Familial aggregation in blood pressure and body composition in portuguese nuclear families

Abstract

The aims of this study were (1) to verify the indirect presence of vertical transmission of genetic factors between parents and children in blood pressure (BP) and body composition (BC), and (2) identify the infl uence of genetic factors in the variability of BP and BC. Sample size comprises 367 subjects (164 parents: 41±4.6 years old and 203 children of 13.2±3 years old) from 107 nuclear families participating in the project “FAMÍLIAS ACTIVAS”; they proceed from different regions of North of Portugal (36 from Vouzela, 36 from Esposende, 25 from Vila Nova de Paiva and 10 from Vila Nova de Famalicão). BP was measured with an automatic digital device, Omron® model M6 (HEM-7001-E). BC phenotypes were assessed with a bioelectric impedance device from Tanita® model BC-418 (Tanita Corp., Tokyo, Japan). PEDSTATS was used to verify the structure of each family and to analyze the generic behavior of the variables in family members. FCOR and ASSOC modules, from Genetic Epidemiology S.A.G.E. 5.3 software, were use to calculate correlations (r) and the heritability (h2) of different phenotypes. Signifi cant level was set at 0.05. Main results evidenced an important familial aggregation between family members for systolic BP (SBP) (0.01? r ?0.35), and diastolic BP (DBP) (0.24? r ?0.50) the same occurred for BC phenotypes (-0.15? r ?0.65). Genetic factors contributed to 43% of the SBP and 49% of DBP variation; the same occurred for BC phenotypes ranging from 35 to 46% of the total variation. The conclusions were that (1) a strong familial aggregation exists in the BP and the BC in this sample of portuguese nuclear families and that (2) genetic factors play important role in these phenotypes.