Bone turnover markers and sex hormones in men with idiopathic osteoporosis.
BACKGROUND
In contrast to osteoporosis in postmenopausal women, osteoporosis in men has received much less attention.


METHODS
We determined various biochemical parameters of bone metabolism and sex hormones in 31 men with idiopathic osteoporosis and 35 age matched control subjects.


RESULTS
In the men with osteoporosis, a significantly increased urinary excretion of deoxypyridinoline (5.3 +/- 0.2 vs. 4.6 +/- 0.2 nmol mmol-1 creatinine; P = 0.033) in addition to increased serum levels of the c-terminal telopeptide of type I collagen (2677 +/- 230 vs. 2058 +/- 153 pmol; P = 0.037) were found. While parameters of bone formation were not significantly different in the patients and controls, serum bone sialoprotein levels were significantly decreased in the patients (3.7 +/- 0.8 vs. 12.4 +/- 4.0 ng mL-1; P = 0.021). Moreover, in men with idiopathic osteoporosis, lower levels of estradiol (91.3 +/- 5.8 vs. 114.6 +/- 7.8 pmol L-1; P = 0.044), higher levels of sex hormone binding globulin (31.5 +/- 3.1 vs. 24.2 +/- 1.4 nmol L-1; P = 0.034) and a decreased free androgen index (42.6 +/- 5.2 vs. 56.4 +/- 5.9; P = 0.016) were seen. Serum estradiol levels correlated negatively with several parameters of bone resorption.


CONCLUSIONS
In men with idiopathic osteoporosis, bone resorption is increased and exceeds bone formation. The excessive bone resorption seen in idiopathic male osteoporosis may be due to decreased estradiol levels and low levels of bioavailable testosterone.
Pietschmann
P
P
University of Vienna, Vienna, Austria. peter.pietschmann@akhwien.ac.at
Kudlacek
S
S
Grisar
J
J
Spitzauer
S
S
Woloszczuk
W
W
Willvonseder
R
R
Peterlik
M
M
D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000378:metabolism; D015415:Biomarkers / Q000097:blood / Q000652:urine; D015519:Bone Density / Q000502:physiology; D016723:Bone Remodeling; D001862:Bone Resorption / Q000097:blood* / Q000201:enzymology / Q000652:urine; D012739:Gonadal Steroid Hormones / Q000097:blood* / Q000652:urine; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000097:blood* / Q000201:enzymology / Q000652:urine
D015415:Biomarkers; D012739:Gonadal Steroid Hormones; D000469:Alkaline Phosphatase