Family history as a predictor of blood pressure in a longitudinal study of Australian children

Background Sex both of parent and of child might influence associations between parental hypertension and blood pressure in offspring. Objective To examine these associations. Design A cohort of Australians was surveyed 3-yearly from age 9 to 18 years. Setting A community-based sample. Participants When they were aged 18 years, 630 of 1565 participants who had been selected randomly at the age of 9 years were re-surveyed. Main outcome measures Systolic and diastolic blood pressures. Results Paternal hypertension was reported by 18% of men and 15% of women and maternal hypertension by 15% of men and 14% of women. By the time they were aged 9 years, systolic blood pressure was significantly higher in sons [117.8 mmHg, 95% confidence interval (CI) 116.4-119.2 versus 114.7 mmHg, CI 113.4-116.0] and daughters (118.2 mmHg, CI 116.9-119.5 versus 114.9 mmHg, CI 112.8-117.0) of hypertensive fathers than it was in sons and daughters of normotensive fathers. When they were aged 18 years, paternal hypertension predicted blood pressures in men and women independently of their weight at birth, fitness, alcohol consumption and weight for height for age. Systolic blood pressures increased more rapidly (by 0.6 mmHg/year) in men with hypertensive fathers. Conclusions Systolic blood pressure in young adults differs in relation to parental hypertension according to the sex of the affected parent and the sex of the offspring. This could reflect unmeasured environmental variables or the action of sex-related genetic or intrauterine factors. (C) 1998 Rapid Science Ltd.