(277) A Symbol of Masculinity: Is there a Correlation Between Men's Lower Body and Serum Testosterone Levels?

Abstract

Abstract Introduction While a robust lower body and strong lower body strength are regarded as symbols of masculinity, the actual relationship with testosterone is not clear. Previous studies have shown a significant correlation between serum testosterone levels and body fat components, but not with skeletal muscle mass. Objective This study aimed to determine if there is any correlation between male lower body strength, lower body size, and testosterone. Methods Serum testosterone levels, waist circumference, weight and BMI measurement, Body composition tests (skeletal muscle mass, body fat mass, body fat percentage, abdominal fat percentage, visceral fat percentage), and physical fitness tests (cardiorespiratory, flexibility, endurance, strength, agility, power, balance) were conducted in 95 men (aged over 40) who visited the hospital for erectile dysfunction. For understanding the lower body size, the circumference of the thigh and calf was measured, and to measure lower body strength, the muscle strength of the knee joint was measured using an isokinetic dynamometer. Patients with serum testosterone levels below 250ng/dL were defined as group I, and those with levels above 350ng/dL were classified as group II. Differences in body composition, physical fitness, adjusted calf and thigh circumference (by weight), and bilateral knee extension and flexion strength (adjusted by weight) were verified using an independent t-test. Pearson's Chi-square test was used to check for differences in lifestyle habits and underlying diseases, and a simple correlation test was conducted to understand the association between serum testosterone levels and lower body size and strength. Results Age did not significantly differ between the groups. Group I had a significantly higher proportion of alcohol consumption and number of underlying diseases. In body composition, Group I had a significant increase in weight, BMI, and waist circumference compared to Group II. The body fat percentage, abdominal fat percentage, and visceral fat percentage were also significantly higher in Group I than in Group II. In physical fitness, cardiorespiratory function, agility, power, and balance showed significantly better results in Group II than in Group I. The comparison of thigh circumference adjusted by weight showed that Group II was significantly larger than Group I, but there was no difference in calf circumference adjusted by weight. Both left and right knee extension strength showed significantly better power in Group II than in Group I, while there was no difference in flexion strength between the two groups. The simple correlation test showed a significant positive correlation between the adjusted values of thigh and calf circumference and serum testosterone levels, and the calf/thigh circumference value showed a significant negative correlation with serum testosterone levels. Left and right knee extension strength also showed a significant positive correlation with serum testosterone levels. Conclusions The circumference of a male's lower body, particularly the thigh, showed a correlation with serum testosterone levels, and in terms of lower body strength, knee extension strength showed a correlation with serum testosterone levels. A robust thigh and strong lower body strength were found to be closely related to testosterone, a symbol of masculinity. Disclosure No.