A validation of estimated total peripheral resistance using twin data.

Chronically elevated total peripheral resistance (TPR) is a suspected contributor to the greater rates of hypertension in African Americans. Previous research suggests that over 50% of the variability in measures of vascular resistance may be attributable to genetic effects and genetic effects may play an even greater role in variability of TPR in African Americans. We have previously demonstrated the coherence of a simple equation-based estimate of total peripheral resistance (TPRest) with TPR obtained via a validated method (Hill et al, 2013). We sought further validation by estimating heritability for this measure. Using quantitative genetic analysis, heritabilites were calculated for TPRest during both a resting baseline and orthostasis in a population-based sample of African American mono- and dizygotic twins (mean age = 49.82 ± 14.62). Estimated heritability was greater for males (h2 = .40) both at rest and during orthostasis, compared to all other groups. This value is consistent with previously published point estimates of heritability. Collectively, these findings provide additional support for the validity of TPRest as a practical alternative for deriving additional hemodynamic data from archival sources.