Based on intrafamilial correlations, a component genetic analysis was used to evaluate the contribution made by genetic and environmental factors to variance in body weight and skin fold thickness in children who had various blood pressure. In children with initially elevated and normal blood pressures, the phenotypic variation in the body weight and adipopexia is largely determined by genetic factors, whereas in those with initially lower blood pressure, the phenotypic variation in the above parameters is greatly affected by environmental factors, mainly by those of occasional nature. The findings provide evidence for a differential approach to the primary prevention of hyper- and hypotension in children and adolescents.