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PubMed1998

Bone mineral density in children with juvenile chronic arthritis.

The aim of this study was to evaluate bone mineral density changes in patients with juvenile chronic arthritis (JCA) and to determine the most likely causes of osteoporosis in these patients. Eighteen (11 male, 7 female) patients suffering from JCA and 14 healthy controls (10 male, four female) were included in this study. The mean age of the patients and control groups were 11.0 +/- 3.2 and 10.9 +/- 2.9 years respectively. Disease activity was determined by clinical and laboratory evaluation and 'Articular Disease Severity Score' (ADSS). Bone mineral density (BMD) of the femoral neck and lumbar spine was measured by dual photon absorptiometry. BMD of the patients at the lumbar spine was significantly lower than the control group (p < 0.05). This difference was more marked in patients treated with steroids. Femoral neck BMD was also lower in the patient group but this difference was not statistically significant. There was a negative correlation between ADSS and BMD at the spine. In conclusion, trabecular bone loss is characteristic for osteoporosis in JCA. Our results indicate that steroid treatment and disease severity are important factors in the development of osteoporosis in JCA.

Absorptiometry, Photon↗

PubMed1994

Bone mineral density predicts non-spine fractures in very elderly women. Study of Osteoporotic Fractures Research Group.

To determine the ability of bone density to predict fractures in very elderly women, we examined the association of bone density with non-spine, hip, wrist and humerus fractures in 8699 Caucasian women aged 65-79 years and 1005 women aged 80 years and older who were participants in the prospective Study of Osteoporotic Fractures. Follow-up averaged 4.9 (+/- 1.0) years after baseline measurement of appendicular bone density (single-photon absorptiometry; Osteon-Osteo Analyzer) and 2.9 (+/- 0.6) years after measurement of hip and anteroposterior lumbar spine bone density (dual-energy X-ray absorptiometry; Hologic QDR 1000) at a later examination. In general, measurements of bone density in the oldest women retained their predictive value for fractures. Among women aged 80 and over a 1 standard deviation decrease in bone density of the distal radius was associated with an increased risk of non-spine (relative risk: 1.6; 95% confidence interval: 1.3, 1.8), wrist (1.7; 1.2, 2.4) and humerus fracture (2.9; 1.8, 4.7), while a 1 standard deviation decrease in femoral neck bone density was associated with an increased risk of non-spine (1.9; 1.6, 2.4), humerus (2.4; 1.2, 4.7) and hip fracture (2.1; 1.4; 3.2). However, only trochanteric but not femoral neck fractures were associated with low bone density in these oldest women. The excess risk of fracture in women with below-median bone density was greater in those aged 80 years and over compared with the younger women: 38.4 v 20.4 per 1000 woman-years for non-spine fracture and 12.2 v 3.2 per 1000 woman-years for hip fracture.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1996

The effect of smoking at different life stages on bone mineral density in elderly men and women.

To assess the effect of smoking on bone mineral density (BMD) at different life stages, to examine whether the effect of smoking differs between men and women, and to discover whether its effect in women differs according to history of estrogen use, a cohort study was carried out with single cross-section measurement of BMD by single and dual photon absorptiometry. The setting was the Framingham Study, a population-based cohort study with over 40 years prospectively collected data on smoking. Subjects (n = 1164) consisted of cohort members participating in the 20th biennial Framingham examination (1988-1989). The measurements included in the study were BMD measured at the hip, spine and radius, smoking history ascertained at all Framingham Study examinations since 1948, and other factors affecting BMD (age, weight, estrogen use, caffeine use, alcohol use and physical activity). Neither current smoking, recent (last 10 years) smoking, nor early adulthood smoking resulted in significantly lower BMD at any skeletal site among women who had not taken estrogen. Among women who had taken estrogen, BMD at most sites was lower among current or recent smokers, although the small numbers of smokers made it difficult to find significant differences at all skeletal sites. Among men, a consistently lower BMD at all skeletal sites was observed for smokers regardless of when in their life they smoked (4-15.3% lower), although the effect of smoking during early adulthood was of a lesser magnitude (4-8% lower). Former male smokers who had quit < 10 years ago had lower BMD than men who had quit > or = 10 years ago. In conclusion, in women who had used estrogen, BMD was lower in current or recent smokers than it was in non-smokers. In men, smoking at any stage of life had adverse effects on the skeleton that was independent of weight, alcohol or caffeine use, implying other mechanisms for smoking's effect on bone.

Absorptiometry, Photon↗

PubMed1996

Can biochemical markers predict bone loss at the hip and spine?: a 4-year prospective study of 141 early postmenopausal women.

A number of recent studies have suggested that non-invasive measures of bone turnover are associated with bone loss at the forearm in postmenopausal women. Whether bone turnover markers are predictive of bone loss from the clinically important sites of lumbar spine and femoral neck remain unclear, and was the aim of this 4-year prospective study. One hundred and forty-one normal, postmenopausal women (mean age 52.0 +/- 3.3 years, mean menopause duration 20.4 +/- 5.7 months) were recruited for the study in 1988. Fasting early morning samples of blood and urine were collected at the baseline visit and stored at -20 degrees C prior to analysis. Serum was assayed for osteocalcin, oestradiol, oestrone, oestrone sulphate, testosterone, sex hormone binding globulin, dehydroepiandrosterone sulphate and total alkaline phosphatase. Urine was assayed for calcium, hydroxyproline, oestrone glucuronide and the collagen cross-links pyridinoline and deoxypyridinoline using high-performance liquid chromatography. Bone density was measured at the lumbar spine and femoral neck using dual photon absorptiometry at time 0, 12, 24 and 48 months. The mean annual percentage change in bone density (SE) was -1.41% (0.18) at the lumbar spine and -0.86% (0.22) at the femoral neck. There was no evidence of bimodality or a fast loser subgroup as the rates of change were normally distributed. Both simple and multiple stepwise regression analyses revealed no significant correlation between the rates of change in bone density with any biochemical marker, either individually or in combination, despite the study having sufficient power (80%) to detect a correlation of 0.5 between any biochemical marker levels and bone loss. We conclude that single measurements of these markers of bone turnover and endogenous sex hormones appear unlikely to be clinically useful in predicting early postmenopausal bone loss from either the spine or the hip.

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PubMed1995

Monofluorophosphate increases lumbar bone density in osteopenic patients: a double-masked randomized study.

To assess the efficacy of combined sodium monofluorophosphate and calcium therapy (FC) in increasing lumbar bone mineral density (BMD) in patients with low bone mass, we conducted a prospective double-masked randomized study in 94 patients aged 50-70 years. Patients were selected on the basis of a lumbar BMD at least 2 standard deviations (SD) below the young adult mean (T-score) but without evidence of previous vertebral fracture (severe osteopenia). They were randomly assigned to receive for 2 years, twice a day, either FC (13.2 mg F-, i.e. 100 mg sodium monofluorophosphate, and 500 mg Ca2+) or C (500 mg Ca2+). Vertebral BMD was measured by dual photon absorptiometry from L2 to L4. Comparison at final assessment in the 76 eligible patients (Student's t-test) showed a statistically significant difference between the two groups in the mean BMD increase in favour of FC. Furthermore, Student's t-test showed a significantly greater increase in lumbar BMD in FC-treated patients at 1 year, at 18 months and after 2 years (mean increase of 7.1%/year). These results were confirmed by ANOVA at 1 year, at 18 months and after 2 years of treatment. Of the FC-treated patients, 71.4% were considered to have responded (i.e. they showed an increase in lumbar BMD of more than 0.034 g/cm2). The dosage of 26.4 mg fluoride ion/day (i.e. 200 mg monofluorophosphate/day) therefore appears to be safe and to increase the BMD effectively in patients with low bone mass prior to vertebral fracture.

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PubMed1992

Hip fracture patients have generalized osteopenia with a preferential deficit in the femur.

Bone density was measured in 31 white women with hip fractures by single- and dual-photon absorptiometry at the radius, lumbar spine and proximal femur. The mean age was 71.4 years. Comparison with premenopausal normals revealed Z-scores as follows: radius, -1.75; spine, -1.45; femoral neck, -2.40; Ward's triangle, -2.41; and trochanter, -1.42. These values altered when calculated for the patient's age by the use of sex- and race-specific regressions against age in a healthy, non-fracture population. The age-corrected Z-scores were as follows: radius, -0.09; spine, -0.18; femoral neck, -0.79; Ward's triangle, -0.44; and trochanter, -0.80. Thus, although our patients had absolute osteopenia at all skeletal sites when compared with young normals, when compared with age-matched normals (relative osteopenia) the only site with a noticeable deficit was the femur. Interpretation of the extent of osteopenia by comparison with young normals may lead to different conclusions than when an age-matched population is used. Patients with hip fractures had a preferential deficit in density of the femur when compared with normal women of their age.

Absorptiometry, Photon↗

PubMed1996

Caffeine does not affect the rate of gain in spine bone in young women.

The effect of nutrition and dietary caffeine consumption and physical activity on bone gain in women during the third decade of life was determined in a longitudinal, descriptive study of 145 healthy college-aged women. Estimates of caffeine and other dietary intakes were determined by repeated 7-day diet diaries. Measurements of bone mineral in the spine and total body mineral content were determined by dual-photon absorptiometry. Measures of physical activity were ascertained by physical activity monitor. The mean estimated caffeine, calcium and protein intakes for the young women students were 103 +/- 106 mg/day (mean +/- SEM), 831 +/- 334 mg/day (mean +/- SEM) and 66 +/- 16 g/day (mean +/- SEM) respectively. The median rates of bone gain were 5.9% for spine bone mineral content, 6.8% for spine bone mineral density and 12.5% for total body bone mineral. In a multiple regression analysis the significant predictors (+ or -) of the rate of gain were age (-), activity (+), calcium intake (+) and protein intake (-). Caffeine consumption was not associated with significant reduction in rates of bone gain. While calcium and protein nutrition affect bone gain in the third decade of life in women, moderate caffeine intake (one cup of coffee per day, or 103 mg) appears to be safe with respect to bone health in this age group.

Absorptiometry, Photon↗

PubMed1992

Bone mineral content in women: trends of change.

Altogether 426 women had their forearm bone mineral content (BMC) measured with single photon absorptiometry (SPA): one group in the early 1970s, another about 18 years later. Both groups represented purportedly healthy subjects. A third group of 328 women, measured at the same time as the second group, was from the same population but chosen by random selection (the population-based group). In the two sets of non-population-based women there was a small percentage reduction in the cortical forearm bone mass in the recent measurement as compared with the earlier measurement. This was significant only in women below 70 years of age. The forearm BMC, both cortical and trabecular, was less in all age groups of women randomly selected from the same population as the healthy control sample. This difference emphasizes the importance of selecting normative data from a population-based sample.

Absorptiometry, Photon↗

PubMed1991

Peripheral and axial bone mass in Austrian free climbers.

The present investigation was carried out in healthy white adult males to determine the effects of exercise, in the form of free climbing, on peripheral and axial bone mass. 13 men who have been regularly engaging in alpine free climbing for a mean period of nine years and, for training purposes, have been performing additional muscle building exercises (4.5 h +/- 1 SEM per week) and 12 age matched controls were included in the study. Bone mineral content of the non-dominant distal forearm was measured by single-photon absorptiometry, and bone mineral density of the lumbar spine was determined by quantitative computed tomography. It was found that consistent exercise in the form of alpine free climbing was associated with increased bone mass of the lumbar spine (162.4 +/- 4.4 vs 184.8 +/- 7.9 mg/ml, p less than 0.025). Peripheral bone mineral content of the distal forearm was slightly but not significantly increased in the free climbers (55.4 +/- 9.0 vs 61.1 +/- 7.4 Units, p less than 0.09 N.S.). The study provides additional evidence that exercise in the form of alpine climbing, is associated with increased lumbar bone mass.

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PubMed1993

Age-related changes in female femoral neck geometry: implications for bone strength.

Bone strength is a function of both bone mass and its geometric distribution, a factor that is obscured in the conventional bone mineral analysis. Structural geometry is particularly important in areas such as the femoral neck that are exposed to bending loads in vivo. Here we present results of a study examining age changes in the structural geometry of the female femoral neck derived from dual photon absorptiometry (DPA) data. In a previous study, differences in the aging patterns of males and females over the entire adult age range were demonstrated. In that study, only males showed "compensatory" geometric restructuring of the femoral neck which tended to offset loss of bone mineral with age. In the present study, femoral neck structural properties from 1044 women were examined for aging trends before and after the approximate age of menopause (50 years). Women in the premenopausal age range showed a 4% decline per decade in femoral neck BMD, but no change in the femoral neck cross-sectional moment of inertia (CSMI). This aging pattern is similar to that of males in our earlier study, and in both cases resulted in little or no increase in femoral neck bending stresses. After age 50, however, women show a more rapid decline in femoral neck BMD (7% per decade) accompanied by a decline in CSMI of 5% per decade. These changes result in increases in femoral neck stresses of 4-12% per decade due to the apparent lack of compensatory restructuring to offset the loss of bone mineral.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1993

Reduction of bone density: an effect of gonadotropin releasing hormone analogue treatment in central precocious puberty.

Gonadal steroids drive the significant bone mineral increase that occurs at puberty. Oestrogen deprivation in women results in bone loss. We investigated bone mineralization by single photon absorptiometry in girls with central precocious puberty (n = 13, age 3.8-8.5 years) before and during 1 year of treatment with gonadotropin releasing hormone analogue (GnRH-a = long-acting D-Trp6-GnRH, 60 micrograms i.m. every 28 days). Before GnRH-a therapy, bone mineral density (BMD) was significantly higher in patients than in ten control girls matched for chronological age (patients 0.575 +/- 0.097 g/cm2, controls 0.433 +/- 0.049 g/cm2, P < 0.001). Patient BMD was not significantly different from that of ten control girls matched according to patient bone, age (0.550 +/- 0.046 g/cm2, P = NS). During GnRH-a treatment, pituitary-gonadal axis was suppressed and patient BMD significantly decreased (6 months: -6.0%, P < 0.002 vs baseline; 12 months: -8.0%, P < 0.001 vs baseline). We conclude that in girls with precocious puberty the activation of gonadal steroid secretion induces an increase in bone mineralization and that oestrogen deprivation by GnRH-a treatment caused a significant decrease in BMD.

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PubMed1996

Bone mineral density in adolescent females treated with L-thyroxine: a longitudinal study.

UNLABELLED: It has been suggested that chronic treatment with L-thyroxine (L-T4) could be implicated in reducing bone mineral density (BMD). The purpose of this longitudinal study was to determine whether appendicular and axial BMD is decreased by L-T4 treatment in adolescent girls. Thirteen adolescent girls with subclinical hypothyroidism caused by chronic lymphocytic thyroiditis were enrolled in the study at the median age of 13.4 years (range 9.2-18.1 years). L-T4 was administered in a single dose of 1-5 micrograms/kg daily. BMD was evaluated at the distal one-third of the non-dominant radius by single photon absorptiometry (SPA) and at the lumbar spine (L2-4) by dual energy X-ray densitometry (DEXA). Osteocalcin levels were measured to assess bone turnover before and during L-T4 treatment. Before the start of therapy, mean BMD at both the radial and lumbar level was not significantly different from that of a control group (median age 13.0 years; range 9.0-18.5 years). during L-T4 therapy for 2-5 years, BMD did not change at any site. Before treatment, osteocalcin levels were not significantly different from those of controls and did not change during follow up. CONCLUSION: Long-term L-T4 therapy in adolescent girls has no adverse effect on BMD and bone turnover. Our data indicate that attainment of peak bone mass is not impaired by L-T4 administration.

Absorptiometry, Photon↗

PubMed1995

Bone mineralisation in type 1 glycogen storage disease.

UNLABELLED: Radial bone mineral content (BMC) was measured using single photon absorptiometry in 11 prepubertal children, aged 3.4-12.6 years, with glycogen storage disease type 1 (GSD-1), 2 of whom were receiving granulocyte colony stimulating factor (G-CSF) therapy for chronic neutropenia. Patients were short (median height SD score -1.35, range -3.74 to -0.27), and had reduced BMC Z scores (median 1.79, range -6.35 to +0.27) and radial bone width Z scores (median -0.72, range -2.00 to +0.68). Those receiving G-CSF did not differ significantly from the rest of the group. Generally dietary calcium intake was low and urinary calcium excretion increased. Urinary lactate excretion was high but did not correlate with BMC Z scores. Factors regulating bone metabolism (parathyroid hormone and 25-hydroxy vitamin D concentrations) and markers of bone formation (osteocalcin and skeletal alkaline phosphatase) were not increased implying that there was no compensation for increased bone resorption. CONCLUSION: Patients with GSD-1 may be at increased risk of fracture in later life and require close attention to metabolic control and calcium balance.

Absorptiometry, Photon↗

PubMed1996

Amount and composition of bone minerals in chronic liver disease.

Alterations in bone mineral are a common complication of chronic liver disease. The aim of the current study was to assess bone mineral status in patients with chronic liver disease not treated with corticosteroids and to investigate any possible correlation with the histological stage of liver disease. Bone mineral status in 27 patient with chronic active hepatitis, and 17 with active cirrhosis was compared to that of matched controls. Partial body neutron activation analysis was applied for measuring hand bone phosphorus, single-photon absorptiometry for measuring forearm bone mineral content, and dual-energy x-ray absorptiometry for measuring spinal bone mineral density. These noninvasive measurements were supplemented with data obtained by high resolution radiography and biochemistry. Decreased metacarpal cortical thickness was found in five patients, all in the cirrhotic group. In addition, both mean intact parathyroid hormone and 25-hydroxyvitamin D levels were reduced in this group of patients. The mean values of the quantities assessed by the in vivo techniques in patients in the early stages of the hepatic disease did not differ statistically from those of matched normal controls. On the contrary, these quantities were reduced by 9% in the patients at the late stages relative to controls. In conclusion, only the late stages of liver disease are associated with an increased risk of fractures.

Absorptiometry, Photon↗

PubMed1995

Heel ultrasound in women after long-term ERT compared with bone densities in the forearm, spine and hip.

To compare heel ultrasound values with bone densities at different measurement sites as determined by single photon absorptiometry (SPA) and dual-energy X-ray absorptiometry (DXA) in long-term users of estrogen replacement therapy (ERT), we analyzed data from 30 users of estradiol implants (mean duration of treatment 16 years) and 32 non-users, comprising 28 complete age-matched pairs. The precision errors in vivo of ultrasound measurements were 0.18%, 1.3% and 1.5% for speed of sound (SOS), broadband ultrasound attenuation (BUA) and stiffness index, respectively. In the controls, ultrasound parameters correlated well with values from SPA and DXA measurements (r = 0.51-0.63, p < 0.004). In long-term users of ERT, however, measurements with ultrasound did not correlate with DXA in the spine and hip (r = 0.01-0.31, NS) but correlated well with SPA in the forearm (r = 0.47-0.66, p < 0.009). Implant users, compared with non-users, had small and just significantly different values when measured by ultrasound (at most 12%, p = 0.03-0.04) but significantly higher bone mineral densities (18%-25%, p = 0.0001-0.01) in the forearm, spine and hip when measured by SPA or DXA. Data indicated that a substantial proportion of long-term users of estrogen may be non-responders concerning the effect of estrogen on bone qualities expressed in heel ultrasound values. In a multivariate regression analysis the effect of increasing age and increasing treatment duration were both negative for the ultrasound parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1995

Reduced bone mass and normal calcium metabolism in systemic sclerosis with and without calcinosis.

Forty-three female patients with systemic sclerosis divided into subgroups based on the extent of skin involvement and the presence of calcinosis, and 50 sex and age-matched healthy controls were investigated for bone mineral density (BMD) on the basis of radial (dual photon absorptiometry, Osteograph, NIM), lumbar, and total body measurements (dual energy X-ray absorptiometry, Lunar DPX, Lunar Corp.), and for parameters of calcium metabolism. The patients showed a lower BMD (mean +/- SD; mg/cm2) than the controls at the radial (313 +/- 69 vs 347 +/- 73; p < 0.005), lumbar (974 +/- 143 vs 1081 +/- 154; p < 0.005), and total body (997 +/- 82 vs 1075 +/- 109; p < 0.05) determinations. The patients with the diffuse form of skin involvement had lower values than those with the limited form. There was a negative correlation between BMD and the duration of the disease. The presence of calcinosis was not found to have any effect on BMD. Calcium metabolism was found to be normal in each subgroup. It may be concluded that generalized osteoporosis is a feature of systemic sclerosis, with and without calcinosis. The extent and duration of the disease may play a role in determining bone loss.

Absorptiometry, Photon↗

PubMed1996

Bone mineral density in ankylosing spondylitis.

Vertebral osteoporosis is a well-recognized feature of ankylosing spondylitis (AS) and also the vertebral compression fractures due to osteoporosis are a common but frequently unrecognized complication of AS. Both may contribute to the pathogenesis of spinal deformity and back pain. The aim of this study was to measure vertebral and femoral neck bone mass in patients with AS by dual photon absorptiometry, to determine the prevalence of compression fractures and to examine the relationship between bone density and disease severity. We found that the bone mass was diminished in the lumbar spine in moderate AS versus mild forms but the patients with advanced disease had the highest BMD values. Examination of spinal radiographs revealed compression and biconcave fractures in 9 (40.9%) cases. Neither the duration of the disease and the degree of sacroiliitis, nor the disease activity assessed by laboratory and clinical parameters was found to significantly affect the results.

Absorptiometry, Photon↗

PubMed1996

Influence of marrow on ultrasonic velocity and attenuation in bovine trabecular bone.

Measurements of ultrasonic velocity and specific differential attenuation (SDA) were obtained on 24 bovine trabecular bone specimens from the femoral condyles. The measurements were obtained using two pairs of ultrasonic transducers, one with a low nominal center frequency (500 kHz) and the other pair with a high nominal center frequency (1 MHz). The ultrasonic velocity and specific differential attenuation associated with the bone samples were determined both with and without marrow, i.e., replacing the marrow with water in the pores of the trabecular bone. Significant increases (2.1% and 2.9%) in the velocity of ultrasound were observed after removal of the marrow, for the low and high frequency transducer pairs, respectively. In contrast, significant decreases (-6.5% and -8.8%) in SDA were observed after removal of the marrow, for the low and high frequency transducer pairs, respectively. The bone densities (BD) of the samples were also determined using single photon absorptiometry (SPA). Correlations between ultrasonic parameters and bone densities for samples both with and without marrow were found to be similar. For example, for the 1 MHz transducer pair, the correlation between BD and velocity was r = 0. 86 with marrow, and r = 0.89 without marrow. This study also compared the results obtained using a contact (no water bath) technique and an insertion (with a water bath) technique of ultrasonic measurements. For the high frequency transducer pair, the correlation coefficients between the two methods were r = 0.99 and r = 0.93, for the velocity and specific differential attenuation, respectively. Similar results were found for the low frequency transducer pair as well. In addition, approximately equal correlations between BD and ultrasonic velocity and SDA were also found, indicating that contact and insertion measurements provide essentially equivalent information.

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