my personal edition > osteoporosis > news


  E-Mail this DGDispatch to a colleague

DGDispatch

Alendronate Helps Maintain Bone Mass In Patients With Asymptomatic Primary Hyperparathyroidism: Presented at ASBMR

By Mary Beth Nierengarten

MINNEAPOLIS, MN -- September 25, 2003 -- Patients with primary hyperparathyroidism treated with alendronate for 1 year can maintain and even increase their bone mass, reports a collaborative study by researchers from Canada, the United States, and China.

The findings were presented here September 20^th at the 25^th Annual Meeting of the American Society for Bone and Mineral Research.

According to the National Institutes of Health 1990 consensus statement, surgical removal of the enlarged thyroid gland is not indicated for some patients with mild asymptomatic primary hyperparathyroidism. The panel recommended close monitoring for signs of disease progression in such patients.

Use of medical therapies in this setting has generated much interest. Because biphosphonates have been shown to increase bone mass in postmenopausal women with osteoporosis, there is speculation that this same benefit may translate to the treatment of mild asymptomatic hyperparathyroidism due to their specific inhibitory action on bone resorption.

To test this theory, Dr. Aliya A. Khan, Associate Professor of Medicine, McMaster University, Hamilton, Ontario, Canada, and colleagues conducted a 2-year, double-blinded, randomised controlled trial of 44 patients treated with alendronate 10 mg daily or placebo for 1 year. During the second year, the placebo group switched to alendronate.

All patients had confirmed hypercalcaemia and elevated levels of parathyroid hormone, and reduced bone density (T less than 1.0, or 1 or more skeletal sites).

At the 1-year analysis, patients treated with alendronate had a significant increase compared to baseline in lumbar spine bone mineral density (BMD) and total hipbone mineral density (BMD) of 4.92% and 4.01%, respectively (P<0.001 for both). No significant increase from baseline in these measurements was seen in the placebo group (P=0.85).

At 2 years, an increase of 6.85% from baseline in lumbar spine BMD was seen in the alendronate group, with a significant increase of 4.1% from baseline seen in the placebo patients who were switched to alendronate therapy at 1 year (P=0.003). A significant increase in total hip BMD was also found for the placebo patients when switching to alendronate at 1 year (P=0.009).

Along with the clinical effects, alendronate also was associated with a rapid 66% decrease in urinary n-telopeptide excretion at 3 months that remained suppressed for the entire 2-year study period. In addition, bone-specific alkaline phosphatase activity also decreased significantly by 49% at 6 months (P<0.001) and by 54% at 9 and 12 months (P<0.001).

Overall, this study shows that alendronate was effective in maintaining bone mass in patients with asymptomatic primary hyperparathyroidism, and conferred significant increases to BMD of the spine and hip after 1 year, the researchers concluded.


[Study title: A Double Blind Randomized Placebo Controlled Trial of Alendronate in Primary Hyperparathyroidism. Abstract F.421]

E-Mail this DGDispatch to a colleague

To print, use this version