Proportionality at birth and left ventricular hypertrophy in healthy adolescents

Background: Perinatal growth has important implications for cardiac development. Low birth weight is associated with cardiovascular (CV) events and mortality, and animal studies have shown that fetal growth restriction is associated with cardiac remodeling in the perinatal period leading to a permanent loss of cardiomyocyte endowment and compensatory hypertrophy. Aims: To determine associations of birthweight (BW) and multiple proportionality indexes (body mass index (BMI); weight/length(2) and Ponderal index (PI); weight/length(3)) at birth on one hand, with left ventricular (LV) structure and function during adolescence. Subjects: 379 healthy adolescents aged 14-18 years in Augusta, Georgia. Outcome measures: LV structure and function parameters, including intraventricular septal thickness in diastole (IVSd), LV internal dimension in diastole (LVIDd), LV internal diameter in systole (LVIDs), LV posterior wall thickness in diastole (LVPWd), relative wall thickness (RWT), midwall fractional shortening (MFS), and ejection fraction, were assessed by echocardiography. Results: When associations of birthweight, birth BMI, and birth PI with LV structure and function parameters were separately evaluated with linear regression adjusting for age, sex, race, Tanner stage, socioeconomic status, and physical activity, significant positive associations of BW with LVIDd (P = 0.004), birth BMI with LV mass index (P = 0.01), and birth PI with IVSd (P = 0.02), LVPWd (P = 0.03), and LV mass index (P = 0.002) were identified. When LV structure and function parameters were compared across PI tertiles, a significant U-shaped trend for LV mass index (Pquadratic = 0.04) was identified. Conclusions: Our adolescent data suggest that proportionality at birth may identify associations between perinatal growth and cardiac remodeling independent of birthweight alone.