Management of osteoporosis in postmenopausal women: 2006 position statement of The North American Menopause Society

Experimental osteoporosis induced by ovariectomy and vitamin D deficiency does not markedly affect fracture healing in rats

BACKGROUND

The question of whether fracture healing and mechanical properties of the callus are influenced by osteoporosis (OP) is still not settled. We therefore studied this issue in vitamin D-depleted ovariectomized (OVX) rats, an OP model previously shown to induce weakening of the femoral neck, and thus thought to be closer to the human condition than the classic OVX rat model.

METHODS

72 female Wistar rats were randomized into two groups: ovariectomy and vitamin D-deficient diet (Ovx-D group) or sham operation and normal rat chow (Sham group). After 12 weeks, a closed tibial midshaft fracture was performed on the right side and fixed with an intramedullary nail. Bone loss and callus formation were monitored with DXA; serum levels of estradiol and vitamin D3 were measured and histomorphometric analyses were performed. Mechanical properties of callus, tibia, femoral shaft, and femoral neck were examined in 3-point cantilever bending 6 weeks after fracture.

RESULTS

The Ovx-D group showed reduced BMD in the spine and femoral neck, and reduced trabecular bone volume in the femoral head. There were no differences in BMD and mechanical properties of callus between the groups. Except for reduced stiffness of the right femoral neck in the Ovx-D group (p = 0.02), no differences in the mechanical strength of long bones were detected.

INTERPRETATION

Our results suggest that the systemic effects of estrogen and vitamin D deficiency are not crucial for fracture healing or mechanical properties of the callus.

Is treatment of early postmenopausal women with bisphosphonates justified?

The decision to treat women in the early postmenopausal period has come under scrutiny because of the low occurrence of fractures in this population and the possible lack of cost-effectiveness for individual patients. This article focuses on the potential use of bisphosphonates for the prevention and treatment of osteoporosis in the early postmenopausal period. Studies have determined that there is a relationship between bisphosphonate treatment and bone mineral density (BMD) gains, even in women in the early postmenopausal period without a diagnosis of osteoporosis. These patients receive benefit from treatment, including improvements in BMD levels and fracture protection. Using BMD scores, rates of bone turnover, and risk-based diagnostic criteria as part of the decision to initiate therapy may allow for the identification of an early postmenopausal patient population that would benefit from preventative therapy. This would improve the cost-effectiveness of using bisphosphonates for the prevention of osteoporosis in this population. The evaluation of women at risk for developing osteoporosis should include an assessment of both BMD scores and additional risk factors. Early postmenopausal women who are in a high-risk group should be considered candidates to receive bisphosphonate therapy.

Options for hormone therapy in women who have had a hysterectomy

OBJECTIVE

To review postmenopausal hormone therapy for women who have undergone hysterectomy with or without bilateral oophorectomy and to make clinical recommendations regarding changes in regimens compared with those for women with their uterus in place.

DESIGN

We conducted a literature review, including a review of current guidelines.

RESULTS

When the uterus is absent, estrogen treatment is all that is needed when hot flashes and/or genital atrophic symptoms are associated with surgical or natural menopause. Reasons to add a progestogen to an estrogen-only therapy regimen after hysterectomy include the need to reduce the risk for unopposed estrogen-dependent conditions, chief among which are endometriosis or endometrial neoplasia. Multiple lines of evidence suggest that regimens containing both estrogen and progestogen versus estrogen alone are associated with a greater relative risk of breast cancer without additional improvement in relief of hot flashes or vaginal symptoms. When a bilateral oophorectomy is performed before natural menopause, the onset of menopausal symptoms, primarily vasomotor symptoms, genital tract atrophy, and/or a decline in sexual function, is rapid, and the symptoms are more severe. Thus, the need for a decision on the use of hormone therapy is accelerated.

CONCLUSIONS

The decision to use or not use menopausal hormone therapy in women without a uterus should involve an individualized risk/benefit analysis just as it should when the uterus is present. After hysterectomy, for most patients, current literature results favor not including a progestogen. Data suggest an attenuation of the potential cardiovascular benefit of estrogen therapy in this situation, yet no better protection against bone fractures and an increase in the risk for breast cancer when both estrogen and progestogen are used.

Plasma organochlorine concentrations and bone ultrasound measurements: a cross-sectional study in peri-and postmenopausal Inuit women from Greenland

BACKGROUND

Inuit women are highly exposed through their traditional seafood based diet to organochlorine compounds, some of them displaying endocrine disrupting properties. We hypothesized that this exposure might be related to bone characteristics that are altered in osteoporosis, because hormone deficiency is a known risk factor for the disease.

METHODS

We measured quantitative ultrasound parameters (QUS) at the right calcaneum of 153 peri- and postmenopausal Inuit women (49-64 year old) from Nuuk, Greenland, and investigated the relation between these parameters and plasma organochlorine concentrations. We used high-resolution gas chromatography with electron capture detection to analyze plasma samples for 14 polychlorinated biphenyls (PCB) congeners and 11 chlorinated pesticides and metabolites. We analysed morning urine samples for cadmium, a potential confounder, by atomic absorption spectrometry. We used a validated questionnaire to document dietary and lifestyle habits as well as reproductive and medical histories.

RESULTS

Concentrations of PCB 153, a surrogate of exposure to most organochlorines present in plasma samples, were inversely correlated to QUS parameters in univariate analyses (p < 0.001). However, PCB 153 concentrations were not associated with QUS values in multivariate analyses that comprised potential confounding factors such as age, body weight, former oral contraceptive use and current hormone replacement therapy (HRT) use, which were all significant predictors of bone stiffness (total R2 = 0.39; p < 0.001).

CONCLUSION

Overall we found little evidence that organochlorines exposure is related to osteoporosis in Greenlandic Inuit women, but the hypothesis that exposure to dioxin-like compounds might be linked to decreased bone quality and osteoporosis deserves further attention.

The role of calcium in peri- and postmenopausal women

OBJECTIVE

To update the evidence-based consensus opinion published by The North American Menopause Society (NAMS) in 2001 on the role of calcium in peri- and postmenopausal women.

DESIGN

NAMS followed the general principles established for evidence-based guidelines to create this document. A panel of clinicians and researchers acknowledged to be experts in the field of calcium and women's health was enlisted to review the previous position statement and data published since then, compile supporting statements, and make recommendations. Their advice was used to assist the NAMS Board of Trustees in publishing this position statement.

RESULTS

Adequate calcium intake (in the presence of adequate vitamin D status) has been shown to reduce bone loss in peri- and postmenopausal women and reduce fractures in postmenopausal women older than age 60 with low calcium intakes. Adequate calcium is considered a key component of any bone-protective therapeutic regimen. Calcium has also been associated with beneficial effects in several nonskeletal disorders, primarily hypertension, colorectal cancer, obesity, and nephrolithiasis, although the extent of those effects has not been fully elucidated. The calcium requirement rises at menopause. The target calcium intake for most postmenopausal women is 1,200 mg/day. Adequate vitamin D status, defined as 30 ng/mL or more of serum 25-hydroxyvitamin D (usually achieved with a daily oral intake of at least 400 to 600 IU), is required to achieve the nutritional benefits of calcium. The best source of calcium is food, and the best food source is dairy products. High-quality calcium supplements (taken in divided doses) are alternative sources for women unable to consume enough dietary calcium. There are no reported cases of calcium intoxication from food sources, and cases associated with supplements are rare (high intake levels of 2,150 mg/day have resulted in a 17% increase in renal calculi in one recent study, but not others). Because no accurate test to determine calcium deficiency exists, clinicians should focus instead on encouraging women to consume enough calcium to meet the recommended levels.

CONCLUSIONS

The most definitive role for calcium in peri- and postmenopausal women is in bone health, but, like most nutrients, calcium has beneficial effects in many body systems. Based on the available evidence, there is strong support for the importance of ensuring adequate calcium intake in all women, particularly those in peri- or postmenopause.

Osteoporosis update: effective prevention and treatment

Osteoporosis is a public health threat to approximately 44 million individuals in the USA, or 55% of men and women over the age of 50 years. The primary goal of osteoporosis management is to prevent fracture, the most devastating consequence. Risk factors and bone mineral density can be assessed to determine appropriate action for prevention and treatment of osteoporosis. Prevention strategies include lifestyle modification, fall prevention, and adequate intake of calcium and vitamin D. Current treatment options include antiresorptive agents and anabolic agents. Adherence and cost issues play major roles in establishing optimal therapy for individual patients. New agents in development are designed to improve osteoporosis treatment and patient adherence. This review focuses on current and future prevention and treatment options for postmenopausal osteoporosis.

Pharmacologic and nonpharmacologic management of osteoporosis

Fractures that occur as a result of osteoporosis are associated with significant morbidity, mortality, and cost. A treatment regimen consisting of both nonpharmacologic and pharmacologic interventions can be used to decrease the risk of fracture. Nonpharmacologic interventions include calcium and vitamin D supplementation, weight-bearing exercise, muscle strengthening, and fall prevention. Pharmacologic options include: the bisphosphonates, estrogen therapy, raloxifene, salmon calcitonin, and the anabolic agent teriparatide. Although bone mineral density is used clinically to diagnose osteoporosis, it is of limited value when evaluating pharmacologic treatment; the primary indicator of treatment efficacy is fracture risk reduction. The bisphosphonates are the preferred therapy for osteoporosis. Studies have demonstrated that in postmenopausal women, both risedronate and alendronate are associated with reductions in vertebral and nonvertebral fracture risk. The newest approved bisphosphonate, ibandronate, reduces vertebral fracture risk. Studies also support a reduction in fracture risk when alendronate and risedronate are used in men with osteoporosis and patients with corticosteroid-induced osteoporosis. When used appropriately, the bisphosphonates are well tolerated. Estrogen and raloxifene decrease fracture risk in postmenopausal women with osteoporosis but are associated with thromboembolic events. Use of estrogen therapy is also limited by concerns about the safety of this type of therapy. Although the anabolic agent teriparatide is associated with reductions in vertebral and nonvertebral fractures, its use has been limited by the necessity of subcutaneous administration and its cost relative to other agents. Regardless of which treatment regimen is selected, health care providers need to emphasize the importance of compliance and adherence to improve persistence with therapy, and subsequent fracture reduction efficacy.