Insulin-like factor 3 (INSL3): a new parameter to assess Leydig cell functionality and primary hypogonadismus in the EMAS population.
Final Report Abstract
INSL3 is a small peptide hormone produced constitutively by the Leydig cells of the testes and secreted into the circulation in substantial amounts. Because of its constitutive nature it offers an excellent biomarker representing the total Leydig cell functional capacity within an individual, and hence also their potential capacity to generate androgens. In aging men, much of age‐related debility can be attributed to low androgen production, giving rise to a popular demand for androgen replacement therapies. Such hypoandrogenemia, however, can have several origins. The measurement of INSL3 promises to differentiate individuals whose low androgen levels are of testicular origin, from others where there are secondary reasons, for example, due to issues within the hypothalamic‐pituitary axis. The present study makes use of the EMAS multicentre European cohort of aging men to examine the relationships between circulating INSL3 and a range of other endocrine and androgen‐related parameters. Moreover, there is experimental evidence in the literature to suggest a direct role for testicular INSL3 in the feedback regulation of bone metabolism. Now that several thousand samples from both the horizontal and longitudinal dimensions of the EMAS cohort have been measured, the resulting analyses should allow a very detailed examination of the value of INSL3 as a clinical biomarker, as well as new interpretations in regard to the causes and consequences of low androgen balance in aging men. Other etiological relationships are also being explored in this cohort.
