Forearm Bone Mineral Content Research Articles

A comparison of the effects of oestrogen/progestogen, high-dose oral calcium, intermittent cyclic etidronate and an ADFR regime on calcium kinetics and bone mass in postmenopausal women with spinal osteoporosis

The effects of four different treatments for osteoporosis were compared in a prospective, randomized, 3-year study in 74 postmenopausal women with spinal crush fracture osteoporosis. Patients were randomly assigned to cyclic oestrogen/progestogen therapy (group 1, n = 20), a daily oral calcium dose of 2 g (group 2, n = 17), intermittent cyclic etidronate therapy (group 3, n = 19), or an ADFR treatment with triiodothyronine as activator and etidronate as depressor (group 4, n = 18). Spine and forearm bone mineral content was measured before entry and every 30 weeks. Combined calcium balance and 47Ca kinetic studies were performed before and after 1 and 3 years of treatment. Bone turnover, estimated by serum alkaline phosphatase and renal hydroxyproline excretion, decreased in all four groups during the first half of the treatment period but remained reduced during the second half in groups 1 and 3 only. Group 1 had a significantly positive calcium balance after 60 weeks of treatment. After 150 weeks, the positive effect on calcium balance was significant and greater in groups 1 and 3 than in the other groups. This was achieved by a greater reduction in resorption rate in group 1 at week 60 and in groups 1 and 3 at week 150 as compared with the other groups. Only group 1 had a significant increase in spinal bone mass while a decrease in bone mass at the distal forearm was observed in the etidronate-treated group. We conclude that treatment of postmenopausal osteoporosis with oestrogen/progestogen for 3 years results in net spinal bone gain and a positive effect on calcium balance slightly better than that of intermittent etidronate. These effects were inferior in the groups receiving a large calcium supplementation or the ADFR group where no change in calcium balance or bone mass was found.

Magnitude and pattern of skeletal response to long term continuous and cyclic sequential oestrogen/progestin treatment

To investigate the magnitude and pattern of the changes in bone mass during five years of continuous and cyclic sequential oestrogen/progestin treatment. Prospective study of normal, early postmenopausal women, initially a double-blind, placebo controlled trial, subsequently an open, controlled investigation. Clinical physiology unit of a general hospital. Sixty-eight normal, early postmenopausal women. 1. Continuous treatment resulted in significantly higher lumbar spine bone density than did sequential treatment (P < 0.001). Lumbar spine bone density was 19% and 15%, respectively, above that of untreated women after three years and onwards, and 10% and 6%, respectively, above the initial value; 2. Both regimens induced a more pronounced rise in lumbar spine bone density than in forearm bone mineral content (P < 0.001); 3. The spontaneous decline (without treatment) in lumbar spine bone density and forearm bone mineral content averaged 1.86% and 1.90% per year, respectively. 4. There was a significant bone loss from the lumbar spine during the last year of active treatment (P < 0.001). This would suggest that lumbar spine bone density rises to a certain level and subsequently declines. However, neither data pooled before computation nor data processed individually for each patient over five years allowed for any definite conclusions regarding the pattern of the long term skeletal response to combined oestrogen/progestin treatment. Five years treatment with oestradiol/norethisterone resulted in a substantial gain in bone mass. The highest values were found in the axial skeleton with daily administration of 2 mg oestradiol and 1 mg norethisterone. It is likely that bone mass after an absolute rise begins to decline after about four years of treatment.

Course of bone mass during and after hormonal replacement therapy with and without addition of nandrolone decanoate

A total of 33 women with postmenopausal osteoporosis were matched pairwise by age, years since menopause, and body mass index and randomized to receive either cyclic estrogen-progestagen replacement treatment (group 1) or the same treatment plus nandrolone decanoate (ND; group 2). Both groups were treated during 3 years and subsequently followed for another year off treatment. A year after cessation of the treatment the distal forearm bone mineral content in group 2 was significantly higher than that in group 1. Bone mass measurements in the axial skeleton already showed a significant difference in favor of group 2 after 3 years treatment, which persisted during the year off treatment. The decline in lumbar bone mineral mass and density in the 1 year off treatment was similar in both groups. Correction for body mass did not change these results. Bone turnover parameters did not show significant differences between the two groups after cessation of treatment. A higher muscle mass, induced by ND, could partly explain the differences between the groups since even 1 year after treatment was stopped an increased serum creatinine level was still observed in group 2.

Bone Mineral Status after Renal Transplantation Assessment by Noninvasive Techniques

Bone mineral status in recipients of renal grafts is related to preexisting renal osteodystrophy and immunosuppressive treatment. The authors assessed bone mineral status after renal transplantation. Bone mineral status of 20 male graft recipients was evaluated using the following noninvasive techniques: 1) neutron activation analysis, to measure hand bone phosphorus (HBP); 2) single photon absorptiometry, to measure forearm bone mineral content (BMC); and 3) single energy spectrum quantitative computed tomography, to measure spinal trabecular bone equivalent density (TBED). The mean (+/- SD, P) HBP, BMC, and TBED were found to be respectively, 4.8% (+/- 8.3%, P = .02), 6.6% (+/- 14.6%, P = .07) and 52% (+/- 8.5%, P < .001) lower than that measured in matched normal controls. Renal graft recipients demonstrated mean HBP and BMC decrements that were similar to those observed in matched patients on extrarenal dialysis, although the decrement in TBED was significantly greater in the graft recipients (P < .001). Repeated measurements performed during a 3-year period showed no statistically significant changes. Renal transplantation was associated with minor degree of osteopenia in the primarily cortical bone tissue. We speculate that the remarkably low TBED values in graft recipients does not reflect a mean 52% decrement of spinal bone minerals, but rather may be attributed in part to the deposition of adipose tissue in the spine as a result of corticosteroid treatment.

Bone density of normal women in relation to endogenous and exogenous oestrogens.

To evaluate the relationship between duration of hormone replacement therapy (HRT) and forearm bone density, a population-based study has been conducted of 4638 women comparing bone density of 1079 women who had taken HRT for varying times with those who had never taken it. Forearm bone mineral content (BMC) was measured by single photon absorptiometry. Additionally, free oestradiol and sex hormone binding globulin levels were measured in women with high and low bone mineral content. There were no detectable differences in BMC in those who took HRT for up to 24 months compared with those who did not. Thereafter there were significant positive regression coefficients for duration periods of 2 to 5 yr (beta = 0.77, P = 0.04 and beta = 1.76, P = 0.03) and more than 5 yr (beta = 1.66, P < 0.0005 and beta = 1.87, P = 0.009) in post-menopausal and oophorectomized women. The major determinants of BMC were height, and in post-menopausal or oophorectomized women, age. Weight and parity also had additional explanatory power for pre- and post-menopausal women. Those who were in the highest quintile of BMC but had never taken HRT showed significantly elevated percentage free oestradiol compared with those in the lowest quintile. Thus HRT is osteoprotective if taken after the menopause for more than 24 months.

Non-responders to hormone replacement therapy for the prevention of postmenopausal bone loss: do they exist?

Hormone replacement therapy (HRT) prevents postmenopausal bone loss, but the prevalence of non-responders in healthy early postmenopausal women is not known. In order to study this, we reviewed data from three published studies, each carried out in a randomized, placebo-controlled, longitudinal design over 2 year, that used seven hormone replacement therapies. Bone mineral content (BMC) was measured in the distal forearm by single photon absorptiometry. A mathematical model for elimination of measurement errors was applied to published BMC data. After this correction, we found that only 1.2% of early healthy postmenopausal women who are receiving HRT in conventional doses will lose more than 1% of forearm BMC per year. In conclusion, most, if not all, healthy early postmenopausal women who might need HRT against loss of bone will respond positively in forearm BMC to such therapy.

Effects of norethisterone on bone related biochemical variables and forearm bone mineral in post-menopausal osteoporosis.

Progestogens may be a useful therapeutic alternative to oestrogen in the treatment of post-menopausal osteoporosis. The purpose of this study was to determine the effects of norethisterone on forearm bone mineral content and bone related biochemical variables in patients with post-menopausal osteoporosis. The effects of treatment with norethisterone (5 mg/day) on bone related biochemical variables was determined in 44 women with post-menopausal osteoporosis. The effects of norethisterone on forearm bone mineral content (FMC) were evaluated by serial measurements in 39 of these women. We measured forearm mineral content, forearm mineral density, forearm fat content and fat-corrected forearm mineral density. Biochemical measurements included plasma calcium and plasma calcium fractions (ionized, protein bound, complexed and ultrafiltrable), alkaline phosphatase, bicarbonate, phosphate, albumin and globulins, serum parathyroid hormone, osteocalcin and 1,25-dihydroxyvitamin D, radiocalcium (45Ca) absorption and fasting urinary calcium/creatinine, sodium/creatinine, phosphate/creatinine and hydroxyproline/creatinine molar ratios. After 4 months of treatment norethisterone produced a fall in plasma calcium (mean +/- SEM from 2.40 +/- 0.14 to 2.32 +/- 0.13 mmol/l, P < 0.001), primarily in the non-ionized calcium, due to a decrease in plasma bicarbonate (from 29 +/- 0.28 to 27 +/- 0.28 mmol/l, P < 0.001). There were decreases in urinary calcium/creatinine (from 0.41 +/- 0.03 to 0.19 +/- 0.02, P < 0.01) and sodium/creatinine (from 15 +/- 1.1 to 10 +/- 0.93, P < 0.001) molar ratios and a rise in the renal tubular maximum for calcium reabsorption (TmCa) (from 2.36 +/- 0.041 to 2.55 +/- 0.059 mmol/l of glomerular filtrate, P < 0.001). Plasma phosphate, urinary phosphate/creatinine and tubular maximum for phosphate reabsorption (TMP) all fell (P < 0.01). Both the urinary hydroxyproline/creatinine (P < 0.001) and plasma alkaline phosphatase (P < 0.001) fell. Serum parathyroid hormone rose from 4.1 +/- 0.36 to 5.5 +/- 0.51 pmol/l (P < 0.02) and radiocalcium absorption increased from 0.67 +/- 0.08 to 0.81 +/- 0.10 fx/h (P < 0.01). There was no change in serum 1,25-dihydroxy vitamin D. After treatment with norethisterone for 4 months there was an increase in forearm bone mineral content (P < 0.05) and a decrease in forearm fat content (P < 0.02). After two years treatment with norethisterone fat-corrected forearm bone mineral content rose (mean change 17.0 +/- 5.5 mg/cm, P < 0.01). These results suggest that norethisterone prevents bone loss in post-menopausal osteoporosis by decreasing bone turnover, has a vitamin-D independent effect on intestinal calcium absorption, and increases serum parathyroid hormone levels.

Is alcohol an osteoporosis-inducing agent for young and middle-aged women?

The effects of alcohol abuse on the bone of women have scarcely been investigated, although women are more prone than men to osteoporosis. We studied 19 noncirrhotic female alcoholics (aged 24 to 48 years) hospitalized for 2 weeks for withdrawal and three groups of control women (n = 182). Sixteen patients and all control subjects had regular menstrual cycles. Forearm bone mineral content (BMC) and axial bone mineral density (BMD) were measured by single-photon absorptiometry and dual-energy x-ray absorptiometry, respectively. Parameters of bone metabolism were analyzed at the beginning and end of the withdrawal period. BMC and BMD did not differ between patients and controls at any of the five measurement sites. On admission, bone formation of the alcoholics was depressed as reflected by osteocalcin levels (−48%, P < .01); it normalized during abstention ( P < .01). Urinary hydroxyproline, a parameter of bone resorption, and serum intact parathyroid hormone were at the control level throughout the observation period. Serum ionized calcium level increased by 4% ( P < .0001), and serum free fatty acid (FFA) levels decreased by 30% ( P < .05) during withdrawal; there was an inverse correlation between changes in these two parameters ( r = −.49, P < .05). On admission, serum concentrations of 25-hydroxyvitamin D 3 [25-OH-D 3] and 1,25-dihydroxyvitamin D 3 [1,25-(OH) 2-D 3] were reduced by 46% ( P < .001) and 16% ( P = .16); these did not normalize during abstention. In conclusion, provided that liver cirrhosis and gonadal dysfunction are not contributing, even heavy drinking does not seem to decrease bone mass in young and middle-aged women. Alcohol-induced suppression of bone formation is quickly reversed during abstention, which is not the case for decreased vitamin D metabolites.

Predicting various fragility fractures in women by forearm bone densitometry: a follow-up study.

This is a follow-up of a previous study on the predictive power of bone mineral measurements; two more observation years have been added. A group of women (n = 1076) had their forearm bone mineral content (BMC) measured from 1970-1976. All fractures that occurred in 1975-1987 (13 years) were recorded. Four hundred sixty-nine fragility fractures occurred during the collection period. Again, it was found that BMC at the distal end of the forearm is a good predictor of future fracture before the age of 70. The measurement at the proximal site (forearm shafts), however, in contrast to our previous study, has a capacity of predicting fracture also in the age group 70-80. BMC measurements were good predictors of vertebral crush fractures and trochanteric hip fracture but lesser predictors of fractures of the distal end of the forearm. In age groups 40-70, BMC was a stronger predictor of fracture than age, and the risk associated with a 1 SD decrease of BMC 6 was 3.2 for a hip fracture as compared with those without any fragility fracture, even when adjusted for age. In addition to BMC, low body weight was a fracture predictor. Body weight 5 kg below age-adjusted mean increased the risk of a trochanteric hip fracture by 30%. The data are used in hypothetical calculations of the effects of screening.

Variability in Bone Mass Measurement-Reply

In Reply. —Drs Kannus and Sievanen question the statistical significance of the findings of gain of bone mass in the third decade of life in women because of the wide range of the 95% CIs. In addition, they asked for a parametric statistical analysis of the results because of their skepticism about the validity of median values and nonparametric tests. The mean slopes (percentage per decade ±SD) were 4.82%±21.17% and 2.96%±18.32% for forearm bone mineral content and bone mineral density, respectively, 5.54%± 15.70% and 6.06%±15.07% for spinal bone mineral content and bone mineral density, respectively, and 12.62%±14.17% for whole body bone mineral content. In fact, we performed parametric tests ( t test) of the mean slopes and found them all to show significant increases in bone mass during the third decade. However, the tests of normality showed that the data were not normally distributed. While the t test is fairly robust,

Bone Mineral Density in Children and Adolescent Females Treated with High Doses of L&amp;middot;Thyroxine

Single-photon absorptiometry was used to assess forearm bone mineral content (BMC) at a proximal site (PBMC) and at a more distal site (DBMC) of the non-dominant distal forearm in 20 children and adolescent females taking high doses of L-thyroxine (120 micrograms/m2/day) for a period of 6-96 months for endemic goiter, Hashimoto's thyroiditis or thyroid cancer. PBMC was significantly reduced compared to controls (p < 0.002). No correlation was found between PBMC, the values of circulating thyroid hormones and the indices of tissue hyperthyroidism such as TSH and systolic time intervals (STI), suggesting that bone is a very sensitive target for thyroid hormones. Further studies are necessary to confirm our findings and to verify their clinical significance. At present, we believe that suppressive doses of L-thyroxine should be reserved for cancer patients only.

Can urinary pyridinium crosslinks and urinary oestrogens predict bone mass and rate of bone loss after the menopause?

We measured urinary pyridinoline and deoxy-pyridinoline by high performance liquid chromatography, and urinary oestrogens by radioimmunoassay, in 68 healthy postmenopausal women to evaluate these assays for the prediction soon after the menopause of the risk of developing osteoporotic fractures in later life. Change in forearm bone mineral content was assessed by single photon absorptiometry over 4 years. Although there was no significant correlation between the pyridinium crosslinks and urinary oestrogens, we found that up to 58% of the variation in the rate of loss of bone mineral content in women soon after the menopause could be explained by pyridinoline and oestradiol glucuronide assays together with body mass index. Measurement of the urinary pyridinium crosslinks and oestradiol glucuronide may make a significant contribution to a biochemical screening procedure for future osteoporotic fracture.

Earlier wrist fracture: A confounding factor in distal forearm bone screening

Thirty-six women aged 60, 70 or 80 years who had fractured one of their distal radii (Colles' fracture) 0 to 35 (median 10) years earlier were examined in this population-based study. Single photon measurements (SPA) were performed on both arms 1 cm and 6 cm proximal to the styloid process of the ulna. All women were questioned about earlier wrist fractures and which, if any, side had been affected. Information about the type and site of the fracture was also gathered from the hospital records. The bone mineral content (BMC) was found to be increased by almost 20% in the once-fractured radius at the distal measuring site (1 cm) when compared with the unaffected side. This difference did not seem to diminish with time. At the proximal measuring site there was no difference between the once-fractured and the non-fractured side. There was a progressive loss of bone mineral in the once-fractured arm during the first years after the fracture however. This appeared to be reversed after about 10 years to a relative gain, even though the correlation was weak. Six of the 36 women could not remember which side had been fractured and five could not remember having had such a fracture at all. Determination of osteoporosis by measuring forearm BMC with single photon densitometry is therefore of limited value in some women of the oldest age groups.

Steroid-induced mandibular bone loss in relation to marginal periodontal changes.

Long-term high-dose glucocorticosteroid treatment may be suspected as causing profound marginal periodontal bone loss due to the immunosuppressive/antiinflammatory effects and due to the osteoporotic side-effects. This study comprised an analysis of the loss of the mandibular and forearm bone mineral content (BMC), measured in vivo by dual-photon scanner, in relation to the concomitant changes of the periodontal indices (visible plaque, gingival bleeding, loss of attachment) in 17 acute nephrotic dentate patients undergoing intensive steroid treatment for 12 months. The measurements were performed at start of treatment, when all patients were considered healthy as regards the skeleton, and at the 6-month and 12-month follow-up. The mean BMC loss at the standard sites of the mandible and the forearm bones was 5.6%/year at both sites. No significant changes could be demonstrated in the periodontal indices (P greater than 0.10), and no relation was found between the mandibular BMC loss and the periodontal condition (R = 0.06, P greater than 0.10). In conclusion, profound marginal periodontal bone loss does not seem to be a prominent side-effect of long-term glucocorticosteroid treatment, although the degree of induced osteopenia in the mandible corresponds to that in other cortical bones of the skeleton.

Bone mineral status in growth hormone-deficient males with isolated and multiple pituitary deficiencies of childhood onset.

In order to determine whether growth hormone (GH) deficiency of childhood onset affects the adult bone mineral status, we assessed bone mineral content (BMC) by photon absorptiometry in 30 full-grown GH-deficient men (8 with isolated GH deficiency and 22 with multiple pituitary deficiencies; 28 previously treated with GH) and in 30 male controls matched for age (within 4 yr) and height (within 10 cm). Forearm BMC was measured by single photon absorptiometry just proximally of the distal one third of the nondominant forearm (PBMC-2 in arbitrary units and PBMC/bone width (BW) after normalization for bone width) and at a more distal site, close to the carpal joint (DBMC-2 and DBMC/BW). Lumbar BMC was measured by dual photon absorptiometry and reported as total BMC for L2-L4 (LBMC in g) and after normalization for projected area (LBMD in g/cm2). The patients had a significantly lower BMC, both at the forearm (P less than 0.0001) and at the lumbar spine (P less than 0.005): 35.7 +/- 1.0 vs. 50.0 +/- 1.6 and 36.9 +/- 1.2 vs. 52.8 +/- 1.9 (mean +/- SEM) for PBMC-2 and DBMC-2 in patients and controls, respectively; 1.36 +/- 0.03 vs. 1.70 +/- 0.04 and 1.07 +/- 0.03 vs. 1.35 +/- 0.04 for PBMC/BW and DBMC/BW; 34.00 +/- 1.08 vs. 42.02 +/- 1.27 g for LBMC and 0.886 +/- 0.016 vs. 0.976 +/- 0.018 g/cm2 for LBMD. Both the patients with isolated GH deficiency and the patients with multiple pituitary deficiencies were osteopenic when compared to their respective controls (P less than 0.01 to P less than 0.0001 for the patients with multiple deficiencies; statistical significance reached for PBMC-2, DBMC-2, and DBMC/BW only, P less than 0.05, in the small group of patients with isolated GH deficiency). For the patients (n = 19) who had at least three serial measurements over a period of 6 to 28 months, no decrease in BMC was detected. Our findings indicate that men with GH deficiency of childhood onset present with a low adult bone mass, despite prior GH substitution in most of these subjects. The observations of a more pronounced bone mineral deficit at the forearm (20-30% lower mean values, depending on the type of measurements) than at the lumbar spine (9-19%) and the findings of osteopenia in both the patients with isolated GH deficiency and multiple pituitary deficiencies, support the view that GH deficiency per se is responsible for part of the observed deficit.(ABSTRACT TRUNCATED AT 400 WORDS)

Discriminatory ability of bone mass measurements (SPA and DEXA) for fractures in elderly postmenopausal women

We investigated the discriminatory ability of forearm bone mineral content (BMCarm) measured by single photon absorptiometry (SPA) and spinal bone mineral density (BMDspine) measured by dual-energy X-ray absorptiometry (DEXA) in 387 elderly postmenopausal women. Of these, 22 had never sustained a fracture (normal), 91 had had less than three vertebral wedge fractures (mild), 51 had experienced a peripheral fracture (moderate), and 24 had had more than three vertebral wedge or compression fractures (severe). BMCarm exceeded BMDspine slightly in the ability to discriminate the mild and moderate groups (P less than 0.01-0.001), whether calculations were performed on raw values or the Z-scores compared with premenopausal women. Receiver operating (ROC) analysis showed that at every cutoff level BMCarm had a similar ability as BMDspine to discriminate between the vertebral fracture (mild and severe) groups and healthy premenopausal and nonfractured postmenopausal women (normal), whereas BMCarm had a significantly higher discriminatory ability of peripheral fractures (P less than 0.05) (moderate) group compared with premenopausal women. We conclude that SPA and DEXA are equally capable as diagnostic procedures in women with established osteoporosis.

Journal of Bone and Mineral Research

Forearm bone mineral content was measured in 28 patients with primary hyperparathyroidism before and 1 year after successful parathyroidectomy. The forearm bone mineral content rose from a mean value of 1.068 to 1.092 g/cm (P less than 0.05, paired t-test). Those patients with the lower initial values had the largest rise. In an additional study, the forearm bone mineral content was measured in 10 women over the age of 40 years (mean age 58.6 +/- 7.9SD years) with hyperparathyroidism before and for 2 years after successful parathyroidectomy and compared with the forearm bone mineral content measured over 2 years in 12 women (mean age 56.3 +/- 5.5SD years) with continuing hyperparathyroidism and with the forearm bone mineral content of 12 eucalcemic control women (mean age 58.8 +/- 8.2SD years), also measured over 2 years. The parathyroidectomized group gained bone, whereas the ongoing hyperparathyroid group and the eucalcemic control group lost bone. The difference between the parathyroidectomized group and the ongoing hyperparathyroid group was significant after 2 years (P less than 0.05). The percentage loss of forearm bone mineral in the eucalcemic control subjects was not significantly different from the percentage loss of forearm bone mineral in the ongoing hyperparathyroid group, although the initial mean bone mineral content in the eucalcemic group was significantly higher than in the ongoing hyperparathyroid group, suggesting that a possible determinant of bone mineral loss in women in this age group is the initial bone mineral content.

The impact of measurement errors on the diagnostic value of bone mass measurements: Theoretical considerations

It has become clear over the last decade that correlations between measurements of forearm bone mineral content (BMCarm) by single-photon absorptiometry (SPA) and measurements of spinal bone mineral density (BMDspine) by dual-photon absorptiometry (DPA) in healthy subjects and patients with spinal fractures are invariably significant, but not very powerful (i.e. r = 0.5-0.7). Nonetheless, several recent studies have shown that appendicular bone mass measurements discriminate between spinal fracture and non-fracture at least as well as do spinal DPA measurements. Correlations of a given parameter with measured BMDspine are less important than those with true BMDspine. To establish the latter we made the following assumptions: (1) accuracy errors or SPA BMCarm and DPA BMDspine measurements of 2%-4% and 8%-10%, respectively; and (2) a measured biological variation of SD = 14% for both BMCarm and BMDspine, corresponding to that of healthy women at the menopause. On these assumptions, we found that a correlation between true BMCarm and true BMDspine at about r = 0.8-0.9 yields a correlation between measured BMCarm and measured BMDspine at about r = 0.6--corresponding to experimental data in healthy women at the menopause. Furthermore, we found that the correlation between DPA measured BMDspine and true BMDspine is about the same as that between the SPA measured BMCarm and the true BMDspine. Thus, with the assumptions given above, spinal (DPA) and fore-arm (SPA) measurements appears to predict equally the true BMDspine in healthy perimenopausal women.

The effects of muscle-building exercise on forearm bone mineral content and osteoblast activity in drug-free and anabolic steroids sell-administering young men

We measured bone mineral content (BMC) and bone density (BD) at appendicular sites by single photon absorptiometry in 18 men engaged in body-building exercises for at least 2 years, and in 14 age- and weight-matched controls. Eight exercises were using anabolic steroids by self-administration. Serum levels of bone Gla-protein (BGP), a reliable index of bone formation were also measured in all subjects. It was observed that muscle-building exercise was associated with increased BMC and BD at the distal radius, which contains both cortical and trabecular (more than 50%) bone. Previous authors have failed to detect any increase in BMC at mid radius, a site consisting almost entirely of cortical bone. Serum BGP levels were significantly higher in exercisers than in controls. If compared to drug-free exercisers, subjects taking steroids showed no significant increase of BMC, BD and serum levels of BGP. This study shows that muscle-building exercise is associated with increase in BMC and BD also at non-weight bearing sites, and that anabolic steroids did not provide, at the time of the observation, any further stimulus for osteoblast activity and bone formation.

The predictive value of bone loss for fragility fractures in women: A longitudinal study over 15 years

Fifteen years after their forearm bone mineral content was measured, 366 women were measured again with the same single photon technique. 96 of the women had sustained one or more fragility fractures during that period. The initial bone mineral content was less in those women who were to have fractures. The rate of loss over the years did not differ between fracture and non-fracture women--the initial bone mass was the better predictor. Peak bone mass in the women in this study occurred before the age of 40.