In women, oestrogen deficiency due to the menopause is the major cause of both the early rapid and late slow phases of age-related bone loss. In ageing men, oestrogen deficiency also appears to be the dominant cause and is due to age-related increases in serum SHBG and to impaired gonadal production of sex steroids. The role played by decreases in bioavailable testosterone in bone loss in men is presently unclear. Thus, although other factors contribute, age-related osteoporosis appears to be primarily an endocrine deficiency disease in both genders.

This work was supported by National Institutes of Health grants AR27065 and AG04875. References

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