Background: Despite of the increase in the prevalence of hypertension in Portugal, the importance of genetic factors in blood pressure (BP) has not been studied extensively in our country.
Objectives: To verify the indirect presence of vertical transmission of genetic factors between parents and children in BP values, and to estimate the magnitude of genetic factors contributing for variation in BP values in the population.
Methods: Sample size comprises 367 individuals (164 parents and 203 children) pertaining the 107 nuclear families participating in 'Familias Activas' project, proceeding from different regions of North Portugal. The BP was measured with Omron model M6 (HEM-7001-E) digital device. SPSS 15.0 was used for data analysis; PEDSTATS was used to verify the structure of each family data. Familial correlations and heritability estimates were computed in FCOR and ASSOC modules of S.A.G.E. version 5.3.
Results: For systolic BP (SBP), correlation values were low to moderate (0.21< or = r < or =0.35); for diastolic BP (DBP) values were found to be moderate (0.24< or = r < or =0. 50). Genetic factors explain 43 and 49% of the total variation in SBP and DBP, respectively.
Conclusion: A moderate amount of the SBP and the DBP is accounted for by genetic factors.