Defining left ventricular remodeling using lean body mass allometry: a UK Biobank study

Purpose The geometric patterns of ventricular remodeling are determined using indexed left ventricular mass (LVM), end-diastolic volume (LVEDV) and concentricity, most often measured using the mass-to-volume ratio (MVR). The aims of this study were to validate lean body mass (LBM)-based allometric coefficients for scaling and to determine an index of concentricity that is independent of both volume and LBM. Methods Participants from the UK Biobank who underwent both CMR and dual-energy X-ray absorptiometry (DXA) during 2014–2015 were considered ( n = 5064). We excluded participants aged ≥ 70 years or those with cardiometabolic risk factors. We determined allometric coefficients for scaling using linear regression of the logarithmically transformed ventricular remodeling parameters. We further defined a multiplicative allometric relationship for LV concentricity (LVC) adjusting for both LVEDV and LBM. Results A total of 1638 individuals (1057 female) were included. In subjects with lower body fat percentage (< 25% in males, < 35% in females, n = 644), the LBM allometric coefficients for scaling LVM and LVEDV were 0.85 ± 0.06 and 0.85 ± 0.03 respectively ( R 2 = 0.61 and 0.57, P < 0.001), with no evidence of sex–allometry interaction. While the MVR was independent of LBM, it demonstrated a negative association with LVEDV in (females: r = − 0.44, P < 0.001; males: − 0.38, P < 0.001). In contrast, LVC was independent of both LVEDV and LBM [LVC = LVM/(LVEDV 0.40 × LBM 0.50 )] leading to increased overlap between LV hypertrophy and higher concentricity. Conclusions We validated allometric coefficients for LBM-based scaling for CMR indexed parameters relevant for classifying geometric patterns of ventricular remodeling.