Where the fat is located matters: body fat location is associated with cardiac remodelling in older adults

Background Fat deposition in certain body locations (such as visceral adiposity), is associated with increased risk of cardiovascular disease (CVD). Ageing-related cardiometabolic dysfunction may interact to induce cardiac remodelling. Due to emerging evidence showing the effects of bilateral cardiac-to-adipose axis crosstalk, we hypothesize that segmental assessment of body fat would reveal distinguishing associations with cardiac remodelling in older adults. Methods We prospectively enrolled community older adults without CVD, to undergo same-day echocardiography and whole-body bioimpedance assessment that computed proportions of their body fat: whole-body fat percentage (WBFP); central fat percentage (CFP); appendicular (all four limbs) fat percentage (AFP). We defined four conventional categories of remodelling phenotypes based on echocardiography-derived relative wall thickness and indexed left ventricular (LV) mass: normal LV geometry; concentric remodelling (CR); concentric hypertrophy (CH); eccentric hypertrophy (EH). We performed multinomial logistic regression to determine the associations between fat percentages and remodelling categories. Sex-stratified analyses were performed after model adjustment for clinical risk factors. Results Among n=924 subjects (mean age 63.3 ± 12.48 years; 516 women), n=797, n=77, n=5, and n=45 subjects had normal LV geometry, CR, CH and EH, respectively; and mean WBFP, CFP, and AFP were 34.43 (IQR 11.61), 33.30 (IQR 10.2), and 33.67 (IQR 10.76) respectively. WBFP was positively associated with CR (odds ratio [OR] 1.048, 95% confidence interval [CI] 1.011-1.086, p = 0.010) and EH (OR 1.059, 95% CI 1.012-1.109, p = 0.014) but not CH. CFP (OR 1.042, 95% CI 1.005-1.079, p = 0.024) and AFP (OR 1.049, 95% CI 1.013-1.086, p = 0.008) were positively associated with CR. Compared with men, women had lower odds of developing CR: ORs of 0.428 (95% CI 0.238-0.769, p = 0.005), 0.495 (95% CI 0.288-0.851, p = 0.011) and 0.389 (95% CI 0.208-0.727, p = 0.003) with WBFP, CFP and AFP as predictors, respectively. Sex-stratified results in the adjusted model (Model 1) are shown in Table 1. AFP was associated with CR in men (OR 1.056, 95% CI 1.004-1.111, p = 0.035) but not in women as seen in Figures 1a and 1b. Conclusion Body fat composition associates with cardiac remodelling in older adults, with qualitative and quantitative differences between the sexes. These findings highlight the notion of cardiac-to-adipose interactions in ageing, and the need for sex-specific considerations in cardiovascular risk assessment.