Visceral fat is stronger associated with electrocardiographic measures of sympathetic activation than subcutaneous fat in individuals with structurally normal hearts: the NEO study

Purpose: Adiposity is associated with sympathetic activation, but the role of different fat depots is unclear. Furthermore, subclinical cardiovascular disease (CVD) may have resulted in the previously observed associations between adiposity and sympathetic activation. We investigated the association of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) with electrocardiographic measures of sympathetic activation in a population with structurally normal hearts. Methods: The Netherlands Epidemiology of Obesity (NEO) study is a population-based prospective cohort study including men and women aged 45 to 65 years. In this cross-sectional analysis of the baseline measurements (2008-2012), abdominal SAT (cm2) and VAT (cm2) were measured using magnetic resonance imaging (MRI). A standard 10 seconds 12-lead electrocardiogram (ECG) was obtained in rest. Vector cardiograms (VCG) were synthesized from the ECGs using the Kors matrix. From the ECG and VCG, resting heart rate (RHR) in beats/min, ventricular gradient (VG) in mV/ms, QRS-T angle (°) and Tpeak-end duration in ms were calculated. We performed linear regression analyses adjusting for age, sex, smoking, ethnicity and physical activity. Results: Participants with prevalent CVD (n=74), diabetes (n=100), cardiac MRI abnormalities (n=49), cardiac medication (n=77) and missing data (n=58) were excluded. We included 467 participants with a mean age (SD) of 55 (6) years, 50% men. After adjustment for confounders SAT was associated with resting heart rate and the ventricular gradient. No association was found with the QRS-T angle and Tpeak-end (Table shows results per SD). VAT was associated with resting heart rate, the ventricular gradient and the QRS-T angle. No association was found with Tpeak-end (Table). Linear regression analyses: β (95% CI) Conclusions: Associations were stronger for VAT, suggesting that excess visceral fat is stronger related with alterations of the sympathetic nervous system than subcutaneous fat. Since our study only included participants with structurally normal hearts, these results indicate that VAT is associated with sympathetic activation before the onset of CVD.