Bone mineral density in the complete androgen insensitivity and 5alpha-reductase-2 deficiency syndromes

J Clin Endocrinol Metab. 2006 Aug;91(8):3017-23. doi: 10.1210/jc.2005-2809. Epub 2006 May 30.

Abstract

Context: Subjects with complete androgen insensitivity (CAI) and 5alpha-reductase-2 deficiency (5alphaRD-2) are natural human models to study the direct effect of androgens on bone mineral density (BMD).

Objective: The objective of this study was to test the hypothesis that androgens have a direct effect on BMD in men.

Design: This was a prospective, observational study (1989-1999) using dual energy x-ray absorptiometry.

Setting: The study was set in an outpatient specialty referral center.

Patients or other participants: All known subjects with these conditions (12 CAI and 16 5alphaRD-2) from diverse sociodemographic backgrounds were recruited for the study.

Interventions: There were no interventions.

Main outcome measure: Mean Z score and weight-matched Z score at lumbar spine and femoral neck for CAI and 5alphaRD-2 subjects were determined.

Results: Twelve CAI subjects had mean Z score at L2-L4 of -2.84 (+/-0.97, P < 0.001) and a mean weight-matched Z score of -2.52 (+/-0.94, P < 0.001). The mean Z score at the femoral neck was -1.33 (+/-0.91, P < 0.001) and the mean weight-matched Z score was -1.10 (+/-0.82, P = 0.001). Sixteen 5alphaRD-2 subjects had a mean Z score at L2-L4 of -0.84 (+/-1.29, P = 0.02) and a mean weight-matched Z score for 15 of 16 patients of -0.44 (+/-1.08, P = 0.14). The mean Z score at the femoral neck was 0.14 (+/-1.02, P = 0.58) and the mean weight-matched Z score for 15 of 16 patients was 0.49 (+/-0.94, P = 0.06). Therefore, in CAI subjects, BMD was significantly decreased in the spine and hip. 5alphaRD-2 subjects had normal BMD values.

Conclusions: 1) Androgens are of direct importance in the development and/or maintenance of BMD; and 2) testosterone and/or low levels of dihydrotestosterone appear to be sufficient for BMD development and/or maintenance.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Absorptiometry, Photon
  • Adolescent
  • Adult
  • Androgen-Insensitivity Syndrome / physiopathology*
  • Androgens / physiology
  • Bone Density / physiology*
  • Castration
  • Cholestenone 5 alpha-Reductase / deficiency*
  • Dihydrotestosterone
  • Femur Neck
  • Humans
  • Lumbar Vertebrae
  • Male
  • Middle Aged
  • Prospective Studies
  • Testosterone / physiology

Substances

  • Androgens
  • Dihydrotestosterone
  • Testosterone
  • Cholestenone 5 alpha-Reductase