Effects of atorvastatin on bone in postmenopausal women with dyslipidemia: a double-blind, placebo-controlled, dose-ranging trial

CONTEXT

In preclinical models, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase have been shown to positively affect bone remodeling balance. Observational studies and secondary analyses from lipid-lowering trials have yielded inconsistent results regarding the effect of these agents on bone mineral density and fracture risk.

OBJECTIVE

Our objective was to determine whether clinically significant skeletal benefits result from hydroxymethylglutaryl-coenzyme A reductase inhibition in postmenopausal women.

DESIGN AND SETTING

We conducted a prospective, randomized, double-blind, placebo-controlled, dose-ranging comparative clinical trial at 62 sites in the United States.

PARTICIPANTS

Participants included 626 postmenopausal women with low-density lipoprotein cholesterol levels of at least 130 mg/dl (3.4 mmol/liter) and less than 190 mg/dl (4.9 mmol/liter), and lumbar (L1-L4) spine bone mineral density T-score between 0.0 and -2.5.

INTERVENTION

Once-daily placebo or 10, 20, 40, or 80 mg atorvastatin was administered.

MAIN OUTCOME MEASURES

We assessed percent change from baseline in lumbar (L1-L4) spine bone mineral density with each dose of atorvastatin compared with placebo.

RESULTS

At 52 wk, there was no significant difference between each atorvastatin and placebo group or change from baseline at any tested dose of atorvastatin or placebo in lumbar (L1-L4) spine bone mineral density. Nor did atorvastatin produce a significant change in bone mineral density at any other site. Changes in biochemical markers of bone turnover did not differ significantly between each atorvastatin and placebo group. All doses of atorvastatin were generally well tolerated, with similar incidences of adverse events across all dose groups and placebo.

CONCLUSIONS

Clinically relevant doses of atorvastatin that lower lipid levels had no effect on bone mineral density or biochemical indices of bone metabolism in this study, suggesting that such oral agents are not useful in the prevention or treatment of osteoporosis.

A cross-sectional study of bone turnover markers in healthy premenopausal women

BACKGROUND

Biochemical markers of bone turnover (BTMs) provide useful information in the diagnosis and management of metabolic bone diseases. Currently, there exist few published reference ranges for bone markers in healthy premenopausal women using the newer, automated assays of bone turnover. This cross-sectional study of healthy premenopausal women was performed to determine reference ranges for four different markers of bone turnover and to compare reference ranges in users and non-users of oral contraceptives (OCs).

METHODS

Urinary N-telopeptide of type 1 collagen (NTX) was determined from fasting second morning-void urine of healthy premenopausal women. In addition, fasting serum was collected for determination of C-telopeptide of type I collagen (CTX), bone-specific alkaline phosphatase (bone ALP), and N-terminal propeptide of type 1 procollagen (PINP). Subjects underwent central dual energy X-ray absorptiometry and completed a questionnaire regarding medical history and activities known to affect bone health.

RESULTS

Serum and urine samples were collected from 237 healthy premenopausal women (119 OC users and 118 non-users) between the ages of 28 and 45 years. The mean age of subjects was 37 years, with a mean bone mineral density T-score of -0.1 at the lumbar spine and 0.0 at the total hip. Logarithmic transformation produced normal distributions for all markers but NTX. Mid-95% ranges for each marker were generally consistent with those reported by manufacturers. For each BTM examined, values were skewed toward the lower end of the range. Median NTX levels for OC users and non-users were 16.0 and 29.0 nmol/mmol creatinine, respectively. The mid-95% ranges for NTX in OC users and non-users were 3-60 and 4-64 nmol/mmol creatinine, respectively. Median levels of CTX, bone ALP, and PINP were also lower in OC users than non-users. The mean level of each BTM was significantly lower in OC users than non-users (P<0.01), whereas reference ranges (geometric mean+/-2 SD) were somewhat similar for the two groups.

CONCLUSION

Values obtained from this well-characterized population provide reference ranges for BTMs in healthy premenopausal women. Median and mean BTM levels for OC users were consistently lower compared with non-users; thus, separate reference ranges are required for these two groups of premenopausal women. The relevance of premenopausal reference ranges for postmenopausal women remains uncertain.

Effect of recombinant human parathyroid hormone (1-84) on vertebral fracture and bone mineral density in postmenopausal women with osteoporosis: a randomized trial

BACKGROUND

Recombinant human parathyroid hormone (1-84) (PTH) increases bone mass and strength and improves bone quality by stimulating new bone formation.

OBJECTIVE

To determine the safety of PTH and its effect on the incidence of vertebral fractures in postmenopausal women with osteoporosis.

DESIGN

18-month, randomized, double-blind, placebo-controlled, parallel-group study.

SETTING

168 centers in 9 countries.

PATIENTS

2532 postmenopausal women with low bone mineral density at the hip or lumbar spine.

INTERVENTIONS

Women received 100 mug of recombinant human PTH or placebo daily by subcutaneous injection. All received calcium, 700 mg/d, and vitamin D3, 400 U/d.

MEASUREMENTS

New or worsened vertebral fractures (primary outcome) and changes in bone mineral density and safety (secondary outcomes).

RESULTS

67.2% of patients who received at least 1 dose of the study drug completed the study. Parathyroid hormone reduced the risk for new or worsened vertebral fractures, but in sensitivity analyses, the magnitude of the reduction was changed with assumptions about fracture incidence in patients who did not complete the study (relative risk assuming no fractures, 0.42 [95% CI, 0.24 to 0.72] [P = 0.001]; relative risk assuming fracture incidence observed in all patients who completed the trial, 0.60 [CI, 0.36 to 1.00] [P = 0.05]; relative risk assuming fracture incidence observed in the placebo group, 0.62 [CI, 0.37 to 1.04] [P = 0.07]). Compared with placebo, mean bone mineral density increased at the spine by 6.9% (CI, 6.4% to 7.4%) and at the hip by 2.1% (CI, 1.7% to 2.5%) but decreased at the forearm in the PTH-treated group. Parathyroid hormone treatment increased the percentage of participants with hypercalciuria, hypercalcemia, and nausea by 24% (CI, 20% to 27%), 23% (CI, 21% to 26%), and 14% (CI, 11% to 16%), respectively, compared with placebo.

LIMITATIONS

Baseline serum PTH and vitamin D levels were not measured. Many patients discontinued the trial prematurely.

CONCLUSIONS

Parathyroid hormone (1-84) reduced the overall risk for new or worsened vertebral fracture in postmenopausal women with osteoporosis. Hypercalciuria, hypercalcemia, and nausea were more common in women who took the drug. Although the magnitude of the reduction was sensitive to assumptions about fracture incidence in patients who did not complete the study, the findings suggest that PTH provides an alternative therapeutic option for fracture prevention.

Disassociation of bone resorption and formation by GLP-2: a 14-day study in healthy postmenopausal women

We have previously shown that a single subcutaneous injection of glucagon-like peptide-2 (GLP-2) at 10 p.m. in postmenopausal women results in a dose-dependent decrease in the nocturnal serum and urine concentrations of fragments derived from the degradation of the C-terminal telopeptide region of collagen type I (s-CTX and u-CTX) and u-DPD, markers of bone resorption. In contrast, bone formation, as assessed by serum osteocalcin and procollagen type I N-terminal propeptide (PINP), appeared to be unaffected by treatment with exogenous GLP-2. These effects were further investigated in a 14-day study. The aim was to demonstrate that a parenteral formulation of GLP-2 is safe and well tolerated after repeated dosing in healthy postmenopausal women for 14 days. It was further investigated whether the effects on bone turnover markers were sustained throughout the study period. The study was a double-blind placebo-controlled trial with 60 postmenopausal women and 2 different doses of GLP-2 (1.6 mg and 3.2 mg GLP-2) against a saline control. The data for bone resorption revealed a similar reduction on Day 1 and Day 14, both based on time course and AUC. There were no signs of tachyphylaxis and no serious adverse reaction. Both GLP-2 doses resulted in similar and significant (p<0.001) reduction in bone resorption indicating that the maximum efficacious dose has been approached. Osteocalcin and PINP levels were unaffected at Day 1 and Day 14, suggesting a disassociation between bone resorption and bone formation during GLP-2 treatment.

Nonmalignant complications of Paget's disease

Paget's disease of bone is a focal or multifocal disorder characterized by intense disorderly remodeling activity at sites of involvement, producing dramatic alterations of local bone architecture. These functional and structural alterations, interacting with the specific characteristics of the site of involvement, account for most of the complications of the disease. This presentation will focus on selected nonneoplastic complications of particular current interest.

Endogenous carbon monoxide production correlates weakly with severity of acute illness

BACKGROUND AND OBJECTIVE

The enzyme haeme oxygenase-1 is highly inducible by oxidative agents. Its product carbon monoxide is thought to exert anti-inflammatory properties. We recently showed, that critically ill patients produce higher amounts of carbon monoxide compared to healthy controls. In the present study we compare endogenous carbon monoxide production with the severity of illness of intensive care unit patients.

METHODS

Exhaled carbon monoxide concentration was measured in 95 mechanically ventilated, critically ill patients (mean age +/- SD, 59.5 +/- 15.7) on a carbon monoxide monitor. Measurements were taken every hour for 24 h in each patient. Data were analysed using Mann-Whitney rank sum test. Correlation analysis was performed with the Spearman's rank order correlation.

RESULTS

Carbon monoxide production correlated weakly with the multiple organ dysfunction score (R = 0.27; P = 0.009). Patients suffering from cardiac disease (median 22.5, interquartile range 16.2-27.4 microL kg(-1) h(-1) vs. median 18.2, interquartile range 14.2-21.8 microL kg(-1) h(-1), P = 0.008) and critically ill patients undergoing dialysis (median 25.0, interquartile range 21.4-30.2 microL kg(-1) h(-1), vs. median 19.4, interquartile range 14.7-23.3 microL kg(-1) h(-1), P = 0.004) produced significantly higher amounts of carbon monoxide compared to critically ill controls.

CONCLUSION

The findings suggest that endogenous carbon monoxide production might reflect the severity of acute organ dysfunction.

New approach to an ovine model of hypodynamic endotoxaemia

BACKGROUND AND OBJECTIVE

Since the moribund hypodynamic phase of septic shock has primarily been studied in small animal models, the objective of this study was to investigate the usefulness of infusing Salmonella typhosa endotoxin at incrementing doses to establish an ovine model of hypodynamic endotoxaemia.

METHODS

In a prospective laboratory experiment, eight adult ewes were instrumented for a chronic study. Following a baseline measurement in the healthy state, a continuous endotoxin infusion was started with 10 ng kg(-1) min(-1) and was doubled every hour seven times. Haemodynamics, key variables of oxygen transport, and arterial lactate concentrations were determined every hour.

RESULTS

In a dose-dependent manner, endotoxin infusion caused pulmonary hypertension, decreased cardiac output and mean arterial pressure, increased heart rate, and to a certain extent, systemic vascular resistance index. Following 4h of endotoxaemia, the maximum decrease in cardiac output occurred (4.8+/-0.2 vs. 7.6+/-0.3 Lmin(-1); P < 0.001). This was accompanied by tissue dysoxia, represented by decreases in oxygen delivery (797+/-20 vs. 1041+/-28 mLmin(-1)), oxygen consumption (277+/-14 vs. 396+/-15 mLmin(-1)) and oxygen extraction rate (0.35+/-0.01 vs. 0.38+/-0.01%; each P < 0.01), as well as an increase in arterial lactate concentration (1.7+/-0.1 vs. 0.7+/-0.1 mmolL(-1); P < 0.05).

CONCLUSIONS

This large animal model may be helpful to study the pathophysiology responsible for cardiovascular failure, and also new therapeutic approaches relevant to management of hypodynamic circulation in the common setting of progressed systemic inflammation.

Ten years' experience with alendronate for osteoporosis in postmenopausal women

BACKGROUND

Antiresorptive agents are widely used to treat osteoporosis. We report the results of a multinational randomized, double-blind study, in which postmenopausal women with osteoporosis were treated with alendronate for up to 10 years.

METHODS

The initial three-year phase of the study compared three daily doses of alendronate with placebo. Women in the original placebo group received alendronate in years 4 and 5 and then were discharged. Women in the original active-treatment groups continued to receive alendronate during the initial extension (years 4 and 5). In two further extensions (years 6 and 7, and 8 through 10), women who had received 5 mg or 10 mg of alendronate daily continued on the same treatment. Women in the discontinuation group received 20 mg of alendronate daily for two years and 5 mg daily in years 3, 4, and 5, followed by five years of placebo. Randomized group assignments and blinding were maintained throughout the 10 years. We report results for the 247 women who participated in all four phases of the study.

RESULTS

Treatment with 10 mg of alendronate daily for 10 years produced mean increases in bone mineral density of 13.7 percent at the lumbar spine (95 percent confidence interval, 12.0 to 15.5 percent), 10.3 percent at the trochanter (95 percent confidence interval, 8.1 to 12.4 percent), 5.4 percent at the femoral neck (95 percent confidence interval, 3.5 to 7.4 percent), and 6.7 percent at the total proximal femur (95 percent confidence interval, 4.4 to 9.1 percent) as compared with base-line values; smaller gains occurred in the group given 5 mg daily. The discontinuation of alendronate resulted in a gradual loss of effect, as measured by bone density and biochemical markers of bone remodeling. Safety data, including fractures and stature, did not suggest that prolonged treatment resulted in any loss of benefit.

CONCLUSIONS

The therapeutic effects of alendronate were sustained, and the drug was well tolerated over a 10-year period. The discontinuation of alendronate resulted in the gradual loss of its effects.

Intravenous bisphosphonate therapy for osteoporosis: where do we stand?

The use of oral bisphosphonates, particularly members of the aminobisphosphonate subclass, is well established for the treatment of osteoporosis. In a number of clinical settings, intravenous administration appears to be advantageous. However, current dosing and efficacy data are limited while definitive, long-term trials with some of these agents are ongoing. In this article, we review the available information and discuss the use of these drugs on that basis.

Combining Bisphosphonates with Hormone Therapy for Postmenopausal Osteoporosis

Osteoporosis affects many women after menopause. It is a major health problem, as fragility fractures create significant morbidity in this population, especially with advancing age. Available therapies include estrogens, selective estrogen receptor modulators, bisphosphonates, and calcitonin. They all inhibit bone resorption, although through different mechanisms. Several combinations of these agents have been studied in order to determine their effectiveness in comparison with monotherapy. We reviewed eight prospective randomized clinical trials of hormone therapies combined with bisphosphonates (etidronate, alendronate, and risedronate) and one study of a selective estrogen receptor modulator (raloxifene) in combination with a bisphosphonate (alendronate). Bone mineral density change at the lumbar spine was the primary endpoint of all the studies, with one or more measurements of the bone density at the femur as secondary endpoints. None of the studies had the statistical power to determine the relative reduction in fracture risk. All the studies reported greater increases in bone mineral density in patients treated with combination therapies as opposed to single agents. The bone turnover markers were also suppressed to a greater degree in the combination treatment groups, remaining however within normal premenopausal ranges. Four studies reported bone histomorphometry data, indicating no impairment of bone quality by combination therapies. The combination treatments were well tolerated in all the trials and the discontinuation rates did not vary among the groups. However, most patients will not require combination therapy. Combining bisphosphonates with hormone therapy may offer an additional benefit to women who either continue to lose bone mass despite taking estrogen or who need estrogen to control postmenopausal symptoms. The benefit of adding raloxifene to a bisphosphonate is smaller. However, it may be clinically useful if raloxifene reduces the risk of breast cancer.

Reduction of nocturnal rise in bone resorption by subcutaneous GLP-2

We have previously shown that a subcutaneous injection of glucagon-like peptide-2 (GLP-2) at 9 a.m. in fasting postmenopausal women results in a dose-dependent decrease in the serum concentration of fragments derived from the degradation of the C-terminal telopeptide region of collagen type I (s-CTX), a marker of bone resorption. In contrast, GLP-2 was found to have a neutral effect on bone formation, as assessed by serum osteocalcin. Since increased s-CTX levels are normally observed at night, we conducted bedtime studies in healthy postmenopausal women. The objective was to study the effect of GLP-2 injection on bone turnover given at bedtime. A total of 81 postmenopausal women were included in two randomised placebo-controlled studies. In conclusion, we found a dose-related reduction of s-CTX after injection of GLP-2 (P < 0.05) and osteocalcin levels was increased as compared to placebo (P = 0.07) by the treatment, suggestive of a stimulative effect on bone formation. An area under the curve (AUC0-10 h) analysis for s-CTX after GLP-2 injection confirmed the dose-related decrease as compared to placebo (P < 0.05).

Pins and plaster aren't enough: a call for the evaluation and treatment of patients with osteoporotic fractures

A history of an osteoporotic fracture is a powerful predictor of future fractures. Older patients who sustain low trauma fractures are candidates for interventions that should include confirmation of the diagnosis of osteoporosis, adequate calcium and vitamin D administration, and use of an osteoporosis therapy that is proven to lower fracture risk. Recently, however, several reports in the literature have indicated that, in general, those physicians who diagnose and treat fractures, i.e. radiologists, orthopedic surgeons, physiatrists, and those who provide general medical care to these fracture patients, the primary care physicians, are not evaluating patients with acute fractures for the presence of osteoporosis and are not prescribing calcium, vitamin D, or specific pharmacological therapy to reduce future fracture risk. These reports suggest that implementation of a standard of care for the subsequent medical management of the older patient with an acute fracture is needed urgently. Diagnostic tools and several effective therapies exist, but these are underused by the physicians who interface with these patients. A call to action is necessary to reduce the human and economic costs associated with this serious and treatable disease.

Study design in osteoporosis: a European perspective

The advent of effective agents for the treatment of osteoporosis has led to the view that placebo-controlled trials to test new agents for efficacy are no longer appropriate. Rather, studies of superiority, equivalence, or non-inferiority have been recommended. Such studies require very large sample sizes, and the burden of osteoporotic fracture in a trial setting is substantially increased. Studies of equivalence cannot be unambiguously interpreted because the variance in effect of active comparator agents is too large in osteoporosis. If fracture studies are required by regulatory agencies, there is still a requirement for placebo-controlled studies, although perhaps of shorter duration than demanded at present.

Therapeutic equivalence of alendronate 35 milligrams once weekly and 5 milligrams daily in the prevention of postmenopausal osteoporosis

OBJECTIVE

To evaluate the efficacy and safety of alendronate 35 mg once weekly compared with alendronate 5 mg daily in the prevention of osteoporosis.

METHODS

We compared the efficacy and safety of treatment with alendronate 35 mg once weekly (n = 362) and alendronate 5 mg daily (n = 361) in a 1-year, double-blind, multicenter study of postmenopausal women (6 months or greater), aged 40-70 years, with lumbar spine and femoral neck bone mineral density T-scores between -2.5 and 1. The primary efficacy end point was the comparability of lumbar spine bone mineral density increases, defined by strict prespecified criteria.

RESULTS

Mean increases in lumbar spine bone mineral density at 12 months were equivalent (difference between the alendronate 35-mg once-weekly group and the alendronate 5-mg daily group [90% confidence interval] at month 12 was -0.3% [-0.6, 0.1], well within the prespecified bounds of +/-1.0%). Bone mineral density increases at other skeletal sites and effects on bone turnover were also virtually identical for the two dosing regimens. Both treatment regimens were well tolerated, and the larger weekly unit dose was not associated with an increased frequency of upper gastrointestinal events.

CONCLUSION

Alendronate 35 mg once weekly is therapeutically equivalent to alendronate 5 mg daily and provides patients with greater dosing convenience, in addition to the proven efficacy of alendronate and good tolerability.

Identification of a novel tandem duplication in exon 1 of the TNFRSF11A gene in two unrelated patients with familial expansile osteolysis

Familial expansile osteolysis (FEO) is a rare autosomal dominant disorder characterized by striking focal expansile osteolytic bone lesions and generalized osteopenia, often accompanied by characteristic early hearing loss and dental disease. The TNFRSF11A gene encodes the receptor activator of nuclear factor-kappaB (RANK), which has been demonstrated to be essential in bone remodeling and osteoclast differentiation. Identical insertional mutations in the first exon of RANK have been identified in all published FEO kindreds. The mutation is an 18 base pair tandem duplication in the sequence coding for the signal peptide of RANK, which causes an increase in NF-kappaB signaling. We report the identification and mutational analysis of two unrelated FEO patients. One had no family history of FEO, but presented with bilateral hearing loss at an early age, deterioration of teeth, and severe pain and swelling in the distal tibia before the age of 20. The second patient had a family history of FEO and exhibited an extensive expansile tibial lesion and lesions in one humerus and a phalanx. She also had early hearing loss and dental disease. Mutational analysis of the TNFRSF11A gene in our patients demonstrated an 18 base pair tandem duplication, one base proximal to the duplications previously reported. This novel mutation results in addition of the same six amino acids to the RANK signal peptide that has been observed previously. Further analysis of the exon 1 sequence demonstrated that it has the ability to form a stable secondary structure that may facilitate the generation of tandem duplications.

Randomized trial of parathyroidectomy in mild, asymptomatic primary hyperparathyroidism as measured by the SF-36 health survey

Background

Management of patients with asymptomatic primary hyperparathyroidism (HPT) remains controversial despite a National Institutes of Health consensus statement on this issue. As part of the above statement, a randomized clinical trial was recommended since none exist to address this issue.

Methods

Informed consent was obtained from 53 asymptomatic patients with confirmed primary HPT who agreed to participate in this randomized clinical trial of parathyroidectomy versus observation. Upon entry to the study and 24 months later the patients completed the SF-36 health survey which is an instrument that measures nine different levels of function. Scores were tabulated and the difference over 24 months between operated and non-operated patients was compared with Student's t test.

Results

Fifty-three patients (42 women and 11 men) with asymptomatic, mild primary HPT (serum calcium 10·1–11·5 mg dl−1) who agreed to participate were randomized into either a surgical group or an observation group. Mean serum calcium for these patients was 10·3 mg dl−1. The only demographic difference between the groups was age; the operated group was older (66·7 versus 62·6 years; P &lt; 0·03). Scores on three of the nine domains (health perception, emotional problems and social functioning) on the SF-36 were significantly different (P &lt; 0·05), all favouring the operated group.

Conclusion

Improved function, as measured by the SF-36 health assessment tool, is seen after parathyroidectomy compared with non-operated patients. This work supports surgical management of mild primary HPT at the time of diagnosis since many patients have reversible non-classical symptoms of the disease.

Significant differential effects of alendronate, estrogen, or combination therapy on the rate of bone loss after discontinuation of treatment of postmenopausal osteoporosis. A randomized, double-blind, placebo-controlled trial

BACKGROUND

Combination therapy with alendronate and estrogen for 2 years increases bone mineral density at the spine and hip more than does therapy with either agent alone. Changes in bone mineral density after discontinuation of therapy have not been compared directly.

OBJECTIVE

To determine the rate of bone loss when therapy with alendronate, estrogen, or both agents is discontinued.

DESIGN

Double-blind, placebo-controlled discontinuation trial.

SETTING

18 U.S. centers.

PATIENTS

244 postmenopausal, hysterectomized women 44 to 77 years of age.

INTERVENTION

2 years of therapy with alendronate, 10 mg/d (n = 92); conjugated estrogen, 0.625 mg/d (n = 143); alendronate and conjugated estrogen (n = 140); or placebo (n = 50). At year 3, women were allocated into five groups: Twenty-eight women continued to take placebo and 44 women continued to take combination therapy, but 50 women taking alendronate, 81 taking conjugated estrogen, and 41 taking combination therapy were switched to placebo.

MEASUREMENTS

Bone mineral density and biochemical markers of bone turnover.

RESULTS

Women taking alendronate or combination therapy who were switched to placebo for year 3 of the study maintained bone mass. Bone mineral density in these women was 4.1% (CI, 2.6% to 5.7%) and 6.6% (CI, 5.0% to 8.2%) higher, respectively, at the spine (P < 0.001 for both treatment comparisons) and 3.5% (CI, 2.3% to 4.6%) and 3.0% (CI, 1.8% to 4.2%) higher, respectively, at the trochanter (P < 0.001 for both treatment comparisons) than that in women previously taking estrogen who were switched to placebo. In contrast, women who were taking estrogen and were switched to placebo during year 3 experienced a 4.5% decrease at the spine (95% CI, -5.0% to -4.0%) and a 2.4% decrease at the trochanter (CI, -2.7% to -2.1%) (P < 0.001 for both changes). Compared with women who took placebo for 3 years, women who took estrogen for 2 years and were then switched to placebo had a bone mineral density that was 2.9% higher (CI, 1.2% to 4.6%) at the spine (P < 0.05) and 2.9% higher (CI, 1.6% to 4.2%) at the trochanter (P < 0.001). Changes in biochemical markers during year 3 did not differ among the groups that discontinued active treatment.

CONCLUSIONS

Accelerated bone loss is seen after withdrawal of estrogen therapy but not after withdrawal of alendronate or combination therapy. The differential effects after withdrawal of therapy should be considered in the management of postmenopausal osteoporosis.

Hydroxyethyl starch does not cross the blood-brain or the placental barrier but the perineurium of peripheral nerves in infused animals

Therapy with hydroxyethyl starch (HES) is associated with a high incidence of persistent pruritus due to HES storage in cutaneous nerves. Up to now it has been unknown if HES also accumulates in the extracutaneous peripheral or central nervous system. To study this, five rats including one pregnant one were infused with a single dose (34-150 mg) of HES (70/200/450 kDa molecular weight) conjugated with fluorescein isothiocyanate (FITC). In addition, four sheep were infused with a cumulative dosage of 30 g, 120 g, and 420 g HES (200 kDa), respectively. After 7-13 days, biopsies from the adult rats, four fetal rats and sheep were taken from various organs. The specimens were analyzed by light, electron, and confocal laser scanning microscopy. Typical HES storage vacuoles were found in macrophages of the skin, liver, spleen, lung, and kidney. HES storage in healthy animals was not associated with signs of either inflammation or apoptosis contrary to a previously described animal hemorrhagic shock model. Beyond that, fetus biopsies did not show any storage phenomenon, confirming that HES does not cross the placental barrier. Deposits of HES could be detected in Schwann cells of cutaneous nerve fibers as well as in perineural and endoneural cells of sciatic nerve in one rat (HES 450 kDa) and three of four sheep. No HES storage was found in the central nervous system. Our findings clearly demonstrate that storage of HES is detectable only in small peripheral nerves, suggesting a cutaneous origin of the HES-induced pruritus.

Alendronate increases bone mass and reduces bone markers in postmenopausal African-American women

Previous studies indicated that aminobisphosphonate alendronate sodium, a potent inhibitor of bone resorption, increases bone mineral density (BMD) at the hip and spine, reduces markers of bone turnover, and reduces the risk of fractures in Caucasian postmenopausal women. The purpose of the present study was to investigate whether alendronate increases BMD and reduces markers of bone turnover in African-American postmenopausal women. In a multicenter, randomized, double-blind, placebo-controlled study, 65 African-American women, aged 45 to 88 yr, were randomly assigned to either placebo (n = 33) or alendronate 10 mg daily (n = 32) for 2 yr. Mean BMD T scores of the lumbar spine at baseline were -3.18 in the placebo-treated group and -3.09 in the alendronate-treated group. All women took 500 mg elemental calcium daily in the form of calcium carbonate and 500 IU vitamin D. Alendronate significantly increased BMD and reduced markers of bone formation and resorption, compared with placebo. At 2 yr, mean changes +/- SE in BMD were 6.5% +/- 0.7% for the lumbar spine (P < 0.001), 4.5% +/- 1.0% for the femoral neck (P < 0.001), 6.4% +/- 0.6% for the femoral trochanter (P < 0.001), 4.1% +/- 0.7% for the total hip (P < 0.001), 0.7% +/- 0.5% for the one third forearm (NS), and 2.0% +/- 0.4% for the total body (P < 0.001) in women treated with alendronate, compared with 0.9% +/- 0.6% (NS), 0.5% +/- 1.1% (NS), -0.2 +/- 0.8 (NS), -1.1 +/- 0.7% (NS), -0.8% +/- 0.6% (NS), and -1.2% +/- 0.6% (P < 0.05) for the lumbar spine, femoral neck, trochanter, total hip, one third forearm, and total body, respectively, in women treated with placebo. At 2 yr, mean serum bone-specific alkaline phosphatase had declined by 46.3% with alendronate (P < 0.001) and 13.6% with placebo (P < 0.01), and mean urinary N-telopeptide of type I collagen/creatinine ratio had declined by 70.5% with alendronate (P < 0.001) and 6.7% with placebo (NS). The incidence of adverse experiences was not different between the two groups. We conclude that in postmenopausal African-American women with osteoporosis, alendronate, 10 mg daily for 2 yr, increases BMD at the lumbar spine, hip, and total body and reduces markers of bone remodeling and is well tolerated.