title: Multilevel analysis of systolic blood pressure and ACE gene I/D polymorphism in 438 Swedish families--a public health perspective.
abstract: BACKGROUND
  Individuals belonging to the same family share a number of genetic as well as environmental circumstances that may condition a common SBP level. Among the genetic factors, the angiotensin converting enzyme (ACE) gene I/D polymorphism appears as a possible candidate as it might influence both SBP and the pharmacological effect of ACE inhibitors. We aimed to combine genetic epidemiology with public health ideas concerning life-course and multilevel epidemiology in order to understand the role of familial factors regarding individual SBP.
  
  
  METHODS
  We applied multilevel regression analysis on 1926 individuals nested within 438 families from South Sweden. Modelling familial SBP variance as a function of age and use of ACE inhibitors we calculates a variance partition coefficient and the proportional change in familial SBP variance attributable to differences in ACE gene I/D polymorphism
  
  
  RESULTS
  Our results suggest the existence of genetic or environmental circumstances that produce a considerable familial clustering of SBP, especially among individuals using ACE-inhibitors. However, ACE gene I/D polymorphism seems to play a minor role in this context. In addition, familial factors--genetic, environmental or their interaction--shape SBP among non-users of ACE inhibitors but their effect is expressed later in the life-course.
  
  
  CONCLUSIONS
  Strategies directed to prevent hypertension should be launched in younger rather than in older ages and both prevention of hypertension and its treatment with ACE inhibitors should be focused on families rather than on individuals.
authors.affiliation: Department of Health and Health Care Management (Epidemiology), Region Skåne, Lund, Sweden. juan.merlo@med.lu.se
authors.forename: Juan
authors.initials: J
authors.lastname: Merlo
authors.forename: Kristina
authors.initials: K
authors.lastname: Bengtsson-Boström
authors.forename: Ulf
authors.initials: U
authors.lastname: Lindblad
authors.forename: Lennart
authors.initials: L
authors.lastname: Råstam
authors.forename: Olle
authors.initials: O
authors.lastname: Melander
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D001794:Blood Pressure / Q000235:genetics*; D005192:Family Health; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000235:genetics*; D011110:Polymorphism, Genetic; D011634:Public Health; D013548:Sweden; D013599:Systole
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D007703:Peptidyl-Dipeptidase A