Relationship between birth weight and blood pressure variability in children

This cross-sectional study investigates the relationship between birth weight, 24-h blood pressure and blood pressure variability in childhood. Blood pressure was measured in 976 schoolchildren, free from cardiovascular disease, aged between 6 and 16 years. Blood pressure variability was estimated as the standard deviation of the 24-h mean (systolic and diastolic) blood pressure values. Linear regression showed that variation in systolic or diastolic blood pressure was not significantly associated with birth weight. Similarly, no association was found between blood pressure variability and birth weight when using the birth weight groups used by a previous study. Adjusting for other covariates, including mean 24-h blood pressure, made little difference to the observed results. No interactions were observed between birth weight and either gender or age on blood pressure variability. The results of this study do not support the suggestion of a significant association between birth weight and blood pressure variation in childhood. This might suggest that blood pressure variability is influenced mainly by environmental or lifestyle factors, but as little research has been published in this area, further investigation is required and in particular it would be important to assess the use of other measures of blood pressure variation.