[Cardiac autonomic nerve function in obese school-age children]

Area of Science:

• Pediatric Cardiology
• Autonomic Nervous System Function
• Obesity Research

Background:

• Childhood obesity is a growing public health concern with potential long-term cardiovascular implications.
• Autonomic nerve function, assessed through heart rate variability (HRV) and its components like deceleration capacity (DC) and acceleration capacity (AC), plays a crucial role in cardiovascular health.
• Understanding autonomic dysfunction in obese children is vital for early risk stratification and intervention.

Purpose of the Study:

• To analyze deceleration capacity (DC), acceleration capacity (AC), and heart rate variability (HRV) in obese school-age children.
• To investigate the correlations between Body Mass Index (BMI) and these autonomic function parameters in obese children.
• To compare autonomic function between obese children with and without dyslipidemia.

Main Methods:

• A cohort of 108 obese school-age children (75 with ortholiposis, 33 with dyslipidemia) and 103 healthy controls underwent 24-hour ambulatory electrocardiography.
• Deceleration capacity (DC), acceleration capacity (AC), and various heart rate variability (HRV) indices (SDNN, SDANN, RMSSD, LF, HF) were measured.
• Statistical analyses compared autonomic function parameters between groups and correlated BMI with DC, AC, and HRV in the obese cohort.

Main Results:

• Obese children demonstrated significantly lower DC and HRV indices (SDNN, SDANN, RMSSD, LF, HF) but higher AC compared to healthy controls.
• Obese children with dyslipidemia exhibited markedly reduced DC and HRV indices, alongside elevated AC and BMI, compared to those with ortholiposis.
• In obese children, higher BMI was associated with decreased DC and HRV indices (SDNN, SDANN, RMSSD, HF) and increased AC.

Conclusions:

• Obese school-age children exhibit impaired autonomic nerve function, characterized by reduced vagal tone.
• This autonomic dysfunction is particularly severe in obese children with dyslipidemia.
• Increased obesity severity correlates with diminished vagal tone, potentially elevating cardiovascular disease risk in this population.