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Biomedical subjects

H Brenner

Publications and source records attributed to H Brenner.

At least 109 records · Page 6Linked to original sources
PubMed2000

Potential gain in precision and power by matching on strong risk factors in case-control studies: the example of laryngeal cancer.

BACKGROUND: To increase the precision and power of case-control studies, controls are often matched on age and sex, but rarely on other known risk factors. Expensive tests of genetic susceptibility in a case-control study of laryngeal cancer made us examine the effect of matching for smoking and alcohol consumption on the power and potential size reduction of the required control sample. METHODS: According to published smoking and alcohol consumption distributions in laryngeal cancer cases and population controls, we simulated 10000 frequency-matched and unmatched studies. The exposure of interest was distributed according to different scenarios concerning its relation with the disease and with smoking and alcohol consumption. Studies were analysed with multivariable logistic regression. RESULTS: Matching increased the precision and power in all scenarios. The gain was most pronounced in scenarios assuming moderate confounding by smoking and alcohol consumption. In such scenarios, equivalent precision or power was only obtained with three times as many unmatched as matched controls. CONCLUSIONS: Matching on strong risk factors may increase the precision and power of case-control studies considerably. In studies employing expensive biologic testing, matching on known strong risk factors may be cost-effective more often than previously thought.

Alcohol Drinking↗
PubMed2000

Helicobacter pylori infection, intake of analgesics or anti-inflammatory medication, and personal factors in relation to dyspeptic symptoms in patients of a general practitioner.

BACKGROUND: Several studies have assessed the relationship between Helicobacter pylori infection and dyspeptic symptoms in highly selected patient populations and they have yielded inconsistent results. AIM: To investigate the relationship between current H. pylori infection, intake of analgesics or anti-inflammatory medication, and personal factors with dyspeptic symptoms in a large, unselected patient population of a general practitioner (GP). METHOD: Consecutive patients of a GP were invited to participate in a cross-sectional study regardless of the reason for their visit. Active infection with H. pylori was measured using the 13C-urea breath test (13C-UBT). A standardised questionnaire covering demographic, socioeconomic and lifestyle factors, and dyspeptic symptoms was completed by the patients. The number and severity of dyspeptic symptoms were quantified using a symptom score. RESULTS: Five hundred and one out of 531 eligible patients returned their questionnaires; a response rate of 94.4%. The prevalence of H. pylori infection, as indicated by a positive 13C-UBT, was 21.1% and was unrelated to dyspeptic symptoms. After adjustment for potential confounders by multiple logistic regression, a symptom score in the upper quartile of the symptom score distribution was significantly associated with female sex (odds ratio [OR] = 1.8, 95% confidence interval [CI] = 1.1 to 3.0) and intake of analgesics or anti-inflammatory drugs other than non-steroidal anti-inflammatory drugs (NSAIDs) (OR = 2.3, 95% CI = 1.1 to 4.7). Older age (60 to 79 years) was associated with fewer symptoms (OR = 0.4, 95% CI = 0.2 to 0.9) when compared with the youngest age group (15 to 39 years). CONCLUSION: Female sex, younger age, and intake of analgesics or anti-inflammatory drugs other than NSAIDs, but not H. pylori infection, were independently associated with dyspeptic symptoms in this population.

Adolescent↗
PubMed1999

Infection with Helicobacter pylori is not a major independent risk factor for stable coronary heart disease: lack of a role of cytotoxin-associated protein A-positive strains and absence of a systemic inflammatory response.

BACKGROUND: There is controversy about the association between Helicobacter pylori infection and manifestations of coronary heart disease (CHD), the potential role of the more virulent H pylori strains, and whether or not a positive serostatus is related to increased levels of markers of systemic inflammation. METHODS AND RESULTS: We assessed the prevalence of an infection with H pylori and in particular the anti-cytotoxin-associated protein A (CagA) antibody response of the more virulent strains expressing CagA in 312 patients with stable CHD and in 479 control subjects. Serological prevalence of H pylori infection (IgG titer) was significantly higher in patients than in control subjects after adjustment for age and sex (44.2% versus 31.3%, P<0.001). After adjustment for various covariates in multiple logistic regression, the odds ratio (OR) for CHD was 1.3 (95% CI, 0.9 to 1.9) given a positive IgG serostatus. The prevalence of CagA-positive strains was 27.9% in patients and 21.7% in control subjects (P=0.076 adjusted for age and sex). The OR for CHD in the fully adjusted model was 1.1 (95% CI, 0.7 to 1.7). None of the inflammatory markers (C-reactive protein, fibrinogen, plasma viscosity, or leukocytes) was significantly different according to serostatus. CONCLUSIONS: In this large case-control study, the association of H pylori infection with stable CHD was strongly reduced and was no longer statistically significant after controlling for potential confounders. We also found no independent association between the more virulent strains and CHD. In addition, a positive serostatus was not associated with a systemic inflammatory response. Thus, these data do not support the hypothesis that infection with H pylori might be a major risk factor for stable CHD.

Aged↗
PubMed1999

[Dose-intensive chemotherapy with continuous infusion 5-fluorouracil].

54 patients with advanced malignancy refractory to chemotherapy were studied to evaluate efficacy and toxicity of continuous infusion of 5-fluorouracil (5FU) given for 3 weeks. We report results of the first 156 courses given in combination with other drugs. 19 (37%) of the 54 responded, including 3 (6%) with complete response. Toxicity was acceptable, with mucositis in 13 (26%) and 3 (6%) with grade II-III toxicity. Results and toxicity profile were compatible with further disease-oriented studies using this dose-intensive program.

Adolescent↗
PubMed1999

Inverse graded relation between alcohol consumption and active infection with Helicobacter pylori.

Alcoholic beverages are known to have strong antibacterial activity. It is unclear, however, to what degree their consumption affects colonization of the human stomach with the bacterium Helicobacter pylori, a risk factor of various chronic diseases. The authors assessed the relation between alcohol consumption and active infection with H. pylori in a cross-sectional study among employees of a health insurance company and their household members (n = 425) in southern Germany. Quantitative information on alcohol consumption by beverage type and other factors that were known or suspected to be related to infection status was collected by a standardized questionnaire, and active infection was measured by the 13C-urea breath test. After control for confounding factors, there was a monotonic inverse graded relation between alcohol consumption and H. pylori infection (p for trend = 0.017). The odds ratio of infection among subjects who consumed more than 75 g of alcohol per week compared with subjects who did not drink alcohol was 0.31 (95 percent confidence interval 0.12-0.81). The inverse relation with H. pylori infection was stronger for alcohol consumed in the form of wine than for alcohol from beer. Notwithstanding its cross-sectional design, this study seems to support the hypothesis that alcohol consumption, particularly wine consumption, may reduce the odds of active infection with H. pylori.

Adolescent↗
PubMed1999

Trends in survival of patients with ovarian cancer in Saarland, Germany, 1976-1995.

PURPOSE: We aimed to monitor recent progress in survival of patients with ovarian cancer. METHODS: We assessed trends in survival in 1976-1995 among patients notified to the population-based cancer registry of Saarland, Germany, with a first diagnosis of ovarian cancer below the age of 80 years. A new statistical methodology was applied that allows the most timely detection of changes in survival rates. RESULTS: There was a dramatic, ongoing increase in 5-year relative survival rates from 36.6% in 1976-1980 to 60.1% in 1991-1995 among patients whose cancer was detected below the age of 55 years, and from 23.7% to 42.9% in patients aged 55-64 years at the time of diagnosis. No such improvement was seen among older patients, who continued to have a very poor prognosis. Therefore, the variation of prognosis with age was strongly increasing over time. CONCLUSIONS: Improvement of prognosis in younger patients most likely reflects the benefits of more aggressive surgery and chemotherapy in these age groups. Efforts should be made to overcome obstacles to more successful therapy for older patients.

Age Distribution↗
PubMed1999

Chronic infection with Helicobacter pylori does not provoke major systemic inflammation in healthy adults: results from a large population-based study.

It has been suggested that chronic infection with Helicobacter pylori (H. pylori), in particular infection with virulent strains producing the cytotoxin-associated protein CagA, may increase the risk of coronary heart disease by generation of a persistent low-grade inflammatory stimulus. We assessed the relation between serological markers of H. pylori infection and various markers of systemic inflammation in a population-based sample of 1834 men and women aged 18-88. A total of 39.3% of the sample had a positive IgG response, and among these a slight majority was CagA positive. Infection with H. pylori was unrelated to C-reactive protein and the leukocyte count, regardless of CagA status. There was an inverse relation between H. pylori infection and serum albumin. The adjusted OR (95% CI) of an albumin level in the bottom versus the top third were 2.2 (1.5-3.1) and 2.0 (1.4-3.1) for infection with CagA-positive and CagA-negative H. pylori strains, respectively. These results do not support the hypothesis that chronic infection with virulent H. pylori strains provokes major systemic inflammation. The mechanisms underlying the inverse association between H. pylori infection and serum albumin and the clinical relevance of this finding require further research.

Adolescent↗
PubMed1999

Active infection with Helicobacter pylori in healthy couples.

The mode of spread of Helicobacter pylori infection is subject to ongoing debate. Recent studies among patients with gastrointestinal disorders suggest a potential role of conjugal transmission. In this study, the clustering of H. pylori infection was assessed among 110 employees of a health insurance company and their partners. Active infection with H. pylori was measured by the 13C-urea breath test. Information on potential confounders was collected by a standardized questionnaire. Overall, 16 employees (14.5%) and 24 partners (21.8%) were infected. While only 7% (6/86) of employees with an uninfected partner were infected, this applied to 42% (10/24) of employees with an infected partner. A very strong relation between partners' infection status persisted after control for age and other potential confounders (adjusted odds ratio, 7.0; 95% confidence interval, 1.8-26.7). Furthermore, the risk of infection increased with the number of years lived with an infected partner. These results support the hypothesis of a major role of spouse-to-spouse transmission of H. pylori infection.

Adult↗
PubMed1999

Helicobacter pylori among preschool children and their parents: evidence of parent-child transmission.

This study assessed the role of parental infection status in the transmission of Helicobacter pylori infection in a large population-based sample of preschool-aged children. The subjects, who lived in Ulm, Germany, and in two nearby communities, were screened for school fitness between January and July 1997. Their H. pylori infection status was determined by 13C-urea breath test. Of 1522 eligible children, 1221 (80.2%) participated in the study. Crude prevalence of H. pylori infection in children was 11.3% (95% confidence interval [CI], 9.5-13.3) and 36.4% in their parents (95% CI, 33.5-39.4). The crude odds ratio (OR) for H. pylori infection of children whose mothers were infected was 16.5 (95% CI, 8.9-30.8) and 7.9 after adjustment for potential confounders (95% CI, 4.0-15.7). The crude OR if the child's father was infected was 7.8 (95% CI, 2. 5-24.2) and 3.8 after adjustment for potential confounders (except maternal infection) (95% CI, 0.8-19.1). The results suggest that infected parents, especially infected mothers, may have a key role in transmission of H. pylori within families.

Adult↗
PubMed1999

Cytomegalovirus infection and coronary heart disease: results of a german case-control study.

This case-control study investigated whether previous infection with cytomegalovirus (CMV) was associated with coronary heart disease (CHD). In total, 312 patients of German nationality aged 40-68 years who had a coronary stenosis of >50% of the luminal diameter were recruited for study. Controls (n=479) were voluntary blood donors. CMV serology was performed to determine presence of specific CMV antibodies (IgG, IgM, IgA ELA test; Medac, Hamburg, Germany). Rheologic and inflammatory markers were determined. The prevalence of specific IgG antibodies against CMV was 54.5% in cases and 49.9% in controls (P=.116). The odds ratio for CHD was 1.21 (95% confidence interval, 0.84-1.75) given a positive serostatus of specific IgG antibodies after adjustment for covariates. With the exception of C-reactive protein in controls, none of the rheologic or inflammatory markers was associated with CMV serostatus. Thus, serologic evidence of previous infection with CMV was not a major risk factor for CHD in this population.

Adult↗
PubMed1999

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Journal Article↗
PubMed1999

Alcohol consumption and Helicobacter pylori infection: results from the German National Health and Nutrition Survey.

Alcohol has strong antimicrobial activity and stimulates gastric acid secretion. Alcohol consumption may therefore compromise the living conditions of Helicobacter pylori in the stomach. We assessed the relation of alcohol consumption with H. pylori infection among 1,785 participants ages 18-88 in the German National Health and Nutrition Survey. Detailed information on dietary and lifestyle habits was obtained in personal interviews using a standardized food frequency questionnaire. Serum samples were analyzed for H. pylori immunoglobulin G antibodies by enzyme-linked immunosorbent assay. Overall prevalence of H. pylori infection was 39.2%. There was a clear inverse dose-response-relation between reported alcohol consumption and H. pylori infection. The relation persisted after control for potential confounding factors. The adjusted prevalence ratios (95% confidence intervals) for H. pylori infection among persons who consumed up to 10, 10 to 20, and more than 20 gm of alcohol per day compared with non-drinkers were 0.93 (0.77-1.13), 0.82 (0.65-1.04), and 0.71 (0.55-0.92). The inverse relation between alcohol consumption and H. pylori infection was even stronger when individuals with an indication of a recent change of alcohol consumption were excluded from the analysis. These findings support the hypothesis that moderate alcohol consumption may facilitate spontaneous elimination of H. pylori infection among adults.

Adolescent↗
PubMed1998

Factors affecting bone demineralization and blood lead levels of postmenopausal women--a population-based study from Germany.

We investigated the influence of various lifestyle factors on blood lead levels in postmenopausal women from the general population of Germany. Particular consideration was given to those factors which are suspected to be related to bone demineralization. The study population consisted of 424 women, aged 45 to 80 years, who were examined in a substudy of the National Health and Nutrition Survey called VERA (Verbundstudie Ernährungserhebung, und Risikofaktorenanalyse) from 1987 to 1988. Mean blood lead level was 61.4 micrograms/liter (SD, 27.3). In multiple linear regression analysis alcohol consumption, former use of oral contraception, hematocrit, and age were positively associated with blood lead levels, whereas calcium intake and high physical activity showed a negative association with blood lead levels. Some of the identified risk factors which are suspected to exert their influence on blood lead levels by affecting bone demineralization can be influenced by change of individual behavior. Thus, we conclude that reduction of alcohol consumption, adequate calcium intake, and physical activity may reduce blood lead levels as well as negative health effects of osteoporosis in postmenopausal women.

Adult↗
PubMed1998

Elevated liver enzyme activity in construction workers: prevalence and impact on early retirement and all-cause mortality.

BACKGROUND: Gamma-glutamyl transferase (GGT), alanine transaminase (ALT), and aspartate transaminase (AST) are widely used as markers of hepatobiliary disorders in occupational health surveillance. Little is known, however, about the prevalence and occupational and non-occupational determinants of elevated levels of these enzymes in specific occupational groups or about the prognostic value of elevated levels with respect to long-term outcomes such as all-cause mortality and vocational disability. METHODS: A cohort study was conducted among 8,043 male construction workers aged 25-64 years who had undergone occupational health examinations in 6 centers in southern Germany from 1986 to 1988 and had been followed until 1994. The prevalence of elevated levels of GGT, ALT, and AST, depending on the sociodemographic and medical characteristics determined at the baseline examination and the risk of vocational disability and all-cause mortality in relation to elevated liver enzyme activity at baseline were assessed. Covariates considered in multivariate analysis included age, nationality, occupation, body mass index (BMI), smoking, and alcohol consumption. RESULTS: The baseline prevalence of elevated activity levels of GGT (>28 U/1 at 25 degrees C), ALT (>22 U/1), and AST (>18 U/1) was 32%, 22%, and 12%, respectively. Factors most strongly related to elevated serum activity levels for all three enzymes were self-reported alcohol consumption, diabetes, and hypertension. BMI was strongly associated with elevations in GGT and ALT but not in AST. Elevated levels of AST and GGT were strongly related to early retirement and all-cause mortality. Men with AST levels exceeding 18 U/1 had a 2-fold risk of early retirement and a 3 times higher risk of all-cause mortality as compared with men with lower AST levels. No significant association was observed between ALT and either of the long-term outcomes. CONCLUSIONS: Our findings suggest that screening for elevated GGT and AST levels, which are a common finding among construction workers, may be a powerful tool for the identification of individuals at increased risk of early retirement and preterm mortality and may be helpful in targeting of prevention efforts.

Adult↗
PubMed1998

History of antibiotic treatment and prevalence of H. pylori infection among children: results of a population-based study.

We investigated the association of commonly prescribed antibiotics with the prevalence of current Helicobacter pylori infection among children. All children who were screened in 1996 for school fitness by physicians of the Public Health Service in Ulm, a city in the south of Germany, were invited to participate in the study. Infection status was determined by 13C-urea breath test. In addition, the parents of the children were asked to fill out a standardized questionnaire. Nine hundred forty-five out of the 1201 eligible children participated in the study (response rate = 79%). The children were aged 5 to 8 years. Seventeen children who were receiving antibiotics at the day of the breath test were excluded from the analysis. Overall, for 683 children (73.6%) a prior usage of antibiotics was reported. Prevalence of H. pylori infection was significantly lower in children with reported antibiotic usage (odds ratio = 0.46; 95% CI, 0.27-0.76 after adjustment for confounders). Our results suggest that information on prior usage of antibiotics should always be considered in studies evaluating prevalence and risk factors of H. pylori infection in children.

Anti-Bacterial Agents↗
PubMed1998

Active infection with Helicobacter pylori in an asymptomatic population of middle aged to elderly people.

The study objective was to investigate prevalence and determinants of current Helicobacter pylori infection in an asymptomatic population of middle-aged to elderly people. A cross-sectional study was conducted among 337 participants of a general education programme of the University of Ulm aged 50-85 years. Prevalence of infection as determined by means of the [13C]urea breath test was 34.8% (95% CI 29.6-40.3%); overall, 33.8% (95% CI 23.0-46.0) in the age group 50-59 years, 32.4% (95% CI 25.4-39.9) in the age group 60-69 years and 41.0% (95% CI 30.0-52.7) in the age group 70-85 years. Duration of school education of the father, sharing a bed with parents or siblings during childhood, and the area in which participants had grown up were independent determinants of current infection status in a multivariable analysis. We conclude that the prevalence of current H. pylori infection in healthy elderly subjects may not be as high as seroprevalence studies have suggested. Socioeconomic characteristics of childhood living conditions appear to be important determinants of infection status even at older age.

Age Factors↗