Objective: Sex steroids play an important role in the maintenance of bone health. However, there is limited information on the association between sex hormones and age-related bone loss in men. Our objective was to study the relationship between sex steroid levels and the changes accompanying aging process, including bone mineral density (BMD), muscle strength and body composition in elderly Egyptian men.
Methods: Free testosterone (FT), estradiol (E2) and sex hormone-binding globulin (SHBG) were measured in thirty elderly men, age range 6073 years, and 15 young men (age range 3036 years). Patients receiving hormonal ablation for prostatic neoplasm and patients with chronic liver, renal disease or receiving corticosteroids were excluded. Sex steroid levels were correlated to BMD measured by DXA, lower limbs muscle strength calculated by isokinetic Biodex dynamometry and body composition assessed by body fat analyzer.
Results: FT and E2 levels were significantly lower in elderly men compared to young group (P<0.01), whereas SHBG significantly increased with age (P<0.01). Peak torque values of both extensors and flexors were significantly lower in elderly men (P<0.01). Low BMD was found in 90% of elderly men; osteopenia (60.5%) and osteoporosis (29.5%). E2 levels were associated positively with BMD at neck of femur in elderly men (P<0.05). FT correlated positively with lean mass and muscle strength (P<0.01), but didnt correlate with BMD. SHBG showed significant negative correlation with lean mass and muscle strength (r=−0.833, P<0.01).
Conclusions: FT is not associated with BMD in elderly men, however, FT has strong relation with muscle strength and lean mass; so older men with lower FT could be more liable to falls. Elderly men with low E2 are more likely to be osteoporotic as E2 is an important determinant of bone density changes in old age.