Treatment for patients with postmenopausal osteoporosis who have been placed on HRT and show a decrease in bone mineral density: effects of concomitant administration of vitamin K 2

Abstract

We have been using hormone replacement therapy (HRT) as the treatment of choice for menopausal symptoms and osteoporosis. Estrogen increases bone mineral density (BMD) for 2 or 3 years, and only maintains BMD thereafter. In the present study, we investigated whether BMD improved with HRT in combination with vitamin K(2). Ninety-four patients with postmenopausal osteoporosis were studied. All patients were placed on HRT for more than 1 year. Ten patients whose BMD had increased up to a plateau and showed a decreasing trend thereafter while they were receiving HRT were placed on HRT in combination with vitamin K(2). The long-term BMD (L(2)-L(4)) profiles of those receiving HRT alone, and the effects of HRT in combination with vitamin K(2) on the BMD profiles were examined. The rate of change in BMD (mean +/- SE) of all patients who underwent HRT alone was 2.9 +/- 1.2% 1 year after the initiation of HRT, 4.6 +/- 1.2% 2 years later, and 5.4 +/- 1.2% 3 years later. The BMD in these patients, which reached a peak increase after 3 years, no longer increased from the following year. When vitamin K(2) was administered concomitantly to 10 patients for 12 months because of the decrease in BMD, their BMD (mean +/- SE) increased significantly, from 0.734 +/- 0.021 g/cm(2) to 0.783 +/- 0.026 g/cm(2) ( P < 0.03; paired- t test). We conclude that HRT in combination with vitamin K(2) significantly improved BMD that was on the decrease after HRT alone. Therefore, as a supplementary drug for postmenopausal osteoporosis, vitamin K(2) is a good therapeutic option for patients who are placed on HRT.