Effect of transdermal 17 beta-estradiol and oral conjugated equine estrogens on biochemical parameters of bone resorption in natural menopause

Postmenopausal hormone therapy: risks and benefits

Postmenopausal hormone therapy (PMHT) is used for the relief of menopausal symptoms, but the dosage has varied greatly throughout its existence. By the end of the 1990s, PMHT was mainly used to prevent chronic diseases such as osteoporosis, coronary heart disease and dementia, and large prevention trials were undertaken in this context. Following the initial negative reports of these trials, use of PMHT dramatically decreased. These reports noted surprisingly increased risks, notably of coronary heart disease, stroke and breast cancer, in people who used PMHT. Nowadays, considering the currently available data, it seems that an important distinction should be made between the treatment of climacteric symptoms in young, generally healthy, postmenopausal women and the prevention of chronic diseases in elderly women. PMHT seems to be beneficial and safe for postmenopausal symptomatic women aged <60 years. Treatments with a high safety profile should be the preferred option, including low-dose PMHT, oestrogen-only therapy in women who have had a hysterectomy, and vaginal oestrogen therapy for women with atrophic vaginitis. Nonandrogenic progestin might have a reduced thrombotic and breast cancer risk, and transdermal oestrogen could have a reduced thrombotic risk. Nevertheless, PMHT should not be used for the prevention of chronic diseases in the elderly (>70 years old) owing to the increased risk of stroke and breast cancer in these patients.

The effects of hormonal contraceptives on bone turnover markers and bone health

Sex hormones are important regulators of bone metabolism. As hormonal contraceptives contain either oestrogens or progestins, or a combination thereof, it is conceivable that these widely used agents have an effect on bone metabolism and bone health. The main users of hormonal contraceptives, adolescent girls and young women, are still building bone and accruing bone mass and may therefore be particularly susceptible to the effects of hormonal contraceptives on bone. Despite these concerns, the effects of hormonal contraceptives on bone health are still poorly understood. As biochemical markers of bone turnover have been proven useful tools in the assessment and monitoring of bone metabolism, we reviewed the effects of combined and gestagen-only hormonal contraceptives on bone turnover markers and related effects on bone mineral density and fracture risk in premenopausal women, as documented in the literature until January 2009.

Different effects of oral conjugated equine estrogens and transdermal estrogen on undercarboxylated osteocalcin concentration in postmenopausal women

OBJECTIVE

Undercarboxylated osteocalcin (ucOC) is a sensitive marker of vitamin K status, and triglyceride (TG) has been shown to be the main transporter of vitamin K. In the present study, we examined the difference between ucOC concentrations in postmenopausal women receiving hormone therapy (HT) with oral conjugated equine estrogens (CEE) and transdermal estradiol (TE2). We also examined the associations of ucOC concentration with estradiol concentration and TG.

DESIGN

Ninety-two postmenopausal women were recruited for this study. Serum concentrations of ucOC, intact osteocalcin, estradiol, and TG were measured before and after 12 months of HT. Forty-six women received oral administration of 0.625 mg of CEE and 2.5 mg of medroxyprogesterone acetate daily, and 46 women received transdermal administration of 50 mug of 17beta-estradiol twice weekly and 2.5 mg of medroxyprogesterone acetate daily.

RESULTS

The ucOC concentration in women during HT with oral CEE was significantly (P < 0.01) lower than that in women during HT with TE2. Serum estradiol concentrations during HT with CEE showed a significant inverse correlation with ucOC concentrations and the ratio of ucOC/OC during HT (P < 0.05 and P < 0.01, respectively). In addition, the serum ucOC concentration in women with an increased percentage of change in TG was significantly (P < 0.01) lower than that in women with a decreased percentage of change in TG during HT with oral CEE.

CONCLUSION

The effect of HT with TE2 on ucOC concentration in women is weaker than the effect of HT with oral CEE. Suppression of ucOC concentration in postmenopausal women during HT with oral CEE might be associated with the effect of vitamin K through increased TG induced by oral CEE.

Influence of estrus status on urinary chemical parameters related to urolithiasis

The present study examines the urinary chemical parameters related to urolithiasis in healthy female volunteers during premenopause and menopause, and discusses the role of menopause in stone formation. We investigated 24-h urine parameters associated with urinary stones and focused upon estrus status. Participants comprised 30 healthy women, 15 childless, premenopausal women and 15 menopausal women without a history of urolithiasis. Our results showed that menopausal women have lower citrate and higher calcium excretion, which might enhance calcium stone crystallization. We propose that the estrus status of female patients should be considered when evaluating metabolic abnormalities.

[Comparison of changes in biochemical markers of bone turnover after 6 months of hormone replacement therapy with either transdermal 17 beta-estradiol or equine conjugated estrogen plus nomegestrol acetate]

OBJECTIVE

To compare changes in biochemical markers of bone turnover in postmenopausal women who received sequential discontinuous hormone replacement therapy (HRT) with either transdermal 17 beta-estradiol gel (group 1) or oral equine sulfoconjugated estrogen (group 2), plus nomegestrol acetate.

PATIENTS AND METHOD

Prospective, open, randomized, controlled trial, conducted on 3 parallel groups of 106 postmenopausal women. All treated groups received estrogen therapy for 25 consecutive days every month. The estrogen used was either 1.5 mg/day of transdermal 17 beta-estradiol gel (group 1) [N = 42, average age (AA) = 51.6 years, average duration of menopause (ADM = 21.5 months)], or 0.625 mg/day of oral equine sulfoconjugated estrogen (group 2) [N = 39, AA = 51.3 years, ADM = 16.8 months]. In all cases nomegestrol acetate 5 mg/day was added for 12 consecutive days every month. The control group comprised 25 patients, [AA = 53.4 years, ADM = 33.7 months]. Two bone resorption markers: urinary cross-linked N-telopeptide and C-telopeptide of type I collagen (U-NTX/Cr, U-CTX/Cr), and a bone formation marker: serum bone specific alkaline phosphatase activity were measured before and 6 months after treatment start.

RESULTS

Significant decreases from baseline values were observed for the 3 biochemical markers in both treated groups compared with control (P < 0.001). There were no significant differences in changes between the 2 treated groups for the 3 biochemical markers. The mean percentage change in the 3 biochemical markers was: from -9.3 to -45.5% in group 1, from -20.5 to -39% in group 2, and from -3.3 to 2% in control group. In group 1, the mean percentage decreases in U-CTX reached optimal threshold of bone turnover change (-45%) which is considered by the International Osteoporosis Foundation as clinically relevant because it predicts an increase in BMD greater than 3% when treatment is maintained over a long term.

DISCUSSION AND CONCLUSION

Both treated groups induced a significant comparable decrease of bone turnover markers after 6 months of intervention, compared with control. The group treated with cyclic administration of transdermal 17 beta-estradiol (1.5 mg/day) and nomegestrol acetate (5 mg/day) showed a bone resorption markers decrease corresponding to the threshold of clinical relevance described in the international literature and predictive of positive BMD response in long term.

The effects of soy protein containing isoflavones on lipids and indices of bone resorption in postmenopausal women

OBJECTIVE

To assess the effect of a dietary soy protein supplement containing isoflavones on lipids and indices of bone resorption in postmenopausal women.

DESIGN

Placebo-controlled, double-blind, randomized study.

PATIENTS

One hundred and six postmenopausal women were randomized to dietary soy supplementation (n = 51) or placebo (n = 55) for 3 months, of which 78 were included in the final analysis.

MEASUREMENTS

Lipid profiles including total, low-density lipoprotein (LDL) and HDL cholesterol as well as triacylglycerol were measured. Pyridinoline and deoxypyridinoline were used as markers of bone resorption. Urinary isoflavone excretion was measured to assess compliance.

RESULTS

There was a significantly greater increase in urinary isoflavone excretion detected in the soy group compared to placebo. Lipid profiles improved with significant decreases in LDL cholesterol (-0.60 +/- 0.10 vs.-0.29 +/- 0.09 mmol/l, P < 0.05), triacylglycerol (-0.22 +/- 0.07 vs. +0.01 +/- 0.05 mmol/l, P < 0.005) and the LDL : HDL ratio (-0.32 +/- 0.10 vs. +0.20 +/- 0.10, P < 0.005) in the soy group compared to placebo. There were no significant differences between the soy and placebo groups for urinary excretion of pyridinoline (-3.8 +/- 3.1 vs.-0.8 +/- 3.1 nmol/mmolCr, P = 0.4) or deoxypyridinoline (-0.8 +/- 0.9 vs.-0.3 +/- 0.7 nmol/mmolCr, P = 0.4).

CONCLUSIONS

In postmenopausal women, dietary supplementation with soy protein containing isoflavones does not appear to have oestrogenic effects on markers of bone resorption. Soy protein favourably affected lipids; however, these effects (fall in triacylglycerol and no change in HDL) differ from those observed with oral oestrogen. These findings suggest that soy may not have biologically significant oestrogenic effects on bone resorption and we hypothesize that the lipid effects may be mediated, at least in part, through nonoestrogenic mechanisms.

Short-term effects of new synthetic conjugated estrogens on biochemical markers of bone turnover

Fifty early postmenopausal women completed a double-blind, placebo-controlled study evaluating the short-term effect of a new synthetic conjugated estrogens formulation (Cenestin) on bone turnover. Subjects were randomized to either 0.625 mg/day synthetic conjugated estrogens (n = 35) or placebo (n = 15) for 3 months. Biochemical markers were evaluated at baseline (three measurements at Days -2, -1, and 0) and Days 30, 60, and 90. Bone resorption assessed by urinary NTX (-31.4%) and serum CTX (-34.2%) was significantly (p < 0.01) decreased in the estrogen-treated group compared to the placebo group within 1 month of treatment. The mean percent decreases for urinary NTX from baseline during estrogen treatment were -58.0% (p < 0.01 vs. placebo) and -34.1% (ns) after 2 and 3 months, respectively. For serum CTX, the percent changes from baseline were -17.6% (p < 0.01) and -16.9% (p < 0.01) at 2 and 3 months, respectively. As expected, the decrease of both bone formation markers (bone ALP and PINP) was delayed compared to that of bone resorption and significant (p < 0.05-0.01) only after 2 months of treatment in the estrogen-treated group compared to the placebo group. Synthetic conjugated estrogens significantly decreased bone resorption and bone formation comparable to that previously reported for estrogen treatments proven efficacious in preventing postmenopausal bone loss.

The use of hormone replacement therapy in postmenopausal women with type 2 diabetes

In healthy postmenopausal women, estrogen or hormone replacement therapy (ERT or HRT) can alleviate menopausal symptoms and prevent osteoporosis and may also protect against cardiovascular disease (CVD). In addition to improving lipid metabolism, there are reports that estrogen also improves parameters regulating carbohydrate metabolism, including insulin resistance, in healthy women. Therefore, it is likely that ERT or HRT would also benefit women with type 2 diabetes, not only in relieving menopausal symptoms but also in improving the metabolic abnormalities associated with diabetes and in preventing cardiovascular disease.

The pharmacokinetics and efficacy of different estrogens are not equivalent

In the next decade many women will turn to the medical community for advice on maintaining or improving health after menopause. Estrogen replacement therapy, with or without progestins, alleviates menopausal symptoms, prevents or manages osteoporosis, and reduces the increased cardiovascular disease risk that results from estrogen deficiency caused by ovarian decline. Although several estrogen replacement products are available, the pharmacokinetics and efficacy of these products may vary depending on either the estrogen formulation or the route of administration, or both. For example, oral estrogens, which elicit a marked hepatic response, induce greater beneficial effects on serum lipoproteins than transdermal estrogens, which circumvent first-pass liver metabolism. Oral conjugated estrogens and transdermal estradiol increase bone density and prevent bone loss. This article summarizes the studies comparing estrogen formulations and discusses the differential effects of various estrogen products that promote postmenopausal health.

Drug concentration effect relationship of estradiol from two matrix transdermal delivery systems: Menorest and Climara

OBJECTIVES

To relate the pharmacokinetics of estradiol to pharmacological effects.

METHODS

Drug concentration effect relationship of estradiol from two matrix transdermal delivery systems, Menorest and Climara, was studied in a single centre, open, randomised, comparative crossover study. The trial consisted of two treatment periods, 14 days for each patch separated by a 4-week washout period. Blood hormone levels were followed during the second week of each treatment. Estradiol levels during treatments were related to three concentration levels previously proposed as efficacy or safety limits. The effect of treatment on FSH-levels was examined and the relationship between the levels of estradiol and FSH was described using an inhibitory sigmoidal I(max) model. Estrone levels and estradiol/estrone before and during treatment were followed.

RESULTS

The C(average) of FSH during treatment was 38% lower than baseline plasma levels. Estradiol had an inhibitory effect on FSH with an I(max) of 0.68 and an IC(50) of 19 pg/ml. The fraction of time above the minimum concentration for therapeutic effect and the tolerability limit did not differ between the two treatments, whereas the fraction of time above the suggested threshold for osteoporosis prophylaxis was significantly larger for Menorest than for Climara (P<0.05). The low baseline estradiol/estrone ratios increased towards pre-menopausal levels during treatment.

CONCLUSIONS

The drug concentration effect relationship of estradiol may be of use in evaluation of the effects of prophylactic estrogen therapy and to facilitate comparisons between different forms of estrogen treatments.

Recent insights into the varying activity of estrogens

Recent advances have added substantially to our understanding of the biology of estrogens. Estrogens are no longer considered to differ only in potency. Two estrogens can have similar effects in one tissue and very different effects in another. Additionally, an estrogen can have different effects in different tissues. It is now recognized that there are at least two estrogen receptors, ER-alpha and ER-beta, and that it is quite likely that estrogens also work through non-genomic mechanisms. The development of new methods of chromatographic separation has aided substantially in our ability to characterize the composition of Premarin, including the identification of estradiene, the fourth-most abundant estrogen in Premarin. Recent studies have contributed to our understanding of the unique profile of Delta(8,9) dehydroestrone sulfate, another of the Premarin estrogens. It was found that Delta(8,9) dehydroestrone sulfate is an active estrogen with a distinct pharmacological profile that results in significant clinical activity in vasomotor, neuroendocrine and bone preservation parameters. However, it displayed little or no efficacy, at the dose studied, on other peripheral parameters normally affected by classical estrogens. Increasing knowledge of the unique profiles of the Premarin components, as well as their complex interaction, will help to increase our understanding of the clinical profile of Premarin.

Significant differences in estradiol bioavailability from two similarly labelled estradiol matrix transdermal systems

OBJECTIVE

To compare the bioavailabilities of estradiol delivered by two transdermal estradiol matrix systems; Alora and Evorel.

STUDY DESIGN

A single-center, open-label, randomized, two-period cross-over study in 33 postmenopausal women. The subjects received two successive 84-h applications of either Alora or Evorel (each labelled to deliver 50 micrograms/day 17 beta-estradiol) in a randomized sequence. Serial serum samples, collected over the 84-h period following the application of the second patch, were analyzed for estradiol using a validated radioimmunoassay method.

RESULTS

The fluctuation index produced by Evorel was significantly higher than that produced by Alora (Evorel, 135%; Alora, 76%; p < 0.0005). In addition, the estradiol baseline-corrected area under the curve for Evorel was significantly lower than that for Alora (Alora, 2871.8 pg h/ml; Evorel, 1870.6 pg h/ml; p < 0.0005). Both patches were found to be generally well tolerated.

CONCLUSION

Alora delivered a higher, more consistent concentration of estradiol into the systemic circulation over the entire dosing interval than did Everol. Although the full clinical significance of these findings is currently unknown, this study demonstrates that there are significant differences in estradiol delivery from these two products, although they are labelled with the same nominal delivery rate.

Effects of intranasal 17beta-estradiol on bone turnover and serum insulin-like growth factor I in postmenopausal women

Estrogen therapy, using either oral or transdermal routes, decreases bone turnover and prevents postmenopausal bone loss. It has been suggested that oral and transdermal 17beta-estradiol (E2) may have different effects on serum insulin-like growth factor I (IGF-I), a potent bone-forming growth factor. In this study we investigated the effects of a new route of administration, the intranasal E2 spray (S21400), on bone turnover and circulating IGF-I and IGF-binding protein-3 (IGFBP-3). Four hundred and twenty early postmenopausal women (<5 yr since menopause; mean age, 52 yr) were enrolled in a 3-month, double blind, placebo-controlled study of four doses of intranasal E2 (100, 200, 300, and 400 microg/day), two doses of oral E2 valerate (1 or 2 mg/day), and placebo. One hundred and twelve women were further treated for 12 months with intranasal E2 (300 microg/day, i.e. the dose that has been shown to be adequate for the majority of postmenopausal women). Markers of bone resorption (urinary type I collagen C telopeptides) and formation [serum osteocalcin, serum type I collagen N-terminal extension propeptide (PINP), and serum bone alkaline phosphatase (BAP)] were measured at baseline, 1 month, 3 months, and 15 months. Serum IGF-I and IGFBP-3 were measured at baseline, 1 month, and 3 months. Urinary type I collagen C telopeptides decreased significantly in all active treatment groups as soon as 1 month (P<0.001 vs. placebo) and continued to decrease at 3 months with a dose effect for intranasal E2. Serum osteocalcin and PINP did not change at 1 month for oral E2 (1 and 2 mg), but decreased significantly at 3 months. In contrast, formation markers increased significantly at 1 month for the two highest doses of intranasal E2 (P<0.01 vs. placebo for osteocalcin and BAP) and did not decrease at 3 months. Oral E2 induced a marked decrease in circulating IGF-I as early as 1 month, which was amplified at 3 months (-29% and -32% for 1 and 2 mg, respectively), whereas no significant change from placebo was observed for intranasal E2 during the 3-month period. Changes in circulating IGF-I correlated significantly (P<0.01) with changes in osteocalcin, PINP, and BAP at 3 months. Oral and intranasal E2 did not induce any significant change from placebo in serum IGFBP-3 at both 1 and 3 months. After 1 yr of treatment with intranasal E2 (300 microg/day), both resorption and formation markers decreased, reaching the levels in premenopausal women, regardless of the type of treatment during the first 3 months. We conclude that E2 administered by this new nasal route normalizes bone turnover to premenopausal levels. The delayed decrease in bone formation observed with intranasal E2 compared to oral E2 may be related to different effects on serum IGF-I levels.

Plasma estradiol concentrations and pharmacokinetics following transdermal application of Menorest 50 or Systen (Evorel) 50

OBJECTIVES

In order to compare the pharmacokinetics of two transdermal estrogen replacement therapy (ERT) systems designed to release 50 micrograms 17 beta-estradiol/day, two studies were performed in healthy postmenopausal volunteers.

METHODS

Both studies had a cross-over design and incorporated a 1-week wash-out period between treatments. In the first study, Menorest 50 and Systen 50 (Evorel 50) were compared over four days of application in 30 women. In the second, 13 women wore each of the two systems for a total of 12 days each (three patches each for 4 days), and comparison was made during the third patch period (steady state, between days 8 and 12). Plasma 17 beta-estradiol levels were assayed using specific direct radioimmunoassays, and pharmacokinetic parameters were calculated by standard methods. All the samples of the first study were re-analysed using a different radioimmunoassay and the results of both assays were compared.

RESULTS

In both studies, plasma 17 beta-estradiol levels rose at a comparable rate and reached similar peak levels with each of the two formulations. Levels then remained relatively constant throughout both evaluation periods with Menorest 50, but began to decline after 12 hours in the first study and after 30 h under steady state conditions in the second study with Systen 50. The difference between the two products was statistically significant in both studies. Analysis of pharmacokinetic parameters confirmed the greater bioavailability of Menorest 50. In addition, 17 beta-estradiol levels remained within the suggested therapeutic ranges for relief of acute symptoms and protection against osteoporosis for longer periods of time with Menorest 50 than with Systen 50.

CONCLUSION

Since the acute efficacy, long-term protective effects, side effects and risks associated with ERT may depend on critical threshold plasma levels, much attention should be paid to the pharmacokinetic profiles of different formulations. The comparison of these two different radioimmunoassays demonstrates the comparability of their results.

Prophylaxis of osteoporosis with calcium, estrogens and/or eelcatonin: comparative longitudinal study of bone mass

OBJECTIVE

To evaluate three different therapeutic regimens for the prevention of osteoporosis in natural and surgical postmenopausal women who had been found to have rapid bone loss in analytical studies.

METHODS

A total of 104 naturally or surgically postmenopausal women were studied, and subsequently followed-up during 1 year for avoidance of the influence of seasonal variation on bone mass, a factor overlooked in several studies. They were randomized into four groups of 26 patients each: the untreated control group (mean age 50 +/- 5 years); the hormonal replacement treatment (HRT) group (mean age 48 +/- 6 years), which was treated for 24 days each month with transdermal 17 beta-estradiol, 50 mg/day, together with medroxiprogesterone, 10 mg during 12 days; the calcium group (mean age 50 +/- 4 years), which was treated with elemental calcium, 1 g/day; and the calcitonin group (mean age 50 +/- 5 years), which was treated for 10 days each month with eel calcitonin, 40 IU/day and with elemental calcium, 500 mg/day. Full-body bone densitometry, for measuring total body bone mineral content (TBBMC), was carried out in all the women at baseline and 1 year. TBBMC was corrected for body weight by dividing its value by body weight (TBBMC/W).

RESULTS

After 1 year TBBMC/W was lower in every group: -2.14% (P < 0.001) in the control group; -0.14% (P = NS) in the HRT group (P < 0.05 vs. controls); -0.18% (P = NS) in the calcium group (P < 0.05 vs. controls); and -0.06% (P = NS) in the calcitonin group (P < 0.01 vs. controls; P < 0.05 vs. calcium and HRT).

CONCLUSIONS

These findings show that all three treatments are effective in the prevention of postmenopausal loss of bone mass.

Plasma concentration of estradiol following transdermal administration of Systen 50 or Menorest 50

Circulating levels of 17 beta estradiol (E2) following the administration of fixed doses of E2, show a great variability in kinetics depending upon the product administrated, the routes of administration, and the interindividual variations in absorption and metabolism. This might have important implications both in terms of tolerance and effectiveness. Two new forms of transdermal E2 (SYSTEN Cilag and MENOREST Rhone-Poulenc Rorer) have been recently accepted in Europe for the treatment of climacteric symptoms. The present study was undertaken to compare the pharmacokinetic characteristics of plasma E2 profile under these two drugs. It was carried out in 30 healthy postmenopausal volunteers according to good clinical practice after informed consent, as a single blind, randomised, cross-over study during the classical wearing period of 4 days. Plasma E2 concentration was determined 24 hours before, 1/2 hour before and then 2, 4, 8, 12, 24, 48, 72, 84, 96 hours after the first patch administration. E2 measurement was performed using a specific direct radioimmunoassay developed in the FRH laboratories. The main criteria for this method were an intraassay coefficient of variation (CV) less than 6%, an interassay CV less than 8% in a concentration range of 15-140 pg/ml and a quantitative detection limit (LOQ) of 2.7 pg/ml with a 20% CV. The following kinetic parameters were analysed: C(max), C(mean), C96 and MRT. The bioequivalence was assessed by analysis of variance of C(max), C(mean), C96 and AuC after logarithmic transformation, complemented by Westlake test (95%). Data show that these two products are identical in terms of C(max) but C(mean), C96 and AuC are statistically greater when MENOREST 50(R) is administered; furthermore, E2 levels decrease more rapidly and more deeply with SYSTEN 50 than MENOREST 50. The differences of pharmacokinetic profiles after administration of two different forms of the same dose of 50 micrograms transdermal 17 beta estradiol might have important medical consequences.

Estrogen dose required to maintain parathyroid hormone mediated bone gain in osteopenic ovariectomized rats is probably higher than in preventive treatment with estrogen

Successful prevention of bone loss in ovariectomized rats with 17 beta-estradiol (E2) at 10 micrograms/kg/d has been reported. Here we show that E2 dose twice that much is not enough to maintain PTH(1-34) mediated bone gain. Three-month-old female Wistar rats were ovariectomized and fed with regular rodent chow and water ad libitum. Three months later they were divided into 9 groups (5-8 per group) and treated cyclically with PTH(1-34) (20 micrograms/kg/d sc, 5d/w for 3w) and E2 (20 micrograms/kg/d sc, 5d/w for 4w). There were also a baseline group and five vehicle control groups. Cancellous bone volume (Cn.BV/TV) of distal femoral metaphyses was measured by computer-aided histomorphometry on trichrome stained thin sections, and 24-hour fasted urine was analyzed for pyridinoline/creatinine (PYR/CREA) by immunoassay. Histomorphometric results showed that PTH(1-34) progressively increased Cn.BV/TV but E2 failed to maintain them. Urinary PYR/CREA results showed that E2-treated groups had lower values. We conclude that E2 dose > 20 micrograms/kg/d is required to maintain the PTH mediated bone gain.

Cyclical clodronate is effective in preventing postmenopausal bone loss: a comparative study with transcutaneous hormone replacement therapy

An investigative study was carried out for 2 years involving 124 randomly selected early postmenopausal women with spine bone mineral density (BMD) below the mean value of a normal premenopausal subject. After random division into three groups, the first 42 patients were treated with transcutaneous 17-beta-estradiol (50 micrograms daily), the second 42 were treated with cyclical intravenous clodronate (200 mg/month iv infusion), and the third group of 40 (controls) was left untreated. After 2 years, the total drop in BMD within the control group was more than 7% as opposed to the values of -0.14% +/- 0.93 in the estradiol group and 0.67% +/- 0.84 in the clodronate group. A change in BMD of < 1% was considered satisfactory, and this result was obtained in 32% of the controls, in 79% of the estradiol group where the percentage change in BMD moderately correlated with serum estradiol levels (r = 0.399), and in 90% of the clodronate-treated patients, in whom the percentage change in BMD inversely correlated with basal values of markers of bone turnover. Both estrogen and clodronate prevent postmenopausal bone loss. The response to transcutaneous hormone replacement therapy may be influenced by transcutaneous absorption and by a lower sensitivity to estrogen. Response to cyclical clodronate seems to be influenced by the rate of bone turnover. An interdosage interval ranging from 2-4 weeks appears suitable for most patients.