The negative effect of birthweight on systolic blood pressure has been suggested to be initiated during fetal growth and amplified with age. Rebecca Hardy from University College London, UK, and colleagues tested whether the effect of birthweight as an indicator of fetal growth on blood pressure changes with increasing age. For comparison, the investigators made a similar assessment of the effect of childhood social class on adult blood pressure.
Over 3600 people from a birth cohort study of men and women born in Britain in 1946 participated; details of their birthweight and blood pressure (previously recorded at ages 36, 43, and 53 years) were assessed.
Those individuals with low birthweight had higher systolic blood pressure at 36 years of age, which was sustained (although not increased) by age 53 years. People from a manual social class in childhood had higher systolic and diastolic blood pressure than those from a non-manual class and this effect was seen to increase between the ages of 36 and 53 years. This indicates that the rate of increase in systolic blood pressure among those from a manual social class was greater than the rate among those from a non-manual social class; the difference (1 millimetre of mercury every 10 years) was largely a result of increased body-mass index.
Rebecca Hardy comments: "These findings highlight the importance of weight control throughout life in the prevention of raised blood pressure during middle age. Understanding the mechanisms linking the childhood socioeconomic environment and adult body-mass index may make prevention strategies more effective."
Contact: Dr Rebecca Hardy, Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London, WC1E 6BT, UK; T): 44-0-20-7679-1732; F): 44-0-20-7813-0280; E) dmjd610@ucl.ac.uk.
Journal
The Lancet