Background and aims

Visceral fat (VF) is a source of pro-inflammatory adipokines implicated in cardiac remodeling. We sought to determine the impact of visceral fat and subcutaneous fat (SQ) depots on left ventricular (LV) structure, function, and geometry in the Multi-Ethnic Study of Atherosclerosis (MESA).

Methods and results

We performed a post-hoc analysis on 1151 participants from MESA with cardiac magnetic resonance quantification of LV mass and LV mass-to-volume ratio (LVMV, an index of concentricity) and computed tomographic-derived SQ and VF area. Multivariable regression models to estimate association between height-indexed SQ and VF area (per cm(2)/m) with height-indexed LV mass (per height(2.7)) and LVMV were constructed, adjusted for clinical, biochemical, and demographic covariates. We found that both VF and SQ area were associated with height-indexed LV mass (ρ = 0.36 and 0.12, P < 0.0001, respectively), while only VF area was associated with LVMV (ρ = 0.28, P < 0.0001). Individuals with above-median VF had lower LV ejection fraction, greater indexed LV volumes and mass, and higher LVMV (all P < 0.001). In multivariable models adjusted for weight, VF (but not SQ) area was associated with LV concentricity and LV mass index, across both sexes.

Conclusion

Visceral adiposity is independently associated with LV concentricity, a precursor to heart failure. Further study into the role of VF in LV remodeling as a potential therapeutic target is warranted.

Objectives

The study sought to determine the associations between local (pericardial) fat and incident cardiovascular disease (CVD) events and cardiac remodeling independent of markers of overall adiposity.

Background

The impact of pericardial fat-a local fat depot encasing the heart-on myocardial function and long-term CV prognosis independent of systemic consequences of adiposity or hepatic fat is an area of active debate.

Methods

We studied 4,234 participants enrolled in the MESA (Multi-Ethnic Study of Atherosclerosis) study with concomitant cardiac magnetic resonance imaging and computed tomography (CT) measurements for pericardial fat volume and hepatic attenuation (a measure of liver fat). Poisson and Cox regression were used to estimate the annualized risk of incident hard atherosclerotic CVD (ASCVD), all-cause death, heart failure, all-cause CVD, hard coronary heart disease, and stroke as a function of pericardial and hepatic fat. Generalized additive models were used to assess the association between cardiac magnetic resonance indices of left ventricular (LV) structure and function and pericardial fat. Models were adjusted for relevant clinical, demographic, and cardiometabolic covariates.

Results

MESA study participants with higher pericardial and hepatic fat were more likely to be older, were more frequently men, and had a higher prevalence of cardiometabolic risk factors (including dysglycemia, dyslipidemia, hypertension), as well as adiposity-associated inflammation. Over a median 12.2-year follow-up (interquartile range: 11.6 to 12.8 years), pericardial fat was associated with a higher rate of incident hard ASCVD (standardized hazard ratio: 1.22; 95% confidence interval: 1.10 to 1.35; p = 0.0001). Hepatic fat by CT was not significantly associated with hard ASCVD (standardized hazard ratio: 0.96; 95% confidence interval: 0.86 to 1.08; p = 0.52). Higher pericardial fat was associated with greater indexed LV mass (37.8 g/m^2.7 vs. 33.9 g/m^2.7, highest quartile vs. lowest quartile; p < 0.01), LV mass-to-volume ratio (1.2 vs. 1.1, highest quartile vs. lowest quartile; p < 0.01). In adjusted models, a higher pericardial fat volume was associated with greater LV mass (p < 0.0001) and concentricity (p < 0.0001).

Conclusions

Pericardial fat is associated with poorer CVD prognosis and LV remodeling, independent of insulin resistance, inflammation, and CT measures of hepatic fat.