Effects of testosterone and growth hormone on the structural and mechanical properties of bone by micro-MRI in the distal tibia of men with hypopituitarism.
J Clin Endocrinol Metab
; 99(4): 1236-44, 2014 Apr.
Article
in En
| MEDLINE
| ID: mdl-24423356
ABSTRACT
CONTEXT Severe deficiencies of testosterone (T) and GH are associated with low bone mineral density (BMD) and increased fracture risk. Replacement of T in hypogonadal men improves several bone parameters. Replacement of GH in GH-deficient men improves BMD. OBJECTIVE:
Our objective was to determine whether T and GH treatment together improves the structural and mechanical parameters of bone more than T alone in men with hypopituitarism. DESIGN ANDSUBJECTS:
This randomized, prospective, 2-year study included 32 men with severe deficiencies of T and GH due to panhypopituitarism. INTERVENTION Subjects were randomized to receive T alone (n = 15) or T and GH (n = 17) for 2 years. MAIN OUTCOMEMEASURES:
We evaluated magnetic resonance microimaging-derived structural (bone volume fraction [BVF] and trabecular thickness) and mechanical (axial stiffness [AS], a measure of bone strength) properties of the distal tibia at baseline and after 1 and 2 years of treatment.RESULTS:
Treatment with T and GH did not affect BVF, thickness, or AS differently from T alone. T treatment in all subjects for 2 years increased trabecular BVF by 9.6% (P < .0001), trabecular thickness by 2.6% (P < .001), and trabecular AS by 9.8% (P < .001). In contrast, testosterone treatment in all subjects significantly increased cortical thickness by 2.4% (P < .01) but decreased cortical BVF by -4.7% (P < .01) and cortical AS by -6.9% (P < .01).CONCLUSION:
Combined T and GH treatment of men with hypopituitarism for 2 years did not improve the measured structural or mechanical parameters of the distal tibia more than T alone. However, testosterone significantly increased the structural and mechanical properties of trabecular bone but decreased most of these properties of cortical bone, illustrating the potential importance of assessing trabecular and cortical bone separately in future studies of the effect of testosterone on bone.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Testosterone
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Tibia
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Bone and Bones
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Growth Hormone
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Magnetic Resonance Imaging
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Hypopituitarism
Type of study:
Clinical_trials
Limits:
Adult
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Aged
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Humans
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Male
/
Middle aged
Language:
En
Journal:
J Clin Endocrinol Metab
Year:
2014
Document type:
Article