Endocrine Abstracts

Background: Bone mineral density measurement sometimes reveals osteoporosis that is a consequence of undiagnosed or neglected long-standing health disorders. These secondary causes of osteoporosis should be carefully investigated, especially in men.

Case Presentation: A 63-year-old male complained of back pain and was referred to endocrinology clinic due to a poor densitometry finding indicating osteoporosis. He presented with severe obesity (body mass index 40.5 kg/m²), grade IV gynecomastia, Tanner IV genital appearance with descended testes. A spine X-ray detected compressive osteoporotic fractures in four thoracic vertebrae (Genant’s grade 1 and 2). Laboratory results showed overt hypergonadotropic hypogonadism, mild normocytic anemia, vitamin D deficiency with plasma glucose and HbA1c in the prediabetes range. Peripheral blood cytogenetic analysis revealed mosaic form of Klinefelter syndrome 47, XXY/46, XY - 19 out of 21 metaphases had XXY trisomy. The patient has been married with no children and has never engaged in infertility evaluation. He had no interest in testosterone treatment for sexual dysfunction and focused only on preventing skeletal difficulties. Severe osteoporosis was treated with teriparatide for two years, followed by risedronate. His lumbar pain improved and no new fractures occurred. During follow-up his hypertension was poorly controlled and he developed diabetes, but declined bariatric surgery.

Conclusions: Bone and metabolic complications in patients with Klinefelter syndrome are mainly related to testosterone deficiency. However, testosterone replacement has not yet been approved for osteoporosis treatment due to lack of evidence that it reduces fracture risk. The benefits of testosterone on cardiometabolic disorders were found, but it is necessary to weigh them against potential risks of this therapy in older patients with established comorbidities. Although effective control of male hypogonadism symptoms is usually reported, patients with Klinefelter syndrome might exhibit psychological, cognitive, and social issues that interfere with timely diagnosis, their preference for masculinization and adoption of a healthy lifestyle.