ESPE Abstracts

Background: Decreased bone density using DXA is reported in mixed cohorts of testosterone treated and testosterone naïve men with Klinefelter syndrome (KS). Bone mass and body composition in men with congenital anorchia (CA) have never been previously reported.

Objective and hypotheses: Men with KS and CA treated with testosterone from adolescence have normal bone mass and body composition.

Method: Whole-body DXA and tibial (66%) and radial (4%) pQCT were performed in 20 hypogonadal men (12 KS and eight CA), treated with long term maintenance testosterone from adolescence, compared with 20 age-matched healthy controls. Results expressed in median (range).

Results: Age, height, and BMI were not different between groups. No significant differences were seen between patients and controls for the following: DXA total body BMD z score −0.7 (−2.4,+3.0) vs −0.6 (−2.3,+1.2) (P=0.93); pQCT total density z score at 4% radius −1.1 (−3.2,+2.6) vs −1.4 (−3.5,+1.4) (P=0.13), cortical density 469.5 mg/cm³(301, 753.1) vs 466.1 mg/cm³ (P=0.28) and trabecular density 223.7 mg/cm³ (151.9, 334) vs 198.6 mg/cm³ (147, 263.9) (P=0.06). DXA total body BMD z score showed modest but significant associations with pQCT total density z score (r=0.68, P<0.0001) and trabecular density z score (r=0.69, P<0.0001). DXA lean mass, lean mass for height, lean mass for fat mass were not different between groups. pQCT muscle density and area at 66% tibia were not different between patients and controls: 77.4 mg/cm³ (56.7, 80.4) vs 77.4 mg/cm³ (P=0.86) and 8079 cm² (6486.4, 1922.6) vs 8122.2 cm² (5429.1, 10258.6) (P=0.92). DXA percentage fat was similar in both groups but trunk: leg fat 1.53 (0.88, 3.0) vs 1.17 (0.78, 2.42) (P=0.01), visceral adiposity mass 464.9 g (156.5, 981.5) vs 289.3 g (137.2, 582.2) (P=0.006) and visceral adiposity volume 502.6 cm² (169.2, 1061.1) vs 312.8 cm² (148.3, 629.4) (P=0.006) were significantly higher in patients.

Conclusion: This first preliminary report of bone assessment using pQCT and DXA in adults with KS and CA treated from adolescence demonstrates BMD similar to healthy controls, with no deficits in cortical and trabecular bone. However despite androgen replacement, increased central adiposity was seen and this requires further exploration.