Heart Rate Variability in Healthy Young Adult Nigerians

Heart rate variability (HRV) is a reliable, non-invasive indicator of autonomic balance. Its application in research and clinical medicine is hindered by the lack of consensus on normal values. This study sought to bridge this gap by providing normative values for short-term HRV measures in apparently healthy young adults.

A descriptive cross-sectional study was carried out to determine short-term HRV measures using a 5-minute ECG recording among 840 healthy young adult Nigerians.

A total of 840 subjects between the ages of 15 - 40 years participated in the study, the majority of whom were women (56%). Mean (±SD) RR (ms), SDNN (ms), RMSSD (ms), LF (ms2), HF (ms2), LF (nu), HF (nu), and LF/HF were 831 (±138), 48 (±35), 57 (±49), 949 (±2598), 1802(±5135), 41 (±19), 58.90 (±19), and 1.42 (±4.6) respectively. Male participants had significantly higher mean RR (890.8 v 782.0, p<0.001), SDNN (52.4 v 43.8, p<0.005), RMSSD (63.6 v 50.9, p<0.005), LF (1218.5 v 731.8, p<0.001) and HF (2260.5 v 1429.5, p=0.002) than the female participants. No significant differences were found across age groups.

Short-term resting HRV shows gender differences and higher vagally-mediated components among healthy young adults of native African descent. Interpretation of HRV parameters should take into account the age, gender, context, spectral analysis method, and duration of recording, among other factors.