Alveolar and postcranial bone density in postmenopausal women receiving hormone/estrogen replacement therapy - A randomized, double-blind, placebo-controlled trial

Background: We conducted a 3-year, double-blind, randomized, placebo-controlled study to determine whether the positive effects of hormone/estrogen replacement therapy (H/ERT) on postcranial bone density are accompanied by similar positive effects on oral bone mass. Methods: A total of 135 postmenopausal women (aged 41-70 years) with no evidence of moderate or severe periodontal disease were randomized to receive daily oral conjugated estrogen (Premarin; 0.625 mg) alone or in combination with medroxyprogesterone acetate (Prempro; 0.625 and 2.5 mg, respectively) or placebo. All subjects received calcium carbonate (1000 mg/d) and cholecalciferol (800 IU/d) supplements. The primary efficacy end points were the changes in alveolar crest height and alveolar bone density. Alveolar crest height was measured on bite-wing radiographs, and changes in alveolar bone mass were assessed by means of digital-subtraction radiography. Postcranial bone density was measured in the lumbar spine and left proximal femur by means of dual-energy x-ray absorptiometry. Results: Hormone/estrogen replacement therapy significantly increased alveolar bone mass compared with placebo (+1.84% vs +0.95% [P=.04]), and tended to improve alveolar crest height (+4.83% vs +3.46% [P=.34]). Bone mineral density of the proximal femur significantly increased in the H/ERT compared with the placebo group (total proximal femur, +3.59% vs +0.22% [P=.00]; neck, +2.05% vs -0.34% [P=.02]; trochanter, +3.49% vs +0.08% [P<.001]), but not the lumbar spine (+1.01% vs +0.17% [P=.39]). Changes in alveolar bone mass correlated with bone density changes in the total femur (r=0.28 [P=.02]) and femoral trochanter (r=0.25 [P=.04]) in the H/ERT but not in the placebo group. Conclusions: Postcranial and oral bone mass were increased in postmenopausal women receiving H/ERT. Improvement in oral bone health constitutes an additional benefit of H/ERT.