Men with sickle cell disease usually have incomplete secondary sexual development, and testicular atrophy is present in one-third. The defect may either be at the testicular level or at the hypothalamic-pituitary level. Decreased Leydig cell function, with or without decreased sperm density, occurs in a variety of chronic systemic diseases; the lowered plasma testosterone level is coupled with a minimal increase in the plasma LH level, suggesting combined hypothalamic-pituitary and testicular defects.
