Effects on bone mass after eight years of hormonal replacement therapy

Pathogenesis of osteopenia/osteoporosis induced by highly active anti-retroviral therapy for AIDS

The advent of highly active anti-retroviral therapy (HAART) has dramatically decreased the rate of AIDS-related mortality and significantly extended the life span of patients with AIDS. A variety of metabolic side effects are associated with these therapies, one of which is metabolic bone disease. A higher prevalence of osteopenia and osteoporosis in HIV-infected patients receiving anti-retroviral therapy than in patients not on therapy has now been reported in several studies. Several factors have been demonstrated to influence HIV-associated decreases in bone mineral density (BMD), including administration of nucleoside reverse transcriptase inhibitors (NRTIs). In this article, discussion will focus on the molecular pathogenesis and treatment of HAART-associated osteopenia and osteoporosis.

The effect of continuous oestradiol with intermittent norgestimate on bone mineral density and bone turnover in post-menopausal women

OBJECTIVE

To assess in post-menopausal women the efficacy and tolerability of a continuous oestradiol/intermittent norgestimate HRT regimen to prevent and to reverse post-menopausal loss of bone mineral density (BMD) and to determine the effects on serum bone turnover markers markers.

METHODS

A 1-year, multicentre, international, placebo-controlled, randomised, double-blind clinical trial was conducted in 146 post-menopausal women with an intact uterus in order to assess the effect on bone loss of continuous oral 17beta-oestradiol (1 mg per day) combined with norgestimate (90 microg per day), for 3 consecutive days out of every 6-day treatment period (E2/iNGM). During a second year extension, all women agreeing to continue were on the E2/iNGM regimen. BMD was assessed prior to treatment and after 1 and 2 years or at the end of treatment in women stopping participation prematurely after at least 6 months of treatment. Serum bone turnover markers were determined prior to and at 1 year of treatment Adverse events were collected at three-monthly intervals during clinic visits over the treatment period.

RESULTS

BMD in the lumbar spine, the primary endpoint, was evaluable in 117 subjects completing >6 months of treatment. BMD increased on average by 2.4% in women on the intermittent progestin regimen. It decreased by 1.4% in placebo treated women. The change from baseline and the difference between active and placebo treatment (Delta placebo) were highly significant (P < 0.0001). On E2/iNGM, also the BMD in the total hip increased (+1.49%, Delta placebo 3.73%, P < 0.0001). The serum markers for bone formation osteocalcin and type I collagen N-propeptide were significantly reduced compared to baseline by 31 and 44%, respectively and the bone resorption marker C-terminal crosslinked telopeptide of type I collagen by 59%. Minor increases (<10%) of markers in the placebo group were not significant. During a second year extension of the trial, all subjects were on active treatment. Subjects on placebo who lost (median+/-CI 95%) 0.66% (-2.3 to +0.5) of spine BMD during the first year now gained 4.41% (2.7-7.6). They also gained 1.6% (0.1-0.3.6) in the total hip. Subjects continuously on oestradiol/intermittent norgestimate (E2/iNGM) gained an additional 5.7% (2.3-13.5) in the lumbar spine and +0.1% (-0.6 to +2.2) at the total hip. Side effects reported by women on the intermittent progestin regimen significantly in excess over reports from the placebo group were uterine bleeding, abdominal and breast pain, but not headache. Back pain and weight gain was reported by significantly fewer women on active treatment compared to placebo.

CONCLUSION

The continuous oestradiol/intermittent norgestimate HRT regimen is well tolerated, reduces bone turnover and prevents post-menopausal bone loss in healthy post-menopausal women.

Relationship of ultrasonographic endometrial thickness and uterine size to bone mineral density in postmenopausal women

OBJECTIVES

The aim of the present study was to investigate the relations of ultrasonographic endometrial thickness and uterine size to bone mineral density (BMD).

METHODS

Subjects were 200 postmenopausal women (mean age +/- S.D., 57.4 +/- 7.7 years; range, 46-75 years). Age, age at menopause, years since menopause (YSM), height, weight, and body mass index (BMI, weight/height2) were recorded. Endometrial thickness and uterine size (i.e. uterine volume and cross-sectional area) were measured by transvaginal ultrasonography. BMD of the nondominant forearm (one-tenth of the distance from the distal end of the radius) was measured by dual-energy X-ray absorptiometry. Relations of these variables to BMD were investigated.

RESULTS

BMD was inversely correlated with age and YSM (r = -0.69, P < 0.0001; r = -0.56, P < 0.001, respectively), while was positively correlated with uterine volume, uterine cross-sectional area, and endometrial thickness (r = 0.52, P < 0.001; r = 0.45, P < 0.01; r = 0.32, P < 0.05, respectively). After adjusting for age, YSM, and BMI, BMD was still correlated with uterine volume and uterine cross-section (P < 0.01 and 0.05, respectively), while correlation of endometrial thickness with BMD disappeared.

CONCLUSION

Ultrasonographic uterine size shows higher correlation with BMD than endometrial thickness in postmenopausal women. This may be attributable to the fact that uterine size rather than endometrial thickness reflects the duration of estrogen deficiency after menopause.

Long term effects of oestrogen therapy on bone loss in postmenopausal women: a 23 year prospective study

OBJECTIVE

To determine the long term effect of oestrogen therapy on bone loss after menopause.

DESIGN

Prospective observational study over 23 years.

SETTING

Malmö, Sweden.

SUBJECTS

Twenty-eight women taking oestrogen and 196 women not taking oestrogen during the follow up.

METHODS

Bone mineral density of the forearm was measured by single-photon absorptiometry at age 48 and 72 years. Use of oestrogen therapy was noted.

MAIN OUTCOME MEASURE

Rate of forearm bone loss between the age of 48 and 72 years.

RESULTS

Women taking oestrogen, for a median of 17 years (range 4 to 26), had 8.7 percentage points (95% CI 3.8-13.5) lower rate of bone loss compared with women not taking oestrogen during the same period. Each year of oestrogen therapy reduced the rate of bone loss by 0.8 percentage points (95% CI 0.2-1.4).

CONCLUSIONS

The use of oestrogen seems to reduce the rate of bone loss over a period of 23 years, and the longer the duration of the therapy, the less bone loss.

Overview on the effects of progestins on bone

In view of the fact that fractures are the clinically relevant events, risk factors for fractures are discussed first. Bone mineral density (BMD) appears to be a much less important risk factor for the most severe hip fractures than the risk of falling. No results of experimental studies on hormones and fractures at advanced age are available. An overview of the effects of progestins on bone is given. Effects of progestins on bone have been studied by in vitro experiments using cell lines and by more relevant clinical observations. Prospective studies have been conducted following the use of progestins contained in oral contraceptives, alone or in combination with oestrogens; long-term contraception by injection of depot preparations; so-called "add-back" hormonal therapy attempting to reverse the adverse effects of gonadotropin releasing hormone agonists on bone and after different regimens of hormone replacement therapy (HRT) in postmenopausal women. From the data there are no indications that the various progestins, used in clinical practice, have either a bone-protective or an oestrogen antagonistic activity. Progestins do not add or subtract much of the protective action of oestrogens on the bones.

The effects of sex and estrogen therapy on bone ingrowth into porous coated implant

Amounts of bone ingrowth into porous cobalt-chromium plugs were compared between male and female dogs, and among sham-operated and ovariectomized female dogs, with or without estrogen treatment, to investigate the effect of gender and estrogen therapy on biologic fixation. Each group consisted of eight skeletally mature dogs. Plugs were implanted bilaterally in the distal femur at 6 months after ovariectomy or sham operation. Estrogen treatment group received estradiol 20 microg/kg/day subcutaneous injection. Three months after implantation, histological examination showed significantly more bone ingrowth in areas with cortical bone contact than in areas with cancellous bone contact (P<0.001 for all groups). Bone ingrowth was essentially the same in male and female control dogs. Ovariectomized dogs showed less overall bone ingrowth than male and female controls (P=0.007). Bone ingrowth in areas with cortical bone contact did not decrease significantly, whereas bone ingrowth in areas with cancellous bone contact was significantly impaired (P<0.001) in ovariectomized dogs compared with female controls. Short-term, high-dose estradiol treatment did not increase bone ingrowth volume fraction. Mechanical tests did not show any statistical differences among groups.

CONCLUSION

Type of bone contact is the key factor affecting the amount and pattern of bone ingrowth into the porous surface. Ovariectomy results in decreased bone ingrowth in areas with cancellous bone contact, but does not compromise bone ingrowth in areas with cortical bone contact. Short-term, high-dose estradiol treatment does not enhance bone ingrowth into the porous surface. Extensively coated or full-coated porous prostheses are recommended to achieve enough cortical bone contact and ingrowth for post-menopausal patients.

Hormone replacement therapy for postmenopausal osteoporosis

The role of HRT for the prevention of osteoporosis has been clarified by the recent results of the WHI. There is consistent and favorable data from RCTs supporting the efficacy of HRT on the surrogate outcome of bone density at both cortical and trabecular sites, including a dose-response relationship. Both observational and RCT data provide support that HRT has a positive impact on the reduction of vertebral and hip fractures. The unfavorable risk/benefit profile of HRT, however, strongly limits its use for prevention of osteoporosis, given that there are other medications that have demonstrated fracture efficacy.

Meta-analyses of therapies for postmenopausal osteoporosis. V. Meta-analysis of the efficacy of hormone replacement therapy in treating and preventing osteoporosis in postmenopausal women

OBJECTIVE

To review the effect of hormone replacement therapy (HRT) on bone density and fractures in postmenopausal women.

DATA SOURCE

We searched MEDLINE and EMBASE from 1966 to 1999, the Cochrane Controlled Register, citations of relevant articles, and proceedings of international meetings for eligible randomized controlled trials. We contacted osteoporosis investigators to identify additional studies, and primary authors for unpublished data.

STUDY SELECTION

We included 57 studies that randomized postmenopausal women to HRT or a control (placebo or calcium/vitamin D) and were of at least 1 yr in duration. Seven of these studies reported fractures.

DATA ABSTRACTION

For each study, three independent reviewers assessed the methodological quality and abstracted the data.

DATA SYNTHESIS

HRT showed a trend toward reduced incidence of vertebral fractures [relative risk (RR) 0.66, 95% confidence interval (CI) 0.41-1.07; 5 trials] and nonvertebral fractures (RR 0.87, 95% CI 0.71-1.08; 6 trials). HRT had a consistent effect on bone mineral density (BMD) at all sites. The difference between HRT and control in the percent change in bone density at 2 yr was 6.76 (5.83, 7.89; 21 trials) at the lumbar spine and 4.53 (3.68, 5.36; 14 trials) and 4.12 (3.45, 4.80; 9 trials) at the forearm and femoral neck, respectively.

CONCLUSIONS

HRT has a consistent, favorable and large effect on bone density at all sites. The data show a nonsignificant trend toward a reduced incidence in vertebral and nonvertebral fractures.

Change in bone mass distribution induced by hormone replacement therapy and high-impact physical exercise in post-menopausal women

The purpose of this intervention trial was to determine whether changes in bone mass distribution could be observed in postmenopausal women following hormone replacement therapy (HRT) and/or high-impact physical exercise. Eighty healthy women, aged 50-57 years, at <5 years after the onset of menopause and with no previous use of HRT, were randomly assigned to one of four groups: HRT; exercise (Ex); HRT + Ex (ExHRT); and control (Co). HRT administration was conducted in a double-blind manner for 1 year using estradiol plus noretisterone acetate (Kliogest). The exercise groups participated in a 1 year progressive training program consisting of jumping and bounding activities. Subjects participated in two supervised sessions per week and were asked to perform a series of exercises at home 4 days/week. Bone measurements using a quantitative computed tomography scanner (Somatom DR, Siemens) were obtained from the proximal femur, midfemur, proximal tibia, and tibial shaft. Data were analyzed with a software program (BONALYSE 1.3) calculating density (g/cm(3)), cross-sectional area (CSA; mm(2)), and moments of inertia (I(max), I(min), I(polar)). In addition, the bone mass spectrum was determined as a function of the angular distribution around the bone mass center (polar distribution) and the distance from the bone mass center through the diaphyseal wall (radial distribution). After the 1 year period, there was an overall interaction of group x time in bone mineral density (BMD) at the proximal femur (p = 0.05) and tibial shaft (p = 0.035). Women in the ExHRT and HRT groups had increased proximal femur and tibial shaft BMD when compared with the change observed in the Co group (p = 0.024-0.011). The change was more pronounced in the cortical tibia, wherein the ExHRT group also differed from the Ex group (p = 0.038). No significant changes were found in bone CSA at any of the measured sites. The radial distribution indicated an increase of BMD in the endocortical part of the measured sites in the HRT and ExHRT groups and in the proximal tibia in the Ex group. The polar distribution showed that bone mass was redistributed in the anteroposterior direction. The changes in I(max), I(min), and I(polar) in the HRT and ExHRT groups differed from those in the Co group at the proximal femur, midfemur, and proximal tibia (p = 0.047-0.001). The Ex group also differed from the Co group in I(max) and I(polar) at the proximal tibia (p = 0.018 and 0.039, respectively). These results support the idea that HRT acts primarily at the bone-marrow interface. The exercise intervention chosen for this study contributed to the maintenance of bone mass. Our results suggest that both HRT and exercise have local effects on bone mass. The change in bone mass distribution induced by HRT and exercise may play an important role in the alteration of bone strength.

Effect of 1 year of discontinuation of raloxifene or estrogen therapy on bone mineral density after 5 years of treatment in healthy postmenopausal women

The beneficial effects of hormone replacement therapy (HRT), selective estrogen receptor modulators (SERMs), or bisphosphonates in the prevention and treatment of osteoporosis in postmenopausal women have been well established. However, little is known about the effects of discontinuation of treatment on bone mineral density. We investigated the effect of 1 year of discontinuation of the SERM raloxifene (Ral; 60 mg and 150 mg), conjugated equine estrogen (CEE; 0.625 mg), and placebo after 5 years of treatment in a double-blind, randomized study. Thirty-eight of 59 healthy and hysterectomized postmenopausal women (mean age 55 years) completed the treatment and 1 year follow-up period. Lumbar spine and femoral neck bone mineral density (BMD) were performed with dual-energy X-ray absorptiometry, before, during, and at the end of treatment, as well as after 1 year of discontinuation of therapy. One year of discontinuation significantly reduced the mean lumbar spine BMD in the raloxifene- and estrogen-treated women (p < 0.05), whereas mean femoral neck BMD was reduced significantly only in women treated with 60 mg Ral (p < 0.05). The mean percentage change (+/-SD) in lumbar spine BMD was: CEE, -6.2% (+/-3.7%); Ral 60 mg, -2.4% (+/-2.4%); Ral 150 mg, -2.6% (+/-3.1%); and placebo, -1.6% (+/-4.3%). Our results show that 5 years of treatment with either Ral or CEE did not protect against bone loss after 1 year of withdrawal of therapy, and that the rate of bone loss was not significantly different from that of placebo-treated women.

Anabolic effect of estrogen replacement on bone in postmenopausal women with osteoporosis: histomorphometric evidence in a longitudinal study

It is well recognized that estrogen (E(2)) prevents postmenopausal bone loss by suppressing bone resorption. Despite evidence that E(2) may also stimulate bone formation in animals, an anabolic effect in humans is still controversial. To investigate this, we studied 22 older postmenopausal females, with a mean age of 65.4 yr and mean interval of 16.9 yr since menopause and low bone mineral density. Transcortical iliac bone biopsies were performed before and 6 yr after E(2) replacement therapy (ERT) [75 mg percutaneous E(2) replaced 6-monthly plus oral medroxy progesterone acetate (5 mg daily) for 10 days each calendar month]. The mean serum E(2) level after 6 yr of treatment was 1077 (range, 180-2568) pmol/L. Bone mineral density improved in every patient, with a median increase of 31.4% at the lumbar spine and 15.1% at the proximal femur. Bone histomorphometry showed an increase in cancellous bone volume from 10.75% to 17.31% (P < 0.001). The wall thickness after 6 yr of E(2) treatment was 38.30 micrometer compared with 31.20 micrometer before commencement of ERT (P < 0.0005), indicating net bone gain. This is the first report showing histological evidence for an increase in cancellous bone volume, together with an increase in wall thickness, in a longitudinal follow-up study of ERT in older postmenopausal women. Our results show that E(2) is capable of exerting an anabolic effect in women with osteoporosis, even when started well into the menopause.

Comparison of different treatment modalities for postmenopausal patients with osteopenia: hormone replacement therapy, calcitonin and clodronate

OBJECTIVE

To evaluate the effectiveness of hormone replacement therapy (HRT), clodronate, calcitonin and a clodronate plus calcitonin combination in postmenopausal patients with osteopenia.

METHODS

One hundred postmenopausal patients with osteopenia, with bone mineral density (BMD) measurements at least one standard deviation below the mean value for young premenopausal subjects (T score < -1), were studied. They had no contraindications to HRT, clodronate or calcitonin use and were randomized to four different treatment groups. Patients in group I were treated with transdermal estradiol 50 micrograms/day and oral medroxyprogesterone acetate 10 mg/day during the last 12 days of the month; group II received oral clodronate 400 mg/day for 1 month out of every 3 months; group III received calcitonin nasal spray 100 IU/day; and patients in group IV were treated with oral clodronate 400 mg/day for 1 month out of every 3 months plus calcitonin nasal spray 100 IU/day. Elementary calcium 1000 mg/day was supplemented to patients in all groups. Spinal and femoral neck BMD measurements and markers of bone mineral metabolism were measured in each patient before treatment and 6, 12 and 18 months after treatment in 86 patients.

RESULTS

Significant increases in mean lumbar spine BMD were found in the group receiving HRT, and at the end of 18 months there was a 2.69 +/- 0.76% increase, compared with baseline. Mean femoral neck BMD also increased by 2.22 +/- 0.57% in the HRT group; this was significantly different from baseline, resulting in a higher bone mass gain than in the other three groups. Increases in both lumbar spine and femoral neck BMD were found in patients treated with clodronate, although the only significant increase was observed in lumbar spine BMD at the end of 18 months. The mean changes in BMD were not significantly different, compared with the other groups, and at the end of 18 months there was a 2.20 +/- 0.58% increase at the lumbar spine. The mean vertebral and femoral neck BMD did not change significantly throughout the study period in patients receiving calcitonin. At the end of 18 months, there was a 0.13 +/- 0.52% decrease and a 0.11 +/- 0.49% increase in mean lumbar spine and femoral neck BMD, respectively, compared with baseline. The combination of clodronate plus calcitonin increased mean lumbar spine and femoral neck BMD by 2.08 +/- 1.05% and 1.46 +/- 1.09%, respectively, at the end of 18 months, but these increases were not significantly different from those in the groups where these agents were used alone. Significant decreases in bone resorption and in markers of bone formation were observed in all groups.

CONCLUSION

HRT was found to be the most effective treatment regimen in postmenopausal patients with osteopenia, compared with clodronate, calcitonin and a clodronate plus calcitonin combination. Clodronate or calcitonin might be alternatives when HRT is contraindicated or refused by the patient; although calcitonin was found to be less effective. The clodronate plus calcitonin combination was not superior to either of these agents when used alone.

The impact of estrogen replacement therapy and raloxifene on osteoporosis, cardiovascular disease, and gynecologic cancers

OBJECTIVE

To compare the clinical utility of estrogen replacement therapy (ERT) and raloxifene in osteoporosis and cardiovascular disease in postmenopausal women and to evaluate the contrasting adverse effects of these therapies.

DATA SOURCES

A MEDLINE search was performed for January 1980 through September 1998 using the key terms raloxifene, estrogen, CVD, lipoproteins, and osteoporosis.

STUDY SELECTION AND DATA EXTRACTION

All clinical studies assessing ERT and raloxifene in cardiovascular disease or osteoporosis were evaluated.

DATA SYNTHESIS

ERT remains the standard for prevention and treatment of osteoporosis in women. Its use increases total bone mineral density (BMD) up to 12.1% and reduces hip fracture risk by 66-73%. It reduces low-density lipoprotein (LDL) cholesterol by 15-19% and increases high-density lipoprotein (HDL) cholesterol by 6-18%. Raloxifene, an alternative to ERT in the prevention of osteoporosis, increases total BMD by 2.2%. It reduces LDL by 6.2-14.1% and increases HDL by 1.5-5.7%. Preliminary data suggest that raloxifene has contrasting effects on gynecologic cancers compared with the increased risk posed by ERT.

CONCLUSIONS

Clinical trials have illustrated greater effects on BMD with ERT than with raloxifene. Studies of significant duration assessing raloxifene and its fracture risk effects are lacking. ERT appears to have greater beneficial cardiovascular risk factor effects than raloxifene. Prospective, primary prevention studies evaluating overall cardiovascular risk reduction do not exist for either intervention. Raloxifene, while more costly, is an alternative that may have a lower associated risk of breast cancer compared with ERT.

Association between bone mineral density and cognitive decline in older women

OBJECTIVE

To test the hypothesis that bone mineral density (BMD), a marker of cumulative estrogen exposure, is associated with cognitive function in nondemented older women.

DESIGN

A prospective cohort study.

SETTING

Clinical centers in Baltimore, Maryland, Minneapolis, Minnesota, the Monongahela Valley near Pittsburgh, Pennsylvania, and Portland, Oregon.

PARTICIPANTS

We evaluated 8333 older community-dwelling women enrolled in the Study of Osteoporotic Fractures who were not taking estrogen replacement.

MEASUREMENTS

Calcaneal and hip BMD were measured at baseline and at follow-up (4-6 years later); vertebral fractures were ascertained radiologically at year 6. Women were administered a modified Mini-Mental State Exam, Trails B, and Digit Symbol at baseline and at follow-up.

RESULTS

Compared with women with higher bone mineral density, women with low baseline BMD had up to 8% worse baseline cognitive scores (P = .001) and up to 6% worse repeat cognitive scores (P = .001), even after multivariate adjustments. For 1 SD decrease in baseline hip BMD or calcaneal BMD, women had a 32% (95% CI, 19-47%) or a 33% (95% CI, 20-48%) greater odds of cognitive deterioration (worst 10th percentile of change). Women with vertebral fractures had lower cognitive test scores and a greater odds of cognitive deterioration than those without fractures (OR = 1.29; 95% CI, 1.03-1.60).

CONCLUSIONS

Women with osteoporosis, whether measured by baseline BMD, reductions in BMD, or vertebral fractures, have poorer cognitive function and greater risk of cognitive deterioration. Our findings suggest a link between two of the most common conditions affecting older women. Further understanding of this association may be important for new treatment and prevention directions.

Drug related negative side-effects is a common reason for poor compliance in hormone replacement therapy

OBJECTIVES

The reasons for poor compliance with hormone replacement therapy (HRT) and, in particular drug-related reasons, have not yet been fully elucidated. In this study, a cohort of peri- or postmenopausal women--mainly workers from a small town and surrounding rural area--was studied. The aim of the study was to investigate why some women never start or discontinue HRT, even when great effort has been made to inform and fulfill the demands of the patient.

METHODS

All women who were given a HRT prescription at a gynecological practice between September 1991 and December 1992 participated in a longitudinal study. A written questionnaire was mailed to these patients in 1996. Data from the questionnaire was supplemented with information from the medical records. Care of patients included initial information, follow-up within 4 months, yearly visits supplemented with contacts on demand.

RESULTS

356 women received the questionnaire, among which 92% replied. A total of 2% never started HRT. Seventy-five percent continued the therapy for more than 3 years. Reasons for discontinuing HRT were negative side-effects (35%), desire to find out if climacteric symptoms had ended (26%), fear of cancer and thrombosis (25%), weariness of bleeding (19%) and a wish to deal with the problems 'naturally' (15%).

CONCLUSIONS

Compliance with HRT can be high if adequate information is given and follow-ups are made. The main reason for poor compliance was negative side-effects, most likely progestin-related. The results of this study suggest that the future challenge will be to minimize negative side-effects of HRT.

Does estrogen stimulate osteoblast function in postmenopausal women?

How estrogen therapy influences bone metabolism in postmenopausal women has previously been studied using several approaches, including bone densitometry, measurement of biochemical markers of bone turnover, and histomorphometry. Taken together, these investigations suggest that conventional doses of estrogen protect from bone loss predominantly through suppression of bone resorption, with little evidence to suggest that a stimulatory action on osteoblasts is also involved. In contrast, studies of patients treated with estradiol implants suggest that, following prolonged exposure to relatively high estrogen levels, an additional stimulatory effect on osteoblast function is observed. The suggestion that estrogen stimulates osteoblast activity in postmenopausal women under certain circumstances is consistent with other evidence that estrogen is an important physiological regulator of osteoblast activity. Furthermore, these findings raise the possibility that it may be useful to develop strategies for treating postmenopausal osteoporosis that aim to reproduce the stimulatory action of relatively high estrogen levels on bone formation in postmenopausal women.

Measurement of distal forearm bone mineral density: can different forearm segments be used interchangeably ?

Many different forearm sites have been used for the measurement of bone mineral density (BMD) and prediction of risk of future fracture among community dwelling populations. In populations where bone densitometry of peripheral sites may be the most cost effective and practical means of measuring BMD, such as the nursing home population, knowing the characteristics of forearm BMD measures would be beneficial. The purpose of this study was to assess the relationship of four common commercially available measures to each other and to estimate the inter- and intrarater reliability of the measures in a sample of nursing home residents as a first step toward identifying appropriate forearm measurement sites. These sites were the distal radius, the distal ulna, a composite of the distal radius and distal ulna, and the ultra distal radius. BMD measurements on 48 nursing home patients were obtained using single X-ray absorptiometry. Inter- and intrarater reliability was excellent at all four sites (interclass correlation coefficients > 0. 85). Moderate to high correlations (0.84-0.91) between the distal radius and ultra distal radius sites of the forearm suggest that these measures may be interchangeable. Although not directly assessed here, differences in bone composition among forearm sites may partially explain moderate rather than high correlations between sites and may affect the ability of each site to predict future fractures. Thus, different forearm sites may be used interchangeably for diagnostic purposes; however, the prognostic value of each site remains unknown.