Osteocalcin and the pituitary‐gonadal axis in older men: a population‐based study. (12th December 2014)

• Record Type: Journal Article
• Authors: Limonard, E.J.; van Schoor, N.M.; de Jongh, R.T.; Lips, P.; Fliers, E.; Bisschop, P.H.
• Is Part Of: Clinical endocrinology. Volume 82:Number 5(2015:May)
• Page Start: 753
• Page End: 759
• Publication Date: 2014-12-12
• Subjects: Endocrinology -- Periodicals; 616.4005
• DOI: 10.1111/cen.12660
• Languages: English
• ISSNs: 0300-0664

Abstract

<abstract abstract-type="main" id="cen12660-abs-0001"> <title>Summary</title> <sec id="cen12660-sec-0001" sec-type="section"> <title>Objective</title> <p>Osteocalcin is a well‐known marker of bone formation. Recently, mice lacking osteocalcin or its receptor were reported to be subfertile with low testosterone and high luteinizing hormone concentrations. In parallel, in humans, a loss‐of‐function mutation of the osteocalcin receptor was associated with hypergonadotropic hypogonadism. This suggests that osteocalcin is necessary for normal pituitary‐gonadal axis function. Our objective was to determine the association between physiological variations in osteocalcin and the pituitary‐gonadal axis in older men.</p> </sec> <sec id="cen12660-sec-0002" sec-type="section"> <title>Design and patients</title> <p>Data were used from the Longitudinal Aging Study Amsterdam (LASA), an ongoing cohort study in a representative sample of the older Dutch population (65–88 years).</p> </sec> <sec id="cen12660-sec-0003" sec-type="section"> <title>Measurements</title> <p>Serum levels of total (T), free (FT) and bioavailable (bioT) testosterone, luteinizing hormone (LH) and osteocalcin were determined. Data were analysed using linear regression analyses and adjusted for age, BMI, 25‐hydroxyvitamin D, parathyroid hormone and vitamin K antagonist use.</p> </sec> <sec id="cen12660-sec-0004" sec-type="section"> <title>Results</title> <p>A total of 614 men participated in the study. The median age was 75·4 (69·8–81·2) years, and the median osteocalcin level was 1·8 (1·3–2·4) nmol/l. Serum osteocalcin was inversely associated with FT (adjusted B = −0·22 ± 0·09 ng/dl, <italic>P</italic> = 0·012) and bioT (adjusted B = −0·26 ± 0·08 nmol/l, <italic>P</italic> < 0·01), but not with total T. Furthermore, osteocalcin was positively associated with LH (adjusted B = 0·09 ± 0·03 U/l, <italic>P</italic> < 0·01).</p> </sec> <sec id="cen12660-sec-0005" sec-type="section"> <title>Conclusions</title> <p>Serum osteocalcin was negatively associated with free and bioavailable testosterone and positively with luteinizing hormone levels.</p> </sec> </abstract>