Does Helicobacter pylori infection explain all socio-economic differences in peptic ulcer incidence? Genetic and psychosocial markers for incident peptic ulcer disease in a large cohort of Danish adults.

BACKGROUND: Peptic ulcer epidemiology has changed considerably within the past century. The aim of this study was to assess the 11-year cumulative incidence of peptic ulcer disease and examine the relationship between ulcer incidence and psychosocial and genetic factors. METHODS: A random sample of 2416 Danish adults with no history of peptic ulcer disease residing in Copenhagen County, Denmark, attended a population-based prospective cohort study in 1983 and 1994. All participants reported whether they had had an ulcer diagnosed within the observation period. Information on socio-economic factors, family history of peptic ulcer disease (PUD) and lifestyle practices was obtained from a questionnaire. Lewis blood group antigens were assessed from blood samples and Helicobacter pylori infection status was determined with an in-house IgG ELISA. RESULTS: The overall 11-year cumulative incidence proportion of PUD was 2.9% (95% CI (2.2; 3.6)), i.e. 1.6% (95% CI (1.1; 2.1)) for duodenal ulcer, and 1.3% (95% CI (0.8; 1.7)) for gastric ulcer. Poor socio-economic status increased the risk of PUD independently of H. pylori infection (odds ratio 2.7, 95% CI (1.1; 6.1)) and accounted for 17% of all ulcer cases. High physical activity at work increased the risk of PUD in people infected with H. pylori (odds ratio 2.6, 95% CI (0.8; 8.0)). Family history of PUD or Lewis blood group antigens did not relate to ulcer incidence. CONCLUSIONS: Poor socio-economic status is an important risk factor for PUD that exerts its effect independently of H. pylori infection. Strenuous work may increase the risk of PUD in people with H. pylori infection. Genetic factors do not influence the risk of PUD in Danish adults.

Risk factors for peptic ulcer disease: a population based prospective cohort study comprising 2416 Danish adults.

BACKGROUND: No population based prospective cohort study has previously assessed the impact of multiple risk factors, including Helicobacter pylori infection, on the incidence of peptic ulcer disease (PUD). AIMS: To identify risk factors for PUD and estimate their relative impact on ulcer incidence. SUBJECTS: Random sample of 2416 Danish adults with no history of PU. METHODS: Sample members were interviewed in 1982 and 1994. PUs diagnosed within the observation period were verified through medical records. Information on psychosocial factors, lifestyle practices, and medication was obtained from a questionnaire completed at study entry. H pylori infection status was determined by ELISA. RESULTS: The main risk factors for PUD were H pylori infection (odds ratio 4.3 (95% confidence interval 2.2; 8.3)), tobacco smoking (3.8 (1.7; 9.8)), and use of minor tranquillisers (3.0 (1.4; 6.6)). Intake of non-steroid anti-inflammatory drugs did not affect the incidence of PUD (0.4 (0.1; 2.3)). In those with increased antibodies to H pylori, tobacco smoking (12.7 (2.8; 56.8)) and intake of spirits (2.4 (1.1; 5.4)) increased the risk of PUD whereas moderate leisure time physical activity (0.3 (0.2; 0.7)) protected against PUD. CONCLUSIONS: Tobacco smoking and H pylori infection are the main risk factors for PUD in Danish adults. Physical activity may protect against PUD in those infected with H pylori.

[Tobacco and alcohol are risk factors of complicated peptic ulcers. A prospective cohort study]. / Tobak og alkohol er risikofaktorer for komplicerede peptiske ulcera. En prospektiv kohorteundersøgelse.

Both the incidence of and mortality from bleeding and perforated peptic ulcers are growing. We assessed the association between smoking, ingestion of alcohol (including the type of alcoholic beverage), and risk of a complicated peptic ulcer in a population-based study of 26,518 Danish subjects followed up for an average of 13.4 years. There were 214 cases of incident bleeding and 107 cases with perforated ulcers. We estimated the relative risks (RRs) of incident bleeding and perforated peptic ulcers with the Poisson regression analysis. Smoking more than 15 cigarettes a day compared with never smoking increased the risk of a perforated ulcer more than threefold (RR = 3.5; 95% confidence interval [CI] = 1.7-7.1). Ingestion of more than 42 drinks a week increased the risk of a bleeding ulcer fourfold (RR = 4.4; 95% CI = 2.3-8.3) compared with ingestion of less than one drink a week. Comparison of the same group, showed that subjects who ingested more than 21 drinks a week, but no wine, were at a higher risk of a bleeding ulcer (RR = 8.8; 95% CI = 2.2-35) than drinkers of the same amount of alcohol, but with more than 25% of their intake as wine (RR = 2.4; 95% CI = 1.0-6.0).

[Exchange of paraclinical information between the primary and secondary health sectors]. / Paraklinisk informationsudveksling mellem den primaere og sekundaere sundhedssektor.

INTRODUCTION: The purpose of the study was to investigate the extent to which, biochemical test results obtained in the primary health sector could be regarded as valid information in the clinical assessment of patients admitted to hospital. METHODS: The study was based on a questionnaire, which was designed to assess the value of historical biochemical data in the initial diagnostic process. The data was transferred from the laboratory of Copenhagen general practitioners (KPLL) database to a computer terminal in the emergency medical ward at H:S Bispebjerg Hospital. RESULTS: It was possible to assess historical KPLL data on close to 80% of all hospitalised patients. In 50% of these patients, doctors indicated that the data always (96%) contributed to the diagnosis. In 70%, the data further contributed to the subsequent planning of diagnostic strategy. With regard to the initial diagnosis, comparison of KPLL data with data obtained on admission always resulted in a further classification of at least one condition. The comparison of KPLL data with admission data always led to a more precise plan for further diagnostic strategy. CONCLUSION: The comparison of KPLL data with admission data, significantly contributes to differentiate the initial diagnostic strategy. In turn, this seems to have a significant bearing on the planning of further diagnostic strategy. It is postulated that a computer-based information system, through which the primary and secondary health sectors can exchange patient-related clinical data, would lead to a more focused use of resources, and hold significant advantages for the patient.

Eradication of Helicobacter pylori compared with long-term acid suppression in duodenal ulcer disease. A randomized trial with 2-year follow-up. The Danish Ulcer Study Group.

BACKGROUND: Trials evaluating long-term management of duodenal ulcer disease have mainly been focused on recurrence of ulcers, disregarding effects on dyspeptic and reflux symptoms. Profound acid inhibition with a proton pump inhibitor is the gold standard therapy in acid-related diseases. We aimed to compare the symptomatic effects of eradication therapy with those of long-term omeprazole treatment in a design with periods both with and without acid inhibition. METHODS: Patients with active duodenal ulcer were randomized either to omeprazole, 20 mg twice daily until healing, followed by omeprazole, 20 mg/ day for 1 year, or to eradication therapy (metronidazole, amoxicillin, and omeprazole for 2 weeks) followed by placebo for 1 year. All patients were followed up passively for an additional year. Clinical controls were performed every 2 months the 1st year (maintenance phase) and every 6 months during the passive follow-up phase. The study was multicentric and double-blind. The primary end-point was discontinuation of treatment, irrespective of reason. RESULTS: Two hundred and seventy-six patients were randomized (139 in the eradication treatment group). In the maintenance phase there were no differences in the reporting of dyspeptic symptoms or in premature withdrawal. In the passive follow-up phase only five patients in the eradication therapy group discontinued owing to relapse of dyspeptic symptoms or ulcer, compared with 51 patients initially randomized to long-term omeprazole. There were no differences in reflux symptoms or in the development of reflux oesophagitis. CONCLUSIONS: Eradication therapy and long-term omeprazole are equally effective in controlling dyspeptic symptoms and reflux in duodenal ulcer patients with healed ulcers. One-quarter of the duodenal ulcer patients who start eradication therapy continue to be symptomatic or fail therapy for other reasons over a 2-year period. Eradication therapy does not increase the risk of reflux in ulcer patients.

Identifying responders to acid suppression in dyspepsia using a random starting day trial.

BACKGROUND: Functional dyspepsia is a heterogeneous condition and a uniform response to drug treatment is not likely. This may be the reason for the general failure of acid suppression in clinical trials in these patients. It may be more rewarding to identify true responders to drug treatment by a single subject trial. AIM: To develop and to test a novel single subject trial design (random starting day trial) in dyspeptic patients. PATIENTS AND METHODS: A total of 301 dyspeptic patients entered a 16-day trial. All patients received placebo for the first 4 days and switched to omeprazole at a randomized and blinded day between day 5 and day 14. Response was defined as a sustained >/= 50% decrease in symptom score occurring in relation to drug shifting. RESULTS: Spontaneous response varied between 0.3% and 10.6% per day, uniformly distributed over time. Overall, 53-61% of patients with organic dyspepsia had a symptom response in relation to shifting to active treatment, compared to only 23% of patients with functional dyspepsia. The only predictor of response was symptoms suggesting gastro-oesophageal reflux. CONCLUSIONS: A random starting day trial may be a valuable tool to identify response to acid suppression in dyspeptic patients.

Smoking and alcohol intake as risk factors for bleeding and perforated peptic ulcers: a population-based cohort study.

Both the incidence of and mortality from bleeding and perforated peptic ulcers are increasing. We assessed the association between smoking, intake of alcohol (including type of alcoholic beverage), and risk of a complicated peptic ulcer in a population-based study of 26,518 Danish subjects followed up for an average of 13.4 years. There were 214 cases of incident bleeding and 107 cases with perforated ulcers. We estimated relative risks (RRs) for incident bleeding and perforated peptic ulcers using Poisson regression analysis. Smoking more than 15 cigarettes per day compared with never smoking increased the risk of a perforated ulcer more than threefold [RR = 3.5; 95% confidence interval (CI) = 1.7-7.1)]. Drinking more than 42 drinks per week increased the risk of a bleeding ulcer fourfold (RR = 4.4; 95% CI = 2.3-8.3) compared with drinking less than one drink per week. Using the same comparison group, subjects who drank more than 21 drinks per week but no wine were at a higher risk of a bleeding ulcer (RR = 8.8; 95% CI = 2.2-35) than drinkers of the same amount of alcohol, but with more than 25% of their intake as wine (RR = 2.4; 95% CI = 1.0-6.0).

[The relationship of Helicobacter pylori to iron status--serum ferritin and hemoglobin. A seroepidemiologic survey of 2794 Danes]. / Helicobacter pyloris relation til jernstatus--serumferritin og haemoglobin. En seroepidemiologisk undersøgelse af 2.794 danskere.

We evaluated the influence of Helicobacter pylori (H. pylori) infection assessed by the levels of H. pylori serum IgG-antibodies, on iron status (serum ferritin and haemoglobin) in 2794 Danes (1425 men), aged 30-60 years. The seroprevalence of H. pylori antibodies increased with age (p < 0.01). Median serum ferritin levels were significantly lower in seropositive than in seronegative men and postmenopausal women (men 114 micrograms/L vs. 120 micrograms/L, p = 0.01; premenopausal women 37 micrograms/L vs. 40 micrograms/L, p = 0.13; postmenopausal women 63 micrograms/L vs. 77 micrograms/L, p = 0.02). Seropositive subjects had a higher prevalence of iron deficiency (serum ferritin < 15 micrograms/L) than seronegative subjects. H. pylori infection has a negative influence on iron status. We hypothesize that this may be caused by increased blood losses from the gastric mucosa.

Seroconversion and seroreversion in IgG antibodies to Helicobacter pylori: a serology based prospective cohort study.

STUDY OBJECTIVES: To assess the incidence of seroconversion and seroreversion in IgG antibodies to Helicobacter pylori within a 11 year observation period using these events as markers for acquisition and loss of the infection, respectively. DESIGN: Population based prospective cohort study. SETTING: Northern part of Copenhagen County, Denmark. PARTICIPANTS AND METHODS: A random sample of 2527 Danish adults were examined and blood obtained in 1983 and in 1994. Matching pairs of sera were analysed for the presence of IgG and IgM antibodies to H pylori with an in house enzyme linked immunosorbent assay. Participants who were seronegative at study entry and seropositive at follow up and had a fourfold increase in baseline IgG antibody levels were categorised as seroconverters and regarded as having acquired H pylori infection. Participants who were seropositive at study entry and had at least a fourfold decrease in baseline IgG antibody levels at follow up were assumed to have lost the infection (seroreverters). RESULTS: The seroprevalence of H pylori infection was 24.7 (95% confidence intervals (95% CI) 23.0, 26.4) % in 1983 and 24.5 (95% CI 22.8, 26. 2) % in 1994. A total of 14 participants seroconverted within the observation period (cumulative 11 year incidence proportion: 1.0 (95% CI 0.5, 1.5) %). Having increased IgM antibody levels at study entry significantly increased the likelihood of IgG seroconversion (relative risk 6.4 (95% CI 2.1, 19.6). Seroreversion was seen in 48 participants (cumulative 11 year incidence proportion: 7.7 (95% CI 5. 6, 9.8) %). CONCLUSIONS: Changes in H pylori infection status with time are rare in Danish adults. Few adults become infected with H pylori in Denmark.

Association of Helicobacter pylori infection with lifestyle, chronic disease, body-indices, and age at menarche in Danish adults.

This study examines the association between lifestyle factors, chronic disease, body-indices, and the seroprevalence of Helicobacter pylori infection in Danish adults. The relationship between age at menarche and H. pylori infection is also assessed. A random sample of 3,608 Danish adults completed a questionnaire about lifestyle factors (smoking habits, alcohol consumption, and coffee and tea intake), doctor diagnosed chronic diseases (heart conditions, diabetes, chronic bronchitis, and hypertension), menarche, and socio-demographic factors. A total of 2,913 participants were eligible for the present study. Electrocardiographs were recorded and blood pressure and serum lipid levels (HDL cholesterol, triglyceride, and cholesterol) were measured. Height and weight were determined and body mass index (BMI) calculated. Sera were analysed with an enzyme-linked immunosorbent assay for the presence of H. pylori specific IgG antibodies. The seroprevalence of H. pylori infection was associated with weekly alcohol intake > or = 6 drinks (odds ratio 0.7, 95% confidence interval 0.6-0.9) due to a low rate of H. pylori infection among wine drinkers (odds ratio 0.6, 95% confidence interval 0.5-0.7). No associations were found with smoking habits or serum lipids. People with upper quartile BMI (> or = 26.8 kg/m2) were more likely to be seropositive for antibodies to H. pylori (odds ratio 1.6, 95% confidence interval 1.1-2.4). Chronic bronchitis (odds ratio 1.6, 95% confidence interval 1.1-2.5) and unspecified heart condition (odds ratio 2.0, 95% confidence interval 1.1-3.3) was more often seen in IgG seropositive women than in uninfected women. The likelihood of being seropositive for IgG antibodies to H. pylori increased with age at menarche (odds ratio per year 1.10, 95% confidence interval 1.02-1.19). Previously reported associations with age and socioeconomic status were confirmed. We conclude that wine drinking is associated with lower rates of H. pylori infection in Danish adults. The seroprevalence of H. pylori infection is increased in people with high BMI. H. pylori infection may relate to a history of late menarche and chronic bronchitis in Danish women.

[Peptic ulcer in Denmark, 1981-1993. Analysis of data from national patient registries]. / Peptiske ulcera i Danmark, 1981-1993. Analyse af data fra landspatient- og dødsårsagsregisteret.

The aim of this study was to determine whether the improvements in the treatment of peptic ulcers are associated with decreasing age- and sex-specific hospitalization and death rates for peptic ulcers in Denmark. The study was based on all discharges as registered in the National Hospital Discharge Registry and all death certificates as registered in the Danish National Board of Health from 1981 through 1993. The age- and sex-specific and age-adjusted hospitalization and death rates were estimated. In women, the age-adjusted hospitalization increased for all types of peptic ulcers. In both sexes the age-adjusted peptic ulcer mortality increased mainly due to complicated duodenal ulcers. The analysis of the age-specific hospitalization and mortality for peptic ulcer complications showed that the increasing trends mainly occurred among the elderly. The improved medical treatment of peptic ulcers has not been associated with decreasing hospitalization or death from complicated peptic ulcers in Denmark.

Lansoprazole and omeprazole in the prevention of relapse of reflux oesophagitis: a long-term comparative study.

BACKGROUND: Proton pump inhibitors are superior to H2-receptor antagonists in the prevention of relapse of oesophagitis, but few data directly compare the relative efficacies of lansoprazole and omeprazole in preventing oesophagitis relapse over a prolonged period. METHODS: Patients with healed Grade II, III or IV oesophagitis were treated with lansoprazole 30 mg o.d. or omeprazole 20 mg o.d. for 48 weeks. Endoscopy and symptom assessment were performed after 12. 24 and 48 weeks of treatment and an additional symptom assessment 36 weeks after starting treatment. RESULTS: Intention-to-treat analysis included 248 patients (lansoprazole n = 126, omeprazole n = 122). Comparison of time to endoscopic and/or symptomatic relapse revealed no difference between the treatments. There was no significant difference between treatments with respect to the proportion of patients in whom endoscopic and/or symptomatic relapse was reported (lansoprazole 12/126 (9.5%), omeprazole 11/122 (9.0%)). No difference between the treatments in either the number or severity of adverse events was reported. CONCLUSIONS: Continuous treatment with either lansoprazole 30 mg or omeprazole 20 mg is effective in preventing the relapse of oesophagitis over a 48-week period in a majority of patients. Both treatments exhibit a similar side-effect profile.

Serum ferritin, hemoglobin, and Helicobacter pylori infection: a seroepidemiologic survey comprising 2794 Danish adults.

BACKGROUND & AIMS: Helicobacter pylori infection was recently associated with iron-deficiency anemia. The aim of this study was to examine the relationship between H. pylori infection, hemoglobin, and iron status using serum ferritin as a marker for total body iron. METHODS: Serum ferritin, hemoglobin, and immunoglobulin G (IgG) antibodies against H. pylori were assessed in 2794 Danish adults who attended a population survey. IgG antibodies were measured with an in-house enzyme-linked immunosorbent assay, serum ferritin with an immunoradiometric assay, and hemoglobin with Coulter-S. RESULTS: The seroprevalence of H. pylori infection did not relate to hemoglobin. Serum ferritin levels were significantly lower in men (114 vs. 120 microg/L; P = 0.01) and in postmenopausal women (63 vs. 77 microg/L; P = 0.02) who were IgG positive than in seronegative individuals. IgG-positive people more often had reduced serum ferritin levels (

[Helicobacter pylori infection and socioeconomic factors among adult Danes]. / Helicobacter pylori-infektion og socioøkonomiske faktorer blandt voksne danskere.

The aim of this study was to examine the relationship between housing conditions, educational level, occupational factors, and serologically diagnosed acute and chronic Helicobacter pylori infection. IgG, IgM, and IgA antibodies against Helicobacter pylori were measured by ELISA techniques in sera obtained from a random sample of 3589 Danes participating in a population study. Poor social status (odds ratio 2.2 [1.7-3.0]), short duration of schooling (odds ratio 2.0 [1.3-2.5]), lack of vocational training/education (odds ratio 1.4 [1.2-1.7]), unskilled work (odds ratio 1.7 [1.2-2.5]), and high work-related energy expenditure (odds ratio 1.4 [1.1-1.9]) increased the likelihood of chronic Helicobacter pylori infection. Chronic Helicobacter pylori infection was frequently found in people with a history of living abroad. Increased levels solely of IgM antibodies to H. pylori, interpreted as a sign of acute infection, were found more often in people who were divorced (odds ratio 2.3 [1.2-4.4]) or unmarried (odds ratio 2.0 [1.1-3.8]) and in people who worked long hours (odds ratio 2.0 [1.1-4.0]). In conclusion, educational and occupational factors relate to the likelihood of chronic Helicobacter pylori infection in adults. The rate of acute Helicobacter pylori infection is probably increased in single adults.

Time trends for peptic ulcer disease in Denmark, 1981-1993. Analysis of hospitalization register and mortality data.

BACKGROUND: Since the mid-1980s there has been great improvement in the available diagnostic tools and treatments for peptic ulcers. The aim of this study was to determine whether these improvements have been paralleled by decreasing age- and sex-specific hospitalization and death rates for peptic ulcers in Denmark. METHODS: The study was based on all discharges from Danish somatic hospitals as registered in the National Hospital Discharge Registry and all the death certificates as registered in the Danish National Board of Health from 1981 through 1993, when a diagnosis of peptic ulcer was recorded. The age- and sex-specific and age-adjusted hospitalization and death rates were estimated. RESULTS: In men the age-adjusted hospitalization rate for all types of peptic ulcers decreased by 0.88, but the mortality increased by 1.19. In women the age-adjusted hospitalization and mortality increased for all types of peptic ulcers. The increasing mortality was mainly due to bleeding and perforated duodenal ulcers. The analysis of the age-specific hospitalization and mortality for peptic ulcer complications showed that the increasing trends mainly occurred among the elderly. CONCLUSION: The improved medical treatment of peptic ulcers has not been paralleled by decreasing hospitalization or death from complicated peptic ulcers in Denmark. On the contrary, we found an increasing hospitalization and mortality from peptic ulcer complications, particularly in elderly Danish people.

Relation between Helicobacter pylori infection and gastrointestinal symptoms and syndromes.

BACKGROUND: Helicobacter pylori is a human pathogen that colonises the gastric mucosa and causes permanent gastric inflammation. AIMS: To assess the symptoms of H pylori infection in an adult unselected population. SUBJECTS: A random sample of 3589 adult Danes who were examined in 1982 and 1987 (n = 2987). METHODS: Abdominal symptoms within the preceding year were recorded at both attendances. Circulating IgG antibodies against H pylori in serum samples drawn in 1982 were measured by using in-house indirect enzyme linked immunosorbent assays (ELISA). RESULTS: People with increased levels of IgG antibodies to H pylori were more likely than uninfected individuals to report heartburn (odds ratio (OR) = 1.26, 95% confidence interval (CI) 1.03-1.54) and abdominal pain characterised by daily length (OR = 1.33, 95% CI 0.92-1.91), nocturnal occurrence (OR = 1.62, 95% CI 1.19-2.19), spring aggravation (OR = 1.68, 95% CI 0.70-4.05), and no relation to meals (OR = 0.62, 95% CI 0.43-0.91) or stress (OR = 0.69, 95% CI 0.50-0.95). The inclusion of people with increased levels of IgG antibodies to H pylori, but without upper dyspepsia, at study entry significantly increased the likelihood of reporting upper dyspepsia at follow up (OR = 1.71, 95% CI 1.24-2.36). People with epigastric pain and increased levels of IgM antibodies to H pylori only indicative of acute H pylori infection were more likely to report nocturnal pain, heartburn, nausea, and vomiting. CONCLUSION: H pylori infection may precede the development of dyspepsia and is associated with a variety of gastrointestinal symptoms in people with no history of peptic ulcer disease.

Antimicrobial susceptibility testing of 230 Helicobacter pylori strains: importance of medium, inoculum, and incubation time.

No standardized method of susceptibility testing for Helicobacter pylori is currently available, so before a large agar dilution study comprising 230 H. pylori strains belonging to more than 80 genetically different groups was initiated, we performed a relatively small preliminary study to determine the influences of medium, inoculum density, and incubation time. Seven media were investigated and were primarily evaluated on the basis of their abilities to support growth both semiquantitatively and qualitatively; Iso-Sensitest agar supplemented with 10% horse blood was found to be well suited for the purpose; this was closely followed by Mueller-Hinton agar with 10% horse blood, Mueller-Hinton with 10% sheep blood, and finally, 7% lysed horse blood agar. Investigations of two inoculum densities and two incubation times resulted in recommendations for the use of 10(9) CFU/ml (10[6] CFU/spot) as the inoculum and 72 h as the incubation time. A modest inoculum effect was noted for amoxicillin and metronidazole. By the methodology derived from our preliminary study, the susceptibilities of 230 H. pylori strains to six antibiotics were subsequently determined. The results were generally in accord with those of others, and apart from metronidazole, the MIC of which for approximately 25% of the strains tested was >8 microg/ml, resistance was low in Denmark. The situation might, however, quickly change when and if the number of indications for antibiotic therapy for H. pylori infections increase. Consequently, susceptibility testing of all H. pylori strains is recommended in order to survey the development of resistance, and in our hands the described methodology was relatively easy to perform and the results were easy to read.

Socioeconomic factors in Helicobacter pylori infection among Danish adults.

OBJECTIVES: This study examined the relationship between housing conditions, educational level, occupational factors, and serologically diagnosed acute and chronic Helicobacter pylori infection. METHODS: Immunoglobulin G and immunoglobulin M serum antibodies against H. pylori were measured in 3589 Danish adults who participated in a population study. RESULTS: Low socioeconomic status (odds ratio [OR] = 2.2, 95% confidence interval [CI] = 1.7, 3.0), short duration of schooling (OR = 2.0, 95% CI = 1.3, 2.5), lack of training/education (OR = 1.4, 95% CI = 1.2, 1.7]), unskilled work (OR = 1.7, 95% CI = 1.2, 2.5), and high work-related energy expenditure (OR = 1.4, 95% CI = 1.1, 1.9) increased the likelihood of chronic H. pylori infection. Infection was frequent in people who had lived abroad. Increased levels solely of immunoglobulin M antibodies were found more often in people who were divorced (OR = 2.3, 95% CI = 1.2, 4.4) or unmarried (OR = 2.0, 95% CI = 1.1, 3.8) or who worked long hours (OR = 2.0, 95% CI = 1.1, 4.0). CONCLUSIONS: Educational and occupational factors relate to the likelihood of chronic H. pylori infection in adults. The rate of acute infection is high in single individuals.

Seroprevalence of immunoglobulin G, M, and A antibodies to Helicobacter pylori in an unselected Danish population.

The seroprevalences of increased levels of immunoglobulin G (lgG), M (lgM), and A (lgA) antibodies to Helicobacter pylori were assessed by enzyme-linked immunosorbent assay techniques in 3,589 Danes who participated in a population study in Copenhagen County in 1982. A total of 33.9% of the study population had one or more classes of increased antibodies to H. pylori. Increased levels of lgG, lgM, and lgA antibodies to H. pylori were seen in 25.9% (95% confidence interval (Cl) 24.5-27.3), 4.5% (95% Cl 2.2-7.0), and 12.0% (95% Cl 10.9-13.1) of the participants, respectively. Women were significantly more likely than men to be seropositive for lgM antibodies (Mantel-Haenszel summary odds ratio = 1.85, 95% Cl 1.34-2.57). Seropositivity for lgM antibodies to H. pylori was found less often with increasing age. An lgG antibody response was not seen in 23.7% of cases with overall increased antibodies to H. pylori. Increased levels of lgG or lgA antibodies were more frequent in people with a history of peptic ulcer disease. Seroprevalences of increased H. pylori antibodies are high in unselected populations. Primary H. pylori infections are contracted at all ages, but infection rates decline with age. Inclusion of measurements of lgA and lgM antibody levels in future screening for H. pylori may improve the diagnostic sensitivity of serologic analyses.

Epidemiology in gastroenterology.

A review of the literature on gastrointestinal epidemiology during the last 25 years shows a comprehensive contribution from Danish studies. This is partly explained by very favourable conditions in Denmark for epidemiological research, due to various valid registers and a long tradition for longitudinal population and patient cohorts. Data are presented on prevalence, incidence, demography, clinical risk factors, clinical course, and prognosis of various gastrointestinal disorders. Main emphasis is put on Danish studies, which are compared with international results. Present possibilities for prophylaxis against gastrointestinal diseases and delimitation of treatment of benign diseases are discussed. It is expected that research within gastrointestinal epidemiology in Denmark will increase in the coming years.