Impaired autonomic function in normotensive obese children.

Purpose: To evaluate baroreflex sensitivity and autonomic control in a cohort of normotensive obese (OB) children.

Method: A cross-sectional investigation, in which, baroreflex sensitivity and autonomic control were evaluated using transfer function and power spectral density analysis (PSDA) of the electrocardiogram and beat-to-beat blood pressures in normotensive OB children and normal weight normotensive controls. All methods used were noninvasive and data were captured while seated and at rest.

Results: The OB and control subjects non-obese (NO) were of similar age (OB 9.1±1.9 years vs. NO 9.2±1.4 years). The OB group was classified as having a BMI greater than the 95th percentile adjusted for age and gender, and a NO group with a BMI at or less than the 95th percentile (BMI percentile OB. 97.5±1.3 vs. NO 58.5±24.1). Both groups had similar normotensive blood pressures. T tests revealed that baroreflex sensitivity and HFRR were significantly reduced in the OB 9.2±2.7 vs. 15.2±4.7 (ms/mmHg) and 6.7±1.1 vs. 8.2±1.1 ms2, respectively, while LFSBP and LF/HF ratio were significantly increased in the OB 11.9±5.6 vs. 8.2±4.7 mmHg2 and 1.2±0.7 vs. 0.54±0.3, respectively.

Conclusions: Normotensive OB children exhibited significantly reduced baroreflex sensitivity, parasympathetic control as well as increased sympathetic control when compared with healthy, NO controls. Findings in this investigation raise the awareness that autonomic dysfunction is present in young OB normotensive children.