Family history of hypertension and left ventricular mass in youth: possible mediating parameters.

Whether positive family history (FH) of essential hypertension (EH) in normotensive youth is associated with increased left ventricular mass (LVM) and hemodynamic, anthropometric, and demographic parameters previously associated with increased LVM in adults is unknown. To examine these issues, 323 healthy youth (mean age, 13.6 +/- 1.3 years), 194 with positive FH of EH (61% African Americans, 39% whites) and 129 with negative FH of EH (33% African Americans, 67% whites) were evaluated. Hemodynamics were measured at rest and during four stressors (ie, postural change, car driving simulation, video game, forehead cold). Echocardiographic-derived measures of LVM were indexed separately to body surface area and height(2.7). Controlling for age and race differences (ie, 74% of African Americans v 47% of whites had positive FH), the positive FH group exhibited greater LVM/height(2.7), LVM/body surface area, higher systolic (SBP) and diastolic blood pressures (DBP), and total peripheral resistance index (TPRI) and lower cardiac index at rest (P < .05 for all). The positive FH group also displayed higher peak SBP or DBP and higher TPRI increases to each stressor and came from lower socioeconomic status backgrounds (P < .05 for all). Regression analyses indicated that FH of EH was not a significant determinant of LVM/height(2.7) after accounting for contributions of gender (greater in men), general adiposity, resting cardiac index and blood pressure (BP), and TPRI responsivity to video game and cold stimulation (P < .05 for all). Thus, greater LVM index in positive FH of EH youth appears in part related to their greater BP and TPRI at rest and during stress.