Heart rate variability in childhood obesity

Area of Science:

• Cardiology
• Pediatrics
• Autonomic Nervous System

Background:

• Obesity presents with significant hemodynamic and metabolic changes.
• The role of autonomic control in cardiac function in obese individuals is not fully understood.
• Early detection of cardiac autonomic dysfunction is crucial in pediatric obesity.

Purpose of the Study:

• To investigate early signs of cardiac autonomic dysfunction in obese children.
• To analyze heart rate variability (HRV) using time- and frequency-domain methods.
• To assess autonomic control of cardiac function in a pediatric population with obesity.

Main Methods:

• Comparison of 32 obese children with 13 healthy lean children.
• Utilized 24-hour electrocardiograph and ambulatory blood pressure monitoring.
• Analyzed time- and frequency-domain heart rate variability (HRV) parameters, including low-frequency (LF) and high-frequency (HF) power, and LF/HF ratio.

Main Results:

• Obese children exhibited higher blood pressure, fasting glucose, insulin, and triglyceride levels.
• No significant overall decrease in HRV was observed in the obese group.
• Obese children showed significantly reduced 24-hour and nighttime high-frequency (HF) normalized units and time-domain measures of vagal activity.
• The obese group displayed significantly greater 24-hour and nighttime LF/HF ratios, indicating sympathetic dominance.

Conclusions:

• Obesity in children is associated with increased heart rate and blood pressure.
• A decrease in parasympathetic heart rate control was identified in stabilized obese normotensive children.
• These findings suggest early cardiac autonomic dysfunction in pediatric obesity.