Osteoporosis: evaluation and treatment

Bone loss after oophorectomy among high-risk women: an NRG oncology/gynecologic oncology group study

OBJECTIVE

Women undergoing premenopausal oophorectomy for a variety of reasons, including to reduce ovarian or breast cancer risk were evaluated for accelerated bone loss.

METHODS

The Gynecologic Oncology Group (GOG)-0215 randomized phase-II trial of zoledronic acid was initiated to determine if postoophorectomy bisphosphonate therapy could prevent this bone loss. The study was closed after slow accrual prevented evaluation of the primary study endpoint. We analyzed changes in bone mineral density (BMD) among the 80 women randomized to the observation arm of this study, as measured 3, 9, and 18 months postenrollment.

RESULTS

The mean change in BMD from baseline to 18 months was -0.09 (95% CI, -0.12 to -0.07), -0.05 (95% CI, -0.07 to -0.03), and -0.06 (95% CI, -0.07 to -0.05) g/cm across the lumbar spine, right hip, and left hip, respectively. This represents a BMD decrease of -8.5% for the lumbar spine and -5.7% for both the right and left hips from baseline to 18 months' observation.

CONCLUSIONS

These results demonstrate that premenopausal women undergoing oophorectomy clearly experience bone loss, an adverse effect of oophorectomy, which requires attention and active management. BMD should be monitored postoophorectomy, and treated per standard practice guidelines. Future studies will be required to determine if early treatment can mitigate fracture risk, and to test promising therapeutic interventions and novel prevention strategies, such as increased physical activity or alternative medications, in randomized trials.

Calcium storage in plants and the implications for calcium biofortification

Calcium (Ca) is an essential nutrient for plants and animals, with key structural and signalling roles, and its deficiency in plants can result in poor biotic and abiotic stress tolerance, reduced crop quality and yield. Likewise, low Ca intake in humans has been linked to various diseases (e.g. rickets, osteoporosis, hypertension and colorectal cancer) which can threaten quality of life and have major economic costs. Biofortification of various food crops with Ca has been suggested as a good method to enhance human intake of Ca and is advocated as an economically and environmentally advantageous strategy. Efforts to enhance Ca content of crops via transgenic means have had promising results. Overall Ca content of transgenic plants has been increased but in some cases adverse affects on plant function have been observed. This suggests that a better understanding of how Ca ions (Ca(2+)) are stored and transported through plants is required to maximise the effectiveness of future approaches.

Effectiveness of Alora estradiol matrix transdermal delivery system in improving lumbar bone mineral density in healthy, postmenopausal women

OBJECTIVE

To determine the lowest effective dose of an estradiol (E ) matrix-type transdermal delivery system (EMTDS; Alora) for preventing bone loss in postmenopausal women.

DESIGN

This double-blind, double-dummy, randomized, placebo-controlled, multicenter study enrolled 355 nonosteoporotic postmenopausal women who had been hysterectomized with or without oophorectomy at least 12 months earlier. Participants were randomly assigned to one of three doses of the EMTDS (0.025, 0.05, or 0.075 mg/day) or placebo administered twice weekly. Lumbar bone mineral density (LBMD) was measured by dual-energy x-ray absorptiometry at screening and after 1 and 2 years of treatment. Safety was assessed at regularly scheduled visits.

RESULTS

EMTDS provided statistically significant and clinically meaningful changes in LBMD relative to placebo. At 2 years, LBMD declined from baseline by 0.59% in the placebo group, but it increased from baseline by 1.65% ( = 0.0065), 4.08% ( = 0.0001), and 4.82% ( = 0.0001) in the EMTDS 0.025, 0.05, and 0.075 mg/day groups, respectively. The corresponding responder rates (defined as no change or increase in LBMD at endpoint) were 39.7% for placebo, 59.6%, 79.3%, and 83.9% in the EMTDS 0.025, 0.05, and 0.075 mg/day groups, respectively. Mean serum E concentrations were proportional to the dose of the E transdermal system and did not accumulate over the course of the study. Adverse events were generally comparable across treatment groups, with the majority being mild or moderate in severity and unrelated to study medication. Mammogram findings and other safety assessments were also comparable across groups and did not reveal any safety concerns with 2-y transdermal E treatment.

CONCLUSIONS

The EMTDS (Alora) administered twice weekly improves lumbar bone mineral density in healthy postmenopausal women, with the benefit of treatment evident by 1 year. The lowest effective dose is 0.025 mg/day.