Leif P. Andersen

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

BACKGROUND & AIMSnHelicobacter 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.nnnMETHODSnSerum 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.nnnRESULTSnThe 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 (</=30 microg/L) than seronegative people. This association persisted in multivariate analysis after adjusting for possible confounding factors (odds ratio, 1.4; 95% confidence interval 1.1-1. 8).nnnCONCLUSIONSnSerum ferritin levels are reduced in people with increased IgG antibodies to H. pylori. H. pylori infection affects iron metabolism in humans.

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.

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. Conclusions—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.

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 ≥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 (≥26.8 kg/m 2) 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.

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 toH 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 inH pylori infection status with time are rare in Danish adults. Few adults become infected with H pylori in Denmark.

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.

Socioeconomic factors in Helicobacter pylori infection among Danish adults

OBJECTIVESnThis study examined the relationship between housing conditions, educational level, occupational factors, and serologically diagnosed acute and chronic Helicobacter pylori infection.nnnMETHODSnImmunoglobulin G and immunoglobulin M serum antibodies against H. pylori were measured in 3589 Danish adults who participated in a population study.nnnRESULTSnLow 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).nnnCONCLUSIONSnEducational and occupational factors relate to the likelihood of chronic H. pylori infection in adults. The rate of acute infection is high in single individuals.

INDIGENOUS GREENLANDERS HAVE A HIGHER SERO-PREVALENCE OF IgG ANTIBODIES TO HELICOBACTER PYLORI THAN DANES

Objective: To assess the sero-prevalence of IgG antibodies to Helicobacter pylori (H. pylori) in Greenlanders and compare with the sero-prevalence in Caucasian Danes. Methods: 71 randomly recruited indigenous Greenlanders (29 men) with a median age of 39 years (range 22–76), living in the capital, Nuuk, and the town of Ilulissat, and participating in a population survey carried out in 1993–1994. The results were compared with those obtained in a 1983–1984 population survey in Copenhagen County, comprising 2794 Caucasian Danes (1425 men) with a median age of 41 years (range 30-60). Serum IgG antibody levels to H. pylori were determined by an indirect enzyme-linked immunosorbent assay in 1995 and categorised as negative, borderline (equivocal), or positive. Results: Greenlanders: 48.3 % of men and 45.2% of women had positive serum IgG antibody levels to H. pylori. In the entire series, 46.5% had positive IgG antibody levels, 25.4% displayed borderline antibody levels and 28.2% had negative antibody levels. There were no age, or gender differences concerning the prevalences of the three H. pylori IgG antibody subgroups. Danes: 25.6 % of men, and of women, had positive IgG antibody levels against H. pylori. In the entire series, 25.6% had positive IgG antibody levels, 19.0% displayed borderline antibody levels and 55.4% had negative antibody levels. There was no gender difference concerning the sero-prevalence of IgG antibodies, but the sero prevalence increased significantly with age. The prevalence of positive serum IgG antibodies against H. pylori was markedly higher in Greenlanders than in Danes (p <0.0001). Conclusion: Indigenous Greenlanders have a significantly higher infection rate with H. pylori than Danes. The results suggest that Greenlanders become infected with H. pylori early in life.

Helicobacter pylori infection does not affect red blood cell characteristics in Danish adults

Recent studies have suggested a relationship between iron deficiency anemia and Helicobacter pylori (H. pylori) infection. Furthermore, we have previously reported an association between 11. pylori infection and reduced serum ferritin values; a marker for total body iron. Purpose: to examine whether H. pylori infection affects red blood cell (RBC) characteristics in humans. Methods: In 1994, 2407 Danish adults with no history of peptic ulcer disease, attended a follow-up examination as part of a prospective cohort study initiated in October 1982. A total of 275 blood donors were excluded from the study group. H. pylori infection status was assessed with a validated IgG ELISA. Red blood eel! count (RBCC), red blood cell volume (hematocrit-RBCV), mean RBC haemoglobin concentration (MCHC), mean RBC volume (MCV), and mean RBC haemoglobin (MCli) were assessed. Information on socio-demographic factors and medical history was ascertained from a questionnaire. Results: The table shows median and interquartile values of RBCC, RBCV, MCIIC, MCV, MCH, by sex and H. pylori infection status in 1994.