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 E_cc 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 E_cc. 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 E_cc, however, CRF remained associated with E_cc 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.