Associations of sedentary behavior, physical activity, and cardiorespiratory fitness with cardiac adiposity

Pericardial adipose tissue (PeAT), a visceral fat depot surrounding the coronary arteries and heart muscles, is a detrimental factor for cardiometabolic health. However, the association of health behaviors and/or cardiorespiratory fitness (CRF) with PeAT is poorly understood. This dissertation project examined the associations of sedentary behavior (SB), TV viewing, light-intensity physical activity (LPA), moderate-to-vigorous intensity physical activity (MVPA), and CRF with PeAT.

We analyzed generally healthy, middle-to-old age US adults from the two research studies: Multi-Ethnic Study of Atherosclerosis (MESA) and Coronary Artery Risk Development in Young Adults (CARDIA) Study. Time in SB, TV viewing, LPA, and MVPA were measured using physical activity questionnaires. CRF was measured using a treadmill exercise test. The volume of PeAT was quantified using computed tomography.

Using data from MESA, we found that LPA is not but high SB and low MVPA are associated with greater PeAT, after accounting for sex, age, race/ethnicity, education level, employment status, location of the measurements, medication use, smoking status, alcohol consumption, diet quality, systolic and diastolic blood pressure, triglyceride, total cholesterol, high-density lipoprotein cholesterol, diabetes status, inflammatory markers, and waist circumference. Using the data from the CARDIA study, we found that both TV viewing and MVPA are associated with 10 years prospectively measured PeAT; however, these associations were attenuated after accounting for waist circumference measured 10 years before. A greater 10-year increase in TV viewing is associated with a greater concurrent increase in PeAT, irrespective of MVPA and other tested covariates. In addition, we observed age-related declines in CRF and increases in PeAT, and repeated measures of CRF over 20 years are inversely associated with prospectively measured PeAT, independent of all tested covariates.

In conclusion, reducing TV viewing and/or SB, increasing MVPA, and maintaining high levels of CRF may be associated with less PeAT accumulation with age in middle-to-old age adults.