AUTHOR=Lin Yu-Kai , Tsai Kun-Zhe , Han Chih-Lu , Lin Yen-Po , Lee Jiunn-Tay , Lin Gen-Min 

TITLE=Obesity Phenotypes and Electrocardiographic Characteristics in Physically Active Males: CHIEF Study

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 8 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2021.738575

DOI=10.3389/fcvm.2021.738575

ISSN=2297-055X

ABSTRACT=Background: Metabolically unhealthy obesity (MUO) has been associated with surface electrocardiographic (ECG) left ventricular hypertrophy (LVH), left atrial enlargement (LAE) and inferior T wave inversions (TWI) in the middle- and old-aged populations. However, the relationship between obesity phenotypes and these ECG abnormalities in physically active young adults is yet to be determined. 
Methods: A total of 2,156 physically active military males aged 18-50 in Taiwan were analyzed. Obesity and metabolically unhealthy status were respectively defined as the body mass index ≥27 kg/m2 and presence of metabolic syndrome based on the ATPIII criteria, for Asian male adults. Four groups were classified as the metabolically healthy non-obesity (MHNO, n=1,484), metabolically unhealthy non-obesity (MUNO, n=86), metabolically healthy obesity (MHO, n=376) and MUO (n=210). ECG-LVH was based on the Sokolow-Lyon and Cornell voltage criteria, ECG-LAE was defined as a notched P wave ≥0.12 seconds in lead II or a notch of ≥0.04 seconds, and inferior TWI was defined as one negative T wave axis in limb leads II, III, or aVF. Physical performance was evaluated by time for a 3-kilometer run. Multiple logistic regression analysis with adjustment for age, smoking, alcohol drinking and physical performance was utilized to investigate the associations between obesity phenotypes and the ECG abnormalities.
Results: As compared to MHNO, MUNO, MHO and MUO were associated with lower risk of Sokolow-Lyon based ECG-LVH [odds ratios (OR) and 95% confidence intervals: 0.80 (0.51-1.25), 0.46 (0.36-0.58) and 0.39 (0.28-0.53), respectively; p for trend <0.001], and with greater risk of ECG-LAE [OR: 0.87 (0.44-1.72), 2.34 (1.77-3.10) and 3.02 (2.13-4.28), respectively; p for trend <0.001] and inferior TWI [OR: 2.21 (0.74-6.58), 3.49 (1.97-6.19), and 4.52 (2.38-8.60), respectively; p for trend <0.001]. However, no associations between obesity phenotypes and Cornell based ECG-LVH were found. 
Conclusion: In physically active young males, obesity was associated with higher risk of ECG-LAE and inferior TWI; whereas the risk between obesity and ECG-LVH might vary by the ECG criteria, possibly due to a high prevalence of exercise induced-LVH in military and greater chest wall thickness in obesity. The cardiovascular prognosis of ECG-LVH in physically active obese adults require further study.