Background & aims: Subjects with obesity had autonomic nervous abnormalities. This study investigated autonomic nervous modulation in subjects with obesity and its association with the indices of obesity, especially the body mass index and waist circumference, by heart rate variability analysis.
Methods: Forty-seven adults with a body mass index (in kg/m(2)) greater than 28 were recruited as the obese group and 30 subjects with a body mass index less than 23 were recruited as the control group. Anthropometric measures and heart rate variability measures were obtained for both groups. The correlation between heart rate variability measures and the anthropometric measures was assessed in subjects with obesity.
Results: Subjects with obesity had lower normalized low-frequency power and normalized high-frequency power than those of the control group. The body height, body weight, waist circumference and waist-to-hip ratio correlated significantly with the spectral heart rate variability measures in Asian subjects with obesity, whereas the body mass index did not.
Conclusions: Abdominal obesity, rather than general obesity, was related to autonomic nervous derangement in Asian subjects with obesity. The close relation between abdominal obesity and autonomic derangement may partially account for the close relationship between abdominal obesity and higher risk of mortality and morbidity in subjects with obesity.