Association between heart rate variability measures and body composition parameters in obesity-related hypertension: a pilot investigation

Obesity-related hypertensive adults are prone to develop cardiovascular disease, which is supposed to be due to autonomic alterations. These autonomic alterations can bring about changes in heart rate variability (HRV) one of the prominent marker to assess cardiac autonomic function.

To identify the association between HRV measures and body composition parameters in obesity-related hypertensive adults.

This pilot investigation was conducted in 11 obesity-related hypertensive adults (body mass index (BMI) >28 kg/m²) and systolic blood pressure/SBP > 130 mmHg and diastolic blood pressure and/or DBP > 80 mmHg. HRV variables were assessed using standard taskforce guidelines. Obesity indices such as body fat percentage, waist circumference (WC), hip circumference (HC), waist–hip ratio (WHR), and BMI were measured and calculated, and they were correlated with HRV indices using Pearson's correlation analysis.

Pearson's correlation between HRV and obesity indices showed significant negative correlation of WC and WHR with number of RR intervals that differ by ?50 ms (NN50 count) (r= -0.606, p= 0.048), (r= -0.658, p= 0.028) and percentage of consecutive RR intervals that differ by ?50 ms (pNN50%) (r= -0.615, p= 0.044), (r= -0.663, p= 0.036) respectively while WC, HC and WHR was positively correlated with low frequency power ms² (LFms²), (r= 0.867, p=0.01), (r= 0.729, p=0.011), (r= 0.682, p=0.021) respectively, LF in normalized unit (LFnu), (r=0.613, p=0.045), (r=0.725, p=0.012), (r=0.574, p=0.032) respectively. HC was negatively associated with high frequency (HFnu), (r= -0.695, p= 0.018). There was no significant correlation of BMI with HRV indices in obesity-related hypertension individuals.

Increased WC, HC and WHR, marker of visceral adiposity was strongly associated with reduced cardiac parasympathetic and increased sympathetic activity in obesity-related hypertensive. However, BMI itself has a weak relationship with HRV indices, indicating even mild increase in WC and WHR can bring about alteration in autonomic function.