Epidemiology and genetics of common mental disorders in the general population: the PEGASUS-Murcia project

BACKGROUND

Multidisciplinary collaboration between clinicians, epidemiologists, neurogeneticists and statisticians on research projects has been encouraged to improve our knowledge of the complex mechanisms underlying the aetiology and burden of mental disorders. The PEGASUS-Murcia (Psychiatric Enquiry to General Population in Southeast Spain-Murcia) project was designed to assess the prevalence of common mental disorders and to identify the risk and protective factors, and it also included the collection of biological samples to study the gene-environmental interactions in the context of the World Mental Health Survey Initiative.

METHODS AND ANALYSIS

The PEGASUS-Murcia project is a new cross-sectional face-to-face interview survey based on a representative sample of non-institutionalised adults in the Region of Murcia (Mediterranean Southeast, Spain). Trained lay interviewers used the latest version of the computer-assisted personal interview of the Composite International Diagnostic Interview (CIDI 3.0) for use in Spain, specifically adapted for the project. Two biological samples of buccal mucosal epithelium will be collected from each interviewed participant, one for DNA extraction for genomic and epigenomic analyses and the other to obtain mRNA for gene expression quantification. Several quality control procedures will be implemented to assure the highest reliability and validity of the data. This article describes the rationale, sampling methods and questionnaire content as well as the laboratory methodology.

ETHICS AND DISSEMINATION

Informed consent will be obtained from all participants and a Regional Ethics Research Committee has approved the protocol. Results will be disseminated in peer-reviewed publications and presented at the national and the international conferences.

DISCUSSION

Cross-sectional studies, which combine detailed personal information with biological data, offer new and exciting opportunities to study the gene-environmental interactions in the aetiology of common mental disorders in representative samples of the general population. A collaborative multidisciplinary research approach offers the potential to advance our knowledge of the underlying complex interactions and this opens the field for further innovative study designs in psychiatric epidemiology.

Consumption of sweet beverages and type 2 diabetes incidence in European adults: results from EPIC-InterAct

AIMS/HYPOTHESIS

Consumption of sugar-sweetened beverages has been shown, largely in American populations, to increase type 2 diabetes incidence. We aimed to evaluate the association of consumption of sweet beverages (juices and nectars, sugar-sweetened soft drinks and artificially sweetened soft drinks) with type 2 diabetes incidence in European adults.

METHODS

We established a case-cohort study including 12,403 incident type 2 diabetes cases and a stratified subcohort of 16,154 participants selected from eight European cohorts participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. After exclusions, the final sample size included 11,684 incident cases and a subcohort of 15,374 participants. Cox proportional hazards regression models (modified for the case-cohort design) and random-effects meta-analyses were used to estimate the association between sweet beverage consumption (obtained from validated dietary questionnaires) and type 2 diabetes incidence.

RESULTS

In adjusted models, one 336 g (12 oz) daily increment in sugar-sweetened and artificially sweetened soft drink consumption was associated with HRs for type 2 diabetes of 1.22 (95% CI 1.09, 1.38) and 1.52 (95% CI 1.26, 1.83), respectively. After further adjustment for energy intake and BMI, the association of sugar-sweetened soft drinks with type 2 diabetes persisted (HR 1.18, 95% CI 1.06, 1.32), but the association of artificially sweetened soft drinks became statistically not significant (HR 1.11, 95% CI 0.95, 1.31). Juice and nectar consumption was not associated with type 2 diabetes incidence.

CONCLUSIONS/INTERPRETATION

This study corroborates the association between increased incidence of type 2 diabetes and high consumption of sugar-sweetened soft drinks in European adults.

Diabetes mellitus, insulin treatment, diabetes duration, and risk of biliary tract cancer and hepatocellular carcinoma in a European cohort

BACKGROUND

Evidence on associations between self-reported diabetes mellitus, diabetes duration, age at diabetes diagnosis, insulin treatment, and risk of biliary tract cancer (BTC) and hepatocellular carcinoma (HCC), independent of general and abdominal obesity is scarce.

PATIENTS AND METHODS

We conducted a prospective analysis in the EPIC-cohort study among 363 426 participants with self-reported diabetes data. Multivariable adjusted relative risks and 95% confidence intervals were estimated from Cox regression models. In a nested case-control subset, analyses were carried out in HCV/HBV-negative individuals.

RESULTS

During 8.5 years of follow-up, 204 BTC cases [including 75 gallbladder cancer (GBC) cases], and 176 HCC cases were identified. Independent of body mass index and waist-to-height ratio diabetes status was associated with higher risk of BTC and HCC [1.77 (1.00-3.13) and 2.17 (1.36-3.47)]. For BTC, the risk seemed to be higher in participants with shorter diabetes duration and those not treated with insulin. Regarding cancer subsites, diabetes was only associated with GBC [2.72 (1.17-6.31)]. The risk for HCC was particularly higher in participants treated with insulin. The results were not appreciably different in HCV/HBV-negative individuals.

CONCLUSION(S)

This study supports the hypothesis that diabetes is a risk factor for BTC (particularly GBC) and HCC. Further research is required to establish whether diabetes treatment or duration is associated with these cancers.

Violence reported by the immigrant population is high as compared with the native population in southeast Spain

Immigrants constitute a population vulnerable to the problem of violence. This study sought to ascertain the prevalence of violence reported by the immigrant population in the Murcian Region of Spain and characterize the related factors, taking the country population as reference. A cross-sectional study was carried out based on a representative population sample of Latin American (n = 672; 48% women), Moroccan (n = 361; 25% women), and Spanish origin (n = 1,303; 66% women), aged 16 to 64 years. Using a specific questionnaire, the prevalence of violence in the preceding year was assessed. The results were compared with the Spaniards using the 2006 National Health Survey (NHS). Multivariate logistic regression models were used to study the factors associated with violence having been reported in each group, both separately and in immigrants versus Spaniards. Finally, the cause and place of last aggression were studied. The prevalence of violence was 6.5% in Latin Americans, 12.0% in Moroccans, and 2.7% in Spaniards. Discrimination was the principal violence-related factor in all three groups. Among Latin Americans, low educational level was also associated with violence. Among Moroccans, those who had perceived discrimination showed the greatest differences in prevalence of violence compared with natives. Intimate partner violence (IPV) registered a prevalence of below 2%. As a conclusion, in this study, violence was little reported and higher among immigrants. The principal violence-related factor was discrimination. More studies of this type are called for to characterize the problem in other population-representative samples.

Major dietary patterns and risk of coronary heart disease in middle-aged persons from a Mediterranean country: the EPIC-Spain cohort study

BACKGROUND AND AIM

No previous study has assessed the association between major dietary patterns and the risk of coronary heart disease (CHD) in a large cohort from a Mediterranean country.

METHODS AND RESULTS

We studied prospectively 40,757 persons, aged 29-69 years, participating in the Spanish cohort of the EPIC study. Food consumption was collected between 1992 and 1996 with a validated history method. Individuals were followed-up until 2004 through record linkage with hospital discharge registers, population-based registers of myocardial infarction, and mortality registers to ascertain CHD events (fatal and non-fatal acute myocardial infarction or angina requiring revascularization). Two major dietary patterns were identified from factor analysis. The first pattern was labeled as Westernized, because of the frequent consumption of refined cereals and red meat; the second was called the evolved Mediterranean pattern, because of the frequent intake of plant-based foods and olive oil. During a median follow-up of 11 years, 606 CHD events were ascertained. No association was found between the Westernized pattern and CHD risk. In contrast, the score for the evolved Mediterranean pattern was inversely associated with CHD risk (p for trend = 0.0013); when compared with the lowest quintile of the evolved Mediterranean pattern score, the multivariable hazard ratios for CHD were 0.77 (95% confidence interval 0.61-0.98) for the second quintile, 0.64 (95% CI 0.50-0.83) for the third quintile, 0.56 (95% CI 0.43-0.73) for the fourth quintile, and 0.73 (95% CI 0.57-0.94) for the fifth quintile.

CONCLUSION

A Mediterranean diet, as consumed in this study population, was associated with a lower risk of CHD.

Design and cohort description of the InterAct Project: an examination of the interaction of genetic and lifestyle factors on the incidence of type 2 diabetes in the EPIC Study

AIMS/HYPOTHESIS

Studying gene-lifestyle interaction may help to identify lifestyle factors that modify genetic susceptibility and uncover genetic loci exerting important subgroup effects. Adequately powered studies with prospective, unbiased, standardised assessment of key behavioural factors for gene-lifestyle studies are lacking. This case-cohort study aims to investigate how genetic and potentially modifiable lifestyle and behavioural factors, particularly diet and physical activity, interact in their influence on the risk of developing type 2 diabetes.

METHODS

Incident cases of type 2 diabetes occurring in European Prospective Investigation into Cancer and Nutrition (EPIC) cohorts between 1991 and 2007 from eight of the ten EPIC countries were ascertained and verified. Prentice-weighted Cox regression and random-effects meta-analyses were used to investigate differences in diabetes incidence by age and sex.

RESULTS

A total of 12,403 verified incident cases of type 2 diabetes occurred during 3.99 million person-years of follow-up of 340,234 EPIC participants eligible for InterAct. We defined a centre-stratified subcohort of 16,154 individuals for comparative analyses. Individuals with incident diabetes who were randomly selected into the subcohort (n = 778) were included as cases in the analyses. All prevalent diabetes cases were excluded from the study. InterAct cases were followed-up for an average of 6.9 years; 49.7% were men. Mean baseline age and age at diagnosis were 55.6 and 62.5 years, mean BMI and waist circumference values were 29.4 kg/m(2) and 102.7 cm in men, and 30.1 kg/m(2) and 92.8 cm in women, respectively. Risk of type 2 diabetes increased linearly with age, with an overall HR of 1.56 (95% CI 1.48-1.64) for a 10 year age difference, adjusted for sex. A male excess in the risk of incident diabetes was consistently observed across all countries, with a pooled HR of 1.51 (95% CI 1.39-1.64), adjusted for age.

CONCLUSIONS/INTERPRETATION

InterAct is a large, well-powered, prospective study that will inform our understanding of the interplay between genes and lifestyle factors on the risk of type 2 diabetes development.

Association of plasma markers of cholesterol homeostasis with metabolic syndrome components. A cross-sectional study

BACKGROUND AND AIMS

Increased plasma phytosterols, which reflect enhanced cholesterol absorption, have been related to an increased risk of cardiovascular disease (CVD). However, high CVD risk conditions, such as obesity, diabetes and the metabolic syndrome (MetS) have been associated with reduced cholesterol absorption. We investigated associations between plasma noncholesterol sterols and MetS components.

METHODS AND RESULTS

With a cross-sectional design, we related MetS components to plasma noncholesterol sterol-to-cholesterol ratios measured by gas chromatography in 674 dyslipidemic patients and 361 healthy subjects participating in a prospective cohort study. Plasma phytosterol-to-cholesterol ratios were inversely associated with all components of the MetS. In the dyslipidemic group, multivariable analyses showed that a 1-SD increase in sitosterol-to-cholesterol ratio was associated with a reduced risk for any MetS feature, ranging from 0.57 (95% CI, 0.45 to 0.71) for visceral adiposity to 0.82 (95% CI, 0.69 to 0.98) for high blood pressure. The risk of having MetS was nearly halved, with ORs of 0.49 (95% CI, 0.38 to 0.64) or 0.56 (95% CI, 0.44-0.70), depending on the definition. Results were opposed for plasma lathosterol, a marker of cholesterol synthesis. Most findings were reproduced in the healthy cohort. ApoE genotype was unrelated to plasma noncholesterol sterols.

CONCLUSION

In both dyslipidemic and healthy populations, MetS is associated with increased plasma lathosterol, a cholesterol synthesis marker, and decreased plasma sitosterol, a marker of cholesterol absorption. Elevated plasma phytosterols related to a lower frequency of cardiometabolic risk factors, suggesting that they are associated with a reduced CVD risk.

Prevalence of dementia and cognitive impairment in Southeastern Spain: the Ariadna study

OBJECTIVES

To estimate the prevalence of amnestic mild cognitive impairment (aMCI), cognitive impairment, no dementia (CIND) and dementia in a general elderly population and to examine the associated socio-demographic factors.

METHODS

The Ariadna study is a population-based cross-sectional study of cognitive function involving 1074 individuals aged 65-96 years from the Murcia Region of southeastern Spain. Prevalence, adjusted odds ratio (OR) and 95% confidence intervals (CI) were calculated.

RESULTS

The overall prevalence was 8.7% (95% CI 7.1-10.5) for aMCI, 14.5% (95% CI 12.4-16.8) for CIND and 5.5% (95% CI 4.3-7.1) for dementia. Dementia was associated with age (OR 1.13 95% CI 1.09-1.18 for a 1-year increase in age). Illiterate subjects were more likely to present aMCI (OR 2.59; 95% CI 1.09-6.14) and dementia (OR 4.09; 95% CI 1.28-13.08) than subjects with secondary or higher education. Rural area residents (OR 2.13, 95% CI 1.07-4.24) and women (OR 1.53, 95% CI 1.06-2.22) were more likely to have CIND.

CONCLUSION

The prevalence of dementia was low, despite a high prevalence of aMCI and CIND. Dementia was strongly associated with age and education. CIND was associated with living in a rural area and with female sex, while aMCI was associated with illiteracy.

Incidence of acute myocardial infarction in the Spanish epic cohort

BACKGROUND

There is some evidence that Mediterranean diet reduces risk of ischemic heart disease, and this is to be investigated in the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC). In this paper we present the incidence of acute myocardial infarction (AMI) in four EPIC Spanish cohorts.

METHOD

Incidence cases were ascertained in EPIC cohort during the follow up period (from recruitment to the end of 2004), by means of self-report questionnaires, hospital morbidity and mortality registries, and population AMI registries. Analysis was restricted to aged 45 to 74. The present study included data from 13,704 women and 19,410 men, after excluding a priori participants with prevalent AMI. Age standardized incidence rate for each cohort was estimated and compared with the available population rates.

RESULTS

The Median duration of follow-up was 9.3 years, yielding a total of 297,704 person-years. 391 men and 99 women presented AMI in the four cohorts studied. Age standardized AMI rates in men of the EPIC cohorts go from the lowest 302 (CI: 268-335) per 100.000 person-year of Gipuzkoa to the highest 330 (CI: 293-367) of Navarra. Women in Navarra presented the lowest AMI incidence with 60 (CI: 43-77) per 100,000 and the highest was observed in Murcia (114, CI: 91-137). The AMI incidence in all EPIC centres are close to the population incidence rates and in any case these are within the EPIC 95% CI.

CONCLUSIONS

The comparison of incidence in EPIC with population rates shows very good agreement for acute myocardial infarction.

Magnetic resonance spectroscopy performance for detection of dementia, Alzheimer's disease and mild cognitive impairment in a community-based survey

BACKGROUND/AIMS

To evaluate (1)H-labelled magnetic resonance spectroscopy (MRS) in patients with a low Mini Mental State Examination (MMSE) score identified during a dementia community-based survey.

METHODS

A population sample of 1,500 individuals (>64 years old) was randomly selected. Two hundred and fifteen individuals (MMSE < or =24) were sorted into clinical groups: dementia, Alzheimer's disease, mild cognitive impairment (MCI), normal. Up to 56 of these individuals attended the MRS appointment. Two single-voxel sequences (TR 1,500, TE 35/144 ms) were carried out in the posterior cingulate gyrus of each individual, and the ratios N-acetylaspartate (NAA)/creatine (Cr), choline (Cho)/Cr, myo-inositol (mI)/Cr, NAA/mI and NAA/Cho were compared statistically. The ability of MRS to distinguish clinical groups was assessed by receiver-operating characteristics analysis. Cognition effects on metabolite ratios were estimated, with gender and cognition as categorical variables and age as a continuous covariate.

RESULTS

NAA/Cr and NAA/Cho ratios were lower in dementia or Alzheimer's disease than in MCI and normal groups. The NAA/Cr ratio at TE 35 ms performed best when distinguishing dementia or Alzheimer's disease from non-demented subjects (cut-off point 1.40). MRS could not distinguish between MCI patients and normal subjects. Dementia was an independent predictor of metabolite values.

CONCLUSION

In a population sample, conventional MRS still proved to be a useful tool for dementia discrimination, but it is potentially far less useful as a surrogate marker for MCI.

Blood pressure and risk of renal cell carcinoma in the European prospective investigation into cancer and nutrition

Elevated blood pressure has been implicated as a risk factor for renal cell carcinoma (RCC), but prospective studies were confined to men and did not consider the effect of antihypertensive medication. The authors examined the relation among blood pressure, antihypertensive medication, and RCC in the European Prospective Investigation into Cancer and Nutrition (EPIC). Blood pressure was measured in 296,638 women and men, recruited in eight European countries during 1992-1998, 254,935 of whom provided information on antihypertensive medication. During a mean follow-up of 6.2 years, 250 cases of RCC were identified. Blood pressure was independently associated with risk of RCC. The relative risks for the highest versus the lowest category of systolic (>/=160 mmHg vs. <120 mmHg) and diastolic (>/=100 mmHg vs. <80 mmHg) blood pressures were 2.48 (95% confidence interval: 1.53, 4.02) and 2.34 (95% confidence interval: 1.54, 3.55). Risk estimates did not significantly differ according to sex or use of antihypertensive medication. Individuals taking antihypertensive drugs were not at a significantly increased risk unless blood pressure was poorly controlled. These results support the hypothesis that hypertension, rather than its medications, increases the risk of RCC in both sexes, while effective blood pressure control may lower the risk.

Consumption of cruciferous vegetables and glucosinolates in a Spanish adult population

OBJECTIVE

To assess the intake of glucosinolates and cruciferous vegetables among Spanish adults.

DESIGN

Cross-sectional analysis of a prospective cohort study.

SETTING

The Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC).

SUBJECTS

We analysed data from 40 684 men and women aged 35-64 years from the EPIC-Spain cohort. The usual diet was assessed by means of the dietary history method, and glucosinolate intake was calculated using a published food composition database.

RESULTS

The average intake of cruciferous vegetables was 11.3 g/day, accounting for about 5% of total vegetable consumption, whereas the daily intake of total glucosinolates was 6.5 mg, among which 35% were of indole type. The absolute intake of glucosinolates was in average higher in men than in women (6.8 vs 6.2 mg/day), whereas glucosinolate density per energy unit was higher in women's diet (3.4 vs 2.7 mg/4200 kJ). Northern regions consumed in average 36% more glucosinolates than Southern regions (7.3 vs 5.4 mg/day). There was a positive association of glucosinolate intake with body mass index, physical activity, educational level and an inverse relationship with alcohol consumption.

CONCLUSIONS

Contrary to the pattern seen for total vegetable intake, our estimate of consumption of cruciferous vegetables, and hence of glucosinolates, is relatively low within Europe, which in turn is lower than in North America and several Asian populations.

Validity of self reported diagnoses of cancer in a major Spanish prospective cohort study

INTRODUCTION

This study aims to assess the validity of self reported diagnoses of cancer by persons recruited for the Spanish EPIC (European prospective investigation into cancer and nutrition) cohort study and to identify variables associated with correctly reporting a diagnosis of cancer.

METHODS

41 440 members of EPIC were asked at the time of recruitment whether they had been diagnosed with cancer and the year of diagnosis and site. The process of validating self reported diagnoses of cancer included comparison of the cohort database with the data from the population based cancer registries. Cancer diagnostic validity tests were calculated. The association between a correct report and certain sociodemographic, tumour related, or health related variables were analysed by logistic regression.

RESULTS

The overall sensitivity of self reported diagnoses of cancer is low (57.5%; 95% CI: 51.9 to 63.0), the highest values being shown by persons with a higher level of education or with a family history of cancer and the lowest values by smokers. Breast and thyroid cancers are those with the highest diagnostic validity and uterus, bladder, and colon-rectum those with the lowest. In both sexes the variables showing a significant association with a correct report of cancer are: higher education level, number of previous pathologies, invasive tumour, and, in women, a history of gynaecological surgery.

CONCLUSIONS

The overall sensitivity of self reported diagnoses of cancer is comparatively low and it is not recommended in epidemiological studies for identifying tumours. However, self reported diagnoses might be highly valid for certain tumour sites, malignant behaviour, and average to high levels of education.

Plasma adiponectin levels and endometrial cancer risk in pre- and postmenopausal women

BACKGROUND

Adiponectin, an adipocytokine secreted by adipose tissue, is decreased in obesity, insulin resistance, type 2 diabetes, and polycystic ovary syndrome, all of which are well-established risk factors for endometrial cancer.

METHODS

We conducted a case-control study nested within the European Prospective Investigation into Cancer and Nutrition to examine the relation between prediagnostic plasma adiponectin levels and endometrial cancer risk. Among pre- and postmenopausal women who were not currently using exogenous hormones, 284 women developed incident endometrial cancer during an average of 5.1 yr of follow-up. Using risk set sampling, 548 control subjects were selected, matched on center, age, menopausal status, phase of menstrual cycle, time of blood draw, and fasting status. Conditional logistic regression models were used to estimate relative risks and 95% confidence intervals.

RESULTS

Adiponectin levels were inversely associated with endometrial cancer risk [body mass index-adjusted relative risk for the top vs. bottom quartile = 0.56 (95% confidence interval 0.36-0.86), P(trend) = 0.006]. There was evidence of a stronger inverse association among obese women than among nonobese women (P(heterogeneity) = 0.03). The inverse association also appeared stronger for women who were postmenopausal or perimenopausal than premenopausal at baseline, but this was not statistically significantly heterogeneous (P(heterogeneity) = 0.51). The association remained statistically significant after separate adjustment for other obesity-related physiological risk factors such as C-peptide, IGF binding protein-1, IGF binding protein-2, SHBG, estrone, or free testosterone but only marginally statistically significant after simultaneous adjustment for these factors.

CONCLUSIONS

High circulating adiponectin levels are associated with reduced endometrial cancer risk, largely independent of other obesity-related risk factors.

Relationship of alcohol intake and sex steroid concentrations in blood in pre- and post-menopausal women: the European Prospective Investigation into Cancer and Nutrition

OBJECTIVE

Women with a moderate intake of alcohol have higher concentrations of sex steroids in serum, and higher risk of developing breast cancer, compared to non-drinkers. In the present study, we investigate the relationships between alcohol consumption and serum levels of sex steroids and sex-hormone binding globulin (SHBG) in 790 pre- and 1,291 post-menopausal women, who were part of the European Prospective Investigation into Cancer and Nutrition (EPIC).

METHODS

Serum levels of testosterone (T), androstenedione (Delta4), dehydroepiandrosterone sulphate (DHEAS), estrone (E1), estradiol (E2) and SHBG were measured by direct immunoassays. Free T (fT) and free E2 (fE2) were calculated according to mass action laws. Current alcohol intake exposure to alcohol was assessed from dietary questionnaires.

RESULTS

Pre-menopausal women who consumed more than 25 g/day of alcohol had about 30% higher DHEAS, T and fT, 20% higher Delta4 and about 40% higher E1, concentrations compared to women who were non-consumers. E2, fE2 and SHBG concentrations showed no association with current alcohol intake. In post-menopausal women, DHEAS, fT, T, Delta4, and E1 concentrations were between 10% and 20% higher in women who consumed more than 25 g/day of alcohol compared to non-consumers. E2 or fE2 were not associated with alcohol intake at all. SHBG levels were about 15% lower in alcohol consumers compared to non-consumers.

CONCLUSION

This study supports the hypothesis of an influence of alcohol intake on sex hormone concentrations in blood.

Diet, serum insulin-like growth factor-I and IGF-binding protein-3 in European women

OBJECTIVE

The aim of this study was to examine the relationship of diet with serum insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 in women.

DESIGN

Cross-sectional study.

SETTING AND SUBJECTS

The population are 2109 women who were control subjects in a case-control study of breast cancer nested in the European Prospective Investigation into Cancer and Nutrition. Control subjects were randomly chosen among risk sets consisting of female cohort members alive and free of cancer (except non-melanoma skin cancer) at the time of diagnosis of the index case. Matching criteria were age at enrolment, follow-up time, time of the day of blood collection and study centre. Diet was measured through validated questionnaires. Serum hormone concentrations were measured by enzyme-linked immunosorbent assays. The relationship between serum IGF-I, IGFBP-3, and intake of nutrients and foods was explored by linear regression in models adjusted for energy intake, age, body mass index, smoking, physical activity, centre and laboratory batch.

RESULTS

Serum IGF-I levels were positively related to protein intake (P(trend)<0.001), but not related to energy, fat or carbohydrate intake. Positive relationships were observed with the intake of milk (P(trend)=0.007), calcium (P(trend)<0.001), magnesium (P(trend)=0.003), phosphorus (P(trend)<0.001), potassium (P(trend)=0.002), vitamin B6 (P(trend)=0.03), vitamin B2 (P(trend)=0.001) and inverse relationships with vegetables (P(trend)=0.02) and beta-carotene (P(trend)=0.02). IGFBP-3 was not related with most of the nutrients and foods in this study.

CONCLUSIONS

In this population, circulating IGF-I is modestly related with the intake of protein and minerals, and with milk and cheese, while IGFBP-3 does not appear to be related with diet.

Multi-factor dimensionality reduction applied to a large prospective investigation on gene-gene and gene-environment interactions

It is becoming increasingly evident that single-locus effects cannot explain complex multifactorial human diseases like cancer. We applied the multi-factor dimensionality reduction (MDR) method to a large cohort study on gene-environment and gene-gene interactions. The study (case-control nested in the EPIC cohort) was established to investigate molecular changes and genetic susceptibility in relation to air pollution and environmental tobacco smoke (ETS) in non-smokers. We have analyzed 757 controls and 409 cases with bladder cancer (n=124), lung cancer (n=116) and myeloid leukemia (n=169). Thirty-six gene variants (DNA repair and metabolic genes) and three environmental exposure variables (measures of air pollution and ETS at home and at work) were analyzed. Interactions were assessed by prediction error percentage and cross-validation consistency (CVC) frequency. For lung cancer, the best model was given by a significant gene-environment association between the base excision repair (BER) XRCC1-Arg399Gln polymorphism, the double-strand break repair (DSBR) BRCA2-Asn372His polymorphism and the exposure variable 'distance from heavy traffic road', an indirect and robust indicator of air pollution (mean prediction error of 26%, P<0.001, mean CVC of 6.60, P=0.02). For bladder cancer, we found a significant 4-loci association between the BER APE1-Asp148Glu polymorphism, the DSBR RAD52-3'-untranslated region (3'-UTR) polymorphism and the metabolic gene polymorphisms COMT-Val158Met and MTHFR-677C>T (mean prediction error of 22%, P<0.001, mean CVC consistency of 7.40, P<0.037). For leukemia, a 3-loci model including RAD52-2259C>T, MnSOD-Ala9Val and CYP1A1-Ile462Val had a minimum prediction error of 31% (P<0.001) and a maximum CVC of 4.40 (P=0.086). The MDR method seems promising, because it provides a limited number of statistically stable interactions; however, the biological interpretation remains to be understood.

DNA repair polymorphisms and cancer risk in non-smokers in a cohort study

Environmental carcinogens contained in air pollution, such as polycyclic aromatic hydrocarbons, aromatic amines or N-nitroso compounds, predominantly form DNA adducts but can also generate interstrand cross-links and reactive oxygen species. If unrepaired, such lesions increase the risk of somatic mutations and cancer. Our study investigated the relationships between 22 polymorphisms (and their haplotypes) in 16 DNA repair genes belonging to different repair pathways in 1094 controls and 567 cancer cases (bladder cancer, 131; lung cancer, 134; oral-pharyngeal cancer, 41; laryngeal cancer, 47; leukaemia, 179; death from emphysema and chronic obstructive pulmonary disease, 84). The design was a case-control study nested within a prospective investigation. Among the many comparisons, few polymorphisms were associated with the diseases at the univariate analysis: XRCC1-399 Gln/Gln variant homozygotes [odds ratios (OR) = 2.20, 95% confidence intervals (CI) = 1.16-4.17] and XRCC3-241 Met/Met homozygotes (OR = 0.51, 95% CI = 0.27-0.96) and leukaemia. The recessive model in the stepwise multivariate analysis revealed a possible protective effect of XRCC1-399Gln/Gln in lung cancer (OR = 0.22, 95% CI = 0.05-0.98), and confirmed an opposite effect (OR = 2.47, 95% CI = 1.02-6.02) in the leukaemia group. Our results also suggest that the XPD/ERCC1-GAT haplotype may modulate leukaemia (OR = 1.28, 95% CI = 1.02-1.61), bladder cancer (OR = 1.38, 95% CI = 1.06-1.79) and possibly other cancer risks. Further investigations of the combined effects of polymorphisms within these DNA repair genes, smoking and other risk factors may help to clarify the influence of genetic variation in the carcinogenic process.

Reliability of bulky DNA adducts measurement by the nuclease P1 32P-post-labelling technique

The aim was to assess the reliability of bulky DNA adducts measurement by means of the 32P-post-labelling assay. The research design consisted of an intramethod reliability study. Buffy coats from 41 subjects were used to obtain two aliquots of 1-5 microg DNA for each subject; bulky DNA adducts were measured using the nuclease P1 32P-post-labelling technique. The reliability of the measurement was assessed by means of the intraclass correlation coefficient (ICC), the distribution of the differences between the two measurements and the limits of agreement. The estimated ICC was 0.977, with a 95% confidence interval between 0.921 and 0.977. The limits of agreement were +/- 0.44 (DNA adducts per 10(8) nucleotides). Only three subjects had differences lying out of such limits. Bulky DNA adduct levels measured by the 32P-post-labelling technique showed good reliability. Only one measurement is needed to use DNA adducts as a biomarker of exposure and, possibly, cancer risk. Besides, as a validation analysis, 32P-post-labelling measurements can be repeated in only 20-30% of samples.

C-peptide, IGF-I, sex-steroid hormones and adiposity: a cross-sectional study in healthy women within the European Prospective Investigation into Cancer and Nutrition (EPIC)

OBJECTIVES

The risk of some cancers is positively associated with body weight, which may influence circulating levels of sex-steroid hormones, insulin and IGF-I. Interrelationships between these hormones and the associations with adiposity were evaluated in healthy women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC).

METHODS

A cross-sectional analysis was performed on anthropometric and hormonal data from 743 pre- and 1217 postmenopausal women. Body mass index (BMI) and waist circumference were used as indicators of adiposity. C-peptide, Insulin Growth Factor (IGF)-I, Insulin Growth Factor binding protein (IGFBP)-3, androgens, estrogens and sex hormone binding globulin (SHBG) were measured by immunoassays; free sex steroid concentrations were calculated.

RESULTS

BMI and waist circumference were positively correlated with estrogens in postmenopausal women and with C-peptide, free testosterone and inversely with SHBG in all women. C-peptide and IGF-I were inversely correlated with SHBG, and positively with free sex steroids in postmenopausal women. IGF-I was positively associated with postmenopausal estrogens and androgen concentrations in all women.

CONCLUSIONS

Sex-steroid concentrations appear to be regulated along several axes. Adiposity correlated directly with estrogens in postmenopausal women and with insulin, resulting in lower SHBG and increased levels of free sex steroids. Independent of adiposity and insulin, IGF-I was associated with decreased SHBG levels, and increased concentrations of androgens and postmenopausal estrogens.

[Physical sports activity in a representative sample of the population of Región de Murcia, Spain]

OBJECTIVE

To estimate the prevalence of intense physical activity according to age and sex in the region of Murcia, Spain, and to analyze its association with major demographic and socioeconomic determinants and other cardiovascular risk factors.

METHODS

Survey of a representative sample of the population aged between 18 and 65 years from Murcia was performed using multistage random sampling with definition of the sample quotas. A total of 3091 individuals were surveyed. The frequency and duration of intense physical sports activity during the two weeks prior to the survey was obtained using a validated questionnaire. Information was also collected on socioeconomic variables, smoking, blood pressure, weight and height and a blood test was performed to determine plasma lipids. Intense or vigorous physical activity (> or = 6 Metabolic Equivalents [MET]) was measured in kcal/day and reduced to hours/week to give three categories: no vigorous physical activity, less than 2 hours/week, and 2 hours/week or more.

RESULTS

Overall, 17.8% (95% CI: 16.6-19.0) of the adult population of the region of Murcia performed intense physical activity for > or = 2 hours/week. The figures were twice as high in men (23.1%; 95% CI: 21.0-25.2) than in women (12.5%; 95% CI: 10.9-14.1). In the logistic regression analysis, a higher frequency of intense physical activity was associated with age, level of education and employment situation. In men it was also associated with occupation and residence in urban areas.

CONCLUSIONS

During the study period, one in five adults in the region of Murcia took intense physical sports activity with a frequency and duration that were compatible with the prevention of episodes of coronary ischemia.

Physical activity of subjects aged 50-64 years involved in the European Prospective Investigation into Cancer and Nutrition (EPIC)

OBJECTIVE

To describe physical activity of participants in the European Prospective Investigation into Cancer and Nutrition (EPIC).

DESIGN

A cross-sectional analysis of baseline data of a European prospective cohort study.

SUBJECTS

This analysis was restricted to participants in the age group 50-64 years, which was represented in all EPIC centres. It involved 236 386 participants from 25 centres in nine countries. In each EPIC centre, physical activity was assessed by standardised and validated questions. Frequency distribution of type of professional activity and participation in non-professional activities, and age-adjusted means, medians and percentiles of time dedicated to non-professional activities are presented for men and women from each centre.

RESULTS

Professional activity was most frequently classified as sedentary or standing in all centres. There was a wide variation regarding participation in different types of non-professional activities and time dedicated to these activities across EPIC centres. Over 80% of all EPIC participants engaged in walking, while less than 50% of the subjects participated in sport. Total time dedicated to recreational activities was highest among the Dutch participants and lowest among men from Malmö (Sweden) and women from Naples (Italy). In all centres, total time dedicated to recreational activity in the summer was higher than in the winter. Women from southern Europe spent the most time on housekeeping.

CONCLUSIONS

There is a considerable variation of physical activity across EPIC centres. This variation was especially evident for recreational activities in both men and women.

Soy product consumption in 10 European countries: the European Prospective Investigation into Cancer and Nutrition (EPIC) study

OBJECTIVE

The aim of this study was to describe the variation of soy product intake in 10 European countries by using a standardised reference dietary method. A subsidiary aim was to characterise the pattern of soy consumption among a sub-group of participants with a habitual health-conscious lifestyle (HHL), i.e. non-meat eaters who are fish eaters, vegetarians and vegans.

DESIGN

A 24-hour dietary recall interview (24-HDR) was conducted among a sample (5-12%) of all cohorts in the European Prospective Investigation into Cancer and Nutrition (EPIC). Study participants totalled 35 955 after exclusion of subjects younger than 35 or older than 74 years of age. Soy products were subdivided into seven sub-groups by similarity. Distribution of consumption and crude and adjusted means of intake were computed per soy product group across countries. Intake of soy products was also investigated among participants with an HHL.

RESULTS

In total, 195 men and 486 women reported consuming soy products in the 24-HDR interview. Although soy product intake was generally low across all countries, the highest intake level was observed in the UK, due to over-sampling of a large number of participants with an HHL. The most frequently consumed soy foods were dairy substitutes in the UK and France and beans and sprouts among mid-European countries. For both genders, the sub-group of soy dairy substitutes was consumed in the highest quantities (1.2 g day-1 for men; 1.9 g day-1 for women). Participants with an HHL differed substantially from others with regard to demographic, anthropometric and nutritional factors. They consumed higher quantities of almost all soy product groups.

CONCLUSIONS

Consumption of soy products is low in centres in Western Europe. Soy dairy substitutes are most frequently consumed. Participants with an HHL form a distinct sub-group with higher consumptions of fruit, vegetables, legumes, cereals and soy products compared with the other participants.

[Sociodemographic differences in adherence to the Mediterranean dietary pattern in Spanish populations]

OBJECTIVES

Lower social classes tend to eat a less healthy diet. The aim of this study was to compare adherence to the Mediterranean dietary pattern among different demographic and social groups in the adult population.

METHODS

A cross-sectional study was performed in southern and northern regions of Spain in healthy volunteers (15,634 men and 25,812 women), aged 29-69 years, who were members of the European Prospective Investigation on Cancer cohort in Spain. Nine groups of food were included in the definition of the Mediterranean diet: vegetables and garden products, fruits, pulses, cereals, red meat, fish, olive oil, milk and milk products, and wine. Two techniques were used in the analysis: comparison of the mean daily intake of each group and calculation of an overall score for all the foods according to educational level and original social class.

RESULTS

Groups with the lowest educational levels consumed more cereals and pulses and lower quantities of vegetables, olive oil (women), milk and milk products (men). Wine consumption was positively associated with education in women and was negatively associated in men. Calculation of a score to measure overall adherence to the Mediterranean dietary pattern eliminated differences according to each food category. No variations were found according to educational level, but small differences were found in original social class. The adherence score was lowest in young adults and women and was slightly higher in the south than in the north of Spain.

CONCLUSIONS

The results suggest that the Mediterranean dietary pattern is fairly uniform, at least in the adult population of the regions included in this study.

Is there a different dietetic pattern depending on self-knowledge of high blood pressure?

This cross-sectional study describes the dietary pattern seen at recruitment in a large Spanish cohort comprising 41,451 people (aged 30-69 years) according to high blood-pressure status. We provide information on adjusted mean daily intake of foods and nutrients, by means of a dietary history, from those people self-reported as having high blood pressure as well as from those self-reported as normotensive but having, after actual blood-pressure measurement, systolic or diastolic blood pressures of > or = 160/95 mmHg. Although with small differences in mean intake people who self-reported high blood pressure have a higher consumption of potatoes, vegetables, vitamin C and E; furthermore, men reported an increased intake of fruit, meat, fish, proteins, dietary fibre, beta-carotene and alcohol, and women tended to consume less alcohol, lipids and cholesterol but more proteins, carbohydrates and dietary fibre. Almost no differences are found in fatty acid intake. This pattern is reversed among those self-reported as normotensive but with high blood pressure after actual measurement. We conclude that in this large prospective cohort, awareness or not of having high blood pressure at recruitment is associated with a differential dietary pattern.

Extremely high prevalence of overweight and obesity in Murcia, a Mediterranean region in south-east Spain

OBJECTIVE

To estimate the prevalence of obesity in the Murcia Region according to age and sex, and to analyse how obesity is related to demographic and socio-economic determinants and to other cardiovascular risk factors of interest to the community.

DESIGN

Survey on a representative population sample using multi-stage random sampling with definition of the sample quotas.

SUBJECTS

A total of 3091 persons aged 18-65 y residing in the Murcia Region.

MEASUREMENTS

: The following data were collected: socio-economic data; tobacco smoking; recent physical activity; blood pressure; weight; height; and blood analysis to determine plasma lipids. Obesity was defined by body mass index (BMI)> or =30. Intense or vigorous physical activity (VPA> or =6 equivalents to baseline metabolic rate or METs) was measured in kilocalories per day and reduced to hours per week.

RESULTS

In all, 20.5% of the adult population of the Murcia Region is obese, and 40.9% is overweight. In the logistic regression analysis, obesity in men is associated with age and level of education. In women it is associated with age, level of education, living in a non-urban area and being a housewife. When adjusted for socio-economic variables and for other cardiovascular risk factors the effect of age and level of education disappears in men and it is directly associated with hypertension and hypertriglyceridaemia and inversely related to more than 2 h VPA per week. Obesity in women is associated positively with age, hypertension, hypertriglyceridaemia and little VPA, and inversely with level of education.

CONCLUSIONS

In the Murcia Region 61.4% of the adult population presents with some form of excess weight. The prevalence of obesity (BMI> or =30) is greater in women (23.7%; CI 95% 19.7-27.7) than in men (17.3%; CI 95% 15.3-19.3). The widespread nature of this factor makes it a mass problem that requires generalised interventions to prevent it.

[Usefulness of the statistical bulletin of deaths to identify extrahospital deaths in the context of a myocardial infarction population registry]

INTRODUCTION AND AIMS

This paper aimed to study the usefulness of the Statistical Bulletin of Deaths (SBD) for identifying extrahospital deaths due to acute coronary ischaemia, and to determine the most efficient strategy in the selection of death causes that appear in the SBD, which are the most efficient for the identification.

METHODS

Those extrahospital deaths, which, among the causes of death, recorded a diagnostic code indicating that they might have been caused by coronary ischaemia, were included. To study the usefulness of the death certificate we calculated the sensitivity and the positive predictive value of cardiac ischaemia. To determine the most efficient strategy for selecting causes of death we compared two selection strategies: the first, using only the basic cause of death; and the second using all the causes appearing in the SBD.

RESULTS

Of the 395 SBD selected, 161 were classed as acute heart attacks. In those SBD in which cardiac ischaemic disease was given as the basic cause of death, we obtained a sensitivity of 82.6% (CI 95%: 75.9-88.1) and a positive predictive value of 72.7% (CI 95%: 65.6-79). The most efficient strategy in SBD selection proved to be the investigation of death certificates in which cardiac ischaemia appeared as one of all the causes of death, and death certificates in which the basic cause of death was coded as diabetes mellitus, essential arterial hypertension, hypertensive heart disease, cardiac dysrhythmia, and cardiac insufficiency.

CONCLUSIONS

The information provided by death certificates for extrahospital deaths due to coronary ischaemia is reliable. A sensitive and efficient SBD selection strategy is proposed for the detection of cases.

Types of fat intake and body mass index in a Mediterranean country

BACKGROUND

Although the fatty acid fractions provide similar metabolizable energy, the type of dietary fat consumed could be relevant to the development of obesity.

OBJECTIVE

To investigate the relationship between body mass index (BMI), obesity and the consumption of different types of fat and olive oil in a Mediterranean country with high prevalence of obesity, and high intake of monounsaturated fatty acids (MUFA) and olive oil.

SUBJECTS

The study was carried out in Spain among 23 289 women and 14 374 men, aged 29-69 years, who were participants of a large European prospective cohort.

METHODS

: Information on usual food intake was collected by interviewers by means of a dietary history questionnaire. The association between obesity (BMI >/= 30 kg m2), dietary fat, other dietary patterns and other non-dietary factors were tested using multilinear regression analysis. The ratio of reported energy intake to energy requirement was used as an estimation of dietary underreporting.

RESULTS

The association between fatty acid fractions intake (saturated fatty acids (SFA) in women, and MUFA and polyunsaturated fatty acids (PUFA) in both sexes) and BMI was very weak, accounting for less than 1% of variance. All dietary and non-dietary variables accounted for 21% of variance in the measurement of BMI in women and only 6.7% of variance in men. Estimated underreporting of energy intake was 17.5% in obese women and 5.5% in obese men.

CONCLUSIONS

The association between consumption of specific types of dietary fat, olive oil and obesity in Spain is not very important. However, because of the cross-sectional design and some level of underreporting of energy intake observed in overweight subjects and overreporting in underweight subjects, systematic bias cannot be completely discarded.

[Factors associated with the accumulation of abdominal fat estimated with anthropometric indexes]

BACKGROUND

To evaluate lifestyle and dietary intake factors influencing the accumulation of abdominal fat in a Mediterranean population.

SUBJECTS AND METHOD

A cross-sectional study was carried-out in Spain (Asturias, Granada, Murcia, Navarra and Guipuzkoa) among 23,228 women and 14,332 men aged 29-69 years, participants of a large European prospective cohort (EPIC). Information on usual food intake and other non-dietary factors were collected by interviews. Height, weight, waist circumference and hip circumference were taken by previously trained interviewers.

RESULTS

In a multiple-linear regression analysis sports activities and educational level were negatively associated with abdominal obesity, while body mass index, age, tobacco and alcohol consumption, saturated fat intake and increased prevalence of hypertension, diabetes and myocardial infarction were positively associated. All dietary and non-dietary variables accounted for 22 and 27% of variance in the waist/hip ratio and 74 and 66% of variance in the waist circumference, in women and men respectively.

CONCLUSIONS

Body mass index and age are the most important factors influencing the accumulation of abdominal fat. Dietary factors and other lifestyle factors seem to play a minor role in increasing abdominal obesity.

Validation of self diagnosis of high blood pressure in a sample of the Spanish EPIC cohort: overall agreement and predictive values. EPIC Group of Spain

STUDY OBJECTIVE

High blood pressure is a variable related to several chronic conditions whose repeated measurement in large cohort studies is often not feasible having to rely on the self reporting of the subjects. The aim of the study is to validate such self diagnosis in a sample of members from the Spanish EPIC cohort study.

DESIGN

Comparison of high blood pressure self diagnosis with the information provided by the personal medical record drawn from the primary health centre of reference for such population.

SETTING

A small town near the EPIC-Murcia centre, one of five Spanish EPIC centres located in the south east, where inclusion in the cohort was offered to the general population.

PARTICIPANTS

The agreement between self reported high blood pressure status and data from medical records was measured in a representative sample of men and women (n = 248) aged 30-69 years. Medical records were studied for a diagnosis of high blood pressure, an anti-hypertensive pharmacological treatment or subject's inclusion in a hypertension control programme run in the medical centre only for hypertensive people (definite high blood pressure cases). As well, in the absence of such a diagnosis, medical annotations of systolic or diastolic high blood pressure > or = 140/90 mm Hg (possible high blood pressure cases) were considered. Sensitivity, specificity, positive and negative predictive values and kappa scores were calculated for all, definite and possible high blood pressure cases. Variables associated with the probability of having a true positive or negative self report of high blood pressure were also tested.

MAIN RESULTS

As expected, sensitivity was higher among definite cases (72.7%) than among possible cases (31.6%). Accordingly, the agreement between self report and medical record was higher for definite cases (kappa = 0.65) than for possible (kappa = 0.29 cases leading to a moderate overall agreement for all cases (kappa = 0.58; 95% CI: 0.47, 0.69). Having some level of education (OR: 0.31; 95% CI: 0.09, 1.05) was negatively associated to a true self report of high blood pressure while being female was positively associated (OR: 4.01; 95% CI 1.04, 16.8). No variable showed any association with having a true self report of being normotensive.

CONCLUSIONS

High blood pressure self report shows a moderate agreement with medical information in this cohort allowing it to be used, with caution, as a surrogate variable of actual blood pressure status. However, because of its moderate sensitivity, it is not possible to rule out some underestimation when using self reported high blood pressure information for high blood pressure frequency measurements such as prevalence or incidence rates. This underestimation will be higher among men and educated people.

Dietary intake of vegetables and fruits among adults in five regions of Spain. EPIC Group of Spain. European Prospective Investigation into Cancer and Nutrition

OBJECTIVE

To assess the consumption of vegetables and fruits (V&F) in adults from five regions in Spain according to sex, age and educational level.

DESIGN

Cross-sectional study within the members of the EPIC cohort in Spain.

SETTING

Three regions of the north of Spain (Asturias, Guipúzcoa and Navarra) and two regions of the south of Spain (Granada and Murcia).

SUBJECTS

41448 healthy volunteers (15365 men, 25813 women), aged 29-69 y.

INTERVENTIONS

Information on habitual diet during the previous year was collected by means of a computerised version of a diet history questionnaire.

RESULTS

Among men, the mean daily consumption of vegetables and of fruits was 273.7 g (3.4 servings) and 348.3 g (4.4 servings) respectively. Among women, the corresponding vegetables and fruit intakes per day were 244.4g (3.1 servings) and 349.4g (4.4 servings). The total V&F intake tended to increase with age and educational level. Overall, 74% of subjects consumed 400 g/d (5 servings) of vegetables and fruit.

CONCLUSIONS

Consumption of vegetables and fruits in healthy adults in Spain is considerably higher than in most European countries and the United States; this complies with what is considered to be the Mediterranean diet. Despite some regional differences, there were no clearly differentiated patterns of V&F intake between southern and northern regions within Spain.

Cardiovascular risk factors and educational attainment in Southern Spain: a study of a random sample of 3091 adults

STUDY OBJECTIVE

To analyze the associations between educational attainment and major cardiovascular disease risk factors in the Murcia Region (Southern Spain).

DESIGN

During 1992 we conducted a survey by interview, with multi-stage random sampling, representative of the general adult population. We calculated odds ratios (OR) and trends by logistic regression as a measure of the association between educational levels and cardiovascular risk factors, taking the university level as the reference category.

PARTICIPANTS

A total of 1514 men and 1577 women aged between 18 and 65 years was included in the study. Rate of response to the questionnaire was 61%. Seventy-eight percent of the respondents provided a blood sample. A telephone survey on a representative sample of non-respondents (n = 347), showed no statistical differences in the level of studies.

MEASUREMENTS

We asked for educational level (highest schooling qualification completed), and according to the WHO MONICA protocol we measured: blood pressure, cigarette smoking, height, weight and total cholesterol, triglycerides and HDL-cholesterol. We also obtained the leisure-time physical activity by a validated questionnaire.

MAIN RESULTS

In a context of a low level of schooling, mainly among the older age groups, the prevalence of risk factors except smoking in women is higher in the lower educational levels. Systolic blood pressure tends slightly to increase as schooling level decreases (both genders, p<0.02). Conversely, serum total cholesterol and triglycerides decrease with higher level of schooling in men. The high levels of HDL-cholesterol observed in all educational groups show no trend in both genders. Arterial hypertension in men and women and overweight in women tend to decrease with higher educational attainment. Moreover, higher level of education is associated with vigorous physical exercise in both genders and cigarette smoking in women. We observed the strongest significant magnitude association in nonschooling with hypertension in men (OR: 1.82; 95% CI: 1.15, 2.89), in women (OR: 2.39; 95% CI: 1.05, 5.44), and with overweight in women (OR: 3.22; 95% CI: 1.97, 5.27), meaning that compared to people at the university level, people without schooling showed two to three times higher prevalence of hypertension and overweight (only women). Also non-schooling obtained the lowest significant association with protective physical exercise for coronary heart disease in men (OR: 0.32; 95% CI: 0.18, 0.56) and in women (OR: 0.31; 95% CI: 0.15, 0.62) pointing out that people at the university level of education had three times the prevalence of vigorous physical activity than their non schoolarized counterparts.

CONCLUSIONS

After adjusting for environmental factors, in our adult general population, educational attainment is inversely associated with arterial hypertension in both genders and with overweight in women, and directly associated with cigarette smoking in women and with leisure-time physical activity in both genders.

Prevalence of hepatitis A antibodies in southeastern Spain: a population-based study

The prevalence of hepatitis A antibodies in the adult population of the Murcia Region (southeast of Spain) was estimated using an anonymous unlinked serosurvey in a population-based sample of 2,203 adults. The overall anti-HAV prevalence was 76.5%. The prevalence increased with age and was higher in individuals living in towns with less than 10,000 inhabitants.

Prevalence and control of arterial hypertension in the south-east of Spain: a radical but still insufficient improvement

Stroke mortality rates in Spain are one of the highest in all of Europe. At the same time, the Murcia region (south-east Spain) shows, for both genders, the highest age-adjusted stroke mortality rates in all of Spain. The earliest available hypertension figure estimations for this area go back to 1981, when a high prevalence combined with an almost nonexistent control was detected. One decade later, updated prevalence estimations of hypertension are presented jointly with their degree of control and their association with other risk factors based on the results of a prevalence survey in a random population sample (n = 3,091). Arterial blood pressure was measured following the MONICA protocol, maintaining a tight quality control on between and within-observer variability. As hypertensive was considered any person with systolic blood pressure (SBP) > or = 140 mmHg or with diastolic blood pressure (DBP) > or = 90 mmHg or with antihypertensive pharmacological treatment. Detected prevalence rises to 32.3% (CI 95%: 29.1%-35.5%) among males and to 23.7% (CI 95%: 21.4%-26%) among females, maintaining its level regarding figures observed back in 1981. However, its control has been increased, especially among hypertensive women [from less than 5% in 1981 to 35% (95% CI: 32%-37.8%) at present]. Hypertension is strongly associated to hipercholesterolemia, overweight, obesity and diabetes (p < 0.01). On the contrary, it shows an opposite association with current smoking, higher educational level and leisure time physical activity (p < 0.01). The highest educational level was associated with better hypertension treatment and control. In summary, while hypertension prevalence is stabilized in our population, its control has improved in a measurable but still insufficient way. These results are in accordance with a decreasing trend in stroke mortality registered in the Murcia Region along the last decade.

Risk factors for HPV DNA detection in middle-aged women

BACKGROUND AND OBJECTIVES

Strong epidemiologic evidence indicates that human papillomavirus (HPV) is the main etiologic factor of cervical cancer. A few cohort studies suggest that most HPV infections are transient in young women and that persistent HPV infections are more common in older women. Little is known about the determinants of persistent HPV infections. The present study was aimed at increasing our knowledge about these determinants.

GOALS

To identify risk factors for genital HPV DNA detection among cytologically normal middle-aged women.

STUDY DESIGN

Eight hundred ten women who participated as control subjects in three case-control studies on cervical cancer in Spain, Colombia, and Brazil were included in this study. After an interview, women underwent a gynecologic examination with collection of exfoliated cells for a Papanicolaou smear and HPV DNA detection. Human papilloma virus DNA was detected by polymerase chain reaction (PCR)-based hybridization techniques.

RESULTS

The HPV positivity rate was 10.5% in the whole population, but was higher in the areas with high incidence of cervical cancer (17% in Brazil and 13% in Colombia) than in Spain (4.9%), which is a low-risk area for cervical cancer. Age was related to the prevalence of HPV DNA in Brazil, but not in Spain and Colombia. In univariate analyses in all three countries, the prevalence of HPV DNA was positively associated with the number of lifetime sexual partners and inversely associated with the levels of family income and with age at first sexual intercourse. There was four times increase in the odds ratio (OR) of HPV infection in women who had six or more lifetime sexual partners compared with those with one or less. The use of any kind of contraceptive tended to decrease the OR for HPV detection. Their ORs ranged from 0.44 (barrier methods) to 0.48 (oral contraceptives). In Spain and Colombia, antibodies against Chlamydia trachomatis were positively associated with the prevalence of HPV DNA. In a final multivariate model, the positive associations with lifetime number of sexual partners, socioeconomic status, and C. trachomatis persisted.

CONCLUSIONS

These results support the sexual transmission of HPV and suggest that socioeconomic status and antibodies to C. trachomatis are independent predictors of HPV detection in middle-aged cytologically normal women.

The multicentre south European study 'Helios'. II: Different sun exposure patterns in the aetiology of basal cell and squamous cell carcinomas of the skin

The role of sun exposure in development of basal cell and squamous cell carcinomas among different populations from south Europe was investigated. Between 1989 and 1993 we interviewed incident cases and a random population sample of controls from five centres where a cancer registry was operating, whereas we selected a sample of hospital-based cases and controls from the other three centres. We gathered information on life-long exposure to sunlight during different activities. Results are analysed for 1549 basal cell carcinoma (BCC) cases and 228 squamous cell carcinoma (SCC) cases compared with 1795 controls. We observed a statistically significant increase of risk of SCC with increasing sun exposure beyond a threshold of 70,000 cumulated hours of exposure in a lifetime. Sun exposures during work and holidays were, however, inversely correlated. Odds ratios (ORs) of SCC were up to eight or nine times the reference for the highest exposures (200,000 cumulated hours or more). BCC exhibited a 2-fold increase of risk for lower exposure (8000-10,000 cumulated hours in a lifetime) with a plateau and a slight decrease of risk for the highest exposures (100,000 cumulated hours or more). Outdoor work showed a significantly increased risk of SCC (OR 1.6 for more than 54,000 cumulated hours of exposure in a lifetime), whereas recreational activities such as sun exposure during holidays at the beach (OR 1.6 for more than 2600 cumulated hours of exposure in a lifetime) or during water sports (OR 1.6 for more than 2600 cumulated hours of exposure in a lifetime) were associated with an increased risk of BCC. Risk patterns were different in poor or good tanners with a significant risk trend for good tanners, whereas poor tanners were on a plateau of increased risk at any level of exposure. Solar radiation is associated with a risk of BCC even for relatively short periods of exposure such as during holidays and sports, whereas SCC develops later if exposure continues. The skin's ability to tan modulates the risk of BCC; subjects who tan poorly have a steady risk increase, whereas people who tan easily develop cancer only after prolonged exposures.

The multicentre south European study 'Helios'. I: Skin characteristics and sunburns in basal cell and squamous cell carcinomas of the skin

The aim of this study was to investigate constitutional and environmental determinants of non-melanocytic skin cancer among different populations from south Europe. Between 1989 and 1993 we interviewed incident cases and a random population sample of controls from five centres where a cancer registry was operating, whereas we selected a sample of hospital-based cases and controls from three other centres. Controls were stratified according to the age and sex distribution of cases. In all, 1549 cases of basal cell carcinoma (BCC), 228 of squamous cell carcinoma (SCC) and 1795 controls were interviewed. Both cancers affected primarily sun-exposed sites such as face, head and neck, but the prevalence of BCC on the trunk was higher than for SCC. Pigmentary traits such as hair and eye colour as well as tendency to sunburn were strong and independent indicators of risk for both BCC and SCC. In SCC, adjusted odds ratios (ORs) ranged from 1.6 for fair hair colour to 12.5 for red hair. Light-blonde hair entailed a risk of about 2 for BCC. Pale eye colour was associated with a risk of 1.8 for SCC and 1.4 for BCC. Subjects who always burn and never tan showed an adjusted OR of 2.7 for BCC and 2.0 for SCC. A history of sunburns and a young age at first sunburn were associated with an increased risk for BCC only (OR 1.7). Pigmentary traits and sun sensitivity of the skin confirmed their role as risk indicators. The effect of sunburns, as an indicator of both exposure and sun sensitivity of the skin, is less clear. Nevertheless, its association with BCC suggests, by analogy with melanoma, a relationship with intense sun exposure. Conversely, SCC would require prolonged exposure to sunlight.

Serological response to HPV16 in CIN-III and cervical cancer patients. Case-control studies in Spain and Colombia

This study evaluates the association of antibodies against HPV-16-derived peptides with cervical cancer and estimates the sensitivity and specificity of the serological assays in relation to HPV DNA detection in cervical cells by PCR. Study subjects were derived from 4 case-control studies carried out in Spain and Colombia. Sera from 544 cases of CIN III and invasive cancer and of 543 age-matched controls were tested for antibodies to 5 peptides derived from E2, E7 (3 partially overlapping frames of HPV 16 denoted E7/ 1, E7/2, E7/3) and L2 open reading frames of HPV 16. HPV DNA was detected using a L1-PCR based method. Among cancer controls, antibody response to E2 and E7/1, E7/2, E7/3 was higher in Colombia (22.5%,7.2%,11.7%,12.6% respectively) than in Spain (17.1 %, 4.7%, 5.9%, 5.9%). E7 antibodies were related to stage, particularly in CIN III vs. invasive stages and less markedly within invasive stages. Detection of antibodies to the E7/1 was associated to CIN III (OR = 1.8). The risk of invasive cervical cancer was increased among those with antibodies to E2 (OR = 2.2), to E7/1 (OR = 4.2), to E7/2 (OR = 4.3), and to E7/3 (OR = 2.5). Presence of antibodies to all the 3 E7 peptides increased the risk of CIN III (OR = 5.6) and that of invasive cancer (OR = 17.5). High levels of antibodies to E7/1 or E7/2 or E7/3 increased the risk of invasive cervical cancer (OR for high levels of antibodies vs. negatives to E7/1 OR = 22.6; E7/2 OR = 7.5, E7/3 OR = 3.4). In the present analysis, antibodies to L2 were not associated with either CIN III or cervical cancer. Serological markers of HPV 16 detected less than half of the HPV-16-DNA-positive cases. It is concluded that antibodies to E2 and particularly E7 antigens are strongly associated with cervical cancer. Antibodies to E7 seem to be a moderate marker of tumor burden.

Prevalence of hepatitis B and C markers in the south-east of Spain: an unlinked community-based serosurvey of 2,203 adults

We conducted an unlinked seroprevalence survey in a community-based sample of 2,203 adults to estimate the prevalence of hepatitis B and C virus markers in the general adult population of the Murcia region (Spain). The influence of age, sex and place of residence on the seroprevalence of hepatitis was investigated. The overall prevalence was 10.2% for anti-HBc antibodies, 0.9% for HBsAg, and 1% for anti-HCV. There was a trend of increasing prevalence with age for anti-HBc and anti-HCV regardless of sex and urban or rural residence. The prevalence of hepatitis B and C markers was higher in individuals living in urban areas, although there was no significant association. The results indicate that the Murcia region may be considered an area of low-intermediate endemicity for hepatitis B virus infection. This is one of the first reports assessing the prevalence rate for hepatitis C markers for a general population in Europe.

Risk factors for cervical cancer in Colombia and Spain

A population-based case-control study of cervical cancer was conducted in Spain and Colombia to assess the relationship between cervical cancer and exposure to human papillomavirus (HPV), selected aspects of sexual and reproductive behaviour, use of oral contraceptives, screening practices and smoking. The study included 436 cases of histologically confirmed squamous-cell carcinoma and 387 age-stratified controls randomly selected from the general population that generated the cases. The presence of HPV DNA in cervical scrapes was assessed by PCR-based methods and was the strongest risk factor (OR = 23.8; 13.4-42.0). Risk estimates for any other factor were only slightly modified after adjusting for HPV status. Among women found positive for HPV DNA, only the use of oral contraceptives was a risk factor for cervical cancer (OR = 6.5; 1.3-31.4 for ever vs. never use). Patients with cervical cancer who were HPV DNA-negative retained most of the established epidemiological features of this disease. This suggests that some instances of HPV infection went undetected or that other sexually transmitted factor(s) contribute to the causation of cervical cancer. Early age at first intercourse (OR = 4.3; 2.1-9.0 for age < 16 vs. 24+) and early age at first birth (OR = 5.0; 1.8-14.2 for age < 16 vs. 24+) were associated with increased risk of cervical cancer; these effects were independent of one another. Low educational level was a risk factor (OR = 2.5; 1.6-3.9). Number of sexual partners was in our study a surrogate for HPV infection. Smoking and parity after age 24 were weakly and inconsistently associated with the risk of cervical cancer. Previous screening (OR = 0.7; 0.5-1.0) and ever having undergone a Caesarean section (OR = 0.4; 0.2-0.8) were protective factors.