Estrogen replacement may be an alternative to parathyroid surgery for the treatment of osteoporosis in elderly postmenopausal women presenting with primary hyperparathyroidism: A preliminary report

Abstract

Parathyroid surgery is indicated in patients presenting with primary hyperparathyroidism (PHPT) and osteoporosis (defined as bone mineral density more than 2 standard deviations below normal). Many are elderly women with complex medical problems, either unwilling or considered unfit for surgery. Estrogen replacement therapy (ERT) may potentially be an alternative form of therapy in this group. We studied 15 consecutive postmenopausal women presenting with PHPT and osteoporosis. Group 1 comprised 5 women who elected to be treated with ERT (conjugated equine estrogen, 0.3-0.625 mg/day). The other 10 women underwent successful parathyroidectomy. These 10 patients were randomly subdivided into group 2 (5 patients who received calcitriol 0.25 micrograms b.i.d. for 12 months following surgery) and group 3 (5 patients who received elemental calcium 1 g/day for 12 months following surgery). Lumbar spine and femoral neck bone mineral density (BMD) were measured prior to and after 12 months of therapy, using a dual-energy X-ray absorptiometer (Lunar DPX-L). The three groups did not differ with respect to their ages (group mean 71.8 years), or baseline serum calcium (group mean 2.77 mmol/l), serum parathyroid hormone (group mean 11.0 pmol/l), lumbar spine BMD (group mean 0.93 g/cm2) and femoral neck BMD (group mean 0.73 g/cm2). Serum calcium normalized in all patients who underwent surgery and none developed hypoparathyroidism. A non-significant decrease in serum calcium was seen in patients treated with ERT only. Lumbar spine (+5.3% per year; 95% CI, 1.1% to 9.6%) and femoral neck BMD (+5.5% per year; 95% CI, -2.1% to 13.2%) increased significantly after 12 months of ERT (p < 0.001 compared with pre-therapy values). These increases in BMD did not differ significantly from those in patients who underwent successful parathyroidectomy followed by either calcitriol therapy or calcium replacement (lumbar spine BMD increase of +6.2% per year, 95% CI 3.1% to 9.4%; and femoral neck BMD increase of +3% per year, 95% CI 0 to 6%). In summary, increases in lumbar spine and femoral neck BMD occur following treatment of PHPT. ERT appeared as effective as parathyroidectomy (combined with either calcitriol or calcium supplements) for the treatment of osteoporosis in elderly postmenopausal women presenting with PHPT.

Primary Hyperparathyroidism of Postmenopausal Women

“…Moreover there was a significant reduction (p = 0.02) in the urine calcium excretion and a trend to an increased serum PTH level. These actions were consistent with previous notions on HRT (Diamond et al 1996, McDermott et al 1994, McKane et al 1995. Surgery in combination with HRT lowered the blood calcium and PTH levels to a significantly greater degree than HRT alone during the first year.…”

“…HPT patients on oestrogen replacement therapy (ERT) had higher bone density than untreated patients (McDermott et al 1994). ERT has been suggested as an alternative to surgery for the prevention of bone loss at least in the elderly women with mild HPT (Diamond et al 1996).…”

17β-Estradiol Potently Suppresses cAMP-induced Insulin-like Growth Factor-I Gene Activation in Primary Rat Osteoblast Cultures

“…Consistent with other opposing effects of estrogen and agents that induce cAMP, estrogen may suppress PTH-stimulated osteoclast formation by interfering with a downstream event in the PKA-dependent signal pathway in osteoblasts (67). Furthermore, osteoporotic postmenopausal women with primary hyperparathyroidism are as effectively treated by estrogen replacement as they are by parathyroidectomy (68).…”

Review: New perspectives in the management of primary hyperparathyroidism

“…These effects are maintained for up to 4 years [Orr-Walker et al 2000]. Two nonrandomized studies have examined the effects of HRT versus parathyroidectomy in postmenopausal women with PHPT [Diamond et al 1996;Guo et al 1996]. Both interventions produced similar positive effects on axial BMD.…”