Male testosterone and estradiol deficiency and BMD
J Clin Endocrinol Metab. 2006 Jul 18; [Epub ahead of print]. Association of Testosterone and Estradiol Deficiency with Osteoporosis and Rapid Bone Loss in Older Men, Fink HA and others. PMID: 16849417. This study was done to see if there is an association with testosterone and estradiol deficiency and/or rapid bone loss in older men and osteoporosis. If such an association exists, then testosterone and estradiol testing could be a fairly simple and inexpensive method to show which older men need bone density testing to rule out osteoporosis. Testosterone deficiency was defined as <200 ng/dl, total estradiol deficiency as <10pg/ml and osteoporosis as femoral neck or total hip BMD </=2.5. Rapid bone loss was defined as >/=3%/yr. Osteoporosis in men with deficient and normal total testosterone was 12.3% and 6.0%, and in those with deficient and normal total estradiol was 15.4% and 2.8%. Men with osteoporosis had more than double the chance of total testosterone deficiency compared to men with normal BMD. As well the prevalence of total estradiol deficiency was about four times greater in men with osteoporosis compared to those with normal BMD. Similar findings resulted for rapid hip bone loss comparing deficient and normal testosterone and estradiol men. The authors concluded: “Older men with total testosterone or estradiol deficiency were more likely to be osteoporotic.” Additionally they noted, “BMD testing of older men with sex steroid deficiency may be clinically warranted.” Editor's comments: This study points to two more possible fairly inexpensive and fast lab tests that can be used in older men as a screening tool to indicate whether they need bone density testing for osteoporosis: testosterone and/or estradiol levels. These results fit well with the previous update which showed that 25-OHD is a simple lab test that could be useful in elderly people as a screening tool to suggest their risk for a future hip fracture. Although this study didn't explicitly test for osteoporosis, instead using hip fracture as its end point, one can fairly safely assume that osteoporosis could have substituted for hip fracture with similar results. This means that older men or their family members should ask their physicians for one or all three of these tests. Should low levels of testosterone, estradiol and/or 25-OHD be found, the results justify bone density testing to rule out osteoporosis.