upper fourth was 2.6 (95% confidence interval (CI) 1.1-5.8). After adjusting for serum hormone levels, the corresponding relative risk was 2.5 (95% CI 0.9-5.2). With body mass index and number of years since menopause added to the multivariate analysis, the relative risk decreased to 1.4 (95% CI 0.5-4.0).Conclusions: BMD may not influence breast cancer risk independent of its relationship with endogenous hormones and measured covariates. [ABSTRACT FROM AUTHOR]

Objective: Nonrandomized comparisons of the incidence of HIV and hepatitis B and C between injection drug users (IDUs) who do and do not attend voluntary needle-exchange programs may be subject to bias. To explore possible sources of bias, we examined characteristics associated with voluntarily beginning or ceasing to participate in the Seattle needle exchange.Methods: In a cohort of 2,879 IDUs, a standardized questionnaire measured characteristics present at enrollment. We examined the relation of these characteristics to the proportion of IDUs who began to use the program during the ensuing 12-month follow-up period and to the proportion of current exchangers who dropped out during that period of time.Results: Of the 494 never-exchangers at baseline, 32% attended the exchange program during follow-up; those who reported sharing syringes or who were homeless at enrollment were more likely to become new exchange users (adjusted risk ratio [ARR] for becoming an exchange user = 1.8 for those who shared syringes, and ARR = 2.2 for those who were homeless). Of 1,274 current exchangers, 16% stopped using the exchange during followup, with daily injectors (ARR = 0.6) and those who reported backloading (ARR = 0.6) being relatively less likely to drop out of the exchange.Conclusions: The analysis suggests that IDUs participating in needle-exchange programs at a given point in time may include a particularly high proportion of those injectors whose pattern of drug use puts them at elevated risk of blood-borne viral infections. [ABSTRACT FROM AUTHOR]

Objective: In randomized trials a higher proportion of women prescribed continuous combined hormone replacement therapy complete the full course of treatment compared with those prescribed sequential therapy. We sought to determine adherence to hormone therapy in a less-selected population.Study Design: Women enrolled in a prepaid health plan participated in a telephone interview 12 to 15 months after newly initiating use of hormone replacement therapy. The interview elicited information on whether the women were still taking the hormones as first prescribed and reasons for switching or discontinuation. A computerized pharmacy database was used to determine initial doses, prescription renewal, and dates of switching or discontinuation.Results: The proportion continuing the originally prescribed hormone regimen at 1 year was higher among continuous combined therapy users (68.9%, 62/90) than among sequential therapy users (54.4%, 62/114). Women who initiated continuous combined therapy were less likely to have switched regimens (10.0%) than were sequential users (20.2%; relative risk, 0.5; 95% confidence interval, 0.2-1.0) but only somewhat less likely to have discontinued use (21.2% vs 25.4%; relative risk, 0.7; 95% confidence interval, 0.4-1.3). Examined as a whole, women prescribed continuous combined therapy were less likely than those prescribed sequential therapy to quit or switch during the first year (relative risk, 0.6; 95% confidence interval, 0.4-1.0).Conclusion: Although adherence was higher among women prescribed continuous combined hormone replacement therapy than sequential therapy, the high level of nonadherence in both groups suggests room for improvement of menopausal therapies so that women find them acceptable for sustained use. [ABSTRACT FROM AUTHOR]

Objectives: The reported mutagenic and carcinogenic effects of some chemicals present in hair dyes have raised concern that hair dye use could increase breast cancer risk. This case-control study evaluated how detailed aspects of hair coloring and hair spray application by reproductive-age women may affect breast cancer risk.Methods: Cases were white female residents of three counties of western Washington state 45 years of age or less, who were diagnosed with breast cancer between 1983 and 1990 (n = 844). A sample of similarly aged women residing in the same counties served as controls (n = 960). Information on hair coloring and hair spray use, as well as other exposures, was ascertained during in-person interviews.Results: Breast cancer cases were slightly more likely than controls to report ever having used some type of hair coloring application, including use of rinses, semi-permanent or permanent dyes, as well as bleaching then dyeing or frosting their hair (relative risk [RR] = 1.3, 95% CI = 1.0-1.6, adjusted for age, fullterm pregnancies, family history of breast cancer, and weight). In subgroup analyses, women with exclusive use of just one of these methods of hair coloring application had no elevation in risk (similarly adjusted RR = 1.1, 95% CI = 0.9-1.3), whereas women who used two or more of these methods did have an elevated risk (RR = 1.9, 95% CI = 1.4-2.5). Hair spray use was not related to the risk of breast cancer (ever versus never users: RR = 1.0, 95% CI = 0.8- 1.3).Conclusion: The lack of an association between exclusive use of a single type of hair coloring application and breast cancer risk argues that hair coloring application does not influence breast cancer risk among reproductive-age women. Thus, the results of the present study, as well as negative ones from most (but not all) prior studies, are most consistent with the conclusion that neither hair coloring application nor hair spray application influences breast cancer risk. [ABSTRACT FROM AUTHOR]

Objectives: We examined the incidence of gastric carcinoma in Chinese, Japanese, and Filipino residents of the United States to obtain additional information about the etiology of this disease.Methods: The age, race, and birthplace of residents of Hawaii, San Francisco/Oakland, and northwestern Washington who were diagnosed with gastric carcinoma during the period 1973-1986 were obtained from population-based registries, and a special tabulation from the 1980 Census was used to estimate the number of person-years at risk for each category of resident.Results: The incidence of gastric carcinoma in Japanese-Americans was three to six times higher than that of US-born whites, with the highest rates occurring in those persons born in Japan. The rate in US-born Chinese and Chinese men who immigrated to the US was similar to that of whites, whereas the rate in Chinese female migrants was twice that of white American women. Filipino men, regardless of birthplace, were only at 60% the risk of US-born white men, while their female counterparts had a rate very similar to that of US-born white women. The high incidence observed among Japanese-Americans and Chinese female immigrants was largely restricted to sites other than the gastric cardia.Conclusions: Our findings suggest that dietary and other lifestyle differences between the different generations of Japanese-Americans, and between Japanese residents of the US and Japan may provide clues regarding the etiologies of stomach cancers that arise beyond the gastric cardia. [ABSTRACT FROM AUTHOR]

Focuses on dexfenfluramine, a drug that reduces the level of risk for cardiovascular diseases. Cardiovascular risk factors as surrogate end points; Clinical trials of drug therapies for cardiovascular risk factors; Validating a surrogate as a risk factor versus using a surrogate to evaluate a therapy; Proposed revisions to the drug-approval process.

Mūhlemann K (Institute of Medical Microbiology, Friedbūhistrasse 51, University of Berne, CH-3010 Berne, Switzerland), Alexander E R, Weiss N S, Pepe M, Schopfer K and the Swiss H.Influenzae Study Group. Risk factors for invasive Haemophilus influenzae disease among children aged 2–16 years of age in the vaccine era, Switzerland 1991–1993. International Journal of Epidemiology 1996; 25: 1280–1285.Background Continued surveillance, and detailed investigation of direct and indirect effects of conjugated vaccines and risk factors for invasive H. Influenzae serotype b (Hib) disease in the vaccine era are important Methods 143 cases with invasive disease between 1991 and 1993 aged 2–16 years were selected retrospectively from a large incidence trend study. Controls (n = 336) were recruited from local vital registries and matched to cases for age, gender, and residence. Hib vaccination histories among study subjects and their siblings and other sociodemographic variables were obtained by questionnaires completed by the parents of these children. Adjusted odds ratio (OR) estimates were calculated by conditional logistic regression analysis. Results Most vaccinated subjects had received the Polysacchande-Diphtheria Toxoid vaccine and estimated vaccine efficacy was high (95%; 95% confidence interval [Cl] 60–99%). Also, the results suggested that protection afforded by vaccination against Hib extended to the family members of vaccinated children. School attendance was found to be protective against invasive Hib disease (OR : 0.33; Cl : 0.14–0.75). Cases more often than controls reported sufferring from asthma and allergies (OR : 4.8; Cl: 1.2–19 4). Conclusions Post-licensure vaccine efficacy is high among children ≥2 years of age. The observed association between asthma and epiglottis is novel and deserves further investigation [ABSTRACT FROM PUBLISHER]