Body fat distribution, incident cardiovascular disease, cancer, and all-cause mortality

Abstract

Objectives: The aim of this study was to determine whether ectopic fat depots are prospectively associated with cardiovascular disease, cancer, and all-cause mortality.

Background: The morbidity associated with excess body weight varies among individuals of similar body mass index. Ectopic fat depots may underlie this risk differential. However, prospective studies of directly measured fat are limited.

Methods: Participants from the Framingham Heart Study (n = 3,086; 49% women; mean age of 50.2 years) underwent assessment of fat depots (visceral adipose tissue, pericardial adipose tissue, and periaortic adipose tissue) using multidetector computed tomography and were followed up longitudinally for a median of 5.0 years. Cox proportional hazards regression models were used to examine the association of each fat depot (per 1 SD increment) with the risk of incident cardiovascular disease, cancer, and all-cause mortality after adjustment for standard risk factors, including body mass index.

Results: Overall, there were 90 cardiovascular events, 141 cancer events, and 71 deaths. After multivariable adjustment, visceral adipose tissue was associated with cardiovascular disease (hazard ratio: 1.44; 95% confidence interval: 1.08 to 1.92; p = 0.01) and cancer (hazard ratio: 1.43; 95% confidence interval: 1.12 to 1.84; p = 0.005). Addition of visceral adipose tissue to a multivariable model that included body mass index modestly improved cardiovascular risk prediction (net reclassification improvement of 16.3%). None of the fat depots were associated with all-cause mortality.

Conclusions: Visceral adiposity is associated with incident cardiovascular disease and cancer after adjustment for clinical risk factors and generalized adiposity. These findings support the growing appreciation of a pathogenic role of ectopic fat.

Keywords: BMI; CI; CVD; HR; MDCT; NRI; SAT; VAT; body fat distribution; body mass index; cancer; cardiovascular disease; confidence interval; hazard ratio; multidetector computed tomography; net reclassification index; obesity; subcutaneous adipose tissue; visceral adipose tissue; visceral fat.

Conflict of interest statement

Disclosures: The authors report no conflicts of interest.

Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1. Multidetector computed tomography images demonstrating SAT, VAT, periaortic fat, and pericardial fat

Fat depots are defined by anatomic landmarks and pixels of adipose tissue within a given fat depot are identified by their characteristic Hounsfield units.

Figure 2. Kaplan Meier Curve of Time to A) CVD and B) Cancer by Tertile of VAT (cm3)

Vertical axes show the percent of subjects developing A) CVD and B) cancer during follow-up; horizontal axes reflect years of follow-up. Tertile cutpoints for VAT are 1242.2 and 2168.4 cm3

Figure 2. Kaplan Meier Curve of Time to A) CVD and B) Cancer by Tertile of VAT (cm3)

Vertical axes show the percent of subjects developing A) CVD and B) cancer during follow-up; horizontal axes reflect years of follow-up. Tertile cutpoints for VAT are 1242.2 and 2168.4 cm3