Abstract P296: Longitudinal Association of Changes in Abdominal Fat Quantity and Quality with Changes in Cardiovascular Disease Risk Factors

Abstract

Introduction: Subcutaneous (SAT) and visceral adipose tissue (VAT) are associated with adverse cardiometabolic risk profiles. We explored the degree to which changes in abdominal fat quantity and quality are associated with changes in cardiovascular disease (CVD) risk factors over time. Methods: Framingham Heart Study Third Generation cohort participants (n=1,106; 44.1% women; mean age 45.1 years) who underwent multi-detector computed tomography assessment for two consecutive examinations from 2002 to 2005 and from 2008 to 2011 were included in this analysis (mean interval 6.1 years). Abdominal adipose tissue volume in cm 3 and attenuation (indirect measure of fat quality) in Hounsfield units (HU) were determined by multi-detector computed tomography-acquired abdominal scans. Multivariable-adjusted linear and logistic regression models were constructed to examine the longitudinal associations between changes in abdominal fat volume and attenuation with changes in CVD risk factors. Multivariable-adjustment included baseline abdominal adipose tissue, baseline CVD risk factors, baseline age, smoking status, alcohol intake, physical activity, postmenopausal status, and hormone replacement therapy. Results: The mean fat volume change was 602 cm 3 for SAT and 703 cm 3 for VAT; and the mean fat attenuation change was -5.5 HU for SAT and 0.07 HU for VAT. An increase in fat volume and decrease in fat attenuation were associated with adverse changes in CVD risk factors. An additional 500 cm 3 increase in fat volume was associated with incident hypertension, hypertriglyceridemia, and metabolic syndrome (all p <0.05). Similarly, each additional 5 HU decrease in fat attenuation was associated with adverse changes in CVD risk factor profiles. For example, a 5 HU decrease in SAT attenuation was associated with an increase of 2.89 mmHg of systolic blood pressure, 2.24 mmHg of diastolic blood pressure, 1.29 mg/dL of fasting plasma glucose, 5.01 mg/dL of total cholesterol, and 0.11 mg/dL of log triglycerides; and a decrease of 3.25 mg/dL of high density lipoprotein cholesterol (all p <0.05). The majority of these associations remained significant even after further accounting for body mass index change, waist circumference change or respective abdominal adipose tissue volumes. Conclusions: Increasing accumulation of fat quantity and decreasing fat attenuation are associated with worsening of CVD risk factors beyond the associations with generalized adiposity, central adiposity, or respective adipose tissue volume. Our findings highlight the importance of quantitative and qualitative aspects of adipose tissue for a better understanding of CVD risk.