Osteoprotegerin serum levels in men : Correlation with age, estrogen, and testosterone status

• Published in: The journal of clinical endocrinology and metabolism Vol. 86; no. 7; pp. 3162 - 3165
• Main Authors: SZULC, P, HOFBAUER, L. C, HEUFELDER, A. E, ROTH, S, DELMAS, P. D
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Endocrine Society 01.07.2001
• Subjects: Adult; Aged; Aged, 80 and over; Aging - blood; Amino Acids - urine; Biological and medical sciences; Bone Density; Bone Remodeling; Calcifediol - blood; Estradiol - blood; Glycoproteins - blood; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Middle Aged; Osteoarticular system. Muscles; Osteoprotegerin; Parathyroid Hormone - blood; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Receptors, Cytoplasmic and Nuclear - blood; Receptors, Tumor Necrosis Factor; Testosterone - blood; Human; Correlation; Androgen; Estrogen; Biological marker; Male; Density; Estradiol; Blood plasma; Testosterone; Bone mass; Tumor necrosis factor; Turnover; Adult; Bone mineral density; Testicular hormone; Hormonal investigation; Sex steroid hormone; Osseous tissue; Elderly; Age; Biological receptor
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.86.7.3162

Previous studies have suggested an important role for androgens and estrogens in bone metabolism in men. However, their local mode of action has not been clearly established. Osteoprotegerin (OPG) is a secreted decoy receptor that inhibits osteoclast formation and activity by neutralizing its cognate ligand. To assess the role of OPG on bone metabolism in men, we conducted a study aimed at evaluating OPG serum levels and their correlation with age, bone mineral density, biochemical markers of bone turnover, and testosterone and estradiol levels in 252 men, aged 19-85 yr. Serum concentrations of OPG increased significantly with age (r = 0.41; P = 0.0001), and were positively correlated with free testosterone index and free estradiol index (r = 0.20; P < 0.002 and r = 0.15; P < 0.03, respectively) after adjustment for age and body weight. Beyond the age of 40 yr, OPG serum concentrations were negatively correlated with urinary excretion of total deoxypyridinoline (r = -0.20; P < 0.01) and PTH serum levels (r = -0.23; P < 0.01). In contrast, there was no correlation with biochemical markers of bone formation, 25-hydroxyvitamin D(3) levels, or bone mineral density at any site. Our data reveal that age as well as androgen and estrogen status are significant positive determinants, whereas PTH is a negative determinant, of OPG serum levels in men. These data suggest that OPG may be an important paracrine mediator of bone metabolism in elderly men and highlight the role of estrogens in the homeostasis of the male skeleton.