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


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


METHODS
The study was set in an outpatient specialty referral center.


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


METHODS
There were no interventions.


METHODS
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.
Sobel
Vivian
V
Division of Endocrinology and Metabolism, Department of Medicine, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA.
Schwartz
Brian
B
Zhu
Yuan-Shan
YS
Cordero
Juan J
JJ
Imperato-McGinley
Julianne
J
D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D013734:Androgen-Insensitivity Syndrome / Q000503:physiopathology*; D000728:Androgens / Q000502:physiology; D015519:Bone Density / Q000502:physiology*; D002369:Castration; D042944:Cholestenone 5 alpha-Reductase / Q000172:deficiency*; D013196:Dihydrotestosterone; D005272:Femur Neck; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013739:Testosterone / Q000502:physiology
D000728:Androgens; D013196:Dihydrotestosterone; D013739:Testosterone; D042944:Cholestenone 5 alpha-Reductase