UC Irvine

OBJECTIVES: To investigate the association of different measures of central (abdominal) and overall adiposity with autonomic nervous system (ANS) function, indexed by heart rate variability (HRV), in apparently healthy human adults. DESIGN AND MEASUREMENTS: Cross-sectional data of 8,538 participants (20% female, age: 41 ± 11 years, body mass index (BMI): 24 ± 4 kg/m2, waist circumference (WC): 91 ± 12 cm, waist-to-height ratio (WHtR): 0.45 ± 0.08) were available for analysis. RESULTS: All measures of adiposity were inversely correlated with vagally-mediated HRV indexed by RMSSD (all p<0.001). Strongest associations were found with WC and RMSSD (r = -0.29). Associations were stronger in males (WC r = -0.32) than in females (WC r = -0.23). Partial correlations revealed the same pattern for RMSSD (WC all pcc = -0.12 p<0.001; WC male pcc = -0.14 p<0.001; WC female pcc = -0.06 p<0.05). Correlation strength of BMI and WHtR with RMSSD were similar and significantly weaker compared to WC (p < .001) in unadjusted analysis. Overall, nonparametric Kendalls τb led to the same conclusions. CONCLUSION: The present data supports previous findings, that HRV is related to measures of adiposity in healthy individuals. In line with previous research, we found that WC is more strongly related to measures of HRV, indicating that WC best captures adiposity related risk.