Ethnicity in relation to incidence of oesophageal and gastric cancer in England.

BACKGROUND: This study investigated the variation in incidence of all, and six subgroups of, oesophageal and gastric cancer between ethnic groups. METHODS: Data on all oesophageal and gastric cancer patients diagnosed between 2001 and 2007 in England were analysed. Self-assigned ethnicity from the Hospital Episode Statistics dataset was used. Male and female age-standardised incidence rate ratios (IRRs) were calculated for each ethnic group, using White groups as the references. RESULTS: Ethnicity information was available for 83% of patients (76 130/92 205). White men had a higher incidence of oesophageal cancer, with IRR for the other ethnic groups ranging from 0.17 95% confidence interval (CI) (0.15-0.20) (Pakistani men) to 0.58 95% CI (0.50-0.67) (Black Caribbean men). Compared with White women, Bangladeshi women (IRR 2.02 (1.24-3.29)) had a higher incidence of oesophageal cancer. For gastric cancer, Black Caribbean men (1.39 (1.22-1.60)) and women (1.57 (1.28-1.92)) had a higher incidence compared with their White counterparts. In the subgroup analysis, White men had a higher incidence of lower oesophageal and gastric cardia cancer compared with the other ethnic groups studied. Bangladeshi women (3.10 (1.60-6.00)) had a higher incidence of upper and middle oesophageal cancer compared with White women. CONCLUSION: Substantial ethnic differences in the incidence of oesophageal and gastric cancer were found. Further research into differences in exposures to risk factors between ethnic groups could elucidate why the observed variation in incidence exists.

Do guidelines improve clinical practice? - a national survey on surveillance colonoscopies.

BACKGROUND: Colonoscopic services are increasingly being utilized in surveillance of conditions predisposing to colorectal cancers (CRC). The ACPGBI/BSG guidelines are the most commonly followed recommendations. Numerous retrospective studies have shown poor compliance with them. We conducted a national survey of colonoscopic practitioners investigating attitudes, awareness and implementation of surveillance guidelines. METHOD: A postal questionnaire was sent to a random population of 250 ACPGBI and 200 BSG members. Questions assessed practice as regards colorectal polyp surveillance, family screening and surveillance for past history of CRC. RESULTS: The ACPGBI/BSG guidelines were the most commonly followed recommendations. Only 17.2% of practitioners used the criteria that would ensure accurate implementation of guidelines for colorectal adenoma surveillance. With regards to familial surveillance for CRC, 53.5% respondents assessed familial risk accurately, while 69.3% recommended surveillance incorrectly. A total of 48.8% of ACPGBI members recommended five yearly colonoscopies following curative treatment for CRC. CONCLUSION: This study has revealed the widespread ignorance of guidelines, which will potentially translate into the gross over utilization of colonoscopic resources. Strategies to improve and audit guideline implementation must be integral to guideline formation. Methods to improve accurate guideline implementation need to be explored.

Systematic review: adipose tissue, obesity and gastrointestinal diseases.

BACKGROUND: Obesity is increasingly being recognized as a risk factor for a number of benign and malignant gastrointestinal conditions. However, literature on the underlying pathophysiological mechanisms is sparse and ambiguous. Insulin resistance is the most widely accepted link between obesity and disease, particularly colorectal cancer. The recognition that intra-abdominal fat is immunologically active sheds new light not only on the pathogenesis of obesity-related gastrointestinal conditions, but also on inflammatory conditions such as Crohn's disease. AIM: To describe the biology of adipose tissue, its impact on the immune system and explores the possible underlying mechanisms linking obesity to gastrointestinal diseases. It also looks at the role of mesenteric fat in determining severity and course of Crohn's disease. METHODS: Relevant English-language literature and abstracts cited on MEDLINE database were reviewed. RESULTS: Our recent finding of an association between obesity and subclinical bowel inflammation suggests that, apart from promoting generalized immune activation, fat also evokes local immune responses. We propose that the proinflammatory milieu promoted by obesity could underlie many of these associations and that the mechanism implicating insulin resistance may merely represent an epiphenomenon. In Crohn's disease, on the other hand, intra-abdominal fat may provide a protective mechanism. CONCLUSION: The potential of adipose tissue as a therapeutic target is vast and needs exploration.

Chlamydia pneumoniae infection and early asymptomatic carotid atherosclerosis.

BACKGROUND: Chronic Chlamydia pneumoniae infection has been implicated in the pathogenesis of atherosclerosis but whether it plays a role at an early stage in the disease is uncertain. An early estimate of atherosclerosis can be obtained by ultrasonic imaging of the carotid artery to determine intima-media thickness (IMT) and the thickness of any atheroma plaques. METHODS AND RESULTS: In 983 normal population individuals aged 30 to 70 years, we measured common carotid artery (CCA) and carotid bulb IMT, and also carotid plaque thickness and the degree of internal carotid artery (ICA) stenosis. C. pneumoniae IgA titers of >/=16 and IgG titers of >/=64 were taken as positive. There was no association between C. pneumoniae IgA or IgG seropositivity with right, left, or mean CCA or bulb IMT, or with the presence of carotid plaques. There was a significant association between IgA seropositivity and >50% mean carotid stenosis with an odds ratio of 5.24 (95% CI 1.24 to 22.21, P=0.0245) after controlling for age and sex; after controlling for other cardiovascular risk factors, this was not significant 3.96 (95% CI 0. 84 to 18.78, P=0.082). No association was found between IgA or IgG seropositivity and markers of fibrinogen, log C-reactive protein, or leukocyte count. CONCLUSIONS: We found no evidence that serological evidence of C. pneumoniae infection is associated with early atherosclerosis. It is possible that IgA seropositivity is associated with more advanced disease but this hypothesis needs to be examined in a population with a higher prevalence of advanced atherosclerosis. We found no evidence that C. pneumoniae results in a chronic systemic inflammatory state.

C-reactive protein concentration in children: relationship to adiposity and other cardiovascular risk factors.

Whether or not C-reactive protein (CRP) predicts heart disease in adults because it is a marker of damage or atherosclerosis is difficult to assess. In children, there is no confounding with coronary disease or active smoking. We measured CRP in 699 children aged 10-11 years. CRP levels were 47% higher in girls than boys, and rose with age by 15%/year. CRP levels were 270% (95% CI, 155-439%) higher in the top fifth than the bottom fifth of Ponderal index (weight/height(3)). After adjustment, CRP levels remained 104% (95% CI, 23-236%) higher in the 56 children of South Asian origin. CRP was unrelated to: birth weight, height, social class, Helicobacter pylori infection or passive smoke exposure. CRP was correlated with several cardiovascular risk factors, but only fibrinogen (r = 0.33, P = 0.0001), HDL-cholesterol (r = -0.13, P = 0.0006), heart rate (r = 0.12, P = 0.002) and systolic blood pressure (r = 0.08, P = 0.02) remained statistically significant after adjustment. We conclude that adiposity is the major determinant of CRP levels in children while physical fitness has a small independent effect. The strong relationships with fibrinogen and HDL-cholesterol suggest a role for inflammation throughout life in the development of atherosclerosis and cardiovascular disease. Longitudinal studies are needed to determine whether these associations reflect long term elevations of these risk factors in some individuals, or short term fluctuations in different individuals.

Review article: faecal markers in the assessment of activity in inflammatory bowel disease.

The fundamental pathological process behind ulcerative colitis and Crohn's disease is intestinal inflammation. As the precise cause of this is not yet completely understood, current treatment strategies are aimed at reducing or eliminating the inflammation. Endoscopic examination and histological analysis of biopsy specimens remain the 'gold standard' methods for detecting and quantifying bowel inflammation; however, these techniques are costly, invasive, and repeated examinations are unpopular with patients. Disease activity questionnaires and laboratory 'inflammatory markers', although widely used, show an unreliable correlation with endoscopy and histology. New markers need to be developed to detect and quantify bowel inflammation. These would be of use diagnostically and also an aid to pharmacological treatment.

Western blotting is useful in the salivary diagnosis of Helicobacter pylori infection.

BACKGROUND: The salivary diagnosis of Helicobacter pylori infection offers attractive possibilities for the epidemiological study of infection in children. Salivary enzyme linked immunosorbent assay (ELISA) is less reliable then serum ELISA, owing to variable transudation of immunoglobulin. In addition, children are more difficult to study because of lower specific serum antibody concentrations to H pylori. The performance of salivary western blotting in comparison with serum western blotting and serum ELISA was investigated in school children. SUBJECTS AND METHODS: Paired serum and saliva specimens were obtained from 669 [corrected] school children aged 9-11 in 10 British towns. All saliva and serum specimens were first analysed by ELISA; subsequently, western blotting of both specimens was performed on 31 and 34 specimens, respectively, to establish the criteria for positivity for western blotting. The remaining 121 specimens were then tested blindly and saliva was compared with the serum. RESULTS: The sensitivity and specificity of salivary ELISA in the 669 [corrected] specimens was 32 of 50 (64%) and 530 of 619 (86%) [corrected], respectively, when compared with serum ELISA. The western blotting validation was performed on 28 subjects with positive serum and positive salivary ELISA, 28 saliva positives with negative serum, 16 saliva negatives with positive serum, and 50 doubly negative subjects. Compared with serum western blots, the sensitivity and specificity of salivary western blots was 38 of 47 (81%) and 68 of 75 (91%), respectively. Using serum ELISA as the gold standard, the sensitivity and specificity were 32 of 44 (73%) and 72 of 78 (92%), respectively, the specificity being significantly higher than salivary ELISA (p < 0.001). CONCLUSION: Salivary western blotting for IgG is useful in the diagnosis of H pylori infection and is superior to ELISA. It also permits the identification of pathogenic strains.

The effects of unsaturated fatty acids on Helicobacter pylori in vitro.

The effects of three unsaturated free fatty acids on Helicobacter pylori growth in vitro was determined. Growth of H. pylori in Brucella broth was inhibited in a dose-dependent manner by arachidonic, linoleic and oleic acids. The degree of inhibition at any one concentration was related to the degree of fatty acid unsaturation. Triolein, a triacylglycerol ester of oleic acid did not inhibit growth. Inhibition of H. pylori growth was associated with disruption of cell membranes. Incubation with 14C linoleic acid and 14C oleic acid showed incorporation of these fatty acids into H. pylori cell mass and phospholipids leading to alteration of the phospholipid composition of the organism. Incorporation was greater with linoleic than oleic acid and this was associated with a greater inhibition of growth. These findings indicate that H. pylori is sensitive to unsaturated free fatty acids through their incorporation into phospholipids and membrane destruction. This may have therapeutic implications.

Prospective relations between Helicobacter pylori infection, coronary heart disease, and stroke in middle aged men.

OBJECTIVE: To determine whether Helicobacter pylori, a chronic bacterial infection often acquired in childhood, is associated with increased risk of coronary heart disease and stroke later in life. DESIGN: Nested case-control study. SETTING: Prospective study of cardiovascular disease in men aged 40-59 years at entry (1978-1980) in 24 British towns. SUBJECTS: 135 cases of myocardial infarction and 137 cases of stroke occurring before December 1991; 136 controls were identified, frequency matched to cases by town and age group. METHODS: Serum samples stored at entry were analysed by an enzyme linked immunosorbent assay for the presence of H pylori specific IgG antibodies. RESULTS: 95 of the myocardial infarction cases (70%) and 93 (68%) of the stroke cases were seropositive for H pylori compared with 78 (57%) of the controls (odds ratio for myocardial infarction 1.77, 95% confidence interval (CI) 1.06 to 2.95, P = 0.03; odds ratio for stroke 1.57, 95% CI 0.95 to 2.60, P = 0.07). Helicobacter pylori infection was associated with manual social class, residence in Northern England or Scotland, cigarette smoking, higher systolic pressure and blood glucose, and a lower height-standardised forced expiratory volume in one second. Adjustment for these factors attenuated the relation between H pylori and myocardial infarction (odds ratio = 1.31, 95% CI 0.70 to 2.43, P = 0.40) and effectively abolished the relation with stroke (odds ratio = 0.96, 0.46 to 2.02, P = 0.92). The relation between helicobacter infection and fatal myocardial infarction was slightly stronger (odds ratio 2.41, 95% CI 1.13 to 5.12) but was also markedly attenuated after adjustment (1.56, 95% CI 0.68 to 3.61). CONCLUSION: In this prospective study the association between Helicobacter pylori infection and increased risk of myocardial infarction and stroke was substantially confounded by the relation between this infection, adult social class, and major cardiovascular risk factors.

Relation of serum cytokine concentrations to cardiovascular risk factors and coronary heart disease.

OBJECTIVE: To determine whether serum concentrations of the cytokines tumour necrosis factor alpha (TNF alpha) and interleukin 6 (IL-6), which regulate C reactive protein, are associated with cardiovascular risk factors and prevalent coronary heart disease. DESIGN: A population based cross sectional study. SUBJECTS AND METHODS: 198 men aged 50 to 69 years were part of a random population sample drawn from south London. Serum cytokine and C reactive protein concentrations were determined by enzyme linked immunosorbent assay. The presence of coronary heart disease was determined by Rose angina questionnaire and Minnesota coded electrocardiogram. RESULTS: Serum TNF alpha concentrations were positively related to body mass index and Helicobacter pylori infection, but inversely related to alcohol consumption. IL-6 concentrations were positively associated with smoking, symptoms of chronic bronchitis, age, and father having a manual occupation. TNF alpha was associated with increased IL-6 and triglycerides, and reduced high density lipoprotein cholesterol. IL-6 was associated with raised fibrinogen, sialic acid, and triglycerides. ECG abnormalities were independently associated with increases in IL-6 and TNF alpha, each by approximately 50% (P < 0.05 for TNF alpha, P < 0.1 for IL-6). The corresponding increases in men with an abnormal ECG or symptomatic coronary heart disease were 28% for TNF alpha and 36% for IL-6 (P = 0.14 for TNF alpha and P < 0.05 for IL-6). CONCLUSIONS: This study confirms that many of the phenomena with which C reactive protein is associated, are also associated with serum levels of cytokine, which may be the mechanism.

Cytomegalovirus seropositivity and incident ischaemic heart disease in the Caerphilly prospective heart disease study.

OBJECTIVE: To assess the role of cytomegalovirus (CMV) infection in primary ischaemic heart disease. METHODS: Plasma specimens collected during 1979-83 from men in Caerphilly, south Wales, were analysed for IgG antibodies to CMV by enzyme linked immunosorbent assay and latex tests. Incident ischaemic heart disease events were ascertained after five and 10 years from death certificates, hospital records, and ECG changes; 195 incident ischaemic heart disease cases were compared with 216 controls of a similar age drawn from the rest of the cohort. RESULTS: 164 cases (84%) and 180 controls (83%) were seropositive for CMV. Optical density, an indicator of CMV antibody titre, was similar for cases and controls. Among controls, seropositivity was not associated with age, socioeconomic status currently or in childhood, smoking, height, body mass index, blood pressure, total cholesterol, fibrinogen, plasma viscosity, or leucocyte count. The unadjusted odds ratio relating CMV seropositivity to incident ischaemic heart disease was 1.06 (95% confidence interval 0.63 to 1.79) and was little changed (1.11, 0.63 to 1.97) after adjustment for age, smoking, body mass index, systolic blood pressure, total cholesterol, and socioeconomic status currently and in childhood. CONCLUSIONS: CMV infection is unlikely to be a strong risk factor for development of myocardial infarction in middle aged men.

Antibiotic use, childhood affluence and irritable bowel syndrome (IBS).

BACKGROUND: Antibiotics cause well defined short-lived disturbances in bowel habit. There is evidence to suggest that antibiotics may play a role in the pathogenesis of IBS. Atopy has been associated with small household size in childhood and could also play a role in IBS. We conducted a survey examining the relation of drug use and other epidemiological correlates of IBS. SETTING: General practice health screening clinic. SUBJECTS AND METHODS: 421 subjects (46% male, mean age 47 years (range 18-80 years) attending a general practice health screening clinic were interviewed by a research nurse and completed a previously validated questionnaire. Symptoms of IBS were said to be present if abdominal pain with 2 or more Manning criteria symptoms occurred more than once per month over the previous 6 months. RESULTS: 48 subjects had symptoms of IBS. The following were strongly related to its presence: antibiotic use [adjusted OR 3.70 (1.80-7.60)], female sex and childhood living density < 1 person per room [OR 3.47 (1.57-7.64)], manual father's occupation [OR 0.35 (0.16-0.76)]. The use of NSAIDS, H2 antagonists or other types of medication was not greater in this group. CONCLUSION: Antibiotic use is associated with IBS. The association with antibiotic use requires testing in prospective studies. Privileged childhood living conditions were also an important risk factor which is consistent with an allergic aetiology for IBS.

Which Helicobacter pylori-positive dyspeptics are likely to respond symptomatically to empirical H. pylori eradication?

OBJECTIVE: To identify which Helicobacter pylori-positive dyspeptic patients have an increased likelihood of having peptic ulcer and may thus be more likely to benefit from empirical H. pylori eradication therapy. METHODS: 622 out of 740 consecutive dyspeptic subjects (median age 45 years, range 14-91, 51% male) attending for rapid access endoscopy were eligible for the study. Demographic data and endoscopic findings were recorded. H. pylori status was determined by urease and histology. RESULTS: In all age groups, peptic ulcers were commoner in males than females [44% (85/195) vs 23% (32/139), P < 0.001] and in smokers than non-smokers [47% (46/97) vs 32% (50/159), P < 0.05]. Males, heavy smokers and those with a family history of peptic ulcer had increased adjusted odds of having a peptic ulcer (2.59, 1.96 and 1.90, respectively). Corresponding odds ratios for those aged under 45 were 2.59, 0.94 and 2.52. In H. pylori-positive dyspepsia, being a male who either smoked heavily or had a family history of peptic ulcer gave a sensitivity and positive predictive value for peptic ulcer of 86 and 45% for all age groups and 85 and 49% for those aged under 45. CONCLUSION: Male H. pylori dyspeptics who smoke >10 cigarettes per day and/or have a family history of peptic ulcer are likely to have peptic ulcer and are thus likely to benefit from empirical eradication therapy.

Screening dyspeptic patients for Helicobacter pylori prior to endoscopy: laboratory or near-patient testing?

BACKGROUND: It is unclear whether near-patient whole-blood diagnostic tests for Helicobacter pylori are of comparable accuracy to laboratory based ELISA for screening of dyspeptic patients prior to endoscopy. AIM: To compare two ELISA and two whole-blood tests in order to determine whether near-patient H. pylori diagnostic tests are an acceptable alternative to laboratory based ELISA tests for screening of dyspeptic patients prior to endoscopy. METHOD: One hundred and seven consecutive patients with dyspepsia (median age, 32 years; range, 16-45 years) were evaluated with Helico-G ELISA, Hmcap ELISA and Helisal whole-blood tests. A further 111 dyspeptic patients (median age, 51 years; range, 16-96 years) were evaluated with the Immunocard whole-blood test only. The 'gold standard' for infection was based on histology and the rapid urease test (CLO). RESULTS: Compared to the Helico-G test, both near-patient tests had a higher false negative rate (23-37% vs 5%, P< 0.003), and lower sensitivity and negative predictive value. The Immunocard had a higher specificity than did the Helisal (87% vs 63%, P=0.006); otherwise both near-patient whole-blood tests had similar performance. At a sensitivity of 95%, the Hmcap ELISA was more specific than the Helico-G ELISA (75% vs 67%) and had fewer false positives (25% vs 32%). The near-patient tests would wrongly classify up to 40% H. pylori positive dyspeptic patients and exclude them from endoscopy, compared to 5-6% for ELISA. CONCLUSIONS: Near-patient whole-blood H. pylori diagnostic tests are less accurate and thus not an acceptable alternative to laboratory based ELISA tests.

Determinants of prescribing costs for ulcer-healing drugs and upper gastrointestinal endoscopy in general practice.

BACKGROUND: Prescriptions for ulcer-healing drugs (UHDs) and endoscopy costs represent major expenditures for dyspepsia in primary care. Healthcare expenditure for dyspepsia could be better understood if the factors contributing to the expenditure for dyspepsia could be identified. AIMS: To determine whether prescribing costs of UHDs and use of endoscopy in general practice were related to the characteristics of the practices or to the characteristics of the population it served DESIGN: Twenty-seven GP practices in south London were studied prospectively over 6 months. Prescribing costs for UHDs were obtained from PACT and data for endoscopies from hospital PAS systems. Demographic data on practice size, age and sex distribution were obtained from the district FHSA. The Jarman index, Townsend score and proportion of ethnic minorities in the practice population were determined from the Population Census Survey. RESULTS: Total expenditure on UHDs by the 27 practices was Pound Sterling 1 million per annum and endoscopy rate was 1.1% per annum. Expenditure on UHDs was negatively correlated with practice size (P = 0.006) and use of open access endoscopy (P < 0.005) and positively correlated with number of patients aged over 45 years (P = 0.007). Endoscopy use was positively correlated with proportion of ethnic minorities (P = 0.008) and negatively with male:female ratio (P = 0.049). CONCLUSIONS: Resource utilization on dyspepsia in general practice is determined by both practice and population characteristics.

Relationship between Helicobacter pylori, gastric parietal cell antibodies and heat shock proteins.

BACKGROUND: The relationship between Helicobacter pylori and autoimmune (type A) gastritis is unclear. Infections may trigger autoimmune phenomena but the underlying mechanisms are unknown. AIM: To determine the relationships between H. pylori infection and gastric parietal cell antibodies (PCA), and PCA and heat shock protein (HSP) antibody. METHODS: Fifty-five serum samples positive for PCA, 22 males and 33 females (median age 61 years, range 29-108 years) were compared with 60 control samples negative for PCA, 24 males and 36 females (median age, 48 years, range 11-91 years). H. pylori infection and HSP65K antibodies were determined by enzyme-linked immunosorbent assay. CagA and VacA status were determined by Western blotting. RESULTS: The prevalence of H. pylori was higher in PCA-positives than controls, 29/55 [53%, 95% confidence interval (CI) 39-66%] versus 13/60 (22%, 95% CI 12-34); P= 0.0009. Age was not a confounding factor. Odds ratio for PCA seropositivity if H. pylori-positive was 4.0 (1.79-9.07), P= 0.003. There was an interaction between age and H. pylori, particularly in younger patients. CagA strains were less common in PCA-positives than controls, 10/29 (35%, 95% CI 19-54) versus 9/13 (69%, 39-91), P< 0.05. HSP65K antibodies were elevated in H. pylori infection but to a similar degree for both PCA-positives and controls. CONCLUSION: H. pylori, particularly CagA-negative strains, are associated with autoimmune gastritis and may be implicated in the pathogenesis of autoimmune (type A) gastritis, particularly in younger persons.

Helicobacter pylori is an aetiological factor for ischaemic heart disease: the case in favour.

The evidence to date concerning the association between Helicobacter pylori infection and coronary heart disease is consistent with a modest increased risk. Research is currently being undertaken into factors which may modify this association. Probably, there is sufficient evidence given the ease of the proposed intervention to make it worthwhile to undertake a trial of eradication therapy.

Chlamydia pneumoniae: risk factors for seropositivity and association with coronary heart disease.

BACKGROUND: Two studies have suggested that seropositivity for Chlamydia pneumoniae (C. pneumoniae) is a risk factor for coronary heart disease (CHD) but the association remains tenuous. Further data is required in other populations to consolidate this observation. AIMS: Initially to determine descriptive risk factors for C. pneumoniae seropositivity in a general population sample and subsequently to examine the relation of seropositivity for this organism to CHD for the first time in a British population. SETTING: A single general practice health screening clinic and a cardiology clinic involving patients predominantly residing in south London and Surrey. SUBJECTS: 210 consecutive caucasian men (62%) and women (38%) aged 18-79 including 67 men aged 45-65. This latter group acting as controls were then also compared with 103 consecutive males aged 45-65 with angiographically confirmed coronary heart disease. METHODS: A questionnaire was administered by a research nurse and serum was analysed for IgG and IgA against C. pneumoniae and other Chlamydiae by a microimmunofluorescence test. Serum was said to be low positive at a specific IgG antibody titre of 16-32, and high positive if 64 or greater. RESULTS: Amongst the general practice health screening clinic population 14 subjects (7%) were excluded due to possible cross-reactivity with other Chlamydia species (predominantly C. trachomatis). Of the remaining 196 subjects, 13 (6%) had high positive C. pneumoniae IgG titres, 68 (35%) had low titres and 125 had no detectable antibody. After adjustment for sex, age, smoking history, social class and family size only one risk factor for high positive titres in this group was identified, which was the number of children currently living in the home (OR 2.29 (1.09-4.80), P = 0.03). No factors were significantly related to low titres. 22/100 (22%) cases with coronary heart disease and 3/64 (4.7%) of controls had high positive IgG titres for C. pneumoniae. Similarly 21% of cases and 9.4% of controls had positive C. pneumoniae specific IgA serology. 45% of cases and 44% of controls had low C. pneumoniae IgG titres. The association of CHD with a C. pneumoniae IgG titre of 64 or above was independent of all risk factors (OR 7.4 (1.7-33.1), P < 0.01). CONCLUSION: Serological evidence of C. pneumoniae infection is common amongst healthy British subjects. Smoking and social class are not important confounding variables in this study. Reinfection from contact with infected children in the home may be important in inducing higher titres in some subjects. These higher titres are more prevalent in subjects with coronary heart disease in the U.K. as reported in Finland and the U.S.A., and provide further evidence that C. pneumoniae may be important in the pathogenesis of this condition in these populations.

Helicobacter pylori infection in childhood: risk factors and effect on growth.

OBJECTIVE: To investigate the current prevalence of Helicobacter pylori infection in childhood, the risk factors for infection, and the effect of infection on growth in preadolescent schoolchildren. DESIGN: Population based sample of 7 year old schoolchildren followed up at age 11; data on risk factors for infection collected at age 7; presence of infection at age 11 determined by measurement of salivary IgG against H pylori by a newly developed enzyme linked immunosorbent assay (ELISA). Height was measured at 7 and 11 years of age. SUBJECTS: 554 schoolchildren from Edinburgh. RESULTS: 62 (11%) children had H pylori infection. Independent risk factors for infection were single parent families (adjusted odds ratio = 2.5; 95% confidence interval 1.1 to 5.7), the 10% most crowded homes (3.1; 1.3 to 7.2), and schools serving predominantly rented housing estates (2.5; 1.0 to 6.5). School catchment area was more important than parental social class or housing tenure. Growth in height between 7 and 11 was diminished in infected children by a mean of 1.1 cm (0.3 to 2.0 cm) over four years. This growth reduction was largely confined to girls (1.6 cm over four years), among whom it correlated with salivary IgG (P = 0.015). CONCLUSION: Data from salivary assay to investigate the epidemiology of H pylori suggest that factors relating to the type of community in which the child lives may now be as important for acquisition of this infection as features of the family home. The greater reduction of growth among infected girls raises the possibility that H pylori infection may delay or diminish the pubertal growth spurt.

C reactive protein and its relation to cardiovascular risk factors: a population based cross sectional study.

OBJECTIVE: To test the hypothesis that minor chronic insults such as smoking, chronic bronchitis, and two persistent bacterial infections may be associated with increases in C reactive protein concentration within the normal range and that variations in the C reactive protein concentration in turn may be associated with levels of cardiovascular risk factors and chronic coronary heart disease. DESIGN: Population based cross sectional study. SETTING: General practices in Merton, Sutton, and Wandsworth. SUBJECTS: A random sample of 388 men aged 50-69 years from general practice registers. 612 men were invited to attend and 413 attended, of whom 25 non-white men were excluded. The first 303 of the remaining 388 men had full risk factor profiles determined. INTERVENTIONS: Measurements of serum C reactive protein concentrations by in house enzyme linked immunosorbent assay (ELISA); other determinations by standard methods. Coronary heart disease was sought by the Rose angina questionnaire and Minnesota coded electrocardiograms. MAIN OUTCOME MEASURES: Serum C reactive protein concentrations, cardiovascular risk factor levels, and the presence of coronary heart disease. RESULTS: Increasing age, smoking, symptoms of chronic bronchitis, Helicobacter pylori and Chlamydia pneumoniae infections, and body mass index were all associated with raised concentrations of C reactive protein. C Reactive protein concentration was associated with raised serum fibrinogen, sialic acid, total cholesterol, triglyceride, glucose, and apolipoprotein B values. C Reactive protein concentration was negatively associated with high density lipoprotein cholesterol concentration. There was a weaker positive relation with low density lipoprotein cholesterol concentration and no relation with apolipoprotein A I value. C Reactive protein concentration was also strongly associated with coronary heart disease. CONCLUSION: The body's response to inflammation may play an important part in influencing the progression of atherosclerosis. The association of C reactive protein concentration with coronary heart disease needs testing in prospective studies.