The Joint Annual Scientific Meetings of the Endocrine Society of Australia and the Society for Reproductive Biology 2018

Testicular size as a reflection of masculinity (#256)

Mark Ng Tang Fui 1 2 , Rudolf Hoermann 2 , Mathis Grossmann 1 2
  1. Austin Health, Heidelberg, Victoria, Australia
  2. Medicine, University of Melbourne, Heidelberg, Victoria, Australia

Importance: Measurement of testicular size is a routine part of the assessment of men presenting with hypogonadism and has long been considered a sign of masculinity

Objective: To determine whether testicular volume is correlated with biochemical and clinical characteristics of masculinity

Design: Cross-sectional study.

Participants: 89 obese men with a total testosterone level <12nmol/L participating in a previously described RCT (  NCT01616732).

Measurements: Testicular volume was measured by an orchidometer as an average of both testes and total testosterone by LCMS/MS. Men completed the ageing male symptoms score (AMS) and international index of erectile function 5 (IIEF5). Handgrip was measured by a dynamometer, physical function testing included the  15m rapid walking, timed up and go, stair ascent and descent with a weighted vest.

Main Outcomes: 89 men participated with median [IQR] age of 53.1y [47.6, 59.2, weight of 116kg [105, 129] and total testosterone of 7.0nmol/L [6.1; 7.9]. The mean testicular volume was 18mL [10; 20]. Testicular volume was not correlated with total or free testosterone, or FSH but was weakly negatively correlated with LH (r = -0.160 p = 0.037). Testicular volume was negatively correlated with body fat mass (r = -0.212, p = 0.005) and BMI (r = -0.120, p = 0.010) but not correlated with age. Testicular volume was positively correlated with IIEF5 (r = 0.201, p = 0.021) but not correlated with handgrip strength, the battery of physical function tests or AMS.

Conclusions: Among obese men with lowered testosterone, testicular volume is associated with, to a small degree, biochemical and clinical markers of masculinity.