[Menopause, menopause hormone therapy and osteoporosis. Postmenopausal women management: CNGOF and GEMVi clinical practice guidelines]

Postmenopausal osteoporosis is a frequent clinical condition, which affects nearly 1 in 3 women. Estrogen deficiency leads to rapid bone loss, which is maximal within the first years after the menopause transition and can be prevented by menopause hormone therapy (MHT). Assessment of the individual risk of osteoporosis is primarily based on the measurement of bone mineral density (BMD) at the spine and femur by DXA. Clinical risk factors (CRFs) for fractures taken either alone or in combination in the FRAX score were shown not to reliably predict fractures and/or osteoporosis (as defined by a T-score<-2.5) in early postmenopausal women. If DXA measurement is indicated in all women with CRFs for fractures, it can be proposed on a case-by-case basis, when knowledge of BMD is likely to condition the management of women at the beginning of menopause, particularly the benefit-risk balance of MHT. MHT prevents both bone loss and degradation of the bone microarchitecture in early menopause. It significantly reduces the risk of fracture at all bone sites by 20 to 40% regardless of basal level of risk with an estrogen-dependent dose-effect. Given the inter-individual variability in bone response, individual monitoring of the bone effect of MHT is warranted when prescribed for the prevention of osteoporosis. This monitoring is based on repeated measurement of lumbar and femoral BMD (on the same DXA measurement system) after 2years of MHT, the response criterion being no significant bone loss. Discontinuation of treatment is associated with a resumption of transient bone loss although there is a large variability in the rate of bone loss among women. Basically, there is a return to the level of fracture risk comparable to that of in untreated woman of the same age within 2 to 5years. Therefore, when MHT is prescribed for the prevention of osteoporosis in women with an increased risk at the beginning of menopause, measurement of BMD is recommended when MHT is stopped in order to consider further management of the risk of fracture whenever necessary (with possibly another anti-osteoporotic treatment).

[Menopause hormone treatment in practice. Postmenopausal women management: CNGOF and GEMVi clinical practice guidelines]

Menopause Hormonal Treatment (MHT) was initially developed to correct the climacteric symptoms induced by postmenopausal estrogen deficiency. In non-hysterectomized women, MHT combines estrogens and a progestogen, the latter opposing the negative impact of estrogen on endometrial proliferation. In France, and contrary to the USA and Northern European countries, MHT mainly combines 17β-estradiol, which is the physiological estrogen produced by the ovary, and progesterone or its derivative, dihydrogesterone. France has been a pioneer in the development of cutaneous administration routes (gel or transdermal patch) for estradiol, allowing better metabolic tolerance and a reduction of the risk of venous thromboembolism compared to the oral route. The choice of the doses as well as the treatment regimen is underpinned by tolerance as well as acceptance and compliance. The risk of breast cancer, which is one of the main risks of MHT, is higher with estro-progestogen combinations than with estrogens alone ; the preferential use of progesterone or dihydrogesterone being likely to limit the excess risk of breast cancer associated with MHT at least for duration of treatment of less than 5 to 7 years. The question of the optimal duration of MHT remains an issue and must take into account the initial indication of treatment as well as the benefit-risk balance, which is specific to each woman. Continuation of MHT is conditioned by the benefit-risk balance, which must be evaluated regularly, but also by the evolution of symptoms when MHT is stopped as well as menopause-related health risks or induced by MHT. After stopping MHT, it is necessary to maintain a medical follow-up to be adapted to the clinical situation of each woman and in particular, her cardiovascular and gynecological risk factors.

Bone mineral density at menopause does not predict breast cancer incidence

In this prospective study in 2,137 perimenopausal and early postmenopausal women who were followed over a 13.1-year period of time, we observed no association between bone mineral density measured at the beginning of menopause and the subsequent risk of breast cancer.

INTRODUCTION

This study aimed to investigate the relationship between BMD and the risk of breast cancer (BC) in young postmenopausal women.

METHODS

As part of a clinical research program, 2,137 women who were perimenopausal or within their 5 first postmenopausal years were scanned between 1988-1990 and reviewed on average 13.1 years after their initial examination. Ninety-eight incident BC cases were recorded throughout the follow-up.

RESULTS

Women with incident BC significantly differed from those who had never had BC with regard to age at menarche, age of birth of 1st child, familial history of BC and postmenopausal hormone therapy (PHT) use. There was no significant difference between the two groups for baseline DXA of the spine. There was a trend for BC cases for having lower femoral neck BMD compared to women without BC. However, women with low BMD were more likely to have taken PHT by the end of the study. In Cox multivariate analyses the relationship between BC risk and femoral neck BMD no longer existed.

CONCLUSIONS

There was no relationship between BMD measured within the first postmenopausal years and the risk of BC, which makes unlikely the possibility of using BMD as a predictor factor for BC in early postmenopausal women.

Ability of peripheral DXA measurements of the forearm to predict low axial bone mineral density at menopause

The aim of this study was to evaluate the ability of peripheral dual-energy X-ray absorptiometry (pDXA) measurement of the forearm to predict low axial bone mineral density (BMD) as defined according to the WHO classification. Two hundred and thirty-four healthy women aged 45-60 years were investigated. BMD was measured at the proximal and distal radius + ulna by pDXA and at the lumbar spine and femoral neck by DXA. There was a significant but moderate correlation between peripheral and axial BMD measurements, with r values ranging from 0.4 to 0.6 (SEE: 13.5-17%). The cutoff values for the proximal and distal radius BMD that allow the identification with 95% sensitivity of postmenopausal women with either a lumbar spine or femoral neck T-score < -1, corresponded to a T-score of +0.5 (proximal radius) and +1 (distal radius). More than 90% of the whole population had a peripheral T-score below these thresholds. Using an axial T-score < or = -2.5 as the definition of abnormality reduced to 48% (proximal radius) to 66% (distal radius) the number of women who would have required DXA axial measurements (i.e., with a pDXA T-score below the cutoff value of -0.7). Of the 33 women (14%) with a proximal radius T-score < or = -2.5 (osteoporosis), only 1 had a lumbar spine and femoral neck T-score > or = -1 (normal). Conversely, of the 50% (proximal radius) to 65% (distal radius) of the women with normal forearm measurement, 5% (proximal radius) to 9% (distal radius) were found to be osteoporotic and an additional 57% (proximal radius) to 59% (distal radius) could be classified as osteopenic (T-score between -1 and -2.5) at either the lumbar spine or femoral neck. In conclusion, use of pDXA forearm measurement as a prescreening tool in early postmenopausal women should allow the direct identification of about 50% of the women with no axial osteoporosis. However, this study highlights the difficulties in using a unique T-score that could be applied to different sites to diagnose osteoporosis.

Randomized trial of effect of cyclical etidronate in the prevention of corticosteroid-induced bone loss. Ciblos Study Group

Osteoporosis is a well-recognized adverse effect of corticosteroid therapy. This study aimed to investigate the effect of etidronate, intermittent cyclical therapy, in the prevention of corticosteroid-induced bone loss. Patients with various medical conditions starting high-dose corticosteroid therapy were enrolled in the study. The treatment had to be expected to continue for at least 12 months with the initial 90 days at a mean daily dose of at least 7.5 mg of prednisone, with subsequent treatment of at least 2.5 mg/day. One hundred seventeen patients were randomly assigned oral etidronate 400 mg/day, or placebo, for 14 days, followed by 76 days of oral calcium carbonate (500 mg elemental calcium), cycled over 12 months. The primary outcome measure was the difference in percent change from baseline in bone mineral density of the lumbar spine between the groups at the end of year 1. Secondary measures included changes in femur bone density and in biochemical markers of bone remodeling. The mean (+/- SEM) lumbar spine bone density changed 0.30 +/- 0.61% and -2.79 +/- 0.63% in the etidronate and placebo groups, respectively. The mean difference between groups after 1 yr was 3.0 +/- 0.84% (P = 0.004). The changes in the femoral neck and great trochanter were not different between the groups. There was a decrease in pyridinium crosslinks, significant from baseline at both 6 and 12 months, in the etidronate group. Osteocalcin increased in the placebo group, and difference between groups was -25.07 +/- 14.89% (P = 0.032) and -34.68 +/- 19.77% (P = 0.051), at 6 and 12 months respectively. There was no significant difference between the groups in number of adverse experiences, including gastrointestinal disorders. Etidronate intermittent cyclical therapy prevents lumbar vertebral bone loss in patients starting high-dose corticosteroid therapy.

[Vertebral bone loss in perimenopause. Results of a 7-year longitudinal study]

OBJECTIVES

Rapid bone loss after menopause is generally recognized although the exact chronology of the events, particularly in relation to onset of amenorrhea, remains poorly understood. We assessed bone loss in perimenopausal women over a 7-year period.

METHODS

Twenty-one women with an uneventful past history were enrolled before menopause and followed until menopause had been completely established. Vertebral bone density was measured by biphotonic absorptiometry annually over two 2-year periods. Individual variations in bone density were calculated according to onset of menopause.

RESULTS

Bone loss in the vertebral body increased during the two years preceding menopause (-1.6 +/- 1.5% per year), reached a peak during the first three post-menopausal years (-2.4 +/- 1.6% per year), and then fell off (-1.2 +/- 1.4% per year).

CONCLUSION

Bone loss was independent of calcium intake and appeared to be related mainly to characteristic hormone changes during the perimenopausal period. These findings raise the question as to the need and means of prevention.

Variability of vertebral and femoral postmenopausal bone loss: a longitudinal study

The rate of postmenopausal bone loss varies considerably between individuals and it has been suggested that about 1 in 3 women loses significant amount of bone mineral in the forearm. The rate of vertebral and femoral bone loss was determined by dual-energy X-ray absorptiometry throughout two consecutive 22-month periods, in 93 healthy women who had passed a natural menopause 6-60 months earlier. In all cases the bone changes were normally distributed, ranging from -6.9% to +2.8% per year in the spine and from -7% to +4.8% per year in the femur. No significant relationship was found between the two fractional rates of bone loss. When the women were stratified into three groups according to their individual rate of bone loss, we found that only 20%-47% retained their first classification during the second period of follow-up. In particular, less than 10% of the women showed a rapid rate of bone loss throughout the study. We conclude that spontaneous vertebral and femoral bone loss exhibit a great variability within the first postmenopausal years and that only a small minority of women sustain a fast rate of bone loss over several years. These results raise the question as to whether the evaluation of individual rates of bone loss at menopause might be useful in the identification of women at higher risk of osteoporosis.

[Hormone replacement therapy and early and late prevention of postmenopausal osteoporosis]

Osteoporosis is one of the main features of the ageing process and the cost of health care for osteoporosis-related fractures and their complications is a major incentive for prevention, particularly in developed countries with a continuously ageing population. The earliest strategies for prevention in menopaused women were based on the anti-osteoclastic effect of hormone replacement therapy. Several epidemiological studies have provided proof of its efficacy showing that in treated populations, there is a significant reduction in osteoporosis-related fractures of about 50%, whatever the site of fracture. Although the effects of hormone replacement therapy in the prevention of post-menopausal osteoporosis have been well established, three problems remain. First, what is the degree of efficacy if replacement therapy is started late? Second, what is the effect in patients who have already suffered an osteoporotic fracture? Third, and most importantly, what is the optimal duration of treatment for effective prevention in a given population particularly at risk of hip fracture? These questions suggest new strategies for preventive hormone replacement are needed.

[Contribution of osteo-densitometry in the definition and diagnosis of osteoporosis]

Since its first characterisation, osteoporosis has always been defined on an anatomical basis. The term osteoporosis refers to a reduction (or atrophy) in the amount of bone tissue and to microarchitectural deterioration without any mineralisation defect. Its clinical significance lies in the fractures (vertebral fracture, Colles' fracture and hip fracture) that occur spontaneously or after a minimal trauma. During the past 15 years, developments in technology of bone mass measurement (osteodensitometry) currently allow a diagnosis of osteoporosis at its anatomical stage characterised by a reduction in bone mass (osteopenia) without any symptom. A definition based on densitometry offers the major advantage of an early diagnosis, well before the development of fractures. It has been validated recently by several prospective studies which have confirmed the close relationship between the decrease in bone mass and the fracture risk. This modern densitometric approach of osteoporosis has major therapeutic implications. Indications of curative treatments of osteoporosis has major therapeutic implications. Indications of curative treatments of osteoporosis should be reconsidered according to the contribution of bone densitometry.

[Effect of menopause on vertebral bone mass. A longitudinal study]

OBJECTIVE

We evaluated bone loss in women during the peri and post-menopausal period in order to determine the exact effect of menopause on vertebral bone density and biochemical markers of bone remodelling.

METHODS

One hundred fifty-seven women who consulted for menopause and who did not wish to receive substitution therapy were enrolled. Menopause was defined as amenorrhoea > or = 1 year and serum 17-beta oestradiol < or = 20 pg/ml and luteinizing hormone > 30 IU/ml. Precocious or surgical menopauses were excluded. Two groups were formed according to the hormone pattern: a peri-menopausal group (n = 32, mean age 51.2 +/- 2.9 years) and a post-menopausal group (n = 125, mean age 54.3 +/- 3.7, menopause 1 to 11 years at entry). Bone density was measured by biphonotonic absorptiometry and blood chemistry was performed with routine laboratory methods. All tests were repeated at successive consultations and mean follow-up was 32 +/- 12 months.

RESULTS

Annual rate of bone loss was during peri-menopause (-1.8 +/- 1.7%) and the first 4 years of menopause (-1.6 +/- 1.6%), then decreased significantly beyond 4 years. Mean bone loss from 5 to 10 years menopause (-0.60 +/- 1%). Initial serum calcium, phosphorus, alkaline phosphatase and osteocalcine levels were significantly higher during post-menopause than during peri-menopause (P < 0.05). The urinary calcium/creatinine ratio was comparable between the two periods and decrease after 4 years of menopause.

CONCLUSION

This longitudinal study indicated that increased vertebral bone loss begins early during peri-menopause and is temporary since it does not continue beyond 5 years. It is important to consider these findings when developing strategy for the prevention of menopausal osteoporosis.

[Bone involvement in endocrinopathies]

Progress in bone densitometry, particularly biphotonic absoptiometry, has made it possible to better identify the effects of endocrinopathies on bone. Both cortical and trabecular bone structures can be evaluated quantitatively and topographically revealing important information on the pathophysiology of bone loss. Sex hormones play a major role in the regulation of bone mineralization and hypogonadism, whatever the origin, can lead to deleterious effects. Bone loss is known to be significative in high performance female athletes with amenorrhoea; long-term consequences are not yet determined, but stress fractures have been reported in up to 50%. Other hypogonadisms leading to bone demineralization include anorexia nervosa, chronic intake of gonadotrophin releasing hormone analogues and anti-oestrogens, and hyperprolactinism. Hyperthyroidism leads to a negative calcium balance and demineralization with remodelling, predominantly in cortical bone. In hypothyroid states a 10% bone loss is observed in vertebrae. In both cases, bone densitometry should be performed in order to evaluate the effect of treatment. The deleterious effect of spontaneous or iatrogenic hypercortisism is well known, leading to spontaneous wedge fractures of the vertebrae due to predominating trabecular bone loss. The mechanism of action of corticosteroids on bone metabolism is complex, but the major effect is an inhibition of osteoblast maturation. Recovery may be possible, but no large long-term series have yet been reported. Hyperparathyroidism and acromegaly also affect bone mineralization. The information provided by bone densitometry is essential to properly manage patients with endocrinopathies affecting bone mineralization.

[Effect of early menopause by ovariectomy on bone loss]

OBJECTIVES

Early menopause is a well-known risk factor for osteoporosis. It could be an aggravating factor when induced ovariectomy. This study was conducted to compare vertebral bone density and biochemical markers of bone remodelling in patients with spontaneous and induced early and "normal" menopause.

METHODS

The main biochemical markers of bone remodelling (serum calcium, albumin, alkaline phosphatase, osteocalcin and urinary calcium/creatinine) together with bone density (L2-L4) were measured in 55 women (age 46-77 at inclusion) with spontaneous (n = 16) or surgically induced (n = 39) early menopause (before age 40) and in 227 women (age at inclusion 47-67 years) with normal menopause (after 40 years) either spontaneous (n = 136) or surgically induced (n = 91).

RESULTS

At equivalent ages, vertebral bone density was 7 to 12% lower (p < 0.05) in women with early menopause than in women menopaused after 40. However, the serum levels of alkaline phosphatase and osteocalcin as well as the Nordin index were similar in the two groups. After adjusting for the duration of menopause, women with early menopause did not have a higher bone density than their "normal" menopause counterparts despite their younger age (9 years younger). No differences were observed between spontaneous and surgically induced menopause.

CONCLUSION

These results suggest that bone loss is more rapid or more long lasting after precocious menopause. Surgically induced menopause does not appear to aggravate bone loss independently of age. Effective prevention of this hormone dependent bone loss is required.

Influence of early age at menopause on vertebral bone mass

Menopause leads to rapid bone loss, mainly as a result of estrogen deficiency superimposed on the age-related linear bone loss. The influence of age at menopause on bone loss is unclear, although early menopause is widely considered a risk factor for osteoporosis. Vertebral bone mineral density (BMD) was measured in 1667 women divided into five groups according to hormonal status and age at menopause. Menopausal status was an independent predictor of BMD in a multiregression analysis, along with current age, years since menopause (YSM), weight, and height. For the same chronologic age (55 years), women with early menopause had a 15% lower BMD and a higher YSM than women whose menopause occurred later ("normal" menopause). After adjusting for the interval since menopause, postmenopausal women with early menopause were found to have lower vertebral BMD than postmenopausal women with normal menopause. Finally, after the age of 60, 66% of the women with early menopause had a BMD that was below the fracture threshold compared to 18% of the women with normal menopause. The results of this cross-sectional study suggest that early menopause is associated with a quantitatively higher bone loss than in women with menopause of later onset and thus constitutes a risk factor for osteoporosis.

The effect of obesity on postmenopausal bone loss and the risk of osteoporosis

There are many data indicating that osteoporotic fractures, and particularly hip fractures, are less frequent in obese subjects. Overweight and obese women have a higher bone mass after menopause than women of the same age who are not overweight, and thus in all probability have a slower bone loss. This protective effect appears to be related both to mechanical factors and to estrogen synthesis in adipose tissue.

[Postmenopausal bone loss: results of a topographic study by X-ray absorptiometry]

Bone density was determined in six areas (head, arms, thorax, spine, legs, and pelvis) using total body dual photon X-ray absorptiometry. Values were compared with the conventional anterior-posterior lumbar spine (L2-L4) absorptiometry measurement in 20 young females (25 +/- 4.2 years), 41 perimenopausal females (51 +/- 2 years), and 39 postmenopausal females (time since menopause 2.7 +/- 1.9 years). The two older groups were of similar age and physical characteristics. Total body bone mineral density and leg bone mineral density were significantly lower in the perimenopausal women than in the younger women, but this difference was no longer apparent after adjustment for height. Postmenopausal women exhibited diffuse bone loss with a particularly marked decrease in the lumbar spine measurement. Lumbar bone mineral density was significantly correlated with bone mineral densities at other sites; correlation coefficients ranged from r = 0.56 for the head to r = 0.83 for the total skeleton. However, one third of females with a lumbar measurement predictive of a high fracture risk had normal bone mineral density at another site, and vice versa. Our findings show that postmenopausal bone loss affects the entire skeleton and that measurements should be performed at several sites in order to identify high-risk women at cessation of menses.

[Postmenopausal osteoporosis: clinical characteristics in patients first vertebral crush fracture. Results of the GRIO National Multicenter Survey. Groupe de Recherche et d'Information sur les Osteoporoses]

This national multicenter study by the French Task Force on Osteoporosis Research and Information (Groupe de Recherche et d'Information sur l'Ostéoporose GRIO) was carried out to define clinical features in women presenting with a first osteoporosis-related vertebral crush fracture. Seventy-four patients with a less than three-month history of back pain due to a first vertebral fracture documented on the basis of stringent roentgenographic criteria, were compared to 74 normal age-matched female controls. Mean age at first vertebral fracture was 67 +/- 7 years. Cases and controls filled out a 78-item questionnaire on morphology, reproductive function, environmental factors, and previous fractures. The circumstances of onset and site of the vertebral fracture were recorded. Both groups were comparable in terms of age, body weight, hair color and eye color, whereas mean height was smaller by 2 cm in cases (p < 0.02). Among data on reproductive function, the only difference was a younger age at last menses among cases (47.7 +/- 5.7 versus 49.8 +/- 4.8 years); number of pregnancies and duration of breast-feeding were comparable in cases and controls. Environmental factors (smoking, alcohol use, physical activity, dietary calcium) were similar in the two groups. Cases were more likely than controls to report a history of appendicular fractures and/or a positive family history for vertebral osteoporosis. This study in French women suggests that the first osteoporotic vertebral fracture occurs approximately 20 years after cessation of menses and that risk factors include earlier age at last menses, a history of fracture, and a family history of vertebral osteoporosis.

[Is it possible to identify women with rapid vertebral bone loss during menopause? Result of a longitudinal study of 92 women at the onset of menopause]

Low bone mass is the main risk factors for osteoporosis. The role of the rate of bone loss following cessation of menses is more difficult to evaluate. We prospectively studied vertebral bone loss in 92 women six months to three years after cessation of menses in order to determine the clinical and biological characteristics of the subgroup of subjects with accelerated bone loss. Clinical characteristics, hormone assay results, and values of the main biochemical markers of bone turnover were recorded at the initial evaluation and correlations between these parameters and the rate of bone loss were investigated. Serial measurements of vertebral bone density were performed using dual photon absorptiometry. Mean duration of the observation period was 31 +/- 13 months. Mean rate of bone loss was -1.66% per year (range 1.6% to 7.7%). In women with accelerated vertebral bone loss i.e., a greater than 2.5% decrease in bone density per year (25th centile), there were trends towards lower values for body mass index and weight (non-significant) and a significantly higher urinary calcium/urinary creatinine ratio (p < 0.05) as compared with the rest of the study group. Rate of bone loss was weakly correlated (p < 0.05) with body mass index (r = 0.22) and with the urinary calcium/urinary creatinine ratio (r = 0.23) but demonstrated no correlations with osteocalcin levels or serum alkaline phosphatase activity. In conclusion, none of the clinical features or laboratory parameters studied proved capable of reliably predicting the rate of vertebral bone loss in individual women shortly after cessation of menses.

[Measurement of femoral bone density using dual photon absorptiometry. Values in osteoporosis]

X-ray absorptiometry allows measuring the density of bone in the upper end of the femur in 3 mains areas: the neck, Ward's triangle and the greater trochanter. Failin prospective data, it is not possible at present to know whether one of these areas has better performances than the others for the assessment of fracture risks. The interpretation of the measurement is based on the idea that bone demineralization is the main risk factor of osteoporotic fracture. It is carried out on the basis of reference normal values, which must be determined in the French population. More sophisticated predictive models of fracture risks are being developed. In young adults, the reproducibility of the measurements is lower than 2% for the neck and the trochanter, and around 2.5 to 3% for Ward's triangle. The density of femoral bone is not well correlated to that of the other bony sites (os calcis, ulna, vertebrae: r = 0.3 to 0.7). On the other hand, the correlation between the right and left femur is good, as well as that of the three femoral measurement areas between them. A fracture of the upper end of the femur is often associated with a decrease in femoral bone density (-12 to -15%, according to the site of measurement), while the measurement in the ulna or the spine is normal or just slightly lowered. Femoral bone rarefaction is also noted in vertebral osteoporosis. Dual photon absorptiometry allows, in most cases, an accurate and reproducible measurement of the femoral bone density. This measurement is indicated to assess the risk of osteoporosis on menopause and in elderly subjects and/or those with lumbar osteoarthritis.

[Fracture of the upper extremity of the femur in elderly women: respective role of fall and bone demineralization]

Fractures of the proximal femur in elderly individuals are becoming increasingly common in the industrialized world and represent a heavy burden in both socioeconomic and human terms. Two factors are key to the pathophysiology of these fractures: falls and decreased bone strength due to osteoporosis. Femoral and vertebral bone density was measured in 40 elderly women (83 +/- 5 years) who experienced a fall; in those who developed a femoral fracture as a result of the fall, femoral bone density was lower by 12 to 21% (z score: -0.7 to -1.04) than in those with no fracture, after adjustment for age, height and weight. Femoral neck and trochanteric area measurements had the best predictive value (area under the RoC curve: 75% +/- 8%). These was no difference by anatomic fracture type (neck or trochanter). Patients with pertrochanteric fractures had lower vertebral bone densities than controls. These findings, together with recent prospective data, demonstrate that in addition to falls, bone loss (osteoporosis) promotes the occurrence of fractures of the proximal femur in elderly patients. This has important practical implications for the detection and prevention of these fractures.

[Lower limb arteriopathy and male osteoporosis]

There are close links between bone metabolism and bone circulation. Osteoblasts are derived from the walls of the venous sinuses. As shown by Burkardt, osteoporosis is accompanied by a decrease in the number of intra-osseous capillaries, and intra-osseous arterioles may be the site of arteriosclerosis lesions. In order to determine the existence of a possible link between arteriosclerosis and male osteoporosis, the etiology of which is often poorly defined, the authors studied phosphorus-calcium balance, X-rays of the spine, and bone density of the spine and the femoral neck in 17 male arterial disease sufferers with a mean age of 61 and at Leriche stage 2, 3 or 4. These 17 patients were compared with 15 age-paired controls. Wedge fractures, absent in the control group, were seen in 9 of the 17 patients. Bone mineral content in the femoral neck was significantly reduced in the arterial disease group.

[Comparative effects of sodium fluoride and hormonal replacement therapy on bone metabolism in osteoporotic women with high fracture risk. Results of monitoring for 2 years]

Thirty seven postmenopausal women aged under 65 with densitometric osteoporosis defined by a bone density value below the 80th percentile of the osteoporotic population but without identifiable crush fractures, were treated and monitored for two years using clinical, laboratory and densitometric parameters. Sixteen of them were given hormonal replacement therapy combining percutaneous or transdermal 17 beta estradiol with a progestogen and the other 21 sodium fluoride at the dose of 50 mg/d combined with calcium and vitamin D. There was a significant increase in vertebral bone density in both groups: 6.3 +/- 0.9 per cent for hormone treatment and 7.1 +/- 1.5% for fluoride after 2 years, while it fell in a control group. The increase was linear with fluoride, while 2/3 of the gain was acquired by the end of the first year of hormonal therapy. Nine of the 16 patients on hormonal therapy and 9 of the 21 taking fluoride showed a significant vertebral gain at 2 years (greater than or equal to 0.043 g/cm2). There was no parameter which enabled the identification of "responders" before treatment. There was no difference in changes in femoral bone density between patients treated with fluoride and controls. From a laboratory standpoint, hormonal therapy caused a significant fall at 12 months in the urinary calcium/urinary creatinine ratio, and a non-significant fall in osteocalcin at 2 years. With fluoride, there was a marked rise in osteocalcin and a more moderate rise in alkaline phosphatase, reflecting stimulation of bone formation without any variation in resorption. In conclusion, this study shows the ability of both these types of treatment of increasing, by different mechanisms, the vertebral bone density of osteoporotic women. However, it does not indicate the extent to which this gain in bone density might have a positive influence on fracture risk.

[Transitory bone loss during substitution treatment for hypothyroidism. Results of a two year prospective study]

The authors report the results of a prospective study designed to assess changes in vertebral and femoral bone density during the first two years of replacement therapy in 10 patients with hypothyroidism (4 men, 6 women). During the first year, bone density measured by dual photon absorptiometry fell significantly in the lumbar vertebrae (-5.4%), neck of the femur (-7%) and the trochanteric region (-7.3%). This bone loss was accompanied by an early increase in serum osteocalcin levels, urinary calcium/urinary creatinine ratio and in Sex Hormone Binding Globulin. During the second year, there was complete recovery of values of vertebral and trochanteric bone density, while density of the neck of the femur remained significantly lower than initial values. None of the patients showed any evidence of overdose during the period of monitoring of clinical and laboratory (free T4, total and free T3, ultra-sensitive TSH) parameters. This transitory bone loss could be indicative of a state of tissue hyperthyroidism and/or "hypersensitivity" of hypothyroid bone to the action of thyroid hormones. Its influence on the subsequent risk of fracture remains unclear. In the current state of knowledge, measurement of vertebral and femoral bone density appears to be indicated in patients given long term treatment which suppresses TSH, or requiring replacement therapy for severe hypothyroidism. Any demineralisation prior to treatment could justify the temporary prescription of an antiosteoclastic agent.

[Performance of X-ray absorptiometry in post-menopausal vertebral osteoporosis. Discriminant value of vertebral and femoral measurements, fracture threshold, reproducibility]

The aim of this study was to assess the performance of a new bone densitometry technique, X-ray absorptiometry, in vertebral osteoporosis with fracture(s). Vertebral and femoral (neck, Ward's triangle and trochanter) bone density was measured in 60 women with at least one vertebral compression fracture of osteoporotic origin (mean age: 61), 100 controls of the same age and in 40 young adults (mean age: 30). Osteoporosis patients had significantly (p less than 0.0005) low bone density values in comparison with the young adults: -40 to -50% (T-score -1.9 to -2.3) for the femur and with control subjects of the same age: -20 to -30% (Z-score -2.2 to -2.6) for the spine; -10 to -20 (Z-score -1.1 to -1.3) for the femur. Measurements using the spine and Ward's triangle had the best discriminant values assessed by the ROC (Receiver Operating Characteristics) technique (areas under the curve: 95% and 84% respectively). The fracture threshold was fixed at a vertebral bone density of 0.78 g/cm2, this value giving the best compromise between sensitivity (83%) and specificity (95%) with 91% of subjects appropriately classified. Reproducibility was assessed in the short term in 9 osteoporosis patients. The mean standard deviation of measurements was 0.017 g/cm2 (coefficient of variation: 2.6%) as compared with 0.010 g/cm2 (coefficient of variation: 0.8%) in the young adult. These results emphasise the true advance represented by X-ray absorptiometry in the area of bone densitometry, notably in the assessment and monitoring of demineralisation disorders.