Regional adiposity, cardiorespiratory fitness, and left ventricular strain: an analysis from the Dallas Heart Study.

Background: Low cardiorespiratory fitness (CRF), high body mass index, and excess visceral adiposity are each associated with impairment in left ventricular (LV) peak circumferential strain (E_cc), an intermediate phenotype that precedes the development of clinical heart failure (HF). However, the association of regional fat distribution and CRF with Ecc independent of each other and other potential confounders is not known. Methods: Participants from the Dallas Heart Study Phase 2 who underwent dual energy X-ray absorptiometry assessment of regional fat distribution, CRF assessment by submaximal treadmill test, and E_cc quantification by tissue-tagged cardiovascular magnetic resonance were included in the analysis. The cross-sectional associations of measures of regional adiposity, namely visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and lower-body fat (LBF) with E_cc after adjustment for CRF and other potential confounders (independent variables) were assessed using multivariable linear regression analysis. Results: The study included 1089 participants (55% female, 39% black). In the unadjusted analysis, higher VAT was associated with greater impairment in Ecc. After adjustment for baseline risk factors, CRF, parameters of LV structure and function, and other fat depots such as SAT and LBF, higher VAT remained associated with greater impairment in E_cc (β: 0.19, P = 0.002). SAT and LBF were not significantly associated with Ecc, however, CRF remained associated with Ecc in the fully adjusted model including all fat depots (β: - 0.15, P < 0.001). Conclusions: VAT and CRF are each independently associated with impairment in E_cc, suggesting that higher VAT burden and low CRF mediate pathological cardiac remodeling through distinct mechanisms. [ABSTRACT FROM AUTHOR]