Effects of oral alendronate in elderly patients with osteoporosis and mildprimary hyperparathyroidism

In a large proportion of the patients with primary hyperparatthyroidism (PH PT), a variable degree of osteopenia is the only relevant manifestation of the disease. Low bone mineral density (BMD) in patients with PHPT is an ind ication for surgical intervention because successful parathyroidectomy resu lts in a dramatic increase in BMD. However, low BMD values are almost an in variable finding in elderly women with PHPT, who are often either unwilling or considered unfit for surgery. Bisphosphonates are capable of suppressin g parathyroid hormone (PTH)-mediated bone resorption and are useful for the prevention and treatment of postmenopausal osteoporosis. In this pilot-con trolled study, we investigated the effects of oral treatment with alendrona te on BMD and biochemical markers of calcium and bone metabolism in elderly women presenting osteoporosis and mild PHPT. Twenty-six elderly patients a ged 67-81 years were randomized for treatment with either oral 10 mg alendr onate on alternate-day treatment or no treatment for 2 years. In the contro l untreated patients a slight significant decrease was observed for total b ody and femoral neck BMD, without significant changes in biochemical marker s of calcium and bone metabolism during the 2 years of observation. Urine d eoxypyridinoline (Dpyr) excretion significantly fell within the first month of treatment with alendronate, while serum markers of bone formation alkal ine phosphatase and osteocalcin fell more gradually and the decrease became significant only after 3 months of treatment; thereafter all bone turnover markers remained consistently suppressed during alendronate treatment. Aft er 2 years in this group we observed statistically significant increases in BMD at lumbar spine, total hip, and total body (+8.6 +/- 3.0%, +4.8 +/- 3. 9%, and +1.2 +/- 1.4% changes vs, baseline mean a SD) versus both baseline and control patients. Serum calcium, serum phosphate, and urinary calcium e xcretion significantly decreased during the first 3-6 months but rose back to the baseline values afterward. Increase in serum PTH level was statistic ally significant during the first year of treatment. These preliminary resu lts may make alendronate a candidate as a supportive therapy in patients wi th mild PHPT who are unwilling or are unsuitable for surgery, and for whom osteoporosis is a reason of concern.