Search

Background: Major efforts in computed tomography (CT) have been focused on reducing radiation dose to patients while maintaining adequate diagnostic quality. To that end, research tools have been developed to simulate reduced-dose images via either image-based or projection-based methods. The former is limited to fully capturing realistic texture, streak, and non-stationary characteristics of reduced dose, while the latter is impractical clinically., Purpose: To develop and validate an image-based noise addition method that accounts for such attributes while being practical in clinical settings., Methods: A noise addition method was developed to add realistic noise in the image domain. The method first estimates the noise power spectrum (NPS) of CT images, which are also forward-projected to form synthetic projections. The projection data are supplemented with random white noise proportional to their attenuation values. The noise sinogram is then back-projected onto the image, filtered by the NPS, and scaled according to the desired dose reduction level. The tool was evaluated using both phantom images and patient data. The phantom images were acquired using a multi-sized image quality phantom (Mercury Phantom 3.0, Duke University), and a thorax anthropomorphic phantom (Lungman Phantom, Kyoto Kagaku) at different dose levels and reconstruction settings. The patient images consisted of two dose levels of various CT examinations and reconstruction settings. The simulated and real reduced-dose images were compared in terms of the noise magnitude and texture (i.e., NPS average frequency, NPS-f av ). The utility of this methodology was also assessed for routine clinical use for CT protocol review., Results: For the phantom images, the percent errors in the noise magnitude between the simulated images and the actual images of the Mercury Phantom and anthropomorphic phantom images were 3.34% and 3.50%, respectively. The difference in f av was 0.07 mm -1 for the Mercury Phantom and 0.06 mm -1 for the anthropomorphic phantom between the simulated and actual images. The average noise magnitude percent error between the simulated and actual patient images was 4.61% with noise texture judged to be visually comparable with some kernel dependencies. When implemented clinically, the tool proved practical to simplify the process of estimating radiation dose reduction for CT protocols, resulting in a 50% dose reduction of our multiple myeloma protocol., Conclusions: The method generated simulated CT images with realistic noise properties similar to images acquired at the same radiation exposure without needing access to raw projection data., (© 2024 American Association of Physicists in Medicine.)

Purpose To determine whether photon-counting CT (PCCT) acquisition of whole-body CT images provides similar quantitative image quality and reader satisfaction for multiple myeloma screening at lower radiation doses than does standard energy-integrating detector (EID) CT. Materials and Methods Patients with monoclonal gammopathy of undetermined significance prospectively underwent clinical noncontrast whole-body CT with EID and same-day PCCT (August-December 2021). Five axial scan locations were evaluated by seven radiologists, with 11% (eight of 70) of images including osteolytic lesions. Images were shown in randomized order, and each reader rated the following: discernibility of the osseous cortex and osseous trabeculae, perceived image noise level, and diagnostic confidence. Presence of lytic osseous lesions was indicated. Contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were calculated. Comparisons were made using paired t tests and mixed linear effects models. Results Seven participants (four women) were included (mean age, 66 years ± 9 [SD]; body mass index, 30.1 kg/m 2 ± 5.2). Mean cortical definition, trabecular definition, image noise, and image quality scores were 83, 67, 75, and 78 versus 84, 66, 74, and 76 for EID and PCCT, respectively ( P = .65, .11, .26, and .11, respectively). PCCT helped identify more lesions (79% [22 of 28]) than did EID (64% [18 of 28]). CNRs and SNRs were similar between modalities. PCCT had lower radiation doses than EID (volume CT dose index: EID, 11.37 ± 2.8 vs PCCT, 1.8 ± 0.6 [ P = .06]; dose-length product: EID, 1654.1 ± 409.6 vs PCCT, 253.4 ± 89.6 [ P = .05]). Conclusion This pilot investigation suggests that PCCT affords similar quantitative and qualitative scores as EID at significantly lower radiation doses. Keywords: CT, CT-Spectral, Skeletal-Axial, Spine, Hematologic Diseases, Whole-Body Imaging, Comparative Studies Supplemental material is available for this article. © RSNA, 2022.

Background: Shoulder computed tomography (CT) is commonly utilized in preoperative planning for total shoulder arthroplasty. Conventional-dose shoulder CT may expose patients to more ionizing radiation than is necessary to provide high-quality images for this procedure. The purpose of this study was to evaluate the utility of simulated low-dose CT images for preoperative planning using manual measurements and common preoperative planning software., Methods: Eighteen shoulder CT scans obtained for preoperative arthroplasty planning were used to generate CT images as if they had been acquired at reduced radiation dose (RD) levels of 75%, 50%, and 25% using a simulation technique that mimics decreased x-ray tube current. This technique was validated by quantitative comparison of simulated low-dose scans of a cadaver with actual low-dose scans. Glenoid version, glenoid inclination, and humeral head subluxation were measured using 2 commercially available software platforms and were also measured manually by 3 physicians. These measurements were then analyzed for agreement across RD levels for each patient. Tolerances of 5° of glenoid version, 5° of glenoid inclination, and 10% humeral head subluxation were used as equivalent for preoperative planning purposes., Results: At all RD levels evaluated, the preoperative planning software successfully segmented the CT images. Semiautomated software measurement of 25% RD images was within tolerances in 99.1% of measurements; for 50% RD images, within tolerances in 96.3% of measurements; and for 75% RD images, within tolerances in 100% of measurements. Manual measurements of 25% RD images were within these tolerances in 95.1% of measurements; for 50% RD images, in 98.8% of measurements; and for 75% RD images, in 99.4% of measurements., Conclusions: Simulated low-dose CT images were sufficient for reliable measurement of glenoid version, glenoid inclination, and humeral head subluxation by preoperative planning software as well as by physician-observers. These findings suggest the potential for substantial reduction in RD in preoperative shoulder CT scans without compromising surgical planning., Clinical Relevance: The adoption of low-dose techniques in preoperative shoulder CT may lower radiation exposure for patients undergoing shoulder arthroplasty, without compromising image quality., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJS/H13)., (Copyright © 2022 by The Journal of Bone and Joint Surgery, Incorporated.)

Patellar instability is a broad term that encompasses patellar dislocation, patellar subluxation, and patellar instability. Although both functional and anatomic considerations contribute to symptoms of patellar instability, the most important are thought to be patella alta, trochlear dysplasia, and lateralization of the tibial tubercle. In patients with a history suspicious for prior patellar dislocation, careful evaluation of MRI and radiographic studies can reveal characteristic findings. The most common methods to address patellofemoral instability are medial patellofemoral ligament reconstruction and tibial tubercle osteotomy with either anteromedialization or medialization. Less commonly trochleoplasty is indicated as well. Patients may be treated with one of or a combination of these techniques, each of which has specific indications and complications., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The cause of rotator cuff tears is multifactorial with both intrinsic and extrinsic contributing factors. Understanding the normal MR anatomy of the rotator cuff and using an appropriate search pattern can help readers identify common pathologic conditions. Accurate designation using classification systems for tear thickness, size, and degree of retraction and muscle fatty infiltration and atrophy are important in guiding surgical management. Knowledge of common disease locations for the rotator cuff tendons can help focus reader searches and increase sensitivity., Competing Interests: Disclosure Neither I nor my immediate family members have a financial relationship with a commercial organization that may have a material interest in the content of this article., (Copyright © 2020 Elsevier Inc. All rights reserved.)

While uncommon, exertional-induced rhabdomyolysis is an important diagnostic consideration when encountering hyperintensity within one or more muscles on fluid sensitive sequences in conjunction with signal abnormality in the overlying superficial fascia and subcutaneous fat. The clinical history of recent extreme exercise helps distinguish this disorder from other possible diagnoses, such as cellulitis, necrotizing fasciitis, compartment syndrome, inflammatory processes and diabetic myonecrosis. Patients diagnosed with severe exertional induced rhabdomyolysis often require hospital admission for intravenous hydration and serial laboratory monitoring due to the potential risk of acute renal failure. While contributory, magnetic resonance imaging findings can be nonspecific, and therefore the clinical history is often essential in making this diagnosis., (© 2020 The Authors. Published by Elsevier Inc. on behalf of University of Washington.)

The bacterial flagellar motor is a remarkable nanomachine that provides motility through flagellar rotation. Prior structural studies have revealed the stunning complexity of the purified rotor and C-ring assemblies from flagellar motors. In this study, we used high-throughput cryo-electron tomography and image analysis of intact Borrelia burgdorferi to produce a three-dimensional (3-D) model of the in situ flagellar motor without imposing rotational symmetry. Structural details of B. burgdorferi, including a layer of outer surface proteins, were clearly visible in the resulting 3-D reconstructions. By averaging the 3-D images of approximately 1,280 flagellar motors, a approximately 3.5-nm-resolution model of the stator and rotor structures was obtained. flgI transposon mutants lacked a torus-shaped structure attached to the flagellar rod, establishing the structural location of the spirochetal P ring. Treatment of intact organisms with the nonionic detergent NP-40 resulted in dissolution of the outermost portion of the motor structure and the C ring, providing insight into the in situ arrangement of the stator and rotor structures. Structural elements associated with the stator followed the curvature of the cytoplasmic membrane. The rotor and the C ring also exhibited angular flexion, resulting in a slight narrowing of both structures in the direction perpendicular to the cell axis. These results indicate an inherent flexibility in the rotor-stator interaction. The FliG switching and energizing component likely provides much of the flexibility needed to maintain the interaction between the curved stator and the relatively symmetrical rotor/C-ring assembly during flagellar rotation.

Background: Socioeconomic differentials have been described in the risk of coronary heart disease (CHD) but the extent to which these differentials are explained by lifestyle factors has been examined to a lesser degree. We have examined the contribution of socio-economic factors to risk of CHD in a large cohort study in France and Northern Ireland., Methods: In all, 10 593 men aged 50-59 years were examined between 1991 and 1994 in centres in Northern Ireland, Lille, Strasbourg, and Toulouse. Details were obtained for a number of socio-economic indicators from the men at the baseline examination. Men were also screened for evidence of CHD and followed annually by questionnaire for incident cases of coronary disease. Coronary events (coronary deaths, myocardial infarction, and angina) were documented by clinical records and were reviewed by an independent medical committee., Results: In all, 842 men (8%) showed some evidence of CHD at screening examination and these men were more likely to be living in poorer material circumstances, be unemployed, or have had less full-time education than men without CHD at screening in both France and Northern Ireland. These relationships persisted following adjustment for all known risk factors for CHD. Among men who were initially free of CHD there were clear socio-economic differentials (years of full-time education, unemployment, and educational level) in the distribution of several risk factors for CHD, notably smoking habit (which differs in France and Northern Ireland), systolic blood pressure, body mass index, and fibrinogen. Total cholesterol in contrast showed no socio-economic differential whilst those with a shorter period of full-time education and the unemployed tended to be high consumers of alcohol. In this cohort of men free of CHD at baseline few socio-economic indicators showed relationships with risk of CHD by 5 years of follow-up. Only years in full education, educational level, and unemployment status when adjusted only for age and country showed significant relationships with CHD risk, but these became non-significant following adjustment for major CHD risk factors., Conclusions: Socio-economic differentials in long-term risk of CHD are apparent in both cohorts of men from France and Northern Ireland, particularly in men with evidence of CHD at baseline. Among men free of CHD at baseline, although there is strong evidence of socio-economic differentials in cardiovascular risk factors these do not contribute independently to risk of CHD at 5 years of follow-up in this large cohort of men from France and Northern Ireland.

Aims: Classical risk factors do not fully explain international differences in risk of coronary heart disease (CHD). We therefore measured thrombotic and inflammatory markers in a substudy of the WHO MONICA project and correlated these with CHD event rates., Methods and Results: We measured levels of fibrinogen (clottable and nephelometric), von Willebrand factor (vWf), tissue plasminogen activator antigen, plasminogen activator inhibitor activity, fibrin D-dimer, plasma viscosity, C-reactive protein, and total cholesterol in 12 MONICA populations (listed at the end of this paper), all but one European. Men and women aged 45-64 years were studied from 10 countries. All samples were collected using a carefully standardized protocol, and analysed centrally. Results were available for 3996 subjects (nephelometric fibrinogen and viscosity), 2378 subjects (other thrombotic assays), and 1757 subjects (C-reactive protein and total cholesterol). Significant differences in levels of thrombotic and inflammatory factors exist in MONICA populations mainly from European countries. These differences persist after adjustment for age, smoking habit, and body mass index. Cross-sectional correlations between coronary event rates and these thrombotic/inflammatory markers were significant for vWF antigen in both sexes, nephelometric fibrinogen in men, and D-dimer in women., Conclusion: In particular, vWF, nephelometric fibrinogen, and D-dimer should be examined in further research as potential risk factors which may help explain differences in coronary risk between European populations.

Spatone Iron-Plus is a naturally occurring mineral water from Trefriw Wells Spa in Conwy County, North Wales, UK. It contains approximately 0.20 mg of iron per millilitre as ferrous sulphate and has been shown to provide iron in a highly bio-available form. A 24 ml sachet contains approximately 5 mg of iron. Iron deficiency is common in the obstetric population. However, compliance with traditional iron supplements is poor because of gastrointestinal side-effects. We designed a randomized, double-blind, placebo-controlled trial. A total of 102 low-risk antenatal patients, who were noncompliant with routinely prescribed ferrous sulphate tablets, were randomized to receive 48 ml of Spatone water or placebo. The study was conducted between 22 and 28 weeks gestation. Primary outcome measures were compliance, gastrointestinal side-effects and changes in ferritin levels during the trial period. Compliance in the intervention group was 57% compared with 67% in the control group, P = 0.22. Dyspepsia scores, as determined by a recognized and well-validated questionnaire, did not differ between the two groups. During the trial period, mean ferritin levels fell by 24% in the Spatone Iron-Plus group compared with a mean fall of 51% in ferritin levels among the control group, P = 0.016.

Background: Environmental, cultural and health care differences may account for variation among countries in the prevalence of asthma and respiratory symptoms in teenagers., Objective: To examine the prevalence of respiratory symptoms and the level of diagnosis, and to compare determinants of asthma and severe wheeze in two countries., Methods: Self-completion questionnaires based on the International Study of Asthma and Allergies in Childhood (ISAAC) protocol were provided to school children in Ireland (Republic and Northern Ireland). In the Republic of Ireland, all children in classes largely aged 13-14 years from 30 post-primary schools were selected by random sampling stratified by school size, composition and Health Board in Spring 1995. In Northern Ireland, all children largely aged 13-14 years of age from 26 post-primary schools were selected by random sampling stratified by school type, composition and Education and Library Board in Spring 1996., Results: Questionnaires were completed by 2,364 children from Northern Ireland and 2,671 from the Republic, about 90% of those eligible to participate. The prevalences of wheeze at various levels of severity, of diagnosed asthma and of treated wheeze were very similar in Northern Ireland and the Republic of Ireland. A significant proportion of those reporting more severe symptomatology (four or more attacks of wheeze in the past 12 months and/or one or more nights disturbed and/or moderate or greater disruption of daily activities and/or speech restriction due to wheeze) had been neither diagnosed nor treated for asthma (20-37%). To investigate the determinants of the more severe symptomatology of asthma or treated wheeze a series of stepwise multiple regression analyses was performed. A history of atopy, cigarette smoking, the possession of a furry pet other than a dog or cat and age were each independently associated with severe wheeze, whilst atopy, a furry pet (as above) and gender were each independently associated with asthma or treated wheeze., Conclusions: Cigarette smoking is closely associated with the reporting of significant respiratory symptoms together with atopy and exposure to furry pets. Some 20-37% of severe symptoms were neither diagnosed nor treated as asthma.

Background: France has a substantially lower level of premature mortality from cardiovascular diseases (CVD) relative to its comparators. Compared with Northern Ireland, France has one-half the rate, despite having a similar cardiovascular risk profile to Northern Ireland. In this prospective longitudinal study the psychosocial risk hypothesis for CVD was tested., Method: A cohort of 9758 men (7359 in France and 2399 in Northern Ireland) aged 50-59 years who were initially free of any CVD were recruited. At baseline the subjects completed a psychosocial questionnaire, measuring hostility, depression, social support, and the Type A behaviour pattern. At 5-years follow-up their clinical status was determined., Results: Multivariate analysis indicated that, contrary to prediction, France had a substantially more negative psychosocial risk profile than Northern Ireland. The psychosocial risk factors were not successful at predicting at 5-years follow-up the hard clinical endpoint of definite fatal/non-fatal myocardial infarction. In the case of the softer clinical endpoint, angina pectoris/unstable angina, only depression predicted outcome with a small effect size., Conclusion: The findings provide little support for the psychosocial risk hypothesis. The psychosocial risk profile was more negative in France, the opposite of that predicted. The finding of a relationship between depression and angina may reflect a tendency for individuals who respond negatively on mood state to report more cardiac symptoms irrespective of physical disease state.

Unlabelled: Concern has been expressed in recent years over the rising trends in overweight and obesity, particularly in children in developed countries. No recent data were available for Northern Ireland, therefore measurements of height and weight were included in a study in Northern Ireland originally designed as part of an international study to estimate the prevalence of symptoms of asthma and atopy in childhood. Twenty-six schools across the province were sampled. 2484 children aged mainly 13 and 14 y completed questionnaires, and 2307 were weighed and measured. Using recently proposed international guidelines on defining overweight and obesity in children the prevalence of overweight in boys was 16%, with 4% being obese. In girls 16% were also overweight and 2% were obese. This concurs with figures for English and Scottish schoolchildren up to 12 y of age from 1994. Less than one-sixth of obese boys but more than one-third of obese girls were on weight-reducing diets (the majority self-prescribed), reflecting differing attitudes towards excess weight., Conclusion: In line with figures in younger children from England and Scotland this study shows that 16% of boys and girls from Northern Ireland are classed as overweight using recent international guidelines. Only 15% of obese boys compared with 38% of obese girls stated that they were on weight-reducing diets.

The prevalence of sleep complaints in Northern Ireland is unknown. Sleep disruption can result in excessive daytime sleepiness (EDS), with significant socioeconomic consequences. The aim of this study was to assess the prevalence of sleep complaints and to determine risk factors for EDS in a Northern Irish community. From an urban and rural community of 499,111 people, a random sample of 3391 adult men were sent a questionnaire by mail. Questions were asked regarding sleep, EDS and medical history. There were 2364 completed questionnaires returned (response rate 70%). The mean age of respondents was 46.0 years (range 18--91 years). 26.7% of men were not satisfied with their usual night's sleep and 68% of men woke up at least once during the night. Based on pre-defined criteria, 24.6% of the population had insomnia and 19.8% had EDS. The strongest risk factor identified for EDS was a history of snoring loudly (odds ratio 2.62; 95% CI 1.82--3.77). Other risk factors included ankle swelling, feeling sad or depressed stopping sleep, experiencing vivid dreams while falling asleep, waking up feeling unrefreshed and age > 35 years. The prevalence rates of sleep complaints and EDS in this community-based study is high, although this does depend directly on the criteria used to define insomnia and EDS. Recognition of risk factors for EDS may help to identify and treat those affected.

Background: Findings relating an association between an insertion/deletion polymorphism of the angiotensin converting enzyme (ACE) gene and myocardial infarction (MI) have been mixed. While other loci, such as the angiotensin II type-I receptor (AT1R), may modulate risk, few studies have adequately documented the risk in women. We aimed to study whether the findings in respect of ACE and AT1R in UK men were borne out in women., Methods: Cases of MI (305 women, 391 men) in Belfast and Glasgow have been compared to controls (291 women, 356 men). These new samples augment the original men (200 cases, 181 controls) included from Belfast in the ECTIM study., Results: Among men, the odds ratio for MI for ACE (DD vs. ID + II) was 1.03 (0.79, 1.34) and among women, 0.69 (0.47, 1.01). This heterogeneity between the risks in men and women was significant in Glasgow (P = 0.02). Among men and women the odds ratio for MI for AT1R (CC vs. AC + AA) was 1.02 (0.71, 1.47). There was a small gradient in risk, such that the odds ratio for DD genotype was 0.86 (0.63, 1.17) among subjects homozygous for the common AT1R allele (AA): 0.94 (0.67, 1.30) among heterozygotes and 1.21 (0.53, 2.77) among CC subjects; but this interaction was not statistically significant., Conclusions: Some of the contradictory findings concerning the ACE polymorphism and the risk of MI may be due to heterogeneity in the risk between men and women. The AT1R1196 polymorphism is not an independent risk factor for MI in either sex.

To assess whether there is a differential hypocholesterolemic response to weight loss for subjects carrying polymorphisms of the apolipoprotein B and other genes. A before and after comparison of lipid parameters following a calorie controlled diet for an intervention period of 12 weeks. A lipid clinic based in a large teaching hospital. The difference in slope coefficients relating the percentage change in lipid parameters to the change in body weight (adjusted for age, gender and initial body mass index (BMI)), for genotype subgroups defined by polymorphisms of the 5'VNTR apoB gene, two mutations of the LPL gene and ApoE. One hundred and forty six subjects completed the intervention diet. While, on average, the intervention was successful (mean weight loss 3.9%), there was no statistically significant difference in the slope coefficients relating lipid change to weight loss for most of the genotypes tested. The slope difference for long versus short 5'VNTR alleles of the apoB gene was 0.445 (-1.307, 2.198) for apolipoprotein B and -0. 104 (-1.486, 1.278) for total cholesterol. However, subjects carrying at least one varepsilon4 allele were significantly hypo-responsive to weight loss, difference in slope coefficients -1.087 (-2.09, -0.084) and -1.320 (-2.589, 0.051) for total cholesterol and apoB, respectively. Although, this study is one of the largest of its kind, it has not replicated the findings of other smaller studies. These findings do not provide support for the use of genotype-targeted dietary advice in routine practice.

Background and Objective: Studies in animal models and humans implicate cell adhesion molecules in atherogenesis but their role in mediating the risk of myocardial infarction is unclear. The ECTIM (étude cas-temoin de l'infarctus myocarde) extension study was established to determine whether a previously implicated polymorphism of the P-selectin gene was associated with myocardial infarction risk in men and women in Belfast and Glasgow. PATIENTS AND STUDY SETTING: 696 cases with a recent myocardial infarction and 561 age matched controls (both male and female) were recruited into a case-control study in MONICA project areas of Belfast and Glasgow., Methods: Demographic and lifestyle information was collected by interview administered questionnaire, and each subject was examined and provided a blood sample for DNA extraction. The polymerase chain reaction (PCR) was used to amplify regions encompassing the P-selectin Thr-->Pro (A/C) polymorphism at position 715. Genotype odds ratios for myocardial infarction were estimated by logistic regression adjusted for population, age, and sex., Results: There was no significant association between conventional risk factors (such as hypercholesterolaemia, increased body mass index, or raised blood pressure) and either the rare or the common Pro(715) allele of the P-selectin gene in controls. Overall, comparing Pro(715)/Pro(715) and Pro(715)/Thr(715) with Thr(715)/Thr(715), with adjustment for centre, age, and sex, the odds ratio was 0.78 (95% confidence interval 0.60 to 1.00) (p = 0.054), indicating a "protective" effect of the less common Pro(715) allele. There was no significant heterogeneity in odds ratios between men and women either in this sample or when combined with the original ECTIM subjects., Conclusions: In a large population based study in two regions of the UK, we have been able to corroborate the earlier ECTIM findings of a lower frequency of the Thr/Pro(715) polymorphism in subjects with myocardial infarction. An apparently "protective effect" of similar magnitude also seems to apply to women.

Study Objective: EURALIM (EURope ALIMentation), a European collaborative study, aimed to determine and describe the extent to which European data on risk factor distributions from different populations could be pooled and harmonised in a common database for international comparisons., Setting: Seven independent population-based surveys from six European countries (France, Italy, Northern Ireland/United Kingdom, Spain, Switzerland, the Netherlands)., Methods: Data for 18 381 women and 12 908 men aged 40-59 were pooled in a common database. Central statistical analyses on major cardiovascular risk factors were conducted with careful consideration of methodological issues, including differences in study designs, data assessment tools, and analytic techniques used., Main Results: Because of the detected variability among methods used, direct comparisons of risk factor distributions and prevalences between studies were problematic. None the less, comparisons of within population contrasts by sex, age group, and other health determinants were considered to be meaningful and apt, as illustrated here for obesity. Results were targeted and disseminated to both the general public and public health professionals and framed in the context of a European information campaign., Conclusions: International and national comparisons between existing locally run studies are feasible and useful, but harmonisation methods need improvement. Development of an international risk factor surveillance programme based on decentralised data collection is warranted. In the meantime, risk factor contrasts across populations can be used as a basis for targeting needed public health intervention programmes.

Objective: To determine and describe the extent to which European dietary data collected in disparate surveys can be meaningfully compared., Design: Seven independent population-based surveys from six European countries were initially included. Differences in study designs and methodological approaches were examined. Risk factor data for 31,289 adults aged 40-59 y were harmonized and pooled in a common, centralized database., Results: Direct comparisons of dietary measures across studies were not deemed appropriate due to methodological heterogeneity. Nonetheless, comparisons of intra-population contrasts by gender across sites were considered valid. Women consumed fruit and vegetables more often than men. Age-standardized gender differences in the prevalence of low fruit and vegetable consumption ranged from 7 to 18% and 5 to 15%, respectively. Data on energy intake showed good agreement across study populations. The proportion of total energy from macronutrients was similar for women and men. Gender differences for relative intakes of saturated fatty acids (percentage energy) were small and only in France were they significant. Dietary fibre density was significantly higher in women than in men. Overall, the participating Southern European populations from Italy and Spain exhibited more healthful food composition patterns., Conclusions: Contrasts in dietary patterns by gender across populations may provide the basis for health promotion campaigns. The most favourable patterns observed may serve as attainable goals for other populations. An international risk factor surveillance programme based upon locally run, good quality studies has the potential to provide the needed data., Sponsorship: European Community (DG V), project 96CVVF3-446-0; Swiss Federal Office for Education and Science, OFES 96.0089.

We have conducted an intervention trial to assess the effects of antioxidants and B-group vitamins on the susceptibility of low-density lipoprotein (LDL) to oxidation. A total of 509 men aged 30-49 from a local workforce were screened for total plasma homocysteine. The 132 selected (homocysteine concentration > or = 8.34 mumol/l) men were randomly assigned, using a factorial design, to one of four groups receiving supplementation with B group vitamins alone (1 mg folic acid, 7.2 mg pyridoxine, 0.02 mg cyanocobalamin), antioxidant vitamins (150 mg ascorbic acid, 67 mg alpha-tocopherol, 9 mg beta-carotene), B vitamins with antioxidant vitamins, or placebo. Intervention was double-blind. A total of 101 men completed the 8-week study. The lag time of LDL isolated ex vivo to oxidation (induced by 2 mumol/l cupric chloride) was increased in the two groups receiving antioxidants whether with (6.88 +/- 1.65 min) or without (8.51 +/- 1.77 min) B-vitamins, compared with placebo (-2.03 +/- 1.50) or B-vitamins alone (-3.34 +/- 1.08) (Mean +/- S.E., P < 0.001). Antibodies to malondialdehyde (MDA) modified LDL were also measured, but there were no significant changes in titers of these antibodies in any group of subjects whether receiving antioxidants or not. Contrast analysis showed that there was no interaction between antioxidants and B-group vitamins. This study indicates that while B-group vitamins lower plasma homocysteine they do not have an antioxidant effect. Thus B-group vitamins and antioxidants appear to have separate, independent effects in reducing cardiovascular risk.

The aim of the study was to establish patterns of respiratory function in Northern Ireland and to examine the relationship between physical activity, physical fitness and respiratory function. We identified 1600 adults over 16 yr using 2 stage probability sampling. Physical activity was measured using a questionnaire, physical fitness from oxygen uptake while walking on a treadmill, and respiratory function using spirometry. The main outcome measures were a physical activity profile based on computer assisted interview, physical fitness by predicted VO2max, Forced Vital Capacity (FVC) and Forced Expiratory Volume (FEV1). We found that the main findings were of relationships between activity and FVC and FEV 1 which remained after adjustment for possible confounders in men, and between fitness and FVC and FEV 1 in both men and women although these were not sustained after adjustment for possible confounders.

Background: Critical reading is an important skill for those trying to practice evidence-based medicine. There are a number of recognized structures for critical reading, including the READER model. These methods should be subjected to high-quality studies., Objectives: We aimed to evaluate the READER method in a practical teaching setting using the highest quality research methodology., Methods: We carried out a modified randomized controlled trial. Two groups of GP trainers were invited to appraise critically the two articles using either the READER acronym or a semi-structured free appraisal., Results: Of 99 participants in the workshop, 92 completed the study. One-third of participants (33.7%) read more than five articles per month and those who had been in practice the longest read fewer articles (P<0.05). Both groups attributed the lowest score to paper 2. The median total scores were higher using the READER method, although only significant for paper 2 (P<0.05). The median score attributed to the methodology was lower using the READER method than the free appraisal, although this difference was only significant for paper 1 (P<0.05). Overall, 51% (70% of the READER group) believed that taking part in the exercise would encourage them to be more critical of published articles in the future., Conclusion: Those using the READER method attributed a higher total score, but were more critical of the methodology than those using a free appraisal. Participants found the study useful and believed that it would be of help in future critical appraisal. The study raises interesting questions about the relative importance to GPs of methodological rigour compared with other factors when evaluating research papers.

Mild hyperhomocysteinemia is accepted as a risk factor for premature cardiovascular disease. In a population with a high prevalence of cardiovascular disease, we screened a group of clinically healthy working men aged 30-49 y (n = 509) for plasma homocysteine and 5,10-methylene tetrahydrofolate reductase (MTHFR) genotype status. Those with mildly elevated homocysteine concentrations (> or = 8.34 micromol/L) were selected for intervention. In a randomized, factorial-design, controlled trial we assessed the effects of B-group vitamins and antioxidant vitamin supplementation on homocysteine concentrations. The 132 men were randomly assigned to one of four groups: supplementation with B-group vitamins alone (1 mg folic acid, 7.2 mg pyridoxine, and 0.02 mg cyanocobalamin), antioxidant vitamins alone (150 mg ascorbic acid, 67 mg RRR-alpha-tocopherol, and 9 mg beta-carotene), B-group vitamins with antioxidant vitamins, or placebo. Intervention was double-blind. A total of 101 men completed the 8-wk intervention. When homocysteine concentrations were analyzed by group, significant (P < 0.001) decreases (32.0% and 30.0%, respectively) were observed in both groups receiving B-group vitamins either with or without antioxidants. The effect of B-group vitamins alone over 8 wk was a reduction in homocysteine concentrations of 27.9% (95% CI: 22.0%, 33.3%; P < 0.001) whereas antioxidants alone produced a nonsignificant increase of 5.1% (95% CI: -2.8%, 13.6%; P = 0.21). There was no evidence of any interaction between the two groups of vitamins. The effect of B-group vitamin supplementation seemed to depend on MTHFR genotype. Supplementation with the B-group vitamins with or without antioxidants reduced homocysteine in the men with mildly elevated concentrations, and hence may be effective in reducing cardiovascular risk.

Background: The detection of IgA anti-gliadin antibodies in adults can either be helpful in the diagnosis of coeliac disease, be persistent in subjects with normal jejunal mucosa, or occur transiently. We decided to investigate the effects of smoking, alcohol consumption, and dietary intake on the development of IgA anti-gliadin antibodies., Methods: Serum samples from subjects enrolled from a large Northern Ireland population sample (MONICA survey) were screened for IgA anti-endomysium and IgA anti-gliadin antibodies. All subjects with positive antibodies were invited for clinical assessment 3-4 years after the initial screening sample. During this follow-up a repeat serum sample was obtained and a jejunal biopsy performed. At enrollment in the MONICA survey, lifestyle information including smoking, alcohol consumption, and dietary intake was obtained., Results: At follow-up 13 subjects had persistent positive serology and villous atrophy, and 9 had persistent positive serology but normal jejunal histology; in 29 the serology had returned to normal, and the jejunal histology was normal There was no difference in smoking, alcohol consumption, or dietary intake between subjects with and without coeliac disease. Subjects with transient serology findings ate significantly more soda bread than the other groups (at the time of initial screening). Analysis of gliadin content of soda bread and plain white bread showed a significantly higher amount of gliadin present in soda bread., Conclusions: Subjects with transient IgA anti-gliadin antibodies eat significantly more soda bread. The gliadin content of Irish soda bread contained a greater amount of gliadin than white bread. Eating breads with high available gliadin content may cause the appearance of anti-gliadin antibody.

Objective: To evaluate the READER model for critical reading by comparing it with a free appraisal, and to explore what factors influence different components of the model., Design: A randomised controlled trial in which two groups of general practitioners assessed three papers from the general practice section of the BMJ., Setting: Northern Ireland., Subjects: 243 general practitioners., Main Outcome Measures: Scores given using the READER model (Relevance, Education, Applicability, Discrimination, overall Evaluation) and scores given using a free appraisal for scientific quality and an overall total., Results: The hierarchical order for the three papers was different for the two groups, according to the total scores. Participants using the READER method (intervention group) gave a significantly lower total score (P < or = 0.01) and a lower score for the scientific quality (P < or = 0.0001) for all three papers. Overall more than one in five (22%), and more men than women, read more than 5 articles a month (P < or = 0.05). Those who were trainers tended to read more articles (P < or = 0.05), and no trainers admitted to reading none. Overall, 58% (135/234) (68% (76/112) of the intervention group) believed that taking part in the exercise would encourage them to be more critical of published articles in the future (P < or = 0.01)., Conclusion: Participants using the READER model gave a consistently lower overall score and applied a more appropriate appraisal to the methodology of the studies. The method was both accurate and repeatable. No intrinsic factors influenced the scores, so the model is appropriate for use by all general practitioners regardless of their seniority, location, teaching or training experience, and the number of articles they read regularly.

Aim: To determine the effect of low to moderate levels of smoking and alcohol consumption on immunoglobulin concentrations., Methods: Serum samples from 1787 subjects with approximately equal numbers in each five year group from 15 to 64 years were obtained from a large random population survey in Northern Ireland. Details were available on each subject concerning the number of units of alcohol consumed per week and the number of cigarettes smoked per day. IgG, IgM, and IgA concentrations were measured by laser nephelometry on all serum samples., Results: Low to moderate consumption of alcohol was associated with a decrease in IgG and IgM median concentrations in contrast to an increase in IgA median concentrations. The decrease in IgM and especially IgG median concentrations appeared to be related to the smoking habits of the subjects. Alcohol consumption alone was associated with increased IgA median concentrations whereas cigarette smoking alone was associated with reduced IgG median concentrations., Conclusion: Low levels of alcohol consumption and cigarette smoking influence IgG, IgM, and IgA serum concentrations. This should be borne in mind when selecting subjects for use in research and clinical settings.

The objective of this study was to investigate the relationship between physical fitness, lipids, and apolipoproteins in a cross-sectional study using a two-stage probability sample of the population of Northern Ireland. The main outcome measures were physical fitness using VO2max estimated by extrapolation from submaximal oxygen uptake while walking on a motor driven treadmill, and total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, HDL2 and HDL3, and Lp(a). There were no significant relationships with fitness, after adjustment for possible confounders, with the exception of a positive relationship with HDL2 in males (P < or = 0.01) and Lp(a) in females (P < or = 0.05). There was also a relationship between physical fitness and HDL:apo AI ratio in males and females after adjustment for possible confounders (P < or = 0.05). We concluded that there were few relationships between lipid parameters and physical fitness after adjustment for possible confounders. The relationship between physical fitness and Lp(a) in females suggests a benefit associated with physical fitness and the relationship between physical fitness and HDL:apo AI ratio was in keeping with improved HDL cholesterol transport.

Background: Despite the widespread prevalence and serious clinical sequelae of infection with Helicobacter pylori, there have been few large population-based studies, using randomly selected subjects, examining the epidemiology of this infection., Aim: To examine the distribution and determinants of H. pylori infection in a developed country., Subjects and Setting: Overall 4742 subjects, aged 12-64, from Northern Ireland were randomly selected., Methods: Helicobacter pylori specific IgG antibodies were measured by enzyme linked immunosorbent assay, using an acid-glycine extract antigen, in stored serum from subjects who had participated in three linked population-based surveys of cardiovascular risk factors performed in 1986 and 1987., Results: The overall prevalence of H. pylori infection was 50.5%. Prevalence increased with age from 23.4% in 12-14 year olds to 72.7% in 60-64 year olds: chi 2 for trend 518, P < 10(-4). In subjects aged > or = 25, infection was more common in males (60.9%) than females (55.2%): chi 2 = 9.53, P < 0.01. This relation remained significant after adjusting for age, and measures of socioeconomic class: odds ratio (OR) for infection, male versus female was 1.19 (95% confidence interval [CI]: 1.02-1.40). Infection was associated with social class: the adjusted OR of infection in subjects from manual social classes relative to those from non-manual classes was 1.7 (95% CI: 1.47-1.98). Infection was significantly more common in current smokers and ex-smokers than in subjects who had never smoked: adjusted OR for infection, ex-smokers versus never smoked was 1.22 (95% CI: 1.01-1.49); for smokers of > or = 20/day versus never smoked OR = 1.33 (95% CI: 1.05-1.67). Infection was not associated with height in adult males but mean height in infected women was lower than in uninfected women after adjusting for age and socioeconomic status: difference in mean height (SE), -0.85 cm (0.32), P < 0.01. There was no demonstrable relationship between H. pylori infection and current alcohol intake., Conclusions: This study demonstrated a high prevalence of infection in a population from a developed country. Previously reported associations between H. pylori infection, age, sex, social class, and reduced height in females were confirmed and smoking was identified as a possible risk factor for H. pylori infection.

Background: Patients with selective immunoglobulin A (IgA) deficiency and coeliac disease, an established association, lack serum IgA class antigliadin and endomysial antibodies (AGA, EmA). Diagnostic protocols relying on AGA and EmA to select patients for small bowel biopsies will not identify these patients., Objective: To determine whether total IgA should be routinely measured in patients, suspected of having coeliac disease as a supplementary screening test before biopsy., Design: Prospective measurement of IgA, AGA and EmA in patients undergoing small bowel biopsy for suspected coeliac disease., Patients: We studied 318 patients suspected of having coeliac disease. Sera from 1959 controls in a random population sample were assayed as controls., Results: Thirty-one (10%) patients had villous atrophy, of whom 27 (87%) had EmA. Five (2%) of the 318 patients had undetectable total IgA (< 0.07 g/l): two (40%) of these five had villous atrophy in the setting of negative EmA. Use of undetectable IgA as a selection criterion for small bowel biopsy as well as positive EmA would have improved sensitivity from 87% (27/31) for EmA alone to 94% (29/31), with a fall in positive predictive value from 100% (27/27) to 91% (29/32), but would have maintained high specificity and negative predictive value. Serum IgA was undetectable in 5 (4%) of 117 patients with AGA in the range 0-10 ELISA units (EU) compared with none of 201 with higher AGA (P = 0.007, Fisher's exact test). Compared with controls who had AGA 0-10 EU, patients were more likely to have undetectable IgA (5/117 (4%) vs. 3/706 (0.4%); P = 0.005). Overall, the median IgA in patients with AGA 0-10 EU was lower than for those with AGA > 10 EU (1.89 g/l, vs. 2.34 g/l, P < 0.001)., Conclusion: There is an association between IgA deficiency and low/negative EmA/AGA. Routine measurement of total serum IgA in patients suspected of having coeliac disease, either with EmA or where AGA is low, improves selection of patients for small bowel biopsy.

Mild hyperhomocysteinaemia is a major risk factor for vascular disease and neural tube defects (NTDs), conferring an approximately three-fold relative risk for each condition. It has several possible causes: heterozygosity for rare loss of function mutations in the genes for 5,10-methylene tetrahydrofolate reductase (MTHFR) or cystathionine-beta-synthase (CBS); dietary insufficiency of vitamin co-factors B6, B12 or folates; or homozygosity for a common 'thermolabile' mutation in the MTHFR gene which has also been associated with vascular disease and NTDs. We quantified the contribution of the thermolabile mutation to the hyperhomocysteinaemic phenotype in a working male population (625 individuals). Serum folate and vitamin B12 concentrations were also measured and their relationship with homocysteine status and MTHFR genotype assessed. The homozygous thermolabile genotype occurred in 48.4, 35.5, and 23.4% of the top 5, 10, and 20% of individuals (respectively) ranked by plasma homocysteine levels, compared with a frequency of 11.5% in the study population as a whole, establishing that the mutation is a major determinant of homocysteine levels at the upper end of the range. Serum folate concentrations also varied with genotype, being lowest in thermolabile homozygotes. The MTHFR thermolabile genotype should be considered when population studies are designed to determine the effective homocysteine-lowering dose of dietary folate supplements, and when prophylactic doses of folate are recommended for individuals.

Background: Gluten sensitivity is thought to be significantly under-diagnosed in the population., Aims: The aims of this study were to investigate the prevalence of antibodies associated with coeliac disease in a large representative sample of the adult population and to determine factors that are associated with their presence., Patients: Serum samples from 5420 subjects with approximately equal numbers in each five year group from ages 15 to 65 years were obtained from the Belfast MONICA project and Change of Heart surveys, set up to monitor and assess risk factors associated with coronary heart disease in the population., Methods: Using immunofluorescence and enzyme linked immunosorbent assay (ELISA) techniques autoantibodies, including those to reticulin, endomysium, and gliadin were determined., Results: The results establish that IgA antigliadin antibody prevalence is high at 5.7%. Antiendomysial antibody was present in 1.2% of samples and gliadin and endomysial antibodies in 0.4%. No significant differences were found between men and women, area of residence in Northern Ireland or the year of sampling over the eight year period. However, there was a significant increase in the prevalence of IgA gliadin antibody, and to a lesser extent IgA endomysial antibody, with increasing age., Conclusion: The high prevalence of these positive antibodies suggests that coeliac disease may be relatively common in Northern Ireland.

In a cross-sectional study using a two-stage probability sample (N = 1,600) of the population of Northern Ireland, there was an inverse association between the highest recorded recent activity and total cholesterol (P < or = 0.01), LDL (P < or = 0.01), triglyceride (P < or = 0.05) and Chol:HDL ratio (P < or = 0.001) in males, and total cholesterol (P < or = 0.001), LDL (P < or = 0.001), and triglyceride (P < or = 0.01) in females; between habitual activity and HDL (P < or = 0.05) in males and total cholesterol (P < or = 0.05) and triglyceride (P < or = 0.01) in females. There was a relationship between the highest recorded activity and apoAI (P < or = 0.01) and apoB (P < or = 0.01) in males and with apoB (P < or = 0.001) in females; between habitual activity and apoAI (P < or = 0.01) and apoAII (P < or = 0.05) in males and apoB (P < or = 0.01) in females; between past activity and Lp(a) in females (P < or = 0.05). After adjustment for possible confounding factors, total cholesterol (P < or = 0.05) and LDL (P < or = 0.05) were unexpectedly higher in males who were active throughout life. Total cholesterol (P < or = 0.05) and LDL (P < or = 0.001) were higher in females with highest recorded activity and triglycerides lower (P < or = 0.05) in those habitually active. An association between highest recorded activity and apoAI (P < or = 0.01), and past activity and apoAI:apoB ratio (P < or = 0.05) was shown in males and in females, after adjustment, and between apoB (P < or = 0.05) and highest recorded activity.

Study Objective: To investigate the relationship between physical activity, physical fitness, blood pressure, and fibrinogen., Design: This was a cross sectional population study using a two stage probability sample., Setting: Northern Ireland., Participants: A sample of 1600 subjects aged 16-74 years from the population of Northern Ireland., Main Outcome Measures: Physical activity profile from computer assisted interview using the Allied Dunbar national fitness survey scales. Physical fitness using estimation of VO2 max by extrapolation from submaximal oxygen uptake while walking on a motor driven treadmill. Systolic and diastolic blood pressure measured with a Hawksley random zero sphygmomanometer. Measurement of fibrinogen using the Clauss method., Main Results: There were significant relationships between both current and past activity and blood pressure. These were of a magnitude that would have been clinically significant, but for the fact that, with the exception of the relationship between habitual activity and diastolic pressure (p = 0.03) and past activity and systolic pressure (p = 0.03) in men, they were not sustained after adjustment for the effect of age using analysis of variance. After adjustment for other potentially confounding factors using multiple regression, there was an inverse relationship between systolic blood pressure and past activity in men, so that those with a life-time of participation compared with a life-time of inactivity had a lower systolic blood pressure of 6 mmHg (p < 0.05). There was a highly significant (p < 0.001) inverse association between both systolic and diastolic blood pressure and physical fitness (VO2 max) which was not sustained after adjustment for possible confounding factors. There were relationships between fibrinogen and highest recorded activity (p < 0.001), habitual activity (p < 0.01), and past activity (p < 0.01) in men but no significant relationship in women. The relationship between fibrinogen and activity was no longer sustained after adjustment for possible confounding factors. There was a highly significant (p < 0.001) inverse relationship with physical fitness using VO2 max. This relationship was sustained after adjustment for possible confounding factors in both men (p < 0.05) and women (p < 0.001)., Conclusions: There was a relationship between physical activity, physical fitness, and blood pressure but the relationship was greatly influenced by age. A reduction of 6 mmHg in systolic blood pressure associated with past activity is of clinical significance and supports the hypothesis that physical activity is of benefit in reducing cardiovascular risk. There was a lower level of fibrinogen in those who were most active but this relationship was not significant after adjustment for possible confounding factors. There was also a lower level of fibrinogen those who were most fit (VO2 max) and this relationship persisted even after adjustment for possible confounding factors.

Serum vitamin E, vitamin E/cholesterol and physical activity and fitness were examined in a representative cross section (n = 1600) of the Northern Ireland population as part of the Northern Ireland health and activity survey. Serum vitamin E levels were measured by high-performance liquid chromatography, cholesterol by an enzymatic method, physical activity profile was recorded by computer assisted interview and physical fitness was determined by estimation of VO2 max. The levels of serum vitamin E and vitamin E/cholesterol ratio in the Northern Irish population were similar or higher than in other populations with lower incidences of coronary heart disease. The assessment of activity showed that 75% of the population fell below recommended activity levels likely to confer a cardioprotective effect. A significant relationship (P = 0.01) was found in males between serum vitamin E levels and lifetime participation in physical activity. Otherwise no relationship was found between serum vitamin E or vitamin E/cholesterol ratio and physical activity or fitness in the population.

The relationship between physical activity, physical fitness and total radical trapping antioxidant potential (TRAP) was examined in the Northern Ireland Health and Activity Survey. This was a cross-sectional population study (n = 1600) using a two-stage probability sample of the population. TRAP was calculated using the sum of the individual serum antioxidant concentrations (urate, protein thiols, ascorbate, alpha tocopherol and bilirubin) multiplied by their respective stoichiometric values. Physical fitness was determined by estimation of VO2max by extrapolation from submaximal oxygen uptake, and physical activity was recorded by computer-assisted interview. Mean serum TRAP concentrations were significantly higher in males (653 +/- 8.2 mumol/l, mean +/- SEM) compared to females (564 +/- 8.0 mumol/l) (p < 0.0001). Both male and female smokers had significantly lower TRAP values than non-smokers (males p < 0.0001, females p = 0.02). In females, there was a positive relationship of TRAP with age (p < 0.001) and body mass index (p < 0.001) but a negative relationship with physical fitness (p < 0.05). The known beneficial effects of exercise and activity do not appear to be directly mediated through increased antioxidant status.

High intakes of antioxidants in fruit, vegetables and wine are thought to protect against coronary heart disease (CHD). Because people in Toulouse have a much lower incidence of CHD compared with Belfast, the plasma concentrations of antioxidant vitamins and carotenoids in the two populations have been compared. The major difference was in some of the plasma carotenoids. Hydroxy-carotenoids were twice as high in Toulouse in both sexes, notably lutein which occurs principally in dark green vegetables and beta-cryptoxanthin which occurs chiefly in citrus fruits. In addition, alpha-carotene was 50% higher in Toulouse, gamma-tocopherol was 50% higher in Belfast. Other plasma vitamins and carotenoids were not significantly different. If antioxidants play a role in preventing CHD, then the hydroxy-carotenoids are major candidates for further investigation.

Objective: To determine whether Helicobacter pylori infection is associated with the development of ischaemic heart disease and whether such infection can explain the social class inequality in ischaemic heart disease., Design: Cardiovascular risk factor levels, prevalence of ischaemic heart disease (Rose questionnaire angina, and/or a history of myocardial infarction), and serum antibodies to H pylori (enzyme linked immunosorbent assay) were assessed in a cross sectional population based survey., Setting: Belfast and surrounding districts, Northern Ireland., Participants: 1182 men and 1198 women aged 25-64 years randomly selected from the Central Services Agency's general practitioner lists., Main Outcome Measures: The relation of H pylori infection with cardiovascular risk factors and ischaemic heart disease. The association of social class with ischaemic heart disease., Results: Systolic and diastolic blood pressure, plasma viscosity, and total cholesterol were not associated with H pylori infection. A weak negative association existed between H pylori infection and fibrinogen (mean (SE) difference in fibrinogen between infected and uninfected individuals -0.09 (0.04) g/l, P = 0.02) and between infection in women and high density lipoprotein (HDL) cholesterol (mean (SE) difference in HDL cholesterol between infected and uninfected individuals -0.06 (0.02) mmol/l, P = 0.006). A potentially important association was demonstrated between H pylori infection and ischaemic heart disease but this did not reach statistical significance (odds ratio (95% confidence interval (CI) 1.51 (0.93 to 2.45), P = 0.1). Social class was associated with ischaemic heart disease independently of cardiovascular risk factors and H pylori infection (odds ratio, manual v non-manual (95% CI) 1.82 (1.14 to 2.91), P = 0.01)., Conclusion: H pylori may be independently associated with the development of ischaemic heart disease but if this is so the mechanism by which this effect is exerted is not through increased concentration of plasma fibrinogen. H pylori infection does not explain the social class inequality in ischaemic heart disease which exists independently of known cardiovascular risk factors.

The WHO MONICA project monitors trends and determinants in cardiovascular disease to relate classical risk factor changes to trends in incidence rates. The Belfast and Toulouse MONICA centres have also collaborated in dietary studies. Both centres have validated incidence and attack rates for ischaemic heart disease using coronary event registration. These data confirm that the disease in middle-aged men is between three and four times as common in Belfast as in Toulouse. Risk factor surveys show some differences between the centres, but the overall risks assessed by two multiple logistic function scoring systems were identical. A weighed dietary survey revealed no important difference in macronutrient intake, although carbohydrate and saturated fat intake in Belfast was significantly higher. Protein, dietary cholesterol and polyunsaturated fat, particularly linoleic acid intake, was significantly higher in Toulouse, as was consumption of wine, cheese, fruit and vegetables, but not potatoes. The Northern Irish diet is typically Northern European, but although the diet in Toulouse has some features of the Mediterranean diet, it is not appreciably different from that in Belfast in terms of total fat intake. Major differences are present for several food items, and in general these differences add support to the antioxidant hypothesis.

The objective of the study was to evaluate the contribution of dietary factors to variation of plasma levels of lipids, apoproteins and lipoparticles in the Northern Ireland population. This study was part of a larger case-control study of the genetic and environmental determinants of myocardial infarction in France and Northern Ireland. A random sample of 175 middle aged men was drawn from the population covered by the Belfast MONICA project register. Habitual diet was assessed by a questionnaire. A blood sample was obtained after an over-night fast for determination of plasma levels of lipids, apoproteins and lipoparticles. All participants had a medical examination and completed a lifestyle questionnaire. In a stepwise regression, after adjusting for co-factors (i) vitamin C and (ii) alcohol consumption were the only nutrients which contributed significantly to the variation in, respectively, (i) Total Cholesterol, LDL Cholesterol and Apolipoprotein B (inverse correlation) and (ii) HDL Cholesterol and LpAI (positive correlation). The amount of variation explained by the final models was modest, ranging from 4% to 15%. In conclusion, in this Northern Ireland population, habitual diet contributes to little of the variation in plasma levels of lipids, apoproteins and lipoparticles.

It has been shown that myocardial infarction survivors are more likely to carry an insertion/deletion polymorphism (I/D) of the angiotensin-converting-enzyme (ACE) gene than age-matched population controls. To test whether the association with coronary risk had been under-estimated, the frequency of the ACE I/D was studied in 213 fatal cases of definite and possible myocardial infarction which came to autopsy in the Belfast MONICA Project area. In comparison to controls from the same population, the autopsy cases had an increased frequency of the ACE D allele (p < 0.02). The overall odds ratios were 2.2 for DD vs. II, and 1.8 for ID vs II (test for trend p = 0.01). The findings bear out the hypothesis that the ACE I/D polymorphism is a risk factor for fatal myocardial infarction and sudden cardiac death.

The relationship between physical activity, physical fitness and serum ascorbate was examined in the Northern Ireland Health and Activity Survey. This was a cross sectional population study (n = 1600), using a two stage probability sample, of the population of N. Ireland. Physical activity profile was recorded by computer assisted interview and physical fitness was determined by estimation of VO2 max by extrapolation from submaximal oxygen uptake. Serum ascorbate was measured using a colorimetric reaction of 2,4 dinitrophenylhydrazine with dehydroascorbate. Mean serum ascorbate was greater in females than males (p < 0.001), and was lower in smokers than non-smokers in both males (p = 0.01) and females (p < 0.001). There was no statistically significant relationship between serum ascorbate and age, social class, body mass index, physical activity or physical fitness in males but there was a relationship with age (p < 0.01) and physical fitness (p < 0.05) in females.

Objective: To assess the reliability of reported family histories of myocardial infarction., Design: A case-control study in which reported histories of first degree relatives were validated from death certificates, general practitioners' records, and hospital notes., Setting: Participants enrolled in the Belfast centre of the World Health Organisation's study monitoring trends and determinants in cardiovascular disease (MONICA)., Subjects: 200 men who survived myocardial infarction and 200 age matched controls drawn randomly from the population., Main Outcome Measures: The sensitivity, specificity, positive predictive value, and proportion of overall agreement with validated records of reported family histories of myocardial infarction in first degree relatives; odds ratios for myocardial infarction, given at least one reported relative or at least one verified relative being affected., Results: 349 of the 400 probands provided detailed family histories, reporting on 2812 first degree relatives. The overall sensitivity, specificity, and positive predictive value of reported histories were 67.3%, 96.5%, and 70.5% for cases and 68.5%, 97.7%, and 73.8% for controls. The kappa coefficients were modest: 0.65 for cases and 0.68 for controls. The odds ratios for myocardial infarction, given at least one affected relative, were not substantially inflated by recall bias. Some recall bias was evident for the probands' reports of their siblings' histories of myocardial infarction, the odds ratio for a reported history being 1.67 (95% confidence interval 1.09 to 2.57) and for the validated history 1.54 (1.01 to 2.37)., Conclusions: Although the relative risk of disease is correctly estimated, the predictive accuracy of a casual family history of myocardial infarction may limit the effectiveness of targeted screening programmes. They may, however, complement other strategies based on genetic testing.

To compare the plasma lipid, lipoprotein and apolipoprotein profiles of people of Chinese and European origin, a sample of 151 male Chinese subjects was selected from Taiyuan, Shanxi Province, P R China to 202 broadly age-matched subjects in Belfast who were selected as controls in a case-control study of myocardial infarction. Mean total cholesterol (TC) was 6.15 mmol/l in Belfast and 4.28 mmol/l in Taiyuan. Low density lipoprotein cholesterol (LDL) was much higher in Belfast. High density lipoprotein cholesterol (LDL) was also higher in Belfast than in Taiyuan but the ratio of HDL to TC was lower in Belfast than Taiyuan. Triglyceride (TG) levels were similar and this was reflected in the relatively high level of apolipoprotein E (apo E) in the Chinese sample.

Background: An association between hypertension and obstructive sleep apnoea (OSA) has been found by some researchers but remains controversial. Since such an association would have important implications for the investigation and management of hypertension, the rate of nocturnal hypoxaemic episodes has been compared in hypertensive and normotensive men., Methods: The study was carried out in the community in Belfast and its environs. Thirty four men with mild to moderate hypertension aged 40-64 years were identified from general practice and a hypertension clinic. Normotensive men, matched for age and body mass index, were selected from a community survey. Subjects answered a sleep questionnaire and underwent overnight pulse oximetry at home. Computer analysis of the results gave the number and magnitude of dips in oxygen saturation (SaO2 dips, 4% or greater)., Results: The median number of SaO2 dips/hour for hypertensives was 2.0, and for normotensives was 0.8. Lowest SaO2 and mean SaO2 levels were significantly lower in the hypertensive group. Only one subject had a rate of SaO2 dips/hour greater than five and symptoms suggestive of OSA., Conclusions: Both hypertensive and normotensive men had relatively few episodes of nocturnal hypoxaemia. The small increase in the rate of SaO2 dips in hypertensive subjects has not yet been fully explained. These results imply that OSA is not common in hypertensive subjects and is unlikely to be an important cause of hypertension.

Serum copper and zinc concentrations (mumol/L) were measured in nonfasting subjects aged 25-64 y participating in two independent population surveys in Northern Ireland. In 1983-84, copper in 1144 males was 17.2 +/- 3.1 (mean +/- SD) and zinc was 12.1 +/- 1.7 (SD). Copper in 1055 females, neither pregnant nor taking estrogens or progestogens, was 19.0 +/- 3.9 and zinc was 11.6 +/- 1.4. In 1986-87 copper in 1142 males was 17.9 +/- 3.3 and zinc was 13.2 +/- 2.1. Copper in 1034 females was 20.1 +/- 3.9 and zinc was 12.7 +/- 2.0. Zinc but not copper concentrations decreased from early morning to late afternoon; both were unaffected by reported postprandial time. There was a positive relationship between copper and age for both sexes but zinc showed only a slight upward trend with age. A positive relationship between copper and the aggregation of classical risk factors for coronary heart disease was demonstrated.

Two methods of long-term epidemiological follow-up were compared by using each to study the survival of 1622 myocardial infarction patients registered by the Belfast MONICA Project. Length of follow-up ranged between 3 and 5 years during which time 277 deaths were recorded. A computer-based method for linking MONICA Project registration records with the Registrar General's death certification data identified 273 of the 277 deaths. Follow-up supplied by the Northern Ireland Central Services Agency through the flagging of patients in their master patient index identified 271 deaths; four of the six deaths which were missed occurred before computerisation of the index was complete. The study illustrates the value of computer-based linkage with death certification data and of flagging in the Central Services Agency master patient index.

During the 1983-85 period, the Belfast MONICA Project registered coronary events in 2,512 individuals (1,913 men and 599 women). The attack rates in men and women per 1,000 person years were 5.9 and 1.7 respectively, and the corresponding mortality rates were 2.4 and 0.61; both rates were heavily age-dependent. There were statistically significant differences in the age and sex-standardised rates for the 107 electoral wards of the Study. The median delay time from onset to delivery of care was 2 hours 30 minutes and 3 hours 2 minutes for men and women, respectively. Delays were shorter in younger and married individuals, and in those with previous infarctions. Unmarried individuals and those with chronic ischaemic heart disease were at significantly increased risk of pre-care death. Sixty per cent of deaths within 28 days of onset occurred before the patient could be admitted to hospital. Sixty-four per cent of males and 67% of females were alive at 28 days. Manual workers and their spouses had a poorer survival at 28 days. Married men and women were at lowest risk of death in the first 28 days, and this could not be attributed to the effects of age.

The Belfast MONICA Project carried out the joint European Economic Community WHO MONICA Project nutrition study (EURONUT) in 1985-1986 in 401 males subjects (45-64 years) using 3-day weighed records. This resulted in 356 reliable records which were analysed. The mean energy intake was 2369 Kcals (9.9 MJ) with 38% of energy (including alcohol) derived from fat (16.5% from saturated fat, 14.0% from monounsaturated fat, 4.8% from polyunsaturated fat), 14.2% from protein, 43.2% from carbohydrate and 4.0% from alcohol. The mean total fat was 100.3 g (saturated fat 43.5 g, monounsaturated fat 36.9 g, polyunsaturated fat 12.5 g), with a P:S ratio of 0.32. The sources of the different kinds of fat and cholesterol are presented as cumulative percentages of the total. This is a useful way of identifying those foods which contribute chiefly to fat in the diet, and it should have important implications for the monitoring of progress towards meeting dietary guidelines.