Osteoporosis in men with hypogonadism because of ApoA-I Leu75Pro amyloidosis under long-term testosterone therapy.

Osteopenia and osteoporosis were highly prevalent in men with Apo A-I Leu75Pro amyloidosis-related hypogonadism under long-term testosterone replacement therapy.

• Study population: 50 men >50 years (median age 64.5) with DXA, hormonal, and biochemical data available at least 3 years after TRT start
• Lumbar and/or femoral osteopenia was found in 54% of patients
• Osteoporosis was found in 10% of patients
• Combined low bone mass (osteopenia or osteoporosis) was present in 64% of patients
• Assessments were made at a median of 7.5 years from start of TRT

Vertebral fractures were found in approximately 15% of patients who underwent morphometric assessment.

• Five of 34 men (14.7%) who had the morphometric assay performed had vertebral fractures (VFs)
• VFs were assessed via DXA-scan with morphometric assay
• Not all 50 patients underwent morphometric assay; only 34 had this assessment performed

Men with osteopenia and osteoporosis were older, had lower body mass index, higher sex hormone binding globulin (SHBG), and more frequently had renal involvement compared to patients with normal bone mineral density.

• Comparisons were made between patients with normal BMD versus those with osteopenia or osteoporosis
• Key distinguishing factors included age, BMI, SHBG levels, and presence of renal involvement
• Renal involvement was one of the characteristic features of this amyloidosis alongside testicular and hepatic involvement

Multiorgan involvement was associated with lower testosterone levels despite similar TRT dosage across patients.

• Patients with multiorgan involvement showed lower testosterone levels
• There was no difference in TRT dosage between patients with and without multiorgan involvement
• This suggests that disease severity (multiorgan involvement) may impair testosterone bioavailability or metabolism rather than being attributable to treatment differences

Apo A-I Leu75Pro amyloidosis is a rare systemic hereditary disease whose hallmark and earliest involvement is testicular impairment characterized by hypogonadism and macrorchidism.

• The disease also involves renal and hepatic organs
• This was described as the first study to evaluate the prevalence of osteopenia, osteoporosis, and vertebral fractures in this patient population
• The study was retrospective, including 50 men with median age 64.5 years