Ipriflavone prevents the loss of bone mass in pharmacological menopause induced by GnRH-agonists

Soy isoflavone intake inhibits bone resorption and stimulates bone formation in menopausal women: meta-analysis of randomized controlled trials

OBJECTIVE

To clarify the effects of isoflavone intake on bone resorption and bone formation.

METHODS

We identified randomized controlled trials related to urinary deoxypyridinoline (Dpyr, a bone resorption marker) and serum bone-specific alkaline phosphatase (BAP, a bone formation marker) listed on MEDLINE (January 1966-April 2006), the Cochrane Controlled Trials Register, EMBASE (1985-January 2006), Science Citation Index and PUBMED (updated till April 2006).

RESULTS

Nine studies with a total of 432 subjects were selected for meta-analysis. The urinary Dpyr concentration in subjects who consumed isoflavones decreased significantly by -2.08 nmol/mmol (95% confidence interval (CI): -3.82 to -0.34 nmol/mmol) in comparison with that in subjects who did not consume isoflavones. Isoflavone intake vs placebo intake significantly increased serum BAP by 1.48 microg/l (95% CI: 0.22-2.75 mug/l). Decreases in the urinary Dpyr concentration with isoflavone intake of <90 mg/day and with treatment lasting less than 12 weeks were -2.34 nmol/mmol (95% CI: -4.46 to -0.22 nmol/mmol) and -2.03 nmol/mmol (95% CI: -3.20 to -0.85 nmol/mmol), respectively.

CONCLUSIONS

Isoflavone intervention significantly inhibits bone resorption and stimulates bone formation. These favorable effects occur even if <90 mg/day of isoflavones are consumed or the intervention lasts less than 12 weeks.

Therapy Insight: osteoporosis and osteonecrosis in systemic lupus erythematosus

Survival of patients with systemic lupus erythematosus (SLE) has improved over the past decade, thanks to improved treatment of the disease, which now results in fewer fatal complications. This improvement has allowed physicians to focus their attention on the prevention of organ damage caused by this chronic, inflammatory disease, and by the medications used to control the disease. Osteoporosis is common in SLE patients; risk factors for osteoporosis include prolonged use of glucocorticoids, cyclophosphamide and possibly gonadotropin-releasing-hormone agonists. In premenopausal women with SLE, inflammation or SLE-related medications can increase bone turnover, which eventually weakens bone architecture, then reduces bone strength and increases the risk of fracture. Prevention and treatment of osteoporosis in SLE patients should entail a multifaceted approach. Levels of calcium, vitamin D and homocysteine should be evaluated, and age-appropriate supplementation instituted. The bone loss that results from systemic inflammation should be treated by reduction of the inflammation with glucocorticoids, potent anti-inflammatory agents or antiresorptive agents. The efficacy of this therapy can be monitored using bone mineral density scans. This Review briefly discusses the pathophysiology of the localized and generalized osteoporosis and osteonecrosis in SLE patients and recommends therapies to both prevent and treat these unfortunate complications of this disease.

Postmenopausal femur bone loss: effects of a low dose hormone replacement therapy

OBJECTIVES

Previous studies indicate that low-dose hormone replacement therapy (LD-HRT) can relieve vasomotor symptoms and prevent spine bone loss.

METHODS

In the present study, we evaluated the effects of a low dose of conjugated equine estrogens (CEE; 0.3 mg) associated with different progestins in continuous combined scheme [2.5 mg of medroxyprogesterone acetate (n=25), 5 mg dydrogesterone (n=27), 2.5 mg nomegestrol (n=11)] as single group, on femur bone mineral density (BMD) and bone metabolism in young postmenopausal women (<or=56 years). All women were supplemented with 1 g of calcium per day, and compared with women treated with 1 g of calcium per day alone (control group, n=15). There were no significant differences in age, body mass index (BMI), hormone values, bone metabolism markers and femur BMD in the treatment and control groups before the study.

RESULTS

In calcium-treated women serum plasma osteocalcin (BGP) and hydroxyproline/creatinine urinary excretion (OHP/Cr) remained stable during all the observation period. In this group, femoral neck, Ward's triangle and trochanter BMD showed a progressive and significant (P<0.05) decrease. In the LD-HRT group, a significant (P<0.05) decrease in serum BGP and OHP/Cr was observed. In these women, the values of these markers of bone turnover at 36 months were significantly (P<0.01) different from those of calcium-treated women. During the LD-HRT administration, all BMD measures did not show any significant modifications. In these women, treated with LD-HRT the BMD values were significantly (P<0.05) different from those measured in calcium-treated women in all the femur sites of measurements. In the control group, BMI significantly (P<0.05) increased from baseline value with a weight gain of 3%, while in the LD-HRT group, BMI did not change after 36 months of treatment and the 1.3% gain in body weight was not significant. LD-HRT was effective in reducing menopausal clinical symptoms and provided a favorable bleeding profile, and minimal side effects.

CONCLUSION

LD-HRT was effective in reducing menopausal clinical symptoms and minimal and transient side effects were reported. In addition, the 0.30 mg/day of CEE, in addition to a proper calcium supplementation, irrespective of the progestin used, can provide effective protection against activation of bone turnover and femur osteopenia.

Phytoestrogens--mechanism of action and effect on bone markers and bone mineral density

Dietary supplements, especially those containing phytoestrogens, frequently are used to either promote health or prevent disease. An estimated 20 billion dollars was spent on dietary supplements in the year 2000. Approximately 40% to 55% of Americans use supplements on a regular basis and 24% of these supplements contain herbs. Phytoestrogens are defined as any compound that is structurally or functionally related to ovarian or placental estrogens and their active metabolites. These compounds are widely used for various disorders related to women's health.

Complementary therapies for reducing the risk of osteoporosis in patients receiving luteinizing hormone-releasing hormone treatment/orchiectomy for prostate cancer: a review and assessment of the need for more research

Osteoporosis in women has received a substantial amount of attention, but its impact in men is also significant and noteworthy. Those men who benefit from treatment for prostate cancer with androgen deprivation therapy (ADT) may also be at a higher risk for osteoporosis. Pharmacologic approaches to reduce this risk have received some attention. For example, agents such as bisphosphonates, estrogen receptor-binding drugs (diethylstilbestrol, tamoxifen, and raloxifene), calcitonin, and fluoride are some of the more promising interventions that have been previously outlined. In addition, statin drugs, or hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, have recently been hypothesized to lower osteoporosis risk. However, complementary therapies, which may also have an impact on reducing osteoporosis risk, have not received attention. Dietary and supplemental calcium and vitamin D have been shown, in some preliminary investigations, to maintain bone density in women and men. Numerous healthy and affordable dietary sources of this mineral and vitamin exist, and large intakes can be realistically achieved through proper education. Similarly, the supplemental dosages required to impact risk have been moderate, appear to be safe, are of low cost, and thus may provide an additional route for reducing risk, especially if these interventions are initiated at the start of medical treatment. More studies in men receiving ADT are needed because the existing work has mostly focused on men without castrate levels of male hormone. Additionally, many studies with conventional and nonconventional agents have only focused on individuals with baseline osteoporosis, rather than normal bone mineral densities or osteopenia. Other promising complementary therapies, such as weight-bearing exercise and abstaining from smoking, may also be of benefit. Newer estrogenic-type supplements (eg, ipriflavone) appear interesting and have some preliminary data, but more research is desperately required to determine their actual impact and potential for adverse effects (such as lymphocytopenia from a recent trial). Simple, inexpensive, and potentially effective dietary and supplemental approaches to reduce the risk of osteoporosis in men exist, and they should be discussed with patients. Whether these approaches effectively reduce the risk of osteoporosis in men receiving androgen ablation remains to be determined. The possibility is intriguing, and future research is needed. In the meantime, it is important to keep in mind that these complementary approaches are, at the very least, an integral part of the conventional options used today to the reduce the risk of osteoporosis in men and women.

The effect of an ipriflavone-containing supplement on urinary N-linked telopeptide levels in postmenopausal women

Osteoporosis is a significant health concern to our aging population. We report here the results of a pilot placebo-controlled trial of a dietary supplement containing ipriflavone, calcium, and vitamin D on a urinary marker of bone breakdown in postmenopausal women. Seven postmenopausal women not currently receiving hormone replacement therapy received either an ipriflavone-containing supplement or placebo for 3 months. Urinary N-linked telopeptides, a marker of bone breakdown, declined by 29% in those receiving the supplement, whereas an increase in this marker was observed in the group receiving the placebo. No changes were observed in salivary hormone measurements. Although our sample size was small, to the best of our knowledge, this is the first report that demonstrates changes in N-linked telopeptide levels as a result of consuming an ipriflavone-containing product. Our findings confirm those of other researchers that demonstrate the usefulness of ipriflavone at slowing the progression of bone loss and suggest that measuring N-linked telopeptides may be a useful tool to assess therapeutic efficacy.

Phytoestrogens as hormone replacement therapy: an evidence-based approach

Postmenopausal women have sought nonestrogen alternatives to hormone replacement in order to avoid possible risks and side effects of the therapy. Selective estrogen receptor modulators have been developed to tailor therapy to a specific risk/benefit profile that will best fit the patient. More women have looked to phytoestrogens, such as the isoflavones found in the soy plant, to tailor their menopausal therapy in a "natural" way. This review examines the evidence regarding the risks and benefits of isoflavones as hormone replacement therapy. Controlled trials have shown a reduction in postmenopausal hot flashes when subjects' diets were supplemented with soy. There is less evidence for a benefit in vaginal dryness symptoms. Furthermore, dietary supplementation also appears to lower total and low-density lipoprotein cholesterol in hypercholesterolemic subjects. A synthetic isoflavone, ipriflavone, has been shown in controlled trials to prevent postmenopausal bone loss, though there is much less evidence that soy isoflavones will accomplish this goal. Finally, although unopposed estrogen replacement may promote breast and endometrial cancer, there is no evidence that phytoestrogens will do the same. In contrast, great interest has been taken in the potential cancer-protective effects of phytoestrogens, though prospective evidence in postmenopausal women is not available. Although data regarding the use of isoflavone extracts are incomplete, dietary supplementation with soy foods appears to be a safe and possibly beneficial option for postmenopausal women.