Sex and Age Variation in Electrocardiographic Parameters of Apparently Healthy Nigerian Athletes

Background: The Athletic heart (AH) exhibits a complex physiologic variation in function and structure caused by remodeling that accompanies regular athletic training. This study investigated the sex and age variations in the electrocardiographic (ECG) parameters of apparently healthy Nigerian athletes.

Methods: A cross-sectional descriptive survey was done on 340 subjects consisting of 170 athletes (males: 63, females: 107) and 170 non-athletes (75 males and 95 females; serving as control). Subjects’ age ranges were 16-35 years. Heart rate, blood pressure, and anthropometric measurements were determined. Physical examination was done to eliminate the existence of co-morbidities. ECG parameters were obtained using a standard-resting 12-lead electrocardiogram. From the results, female athletes were significantly (P<0.05) older than male, and had higher SBP and weight.

Results: The ECG variables of athletes were sex-influenced and not necessarily age-influenced. For the adaptive features, significant differences were found in T-inversion (M=31.7% vs F=16.8%), isolated QRS voltage [Criteria for LVH] (M=11.5% vs F=52.3%), sinus bradycardia (M=14.3% vs F=41.1%), and 1st degree AV block (M=11.1%, F=2.8%). For the mal-adaptive ECGs; left axis Deviation (M=0% vs F=9.3%), repolarization abnormality (M=1.6% vs F=8.4%), abnormal LVH (M=0% vs F=11.3%), and ST-T elevation abnormality (M=1.6% vs F=8.4%) were found higher in females. Sex rather than age influence was indicative as there were significant correlations (P<0.05) between age and some ECG parameters; QT-interval, heart rate, and QRS voltage in males but not females.

Conclusion: Variability in ECG (adaptive and maladaptive) features of elite Nigerian athletes was indicative of sex influence but not age.