Abstract P075: Stroke Volume and Visceral Fat Drive Differences in Blood Pressure Between Two Generations: A Population-Based Study of Adolescents and Their Parents
Excess total body fat (TBF) and visceral fat (VF) are major risk factors of hypertension. Blood pressure (BP) increases with age, as do TBF and VF. Here we investigated whether TBF and VF contribute to BP differences between adolescents and adults. A population-based sample of adolescents (n=933, 12-18 years) and their parents (n=429, 38-65 years) was studied as part of the Saguenay Youth Study. In all participants, beat-by-beat values of SBP, DBP and underlying hemodynamic parameters (heart rate, stroke volume [SV] and total peripheral resistance) were obtained with a Finometer during a 52-minute protocol mimicking daily life activities and including posture and math-stress tests. TBF was assessed by bioelectrical impedance and VF was examined by magnetic resonance imaging. SBP was higher in parents than adolescents by an average of 10.2±0.3 mmHg in males and 9.1±0.3 mmHg in females (p<0.0001 for both sexes). DBP differed minimally throughout the protocol (p=0.3 and 0.1, respectively). In males and females, respectively, the ‘generation’ differences in SBP were reduced to 6.0±0.1 and 4.3±0.1 mmHg when adjusted for height and TBF (p<0.0001 for both), and were further reduced to 1.9±0.1 and 2.5±0.2 mmHg when additionally adjusted for VF (p=0.1 and 0.02). Of the underlying hemodynamic parameters, only SV was higher in parents than adolescents (by 46±2 ml in males and 39±2 ml in females, p<0.0001 for both). Again, the ‘generation’ differences in SV were reduced to 23±1 (males) and 20±1 ml (females) when adjusted for height and TBF (p<0.0001 for both sexes), and were further reduced to 11.8±0.6 and 15.7±0.8 ml when additionally adjusted for VF (p<0.0001 for both sexes). These results suggest that the transition from adolescence to middle-aged adulthood is associated with an increase in SBP (but not DBP), which is driven mainly by SV augmentation. They also suggest that VF contributes to the generational differences in both SBP and SV above and beyond the contribution of TBF, despite VF being a relatively small fraction of TBF. The co-occurrence of these differences in VF, SV and SBP may be related to sympathoactivation and renal handling of sodium and water reabsorption; further research is required to confirm this possibility.
Author Disclosures: C.A. Syme: None. M. Abrahamowicz: None. G. Leonard: None. M. Perron: None. L. Richer: None. S. Veillette: None. D. Gaudet: None. T. Paus: None. Z. Pausova: None.
- © 2015 by American Heart Association, Inc.