Endocrine Abstracts

Sex steroid hormones play a pleomorphic role in preservation of BMD. The BMD, the blood circulating 25-hydroxyvitamin D [25(OH)D], testosterone and estradiol levels may decline with age and to contribute to bone fragility. Low vitamin D is associated with increased falls number and fractures.

Recently, a new software solution, 3D-SHAPER - allows measurements of both trabecular and cortical bone as well as 3D images -, it incorporates a model-based algorithm to analyse the bone in 3D from a standard DXA scan, with no additional radiation to the patients.

However, the role of the blood steroid hormones on the 3D analysis of the proximal femur is not yet recognized.

Objectives: To correlate the 3D parameters analysis, as assessed by 3D-SHAPER, with blood steroid hormone levels of adult men.

Material and Methods: All participants (adult men = 97) had a DXA exploration (QDR4500 Acclaim and Discovery W, Hologic Inc, USA) at spine and at non-dominant femur (g/cm²). 3D DXA modeling was performed using a software algorithm (3D-SHAPER v2.9, Galgo Medical, Spain) in order to derive QCT-like subject-specific 3D models from the hip DXA scans of the study subjects. The following 3D measurements were extracted: the trabecular and cortical volumetric BMD (Trabecular/cortical vBMD), the cortical thickness (Cth) and the cortical surface BMD (Cortical sBMD) as well as neck cross-sectional moment of inertia (CSMI) and Z modulus. In addition, appendicular fat and lean mass were assessed using dedicated DXA acquisition.

Blood was collected for 25(OH)D (ng/ml), total testosterone (T, ng/ml), 17β-estradiol(E₂, pg/dl) and sex hormone binding globulin (SHBG, nmol/ml) measurements.

Adequate statistical tests were used.

Results: In 97 adult men [mean (± SD) age 60.1( ± 13.5) years, mean BMI 25.3 (2.7)kg/m²] the mean BMD at the lumbar spine BMD = 1.030 (± 0.2) and at the total femur = 0.978 (±0.1), total body fat mass = 20.7 (±15.7) kg and total body lean mass = 52.8 ( ± 15.5)kg. The mean E₂ = 28.3 (±19.6), T = 4.9 (±11.8), SHBG = 43.2 (±19.2) and 25(OH)D = 24.1 (±11.0). The some of correlation coefficients are in Table below. No correlations were detected for the 3D parameters and 25(OH)D and the E₂ levels.

Conclusions: It seems that androgens play a very important role on bone strength; normal men with low blood testosterone levels may have low 3D parameters and thus worse bone strength; it is possible that testosterone acts positively in bone strength. Further studies are needed on a larger cohort and it might be worth to investigate men with hypogonadism.