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[Dual-energy x-ray absorptiometry and quantitative ultrasound bone density examinations in primary hyperparathyroidism].

The aim of this study was the analysis and comparison of bone density data obtained by dual-energy X-ray absorptiometry (DEXA) and quantitative ultrasound (QUS) and the follow up of bone density after parathyroidectomy of our patients with primary hyperparathyroidism. The authors performed bone mineral density (BMD) measurements using DEXA (Hologic QDR 4500 C) and QUS (Lunar Achilles Plus) devices in 22 patients with primary hyperparathyroidism between 1997 and 1999 (19 sporadic, 1 MEN 1., 2 MEN II.). Fifteen patients underwent parathyroidectomy (13 adenoma, 2 carcinoma). According to DEXA measurements all patients had osteoporosis. The lowest bone mineral density was detected at the wrist: the mean t-score was -4.00 +/- 1.79. After parathyroidectomy nine patients were followed for a mean of 12.8 months. After one year following surgery the most significant increase in BMD was 14.6%. The QUS values did not correlate with the DEXA data before the operation and no significant changes in stiffness were detected after surgery. The QUS values do not reflect the severity of the BMD decrease by DEXA in patients with primary hyperparathyroidism.

Absorptiometry, Photon↗

[Variation of bone density in relation to age: analysis of 259 necropsies].

In a previous study we reported a relatively low incidence of hip fracture in our population compared to figures reported elsewhere and speculated that this could be related to differences in bone density. Accordingly, we measured bone density in 259 subjects at necropsy. In 172 males we found that bone density decreased from 0.88 g/cc at age 21-30 to 0.80 at age 70 (NS). In women, density decreased from 1.0 at age 21-30 to 0.84 at age 50, 0.69 at age 60 and 0.64 in those older than 70 years (p less than 0.01). These figures are higher than those reported from USA at all ages and could explain the lower incidence of hip fractures in our population.

Adult↗

[Prevention of osteoporosis by foods and dietary supplements. "Mainichi Hone Kea MBP": A foods for specified health uses (FOSHU) product containing MBP that has an effect to increase bone density].

"Mainichi Hone Kea MBP" is a foods for specified health uses (FOSHU) product. It has been approved to write the next claim, "This product is suitable for those who care about bone health, because it contains MBP that has an effect to increase bone density", on this product. MBP is a complex of protein with a basic isoelectric point in milk protein. It has been shown that MBP promotes bone formation, suppresses bone resorption, increases bone mineral density, and increases bone strength in in vitro and in vivo studies. And, we also examined the effect of MBP in healthy adult women from twenties to fifties. A beverage containing MBP or a placebo beverage without MBP was given to volunteers for six months. The percentage increase of radial bone density was significantly higher in the MBP group than in the placebo group. This result has confirmed that MBP contributes to increased bone density in humans. To sum up, we believe that MAINICHI HONE KEA MBP, which contains MBP that has an effect to increase bone density, contributes to bone health.

Adult↗

The effect of nondirective questioning on women's decisions whether to undergo bone density screening: an experimental study.

This study investigated the effects of nondirective counseling on health screening decisions. Ninety women (mean age = 51 years) received information about bone density screening and osteoporosis. They were then randomly allocated to 1 of 4 groups and were encouraged to focus on positive issues about bone density screening (positive group), on negative issues (negative group), on both positive and negative issues (all-focusing group), or on issues relating to the common cold (control group). Women were asked to rate how likely they would be to opt for bone density screening if they saw it available. After being informed that they could have bone density screening, actual uptake was assessed. It was found that the issues on which individuals focused significantly influenced their rate likelihood of opting for the scan. Rated likelihood of testing was significantly associated with whether individuals actually did opt for testing when it was subsequently offered to them.

Adult↗

[Distribution of calcaneal bone density according to the mechanical strain of exercise and calcium intake in premenarcheal girls].

OBJECTIVES: The effects of exercise on bone density have been found to be inconsistent in previous studies. We conducted a cross-sectional study in premenarcheal girls to test two hypotheses to explain these inconsistencies. Firstly, "the intensity of mechanical strain, in terms of the ground reaction force(GRF), has more important effects on the bone mass at a weight-bearing site", and secondly, "calcium intake modifies the bone response to exercise". METHODS: The areal bone mineral density was measured at the Os calcis, using peripheral dual energy X-ray absorptiometry, in 91 premenarcheal girls aged between 9 and 12 years. The intensity of mechanical strain of exercise was assessed by a self-report questionnaire and scored by the GRF as multiples of body weight, irrespective of the frequency and duration of exercise. The energy and calcium intake were calculated from the 24-hour dietary recall. An analysis of covariance(ANCOVA) was used to determine the interaction and main effects of exercise and calcium on the bone density, after adjusting for age, weight, height and energy intake. RESULTS: The difference in the bone density between moderate and low impact exercise was more pronounced in the high than low calcium intake group. The bone density for moderate impact exercise and high calcium intake was significantly higher than that for low impact exercise (p=0.046) and low calcium intake, after adjusting for age, weight, height and energy intake. CONCLUSIONS: Our study suggests that the bone density at a weight-bearing site is positively related to the intensity of mechanical loading exercise, and the calcium intake may modify the bone response to exercise at the loaded site in premenarcheal girls.

Bone Density↗

Influence of birth weight on adult bone mineral density.

Bone mineral density (BMD) increases during growth until a peak is reached at maturity. The risk of development of postmenopausal osteoporosis depends on the peak bone density and the rate of its subsequent loss. To identify whether low weight at birth could affect the peak bone density, we measured BMD at both the lumbar spine and femoral neck using dual energy X-ray absorptiometry (DXA) in a group of women who had low weight at birth and in a control group of normal birth weight. There was no significant correlation between the weight at birth and the adult BMD. It appears, therefore, that low weight at birth does not influence the peak bone density and that prematurity is not a risk factor for osteoporosis.

Adult↗

Bone-density changes after stroke.

It has been many years since bone loss and fracture risk were first recognized as serious complications of stroke. Hip fracture is associated with a substantial increase in morbidity and mortality for stroke survivors, and therefore, assessing and maintaining skeletal health after stroke should be an important clinical goal. Recent long-term, prospective studies have illustrated a highly nonuniform pattern of bone changes after stroke. In general, there is significant bone loss on the paretic side, which is greatest in those patients with the most severe functional deficits. In some patients, bone loss in the paretic arm during the first year after stroke is the equivalent of >20 yrs of bone loss in healthy individuals of comparable age. Bone density in the nonparetic upper limb can actually increase after stroke, consistent with an increase in habitual use of the nonparetic hand. Bone density in the paretic lower limb can decrease by >10% in <1 yr, with smaller decreases being typical for the nonparetic lower limb. Despite the recent increase in the number of prospective, longitudinal studies, important questions about bone changes after stroke remain unanswered. Longer-term studies quantifying bone loss for periods of >12 mos poststroke are needed to determine how long excess bone loss continues after stroke. Studies with more subjects and with more varied disability levels are needed to better understand the relationships between functional deficits and bone loss. New metrics are needed to quantify the intensity and duration of physical activity in the upper and lower limbs that are consistent with previous research on the role of mechanical stimuli in bone adaptation. Finally, an assessment of skeletal health and the factors that affect bone quantity and quality should be a standard component in the clinical management of all survivors of stroke.

Absorptiometry, Photon↗

Bone density is not reduced during the short-term administration of levothyroxine to postmenopausal women with subclinical hypothyroidism: a randomized, prospective study.

PURPOSE: Controversy exists as to whether patients with subclinical hypothyroidism benefit from treatment. Two randomized trials reported that hypothyroid symptoms improved following thyroid hormone replacement therapy. However, during the initial treatment of overt hypothyroidism with levothyroxine, three studies have demonstrated short-term (6 to 12 months) 5% to 13% reductions in bone density. The current study measures bone density during the initial treatment of subclinical hypothyroidism. PATIENTS: Seventeen postmenopausal women with subclinical hypothyroidism (elevated serum thyrotropin [TSH] and normal serum free thyroxine concentrations) and no prior history of thyroid disease were randomly assigned to levothyroxine treatment or no treatment and followed prospectively. Patients in the treatment group had similar initial serum TSH concentrations (9.8 +/- 3.3 versus 8.4 +/- 2.7 microU/mL) but were slightly older (68 +/- 7 years versus 60 +/- 5 years [p < 0.02]). The average dose of levothyroxine needed to normalize serum TSH concentration was 0.072 +/- 0.027 mg. RESULTS: Bone density determinations were not significantly different between the two groups at baseline. After 14 +/- 1 months, single-photon absorptiometry of the wrist decreased by 1.8% +/- 3.2% in the untreated patients and 0.5% +/- 4.1% in the levothyroxine-treated patients (p = NS). Dual-energy X-ray absorptiometry of the lumbar spine decreased by 0.7% +/- 2.9% in the untreated patients and rose 0.1% +/- 4.75% in the levothyroxine-treated patients (p = NS). CONCLUSIONS: Unlike the early treatment of overt hypothyroidism, there is no short-term reduction of bone density with levothyroxine treatment of subclinical hypothyroidism in postmenopausal women. These data suggest that potentially symptomatic women with subclinical hypothyroidism should be given a trial of levothyroxine therapy without concern about adverse effects on skeletal integrity.

Absorptiometry, Photon↗

Bone density and skeletal metabolism are altered in idiopathic hypercalciuria.

OBJECTIVE: To study bone density in hypercalciuric patients, when classified according to the main metabolic defect. METHODS: We studied 49 patients, aged 19-60 years with calcium stones and idiopathic hypercalcuria. All subjects underwent an evaluation of mineral metabolism and a spinal and femoral DEXA measurement. Then, patients were classified as having Fasting (FH, 31 subjects) or Absorptive (AH, 18 patients) Hypercalciuria according to a standard oral calcium load. RESULTS: Spinal bone density was lower only in FH patients as compared to controls (p <0.001). Bone alkaline phosphatase and urine hydroxyproline were higher with respect to controls only in patients with FH (p <0.005 and p <0.015, respectively). After low calcium diet, hydroxyproline excretion continued to be higher in FH patients (p <0.05). Although in the normal range, serum and urine uric acid were higher in hypercalciuric subjects (p <0.03 and p <0.005, respectively); blood pH was lower in hypercalciuric patients than in controls (p <0.01). In FH patients urine hydroxyproline negatively correlated with spinal and femoral density (p <0.001 and p <0.005, respectively), and blood pH positively correlated with spinal density. CONCLUSIONS: a disordered bone metabolism and bone loss are present only in patients with fasting hypercalciuria. An excessive acid load, possibly of dietary origin, might be involved as a pathogenetic factor.

Absorptiometry, Photon↗

Ultradistal and cortical forearm bone density in the assessment of postmenopausal bone loss and nonaxial fracture risk.

Forearm bone mineral density (BMD) was measured by single-energy photon absorptiometry in 360 healthy females without known axial fractures, 202 of whom were postmenopausal. The three sites addressed included an ultradistal (U) region containing approximately 60% trabecular bone. The other sites, distal (D) and shaft (S), were progressively more cortical. Reproducibility was 1.7-1.9% CV. The earliest evidence of a significant correlation between BMD and years since menopause was seen in trabecular bone in subjects aged 45-55 years. Fractional decrease in BMD, relative to the premenopausal value, was significantly larger at U than at S for the decades 55-65 years and above. Fractional rates of bone loss at all sites were a maximum in the first postmenopausal decade, the rate at U being 0.035, approximately 1.5 times that at D or S. A total of 33 subjects reported 54 previous minimally traumatic nonaxial (MTNA) fractures. When BMD measurements of the entire study were divided into quintiles, the prevalence of MTNA fracture cases in the lowest quintile was eight times that of each of the upper three quintiles. Prevalence of fracture cases ranked by quintiles of BMD were not different for the three scan sites. Therefore, ultradistal measurements confer no advantages over distal or shaft BMD for discriminating past MTNA fracture cases but do show larger fractional rates of loss during the first postmenopausal decade.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Calcium supplementation increases bone density in adolescent girls.

In a longitudinal calcium intervention study, bone density was assessed in pubertal girls for 18 months. Significant additional increases in total body bone mineral density (1.3%) and spine bone mineral density (2.9%) and content (4.7%) were noted in the calcium-supplemented group. Increasing bone mass during adolescence with adequate calcium intake, if maintained into adulthood, could decrease the risk of osteoporosis later in life.

Adolescent↗

The (CA)n polymorphism of the TNFR2 gene is associated with peak bone density in Chinese nuclear families.

Low peak bone density (PBD) in adulthood is an important determinant of osteoporotic fracture (OF) in the elderly. The tumor necrosis factor receptor 2 (TNFR2) gene has been considered as an important candidate gene for PBD due to its important role in bone turnover. In this study, we recruited a total of 1,263 subjects from 402 Chinese nuclear families composed of both parents and at least one daughter, and tested the association of the (CA)(n) polymorphism in intron 4 of the TNFR2 gene with PBD using a more contemporary quantitative transmission disequilibrium test (QTDT). Significant within-family association was detected between the CA16 allele and bone mineral density (BMD) at the lumbar spine with the P-value of 0.005 after permutations, which is still significant after correction for multiple testing. Some evidence of total-family association between the CA16 allele and lumbar spine BMD was found (P=0.021), although the significant level did not reach the empirical threshold (P< or =0.007). About 3.14% of lumbar spine BMD variation can be explained by the CA16 allele. In summary, our results suggest that the TNFR2 gene may play an important role in determining lumbar spine BMD variation in Chinese women.

Bone Density↗

Lifestyle factors and bone density in the elderly: implications for osteoporosis prevention.

Epidemiologic evidence suggests that lifestyle factors, such as exercise, calcium intake, and tobacco consumption, have effects on bone density. However, the influence of these factors in the elderly has not been well documented. To examine the effects of lifestyle factors in the elderly, we measured bone density (BMD) at the lumbar spine and proximal femur in 709 elderly men and 1080 women participating in the Dubbo Osteoporosis Epidemiology study (DOES), a community-based, longitudinal, epidemiologic study of osteoporosis in men and women over the age of 60. BMD was significantly higher in men than in women (20% at all sites). There was an age-related decline in BMD at the femoral neck in both sexes and at the lumbar spine in women. Between the ages of 60 and 80, the decrease in BMD at the femoral neck among women was 18.9%, which is almost twice the decrease in BMD among men (10.1%). Tobacco consumption was associated with a reduction in BMD at both sites in both sexes (5-8%), and this effect was independent of calcium intake or body weight. Exsmokers had BMD intermediate between that of current smokers and never smokers, suggesting the influence of tobacco was partially reversible. Quadriceps strength predicted bone density at the proximal femur in elderly men but not in women. Analyzing BMD (adjusted for age and weight) in tertiles of muscle strength and calcium intake revealed an interaction between calcium intake and muscle strength on bone density; BMD at the femoral neck among those with higher quadriceps strength and calcium intake was approximately 5% higher (P < 0.05) than in those with low quadriceps strength and calcium intake in both men and women.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

Bone density monitoring with the total hip site: time for a re-evaluation?

Serial measurement of bone density is important in the clinical management of osteoporosis because it helps to confirm therapeutic response and identify individuals who continue to lose bone density. The lumbar spine is often stated to be the preferred site for monitoring purposes, but much of the supporting information derives from the relatively poor precision of the femoral neck, which is known to be less reproducible than the total hip. The Manitoba Bone Density Program delivers clinical services to the Province of Manitoba, Canada and maintains a detailed quality assurance program. We compared lumbar spine and total hip reproducibility using a pencil-beam scanner (n = 82), a fan-beam scanner (n = 92), and a cross-calibration between the two scanners (n = 61). Each comparison showed significantly lower measurement error at the total hip than at the lumbar spine (p < 0.001). We assessed the likelihood that follow-up measurements would show an absolute difference exceeding the least significant change in routine clinical practice (n = 2412 paired examinations). The total hip measurement detected change more frequently than the lumbar spine in each of these comparisons. In summary, we believe that the total hip site has been undervalued for monitoring purposes and might actually be the preferred site in older individuals with a high prevalence of lumbar spine artifact.

Absorptiometry, Photon↗

Lack of correlation of skin thickness with bone density in patients receiving chronic glucocorticoid.

The objective was to test the hypothesis that there is a correlation between thinning of the skin and bone in patients on chronic oral glucocorticoids (GCs). This was a one-time cross-sectional analysis performed in an academic referral center. The study group consisted of 14 patients on GCs for a variety of disorders, including dermatomyositis, pemphigus vulgaris, pyoderma gangrenosum, and urticarial vasculitis. Skin thickness was compared with that of 24 sex- and age-matched controls. The main outcome measures were the bone density of the lumbar spine (L2-L4) and the skin thickness. The skin thickness (mm, mean +/- SEM) in GC-treated (n = 7) vs unmedicated age-matched Caucasian women (n = 20) was 0.84 +/- 0.04 vs 1.02 +/- 0.04 (t = 3.07, P < 0.01) in the upper arm, 1.13 +/- 0.09 vs 1.49 +/- 0.05 (t = 3.65, P < 0.002) in the dorsal forearm, and 0.96 +/- 0.07 vs 1.17 +/- 0.02 (t = 2.92, P < 0.01) in the ventral forearm. L2-L4 bone densities averaged 106 +/- 2% in the GC-treated female patients relative to the age and sex-matched controls. There was no correlation between skin thickness and bone density. In GC-treated (n = 4) vs unmedicated Caucasian men matched for age (n = 4), skin thickness was 1.09 +/- 0.4 vs 1.33 +/- 0.05 (t = 3.51, P < 0.02) in the upper arm, but was not significantly different at the two forearm sites. No correlation between skin thickness and bone density was observed. The level of type I procollagen mRNA in skin from three GC-treated patients was 45% of the value in three age-matched controls. In conclusion, GCs cause statistically significant thinning of skin independently of the effects on bone.

Absorptiometry, Photon↗

Osteoporosis: What a clinician expects to learn from a patient's bone density examination.

Osteoporosis has lately become recognized as an important disease on two accounts. On one hand, demographic change has resulted in a greatly increased and increasing burden of morbidity and mortality due to osteoporotic fracturing. On the other hand, lifestyle changes and preventive measures have become recognized as important factors in prevention of both osteoporosis and osteoporotic fractures, while several effective drug treatments have recently become available to treat osteoporosis by increasing bone density and reducing fracture incidence. Because bone density is, with age, the best predictor of fracture risk, its measurement has become central to the care of those potentially at risk. When a clinician refers a person for a bone density examination, the clinician should be concerned less with an "imaging diagnosis" than with the requirement that the laboratory has procedures in place for rigorous quality assurance and precision measurements, as well as for education of the staff involved. Implementation of these measures and an understanding of their clinical relevance in diagnosis and follow-up, as well as communication with clinicians in this context, are more important than any diagnostic insight that might be provided by "interpreting" a bone density study.

Absorptiometry, Photon↗

Population-based geographic variations in DXA bone density in Europe: the EVOS Study. European Vertebral Osteoporosis.

The purpose of this study was to investigate variations in bone density between 16 European populations, 13 of which were participants in the European Vertebral Osteoporosis Study (EVOS). Men and women aged 50-80 years were recruited randomly from local population registers, stratified in 5-year age bands. The other three centres recruited similarly. Random samples of 20-100% of EVOS subjects were invited for dual-energy X-ray absorptiometry (DXA) densitometry of the lumbar spine and/or proximal femur using Hologic, Lunar or Norland pencil beam machines or, in one centre, a Sopha fan-beam machine. Cross-calibration of the different machines was undertaken using the European Spine Phantom prototype (ESPp). Highly significant differences in mean bone density were demonstrated between centres, giving rise to between centre SDs in bone density that were about a quarter of a population SD. These differences persisted when centres using Hologic machines and centres using Lunar machines were considered separately. The centres were ranked differently according to whether male or female subjects were being considered and according to site of measurement (L2-4, femoral neck or femoral trochanter). As expected, bone mineral density (BMD) had a curvilinear relationship with age, and apparent rates of decrease slowed as age advanced past 50 years in both sexes. In the spine, not only did male BMD usually appear to increase with age, but there was a highly significant difference between centres in the age effect in both sexes, suggesting a variability in the impact of osteoarthritis between centres. Weight was consistently positively associated with BMD, but the effects of height and armspan were less consistent. Logarithmic transformation was needed to normalize the regressions of BMD on the independent variates, and after transformation, all sites except the femoral neck in females showed significant increases in SD with age. Interestingly, the effect of increasing weight was to decrease dispersion in proximal femur measurements in both sexes, further accentuating the tendency in women for low body mass index to be associated with osteoporosis as defined by densitometry. It is concluded that there are major differences between BMD values in European population samples which, with variations in anthropometric variables, have the potential to contribute substantially to variations in rates of osteoporotic fracture risk in Europe.

Absorptiometry, Photon↗

Ethnic differences in bone density in female South African nurses.

In the United States, the higher prevalence of osteoporosis and the higher incidence of fractures in whites than in blacks may be attributed to the finding of lower bone density (BD) in both white children and adults. In South Africa, osteoporosis and fractures also occur more frequently in whites than in blacks. Appendicular BD has been found to be similar in black and white children in South Africa, but there is little information available on BD of adults in South Africa. This cross-sectional study aimed to assess changes in BD with age in adult females in South Africa and to assess possible differences in peak BD and in the rate of postmenopausal bone loss between blacks and whites. Data for 180 black and 184 white female nurses aged 20-64 years were analyzed. The distal radius bone density (RBD) was measured by single photon absorptiometry. The lumbar spine bone density (SBD) and the femur bone density (FBD) were measured by dual-energy X-ray absorptiometry. Blacks were shorter than whites (p = 0.0001), and blacks' weight, body mass index, and skinfold thickness increased with age. Peak SBD and RBD were similar in blacks and whites, but peak FBD was higher in blacks (p = 0.0001). This ethnic difference in peak FBD became apparent in the fourth decade. Peak FBD was similar in black and white subjects with normal body mass indices (p = 0.09), but in overweight subjects peak FBD was higher in blacks than in whites (p = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗