Birth Weight as a Determinant of Ambulatory Blood Pressure Variability in Children and Adolescents
To study the impact of birth weight (BW), as a crude measure of fetal growth, in the variability of ambulatory BP in children. Six hundred and thirty subjects (369 girls), with a BW ranging 2.3 to 4.8 kg, were included. Ambulatory BP was assessed at the age of 4 to 18 yr during a 24-hour period (Spacelabs 90207). In each subject average and standard deviation of SBP, DBP, HR for 24hour, daytime and nighttime were calculated. The 24hour SBP (mmHg) and variability (mmHg) values for each tertile of BW were 112.7±9.8/10.9±2.7 (BW <3.1 kg), 109.1±8.8/10.4±2.0 (BW 3.1-3.6 kg), 111.8±9.5/10.2±2.0 (BW >3.6 kg). In a multiple regression model, current weight and BW were independent determinants of 24hour SBP variability. At the same 24hour SBP, children with the lowest BW had the highest SBP variability when the parameters were adjusted by age, sex, current height and weight (figure). In conclusion children who had lower BW, not only tended to have the highest BP values but also the highest variability. The increased variability might predispose to hypertension later in life.