Short-term changes in serum sex steroid levels and cardiac function in healthy young men
Maarten De Smet1,2, Bruno Lapauw1, Tine De Backer2 & Johannes Ruige1
Introduction: Male obesity is associated with an increase in estradiol (E2) and a decrease in testosterone (T). And, although sex steroids are associated with cardiovascular disease, direct effects on cardiac structure and function are hardly investigated in humans.
Methodology: Twenty healthy men aged 2040 years were randomized into two groups. One group was given an aromatase inhibitor (letrozole) only, thus obtaining a high testosterone and low E2 (group T). The other group received an aromatase inhibitor plus an E2 patch (dermestril), reaching a low testosterone and high E2 (group E). Serum levels of both testosterone and E2 remained within the normal reference range. The men underwent an echocardiography by a single cardiologist before the start of the intervention and after 7 days.
Results: Total and free E2 serum levels were positively associated with ejection fraction (r=0.7, P=0.002 and r=0.6, P=0.007 respectively) at baseline in the whole group. In group E global circumferential strain decreased significantly from −25.3%±3.9 to −19.6%±2.5 after 1 week as compared to baseline (P=0.01). No significant changes in systolic function were observed in group T. Cardiac structure remained unaltered.
Conclusion: In young healthy men, an increase in E2 and decrease in testosterone levels significantly decreased circumferential strain. The finding justifies larger studies of longer duration to discover the exact nature of the impact of changed sex steroids on cardiac function and remodelling in obesity.