Bone loss in perimenopausal women: a longitudinal study

Postmenopausal Osteoporosis: Menopause Hormone Therapy and Selective Estrogen Receptor Modulators

Introduction

Osteoporosis is a debilitating silent disease with a huge socio-economic impact. Prevention strategies and early detection of osteoporosis need to be carried out in every health care unit to substantially reduce the fracture rates. Indian studies have indicated a knowledge gap on diagnosis and management of osteoporosis amongst medical professionals and consumers.

Areas Covered

This article reviews the evidences available on searches from PubMed and The National Library of Medicine, author's opinions based on clinical experience. There is a need for escalating the efforts to bridge the knowledge gap regarding various aspects of osteoporosis amongst professionals and consumers. Three indications for postmenopausal hormone therapy (HT), which have constantly withstood the test of time, are symptom relief, urogenital atrophy, and bone health. This article specifically focuses on management of postmenopausal osteoporosis by HT alone or in combinations.

Expert Opinion

Early menopause is within 10 years of menopause and late menopause is considered beyond 10 years of menopause. HT is a cost-effective therapy in the early post menopause especially in symptomatic women at risk for osteoporosis unless contraindicated. HT prevents all osteoporotic fractures even in low-risk population. All HT preparations including low dose and non-oral routes of estrogen are effective for bone health. The bone protective effect lasts while on HT. Extended use of HT in women after 10 years of menopause with reduced bone mass is an option after detailed counselling of the risk benefit analysis compared with the other available therapies for osteoporosis. The primary therapy to prevent bone loss in women with premature menopause and secondary amenorrhea is HT. HT work up and annual follow-up is essential before prescribing HT.

Change in bone mineral density and its determinants in pre- and perimenopausal Chinese women: the Hong Kong Perimenopausal Women Osteoporosis Study

This 30-month study investigating bone change and its determinants in 438 perimenopausal Chinese women revealed that the fastest bone loss occurred in women undergoing menopausal transition but maintenance of body weight and physical fitness were beneficial for bone health. Soy protein intake also seemed to exert a protective effect.

INTRODUCTION

This 30-month follow-up study aims to investigate change in bone mineral density and its determinants in Hong Kong Chinese perimenopausal women.

METHODS

Four hundred and thirty-eight women aged 45 to 55 years were recruited through random telephone dialing and primary care clinic. Bone mass, body composition, lifestyle measurements were obtained at baseline and at 9-, 18- and 30-month follow-ups. Univariate and stepwise multiple regression analyses were performed with the regression coefficients of BMD/C (derived from baseline and follow-up measurements) as the outcome variables. Menopausal status was classified as pre- or postmenopausal or transitional.

RESULTS

Menopausal status was the strongest determinant of bone changes. An annual bone loss of about 0.5% was observed among premenopausal, 2% to 2.5% among transitional, and about 1.5% in postmenopausal women. Multiple regression analyses, revealed that a positive regression slope of body weight was protective for follow-up bone loss at all sites. Number of pregnancy, soy protein intake and walking were protective for total body BMC. Higher baseline LM was also protective for neck of femur BMD.

CONCLUSION

Maintenance of body weight and physical fitness were observed to have a protective effect on for bone loss in Chinese perimenopausal women.

Ultra low-dose hormone replacement therapy and bone protection in postmenopausal women

OBJECTIVES

The aim of the present study was to evaluate the effects of low doses of hormone replacement therapy (HRT) in normal young postmenopausal women.

METHODS

In an open trial healthy, non-obese postmenopausal women received for 2 years a low-dose continuous combined HRT (LD-HRT) containing 1mg estradiol+0.5 mg norethisterone acetate each pill for 28 days, or 0.5 mg of 17beta-estradiol and 0.25 mg of norethisterone acetate (Ultra low dose, Ultra-LD-HRT) along with 1000 mg of calcium per day. Control group consisted of women receiving only 1000 mg of calcium per day, for 2 years. Menopausal symptoms were evaluated by the Green climacteric scale for the first 12 weeks of the study while bleeding profiles, bone mineral density (BMD) and bone turnover were assessed for 24 months.

RESULTS

LD-HRT and Ultra-LD-HRT were effective in reducing menopausal clinical symptoms. In the control group, BMD significantly (P<0.05) decreased at the spine (-2.8+/-0.2%), and femoral neck (-2.8+/-0.7%). In LD-HRT treated group BMD showed a significant (P<0.05) increase at the spine (5.2+/-0.7%), and femoral neck (2.8+/-0.4%) after 24 months. In the Ultra-LD-HRT treated women spine and femoral neck BMD showed a significant (P<0.05) increase (2.0+/-0.3 and 1.8+/-0.3%, respectively) after 24 months. In these women treated with LD-HRT and Ultra-LD-HRT the BMD values were significantly (P<0.05) different from those measured in calcium-treated women.

CONCLUSIONS

LD-HRT and Ultra-LD-HRT can alleviate subjective symptoms providing an effective protection against the postmenopausal decrease of BMD.

Beneficial effect of pretreatment and treatment continuation with risedronate and vitamin K2 on cancellous bone loss after ovariectomy in rats: a bone histomorphometry study

The purpose of the present study was to examine the effect of pretreatment with risedronate and/or vitamin K2 and treatment continuation with reduced dosing frequency of the drugs on the early cancellous bone loss induced by ovariectomy (OVX) in rats. Eighty female Sprague-Dawley rats, 4 mo of age, were randomized by the stratified weight method into eight groups (n= 10 in each group); rats subjected to OVX, but not sham-operated rats, were treated with vehicle, risedronate, vitamin K2 (menatetrenone), or risedronate+vitamin K2 for 4 wk before the surgery, and the treatment was either discontinued (pretreatment groups) or continued after the surgery (treatment continuation groups) for 2 wk. Sham-operated rats (controls) were treated with the vehicle throughout the experimental period. During the 4 wk prior to the surgery (pretreatment), risedronate and vitamin K2 were administered five times a week either subcutaneously at a dose of 2.5 microg/kg body weight (risedronate) or orally at the dose of 30 mg/kg body weight (vitamin K2). During the 2 wk after the surgery (treatment continuation), the dosing frequency of the drugs was reduced to twice a week. Risedronate and vitamin K2 had an anti-resorptive effect on the bone. Pretreatment with risedronate alone, but not vitamin K2 alone, prevented the loss of the cancellous bone volume/total volume (BV/TV) of the proximal tibial metaphysis after OVX. Treatment continuation with vitamin K2 alone prevented the loss of the cancellous BV/TV after OVX, while treatment continuation with risedronate alone increased the cancellous BV/TV to beyond the values in controls. Pretreatment with risedronate+vitamin K2 had a more beneficial effect in increasing the cancellous bone mass than pretreatment with risedronate alone. Treatment continuation with risedronate and/or vitamin K_ appeared to have a more beneficial effect in increasing the cancellous bone mass than the respective pretreatment. Neither the total tissue area nor the cortical area of the tibial diaphysis was affected by any treatment. The present study demonstrated that pretreatment with risedronate had a beneficial effect on the early cancellous bone loss after OVX in rats, with a more beneficial effect when combined with vitamin K2. Moreover, even though the dosing frequency of the drugs was reduced after OVX, treatment continuation appeared to be more beneficial than pretreatment for increasing the cancellous bone mass.

Menstrual cycle lengths and bone mineral density: a cross-sectional, population-based study in rural Chinese women ages 30-49 years

INTRODUCTION

The menstrual cycle involves periodic fluctuations in estrogen and progesterone levels. Longer cycles have been associated with longer follicular phase, delayed estrogen peak and a lower mean oestradiol level of the entire cycle.

METHODS

We hypothesized that prolonged menstrual cycle length is associated with decreased bone mineral density (BMD) in a population of pre- and perimenopausal women. This population-based cross-sectional study was conducted in rural Anhui province, China. It includes 4,771 women, aged 30 to 49 years, who did not smoke or drink alcohol, and did not use oral contraceptives or breastfeed during the previous year. Dual-energy X-ray absorptionometry (DEXA) BMD measurements were taken at four skeletal sites: whole body, total hip, femoral neck and lumbar spine. Menstrual cycle characteristics (polymenorrhea, short normal, long normal, oligomenorrhea, 90-day amenorrhea, irregular cycle) in the prior year were assessed by questionnaire.

RESULTS

Prolonged menstrual cycle was consistently associated with decreased BMD at whole body, total hip, and femoral neck in both age 30-39, and age 40-49 stratum (p(trend)<0.05). Prolonged menstrual cycle was also associated with decreased lumbar spine BMD for women aged 40-49 (p(trend)<0.05). Among women with normal cycles aged 30-39, menstrual cycle length in the previous year was inversely associated with whole-body BMD (p<0.05). Women with 90-day amenorrhea had significantly lower mean total hip and femoral neck BMD relative to women with short normal cycles in the 30-39 age group; and had significantly lower whole body and total hip BMD relative to short normal cycles in the 40-49 age group. BMD in polymenorrheic women did not differ from BMD in women with short normal cycles at any of the skeletal sites.

CONCLUSIONS

We conclude that prolonged menstrual cycle length is associated with decreased BMD in pre- and perimenopausal women in this population.

Longitudinal evaluation of perimenopausal bone loss: Effects of different low dose oral contraceptive preparations on bone mineral density

OBJECTIVES

To evaluate the pattern of mineral density in eumenorrhoic and oligomenorrhoic perimenopausal women, and assess the effects of different low dose oral contraceptives (OC) on bone metabolism and spine bone density.

METHODS

Spine bone density was evaluated in a longitudinal 2-year follow-up, randomized, unblinded, uncontrolled clinical trial conducted in healthy, normally menstruating perimenopausal women, perimenopausal oligomenorrhoic women and in perimenopausal oligomenorrhoic women treated with an oral contraceptive containing 20 microg ethinyl estradiol plus 0.15 mg desogestrel, 0.100 mg levonorgestrel, 0.75 mg of gestodene (n=15 in each group). The results were analyzed by factorial or repeated measures analysis of variance, as appropriate.

RESULTS

During the observation period, in normal menstruating women there were no changes in menstrual cycle, plasma FSH and estradiol levels, and spine bone density. In oligomenorrhoic untreated women an increase in cycle length, with a concomitant decrease in plasma estradiol and an increase in plasma FSH levels were evidenced (p<0.05). In this group a significant decrease in bone density (p<0.05) occurred. In OC-treated women, a significant (p<0.05) increase in bone density was observed, with no differences among different groups.

CONCLUSION

Different progestins used in OC preparations do not modify the bone sparing effect of perimenopausal OC administration avoiding the decrease in bone density.

Effect of Pre- and Post-Surgery Treatment with Risedronate on Trabecular Bone Loss in Ovariectomized Rats

The purposes of the present study were to differentiate the effects of pre-surgery treatment with risedronate and post-surgery treatment with a reduced dosing frequency of risedronate on trabecular bone loss in ovariectomized rats and to determine whether post-surgery treatment with a reduced dosing frequency of risedronate would have a beneficial effect on trabecular bone loss after pre-surgery treatment with risedronate by means of bone histomorphometric analysis. The short-term experiment (6 weeks) was performed on fifty, 4-month-old, female Sprague-Dawley rats randomized into five groups (n=10 in each group). Forty rats were treated with vehicle or risedronate for 4 weeks before ovariectomy (OVX), and then treated with either vehicle or risedronate for 2 weeks following OVX (the Vehicle-OVX-Vehicle [OVX control], Vehicle-OVX-Risedronate [post-OVX treatment with risedronate], Risedronate-OVX-Vehicle [pre-OVX treatment with risedronate], and Risedronate-OVX-Risedronate [continuous treatment with risedronate] groups). The remaining 10 rats were treated with vehicle for 6 weeks, with a sham operation performed 4 weeks after the start of the experiment (the Vehicle-Sham-Vehicle [Sham control] group). During the 4 weeks prior to surgery, risedronate was administered five times a week subcutaneously at a dose of 2.5 microg /kg body weight, and during the 2 weeks after surgery, the dosing frequency was reduced to twice a week. The long-term experiment (10 weeks) had the same design as the short-term one, except that the post-OVX treatment was 6 weeks. In the short-term experiment, both pre- and post-OVX treatments with risedronate prevented trabecular bone loss of the proximal tibial metaphysis 2 weeks after OVX. In long-term experiment, however, pre- and post-OVX treatments with risedronate attenuated trabecular bone loss until 6 weeks after OVX, with pre-OVX treatment having a less pronounced effect than post-OVX treatment. In the short- and long-term experiments, pre-and post-OVX treatments had an additive effect on trabecular bone mass. The present study has shown the efficacy of pre-OVX treatment with risedronate or post-OVX treatment with a low dosing frequency of risedronate for preventing trabecular bone loss early after OVX. Post-OVX treatment with a low dosing frequency of risedronate was beneficial for attenuating trabecular bone loss late after OVX. Treatment with risedronate before OVX had an additive effect on trabecular bone mass with the treatment after OVX, suggesting that treatment with a low dosing frequency of risedronate might be acceptable for reducing OVX-induced trabecular bone loss after treatment with risedronate prior to OVX.

Effects of oral contraceptives on bone mineral density

Osteoporosis is a major health problem that leads to a high incidence of spine, radial, and hip fractures. It is now well recognized that a chronically hypoestrogenic state increases bone turnover that, in turn, causes a critical decrease in bone mineral density (BMD), an important determinant of fracture risk. During the premenopausal period, hypogonadism can have deleterious effects on skeletal health by reducing peak bone mass or inducing precocious bone loss. In young women, hypothalamic amenorrhea, caused by gonadotropin-releasing hormone pulsatility dysregulation, is often associated with bone loss. Although the relationship between hypothalamic amenorrhea and bone density is not completely understood, the most plausible intervention for this disorder at the moment seems to be the use of hormone replacement. Oral contraceptives are associated with an improvement in BMD if assumed upon the onset of anovulatory cycles and, therefore, estrogen deficiency, but confer no benefit in healthy women with normal ovarian function. In perimenopausal oligomenorrheic women, the use of oral contraceptives seems to have bone-sparing effects. In conclusion, the protective role of oral contraceptives on bone density is biologically plausible, since this treatment represents a replacement therapy with continuous exposure to exogenous estrogens.

Ovarian aging and bone metabolism in menstruating women aged 35–50 years

OBJECTIVES

The aim of this study was to investigate the relationships between the levels of gonadotrophins, estradiol, inhibin-b and bone mass and turn-over in regularly menstruating women aged 35-50 years.

METHODS

The study group included 87 healthy volunteers from the community aged 35-50 years. Bone mineral density of lumbar vertebras, wards triangle, throchanter, femur neck, bone resorption and formation markers were studied as well as the serum levels of gonadotrophins, estradiol and inhibin-b on the day 3 of menstrual cycle.

RESULTS

The gonadotrophin levels showed significant positive relation with age, whereas inhibin-b and estradiol levels showed significant negative correlation with age. The gonadotrophins and estradiol levels had no significant association with bone mass and bone formation markers. Increased gonadotrophin (p < 0.001) levels and decreased inhibin-b (p < 0.01) levels independent from age were correlated with increased bone resorption. Gonadotrophins, estradiol, age, inhibin-b, body mass index (BMI) were the confounding factors for bone resorption (p = 0.015, R(2) = 0.190) and lumbar bone mass (p = 0.041, R(2) = 0.148). Multivariate analysis showed an independent contribution of inhibin-b and BMI in the prediction of lumbar bone mass.

CONCLUSION

This findings suggested that estradiol was not the only factor responsible for bone loss and decrease in reproductive function because increased gonadotrophins and decreased inhibin-b levels might trigger some changes in bone metabolism prior to the menopause.

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.

A longitudinal study of bone density in midlife women

A longitudinal study of 386 healthy Black and White women aged 35-60 years was conducted to determine the effects of physical activity and other related factors on lumbar bone mineral density over 24 months. Bone mineral density of the lumbar spine, L2-L4, was measured using dual energy x-ray (Hologic 1000). Physical activity levels in three dimensions (leisure, household, and occupational) from both a lifelong and current perspective were obtained by questionnaire. Body mass index was calculated from measured weight in kilograms divided by measured height in meters squared. Calcium, caffeine, and alcohol intake was estimated using a food frequency questionnaire. Age, race, and smoking were determined by self-report. Radioimmunoassays of follicle stimulating hormone (FSH) and estradiol were used to validate self-reports of menopausal status. Multiple regression analysis revealed that race, age, weight, FSH, calcium, and years of tobacco intake formed the best model at baseline (r(2) = 0.32) and at 24 months (r(2) = 0.303). Physical activity was not a significant predictor for bone mineral density at either time point. There were cross-sectional changes of bone mineral density with race, age, and menopausal status. Black women had significantly higher bone mineral density than White women. However, an age-related decline in bone mineral density was exhibited in both Black and White women. Perimenopausal women had significantly lower bone mineral density as compared with premenopausal women. Furthermore 37 (9.6%) women at baseline and 34 (11%) at 24 months were designated at risk for fracture.

Effects of low-dose continuous combined conjugated estrogens and medroxyprogesterone acetate on menopausal symptoms, body weight, bone density, and metabolism in postmenopausal women

OBJECTIVE

The purpose of this study was to determine the effects of a low dose of conjugated equine estrogens and medroxyprogesterone acetate plus calcium supplementation on bone density, metabolism, body weight, and symptoms in young postmenopausal women.

STUDY DESIGN

Sixty postmenopausal women, aged 45 to 56 years, were randomized in an open-label, 2-year trial that compared treatment with low-dose continuous combined hormone replacement therapy that contained 0.3 mg of conjugated equine estrogens and 2.5 mg of medroxyprogesterone acetate plus 1000 mg of calcium per day or treatment with 1000 mg of calcium per day alone. Menopausal symptoms were evaluated for the first 12 weeks of the study; bleeding profiles, bone mineral density, bone turnover, and body weight were assessed for 24 months.

RESULTS

After 24 months, we evaluated 15 subjects in the control group (with a 50% drop-out rate) and 23 patients (with a 23% drop-out rate) in the low-dose continuous combined hormone replacement therapy group. Low-dose continuous combined hormone replacement therapy was effective in reducing menopausal clinical symptoms and provided a favorable bleeding profile and minimal side effects. In comparison with basal values, bone mineral density significantly (P <.05) increased by 2.72% +/- 0.3% in the low-dose continuous combined hormone replacement therapy group and decreased by 7.9% +/- 0.8% (P <.05) in the control group after 24 months, with parallel changes in bone metabolism marker action. In the control group, body mass index significantly (P <.05) increased from baseline value with a weight gain of 3%; in the low-dose continuous combined hormone replacement therapy group, the body mass index did not change after 24 months of treatment, and the 1.3% gain in body weight was not significant.

CONCLUSION

Low-dose continuous combined hormone replacement therapy can alleviate subjective symptoms and minimize body transformations that are associated with early menopause and provide an effective protection against the activation of bone turnover and osteoporosis.

Women's health care during the perimenopause

OBJECTIVE

To review the perimenopause, its associated symptoms, and current management options.

DATA SOURCES

Published articles identified through MEDLINE (1966-2000) using the search terms perimenopause and treatment. Additional articles and books were identified from the bibliographies of the retrieved articles.

DATA SYNTHESIS

The perimenopause is the transition period from normal ovulatory cycles to menopause. It is associated with erratic fluctuations in reproductive hormone levels, often leading to irregular menstrual cycles, vasomotor symptoms, changes in mood or cognition, and sexual dysfunction. The perimenopause is an ideal time to evaluate a woman's health risks for such common chronic midlife conditions as heart disease, osteoporosis, and some cancers, and to initiate appropriate preventive health measures. Low-dose oral contraceptives and other hormonal therapies are often effective in managing perimenopausal symptoms.

CONCLUSION

The transition to menopause is an important time in the female life span that is associated with varied physical and psychological symptoms. Pharmacists should be prepared to provide education about the perimenopause and counsel women on the benefits and risks of various pharmacologic and nonpharmacologic treatments that can ease their passage through this often difficult transition. Pharmacists also are well-positioned to educate and encourage perimenopausal women to initiate lifestyle changes that can enhance their health for the rest of their lives.

Postmenopausal osteoporosis management

Osteoporosis is perhaps the widest-ranging social, physical, and economic impact of estrogen deficiency. Postmenopausal bone loss is the major determinant of osteoporosis. Osteoporotic risk can be determined by measuring bone mineral density using dual X-ray absorptiometry. The radiation free quantitative bone ultrasound is emerging in the assessment of bone structure giving reliable estimates of fracture risk. Diet and exercise are important in determining a woman's risks for osteoporosis. Hormone replacement therapy clearly decreases bone turnover and prevents postmenopausal bone loss and reduces fractures. Tibolone as well as raloxifene prevent bone loss and solid data demonstrate a reduction of vertebral fractures after raloxifene administration.

Forearm bone density in users of Depo-Provera as a contraceptive method

OBJECTIVE

To determine the influence of depot medroxyprogesterone acetate (MPA) on bone mineral density when used as a contraceptive method.

DESIGN

Cross-sectional study.

SETTING

Academic tertiary-care hospital.

PATIENT(S)

Fifty premenopausal women who had used depot MPA as a contraceptive method for > or =1 year and 50 women who had never used hormonal contraceptive methods.

INTERVENTION(S)

Bone mineral density was evaluated at the midshaft and at the distal radius of the nondominant forearm using single x-ray absorptiometry.

MAIN OUTCOME MEASURE(S)

Bone mineral density.

RESULT(S)

Bone mineral density at the midshaft of the forearm was lower in depot MPA users than in women who had never used hormonal contraceptive methods, but the difference was not statistically significant. At the distal portion, bone mineral density was significantly lower in the study group. The duration of depot MPA use was not related to bone mineral density.

CONCLUSION(S)

Women > or =35 years of age presented with a lower bone mineral density only at the distal portion of the forearm after the use of depot MPA for > or =1 year. However, this decrease was not related to the duration of depot MPA use. It is not possible to conclude that women who use depot MPA are at risk of osteoporosis.

Quantitative bone ultrasonometry in climacteric women

Quantitative bone ultrasound (QUS) measurement is an emerging technique in the assessment of osteoporosis risk. In this study, bone mineral density (BMD) (mg/cm2) of lumbar vertebrae, neck, Ward's triangle and trochanter were measured by DXA and the phalanx amplitude dependent speed of sound (AD-SOS) was measured by QUS in climacteric (n = 1025) women. The relationship between AD-SOS and BMD values at different skeletal sites was significant, even if the analysis showed poor correlation coefficients. These data seem to indicate that QUS can detect bone characteristics in addition to density. The AD-SOS was higher in premenopausal than in perimenopausal women. The AD-SOS further decreases in postmenopausal women without hormone replacement. The age at menopause is relevant for predicting the AD-SOS in the postmenopausal years. Conversely, the maintenance of a regular menstrual function is associated with higher AD-SOS. Thus, the early impairment and cessation of ovarian function can lead to an earlier and/or sharper decline in bone homeostasis that can be detected by QUS. In conclusion, AD-SOS is a valuable index in detecting menopausal bone loss, and could be used for the patient follow-up during menopausal transition and in therapeutic trials.

Oral contraceptives and bone metabolism

In women, the bone metabolism is markedly influenced by gonadal steroids and by their fluctuations. Indeed, estrogens influence bone metabolism by influencing endocrine and paracrine functions involved in bone remodelling. In normally cycling women, the administration of oral contraceptives does not increase bone mineral density and does not induce deleterious effects on bone. In women with ovulatory disturbances, bone turnover is increased and bone mineral density is lower than in normally cycling women. In these cases, administration of oral contraceptives is capable of blocking increased bone loss and of restoring a normal bone mineral density. Similarly, in women treated with gonadotropin releasing hormone (GnRH) analogs, the concomitant administration of oral contraceptives completely antagonizes GnRH analog-induced bone loss. The progestogenic component of oral contraceptives seems to contribute to the protective effect of estrogens on bone. Oral contraceptives are safe for bone maintenance in normal adult women, and are indeed indicated to prevent postmenopausal osteoporosis in women with ovulatory disturbances.

Influence of weight and gonadal status on total and regional bone mineral content and on weight-bearing and non-weight-bearing bones, measured by dual-energy X-ray absosorptiometry

OBJECTIVE

To evaluate the influence of weight on total body bone mineral content (BMCTB) and regional body bone mineral content (head, arms, trunk and legs). This was studied in accordance with gonadal status and the weight-bearing or non-weight-bearing status of each region.

METHODS

The study included 94 postmenopausal women (mean age 60.6 +/- 10.5 years), 36 perimenopausal women (mean age 49.0 +/- 2.3 years) and 60 premenopausal women (mean age 36.1 +/- 6.9 years). Full-body bone densitometry (DXA), for measuring total body bone and regional bone mineral content, was carried out in all the women.

RESULTS

Among these groups, the influence of 1 kg of body weight on total and regional bone mineral content (percent) did not differ (paired test P ns). In the overall group of women, paired comparison showed differences between the head and other zones measured (P = 0.036-0.004). In the overall group of women, no differences were found in the percent influence of 1 kg body weight on bone mineral content in any study zone (by ANOVA, Fisher's PLSD post hoc test and the Kruskal-Wallis test). In the overall group of women, Fisher's r to z test revealed a non-significant relationship between weight and the bone mineral content of the head (r = 0.49, P ns) but in every other region the relationship between weight and bone mineral content was significant (r = 0.36-0.54, P < 0.0001 in all).

CONCLUSIONS

The effect of body weight on BMCTB and regional did not differ significantly with either gonadal status or weight-bearing (legs) and non-weight-bearing bones (arms).

Bone mass density in post-menopausal women

OBJECTIVES

To evaluate the effect of age, years since menopause and body weight on bone mass density (BMD) in 283 patients.

METHODS

Bone mass density was assessed by bone computerized mineralometry at two sites of the forearm.

RESULTS

The mean distal BMD and ultra BMD in the postmenopausal group were negatively correlated with age (P < 0.001, r = -0.48 and P < 0.001, r = -0.50, respectively) and years since menopause (P < 0.001, r = -0.32 and P < 0.001, r = -0.33, respectively). When body-mass index was regressed against distal and ultra distal BMD, positive correlations were found (P = 0.008 and P = 0.007).

CONCLUSIONS

From our data, forearm computerized mineralometry seems to be a reliable method for the evaluation of the effects of age and body-mass index on bone mass.

The menopausal transition

The menopausal transition is that period beginning with the first indications of the approach of menopause and ending with the final menses. Its morphological basis is a rapidly declining number of primordial follicles within the ovary; a decline which appears to result from an increased rate of follicular atresia. The most characteristic hormonal change in the menopausal transition is a progressive, though often fluctuating, rise in the level of serum FSH. Oestradiol and inhibin levels fluctuate markedly when observed in individual subjects but remain relatively preserved during the follicular phase of the cycle, until late in the menopausal transition. The frequency of anovulatory cycles increases as the final menstrual period approaches. The rate of symptom reporting varies among different populations of women, with maximum symptom frequency being seen during the menopausal transition. There are some indications that cardiovascular and osteoporosis risk factors may change adversely during the menopausal transition and medical practitioners should be ready to offer hormonal supplementation to women at increased risk of cardiovascular disease and osteoporotic fracture.

High bone turnover is associated with low bone mass in both pre- and postmenopausal women

In 979 healthy women, aged 30-75 years, bone mass was measured by DXA in the lumbar spine and proximal femur, and by SXA in the distal forearm. Bone turnover was assessed by urinary CrossLaps (CrossLaps ELISA), a new assay which measures type I collagen degradation products in urine and by osteocalcin (two-site N-Mid hOsteocalcin ELISA), a new assay which measures the N-terminal-mid fragment (1-43) as well as the intact (1-49) osteocalcin (OCN-Mid) in serum. For comparison data on urinary hydroxyproline (fU Hpr/Cr) and serum, total alkaline phosphatase were included (AP). In premenopausal women below 50 years of age, the concentrations of the biochemical markers were stable with age. At menopause CrossLaps and OCN-Mid increased abruptly to a level 60% and 35% above the premenopausal mean values (p < 0.001). Premenopausal women in the highest quartiles, stratified according to the concentration of CrossLaps and OCN-Mid corrected for height and weight, had 6%-11% lower bone mass in all regions (p < 0.01) as compared to women in the lowest quartiles. CrossLaps and OCN-Mid corrected for height and weight correlated with bone mass in the spine and proximal femur, r = -0.13 to r = -0.28, p < 0.05. In postmenopausal women, the difference in bone mass between the highest and lowest quartiles was 8%-14% (p < 0.001). CrossLaps and OCN-Mid correlated with bone mass measured in all regions, r = -0.14 to r = -0.32, p < 0.05. The correlation between bone mass and AP and Fu Hpr/Cr was lower; r = -0.06 to r = -0.20 for premenopausal women, NS to p < 0.01, and r = -0.01 to r = -0.23, NS to p < 0.001 for postmenopausal women. In conclusion, the present data indicate that high bone turnover is associated with a significantly lower bone mass in not only postmenopausal, but interestingly also in premenopausal women. In consistence with previous results, we found that bone turnover increased perimenopausally and in the early menopause.

Prospective evaluation of calcium and estrogen administration on bone mass and metabolism after ovariectomy

We evaluated the effects of low-dose ethinylestradiol administration in the prevention of the rapid bone loss that follows ovariectomy in women. After 10-30 days from surgery, patients received either a sole calcium supplementation 500 mg/day (n = 20) or ethinylestradiol 20 micrograms/day in addition to the same daily calcium supplement (n = 21), for 12 months. In the control group, urinary hydroxyproline excretion, serum alkaline phosphatase and plasma bone Gla protein levels presented a substantial (p < 0.05) increase, while radial bone density significantly (p < 0.05) decreased 6 months after surgery. In the ethinylestradiol-treated group, the patterns of biochemical markers indicated that ethinylestradiol can restrain the bone remodelling processes. Radial bone density showed no significant modification during the 12 months' study period. In conclusions, these results demonstrate that the administration of 20 micrograms/day of ethinylestradiol can prevent the rapid bone loss that follows ovariectomy.

Hormone replacement therapy in perimenopausal women with a low dose oral contraceptive preparation: effects on bone mineral density and metabolism

In a 2-year longitudinal, calcium-controlled study we evaluated bone density and metabolism in perimenopausal women with initial ovarian failure, and the effects of hormone replacement with a low dose oral contraceptive preparation (OC). In perimenopausal oligomenorrhoic women (n = 16) a significant (P < 0.01) increase in cycle length and plasma FSH levels as well as a parallel decrease in plasma estradiol levels (P < 0.01) were evident. In this group, despite the calcium supplementation (500 mg/day), a significant (P < 0.001) increase in the biochemical markers of bone remodelling paralleled a significant (P < 0.001) decrease (-3.4% after 24 months) in bone density. Conversely, in premenopausal oligomenorrhoic women treated with a low dose oral contraceptive (OC) formulation (30 mcg ethinyl estradiol plus 75 mcg gestodene, n = 16), bone markers showed a significant (P < 0.01) decrease, that paralleled a slight but significant (P < 0.01) increase (+1.71%) in bone density. These data suggest that premenopausal administration of OC can prevent the acceleration of bone turnover and reverse the decrease in bone density that follows the premenopausal impairment of ovarian function.