Low birth weight is associated with elevated systolic blood pressure in adolescence:: a prospective study of a birth cohort of 149378 Swedish boys

Objectives To determine the association between birth weight and systolic blood pressure (SBP) in male adolescents at the age of 18 years. Design A prospective study by means of a register linkage between the Swedish Medical Birth Register and the national register for conscript testing before military service. Methods From the birth registry we collected data on birth weight, gestational age, maternal age and parity for 149 378 individuals. At conscript testing, subjects were given a physical examination, and weight, height, and mean blood pressure were recorded after 5-10 min rest. Results Mean +/- SD birth weight was 3543 +/- 551 g after a mean of 39.7 +/- 2.0 gestational weeks. Mean +/- SD blood pressure at the conscript testing was 128.8 +/- 10.9/65.2 +/- 10.6 mmHg. SBP, but not diastolic blood pressure, differed significantly (test for trend, P < 0.001) between birth weight strata (deciles), with a higher SBP in strata with lower birth weight. A difference in birth weight of 1000 g decreased SBP by 0.8 mmHg. This was most pronounced in subjects with a rapid growth development (n = 1057), coming from the lowest decile of birth weight and reaching to the highest decile of body mass index, in a very consistent manner. The odds ratio for being in the top decile of SBP was 1.55 (95% confidence interval 1.32-1.81) for this growth `catch-up' group compared with the rest of the cohort. Conclusions Birth weight was inversely associated with SBP in a large cohort of young men in their late teens. This supports the notion of a programming effect of fetal growth retardation in utero on haemodynamic regulation in early adult life. (C) Rapid Science Publishers ISSN 0263-6352.