title: Environmental and genetic contribution to hypertension prevalence: data from an epidemiological survey on Sardinian genetic isolates.
abstract: OBJECTIVE
  Hypertension represents a major cause of cardiovascular morbidity and mortality worldwide but its prevalence has been shown to vary in different countries. The reasons for such differences are still matter of debate, the relative contributions given by environmental and genetic factors being still poorly defined. We estimated the current prevalence, distribution and determinants of hypertension in isolated Sardinian populations and also investigated the environmental and genetic contribution to hypertension prevalence taking advantage of the characteristics of such populations.
  
  
  RESULTS
  An epidemiological survey with cross-sectional design was carried out measuring blood pressure in 9845 inhabitants of 10 villages of Ogliastra region between 2002 and 2008. Regression analysis for assessing blood pressure determinants and variance component models for estimating heritability were performed. Overall 38.8% of this population had hypertension, its prevalence varying significantly by age, sex and among villages taking into account age and sex structure of their population. About 50% of hypertensives had prior cardiovascular disease. High blood pressure was independently associated with age, obesity related factors, heart rate, total cholesterol, alcohol consumption, low education and smoking status, all these factors contributing more in women than in men. Heritability was 27% for diastolic and 36% for systolic blood pressure, its contribution being significantly higher in men (57%) than in women (46%). Finally, the genetic correlation between systolic and diastolic blood pressure was 0.74, indicating incomplete pleiotropy.
  
  
  CONCLUSIONS
  Genetic factors involved in the expression of blood pressure traits account for about 30% of the phenotypic variance, but seem to play a larger role in men; comorbidities and environmental factors remain of predominant importance, but seem to contribute much more in women.
authors.affiliation: Institute of Population Genetics, National Research Council of Italy, Sassari, Italy. biino@igm.cnr.it
authors.forename: Ginevra
authors.initials: G
authors.lastname: Biino
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Parati
authors.forename: Maria Pina
authors.initials: MP
authors.lastname: Concas
authors.forename: Mauro
authors.initials: M
authors.lastname: Adamo
authors.forename: Andrea
authors.initials: A
authors.lastname: Angius
authors.forename: Simona
authors.initials: S
authors.lastname: Vaccargiu
authors.forename: Mario
authors.initials: M
authors.lastname: Pirastu
mesh_terms: D000367:Age Factors; D000428:Alcohol Drinking; D001794:Blood Pressure / Q000502:physiology*; D001835:Body Weight; D002784:Cholesterol / Q000097:blood; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D058685:Genetic Pleiotropy / Q000502:physiology; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000453:epidemiology* / Q000235:genetics*; D007558:Italy / Q000453:epidemiology; D008297:Male; D010641:Phenotype; D015995:Prevalence; D012044:Regression Analysis; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking
chemical_list: D002784:Cholesterol