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1.
A causal role in age-related bone loss has been attributed to alterations in vitamin D status, the bone mineral regulating hormones, and/or renal function. We assessed biochemical parameters of bone metabolism and renal function in healthy subsets of young and old men (n = 191) and women (n = 120) and evaluated the relationships between these parameters and bone mineral density (BMD) in the radius, spine, and femur. There were no significant associations between BMD at any site and serum 25-OHD, 1,25-(OH)2D, PTH, or creatinine clearance in either young men or in young or old women, after controlling for age. In old men, however, lower radius BMD was significantly related to higher PTH and higher 1,25-(OH)2D and marginally related to lower 25-OHD values. In young men, there were unexpected but significant associations between lower femoral neck BMD and higher serum osteocalcin and urinary calcium/creatinine excretion after age adjustment. In old women, lower spine and radius BMD was also significantly correlated with higher serum osteocalcin. In this healthy, vitamin D-replete population, there were significant cross-sectional declines in BMD in the femur in young and old men and at all sites in old women. Elevated remodeling may be an important feature that contributes to reduced femoral BMD in young men and reduced spine and radius BMD in old women. However, compromised renal function or levels of 1,25-(OH)2D or elevated PTH appear to be neither necessary nor relevant as determinants of osteopenia in the spine or femur in these normal, healthy men and women.  相似文献   

2.
To examine the effects of race and sex on bone density and geometry at specific sites within the proximal femur and lumbar spine, we used quantitative computed tomography to image 30 Caucasian American (CA) men, 25 African American (AA) men, 30 CA women, and 17 AA women aged 35–45 yr. Volumetric integral bone mineral density (BMD), trabecular BMD (tBMD), and cross sectional area were measured in the femoral neck, trochanter, total femur, and L1/L2 vertebrae. Volumetric cortical BMD (cBMD) was also measured in the femur regions of interest. Differences were ascertained using a multivariate regression model. Overall, AA subjects had denser bones than CA subjects, but there were no racial differences in bone size. Men had larger femoral necks but not larger vertebrae than women. The AA men had higher tBMD and cBMD in the femur than CA men, whereas AA women had higher femoral tBMD but not higher femoral cBMD than CA women. These data support the idea that higher hip fracture rates in women compared with men are associated with smaller bone size. Lower fracture rates in AA elderly compared with CA elderly are consistent with higher peak bone density, particularly in the trabecular compartment, and potentially lower rates of age-related bone loss rather than larger bone size.  相似文献   

3.
Our study surveyed age-related bone mineral density (BMD), bone loss rate, and prevalence of osteoporosis in women at multiple research centers in China. Survey results were used to establish a BMD reference database for the diagnosis of osteoporosis in Chinese women nationwide. We used dual-energy X-ray absorptiometry bone densitometers to measure BMD at posteroanterior (PA) lumbar spine (L1-L4; n=8142) and proximal femur (n=7290) in female subjects of age 20-89 yr from Beijing, Shanghai, Guangzhou, Chengdu, Nanjing, and Jiaxing. A cubic regression-fitting model was used to describe the change of BMD with age at various skeletal sites. Peak BMD occurred between 30 and 34 yr of age for femur neck and total femur, and between 40 and 44 yr for spine and trochanter measurement sites. Young adult (YA) BMD values (mean and standard deviation [SD], calculated as the average BMD in the age range of 20-39, were 1.116+/-0.12, 0.927+/-0.12, 0.756+/-0.11, and 0.963+/-0.13 g/cm2 at PA spine, femoral neck, trochanter, and total femur, respectively. The BMD of 85-yr-old women reflected a loss of 32% at the spine and 30-35% at femur measurement sites. The prevalence of osteoporosis, defined as a BMD of 相似文献   

4.
This study aimed to investigate the associations of body composition and fat distribution with bone mineral density (BMD) in elderly Italian subjects. In 866 women (age 64.2 ± 6.5 yr) and 168 men (age 65.1 ± 6.1 yr), we measured BMD at lumbar spine, at femur, at the total body, and at the right hand. In all subjects, we also measured sex hormones, 25-hydroxyvitamin D, bone markers, and calcium intake. In both men and women, all body composition parameters had significant positive correlations with BMD at all sites after adjusting for age only; after adjusting also for body weight only lean mass (LM) remained positively associated with BMD at all sites except BMD at lumbar spine. In males, LM was associated with BMD at all sites, whereas android fat was associated with BMD at lumbar spine, at femur, and at whole body. In females, fat mass (FM) was positively and age inversely associated with BMD at all sites, whereas gynoid fat and alkaline phosphatase were inversely associated with BMD at lumbar spine and at femur. In conclusion, the role of LM seems more important in males, whereas in women the role of FM prevails with negative associations between gynoid fat and BMD.  相似文献   

5.
Obesity has been associated with increased bone mineral density (BMD). There is evidence of differential effect of regional fat on BMD. Hence, we undertook this study to evaluate the correlation between total body fat and its distribution with BMD in nonobese (mean body mass index: 25.0 ± 4.7 kg/m2) Indian adult volunteers. A total of 2347 participants (men: 39.4% and women: 60.6%) included in this cross-sectional study were divided according to sex and age. Fasting blood samples were drawn for biochemical parameters. Percent total body, truncal, and leg fat and BMD at lumbar spine, femur, and forearm were measured by dual-energy X-ray absorptiometry. The BMD at all sites (radius, femur, and spine) increased from lowest to highest quartiles of percent body fat. Percent truncal fat was positively correlated with BMD at all sites in both sexes, except for femoral neck in men, where it had negative correlation. Percent leg fat was positively related with BMD at all sites in premenopausal women, and spine and radius BMD in postmenopausal women. However, in men, it had negative correlation with femoral neck BMD. On multiple regression analysis, regional fat had positive association with BMD at all sites after adjusting for age, sex, lean mass index, 25-hydroxyvitamin D, and intact parathyroid hormone levels. Leg-to-total body fat ratio was negatively associated with BMD at all sites in men and pre- and postmenopausal women. Percent total body and regional fat have positive association with BMD at all sites in men and women.  相似文献   

6.
ESR2 is expressed in bone cells, yet few studies have tested its variation for association with BMD, an important determinant of osteoporotic fractures. This was investigated in 723 men and 795 women from the Framingham study. Results show association of variation in this gene with BMD in both women and men. INTRODUCTION: Osteoporotic fracture risk is highly dependent on bone density, a quantitative multifactorial trait with a substantial genetic component. In contrast to the growing body of evidence that estrogen receptor alpha (ESR1) plays a role in bone metabolism, few studies have examined the estrogen receptor beta (ESR2) gene for association with BMD. An ESR2 CA repeat polymorphism, D14S1026, was associated with BMD in two small studies, each with <200 women. MATERIALS AND METHODS: The objective of this investigation was to assess whether D14S1026 or four other intronic polymorphisms were associated with BMD in 723 men and 795 women (mean age, 60 years) from the offspring cohort of the population-based Framingham Study. BMD was measured at the femur (neck, trochanter, and Ward's area) and the lumbar spine (L(2)-L(4)). RESULTS: In both women and men, there was significant association of D14S1026 genotype with measures of femoral but not spinal BMD. In addition, genotypes of two common single nucleotide polymorphisms, rs1256031 and rs1256059, in strong linkage disequilibrium with one another but not with D14S1026, were associated with measures of femoral BMD in men. The rs1256031 genotypes had up to a 4.0% difference in mean femoral BMD. An inferred rs1256031-D14S1026-rs1256059 haplotype C-23CA-T was significantly associated with reduced femoral BMD in women (p = 0.03, 0.003, and 0.01 for neck, trochanter, and Ward's area, respectively). Haplotype-based BMD differences ranged from 3.0% to 4.3%. CONCLUSIONS: We have observed significant association of common ESR2 variants with measures of femoral BMD in both men and women.  相似文献   

7.
Although the menopause has been associated with increased bone loss at several skeletal sites, it has not previously been noted in the hip, yet estrogen therapy has been reported to reduce the incidence of hip fractures. We investigated the effect of age and menopause on bone loss in the proximal femur by measuring bone mineral density (BMD) of the femoral neck, Ward's triangle, and trochanter by dual-photon absorptiometry in 263 normal women aged 20-84. Multiple regression analyses revealed a significant decrease in BMD of the femoral neck and Ward's triangle with age in both pre- and postmenopausal women (p less than 0.001). In the trochanter the decrease with age was significant only in postmenopausal women (p less than 0.001). Further analysis revealed that BMD decreased faster at all sites in the early postmenopausal years. During the first 6 years postmenopause, the decrease in BMD of the femoral neck and trochanter was 3-10 times higher than the change in the decade prior to menopause. About 20% of the lifetime femoral neck loss and 30% of the trochanteric loss occurred in the early postmenopausal period. It is concluded that both age and menopause are major determinants of BMD in the proximal femur. These findings could explain why estrogen therapy has been reported to prevent hip fracture. The rapid early postmenopausal loss in BMD of the proximal femur demonstrates the importance of starting estrogen replacement therapy immediately after menopause for maximum effect.  相似文献   

8.
Although relatively little is known about osteoporotic risk factors in women from the Indian subcontinent, osteoporotic fractures usually occur 10–20 years earlier in Indian men and women compared with their western Caucasian counterparts. The primary purpose of this cross-sectional study was to determine the relative contributions of ethnicity, reproductive history, body size (height, weight) and composition, bone turnover, serum 25(OH)vitamin D3 [25(OH)D3], dietary intake (of calcium, fiber and alcohol) and energy expenditure to femoral bone mineral density (BMD) in Indian and Pakistani (Indian/Pakistani; n= 47) versus American (n= 47) Caucasians. We also contrasted femoral BMD and hip axis length in these two distinct groups of premenopausal females living in the USA. The Indian/Pakistani (0.875 ± 0.096) women had lower (p= 0.0014) femoral BMD (g/cm2) than their American (0.937 ± 0.088) counterparts, placing them at greater osteoporotic risk. However, the shorter (p= 0.0002) hip axis length (cm) of the Indian/Pakistani (10.54 ± 0.57) versus American (11.11 ± 0.78) Caucasians might attenuate hip fracture risk in the former group. Significant contributors to proximal femur BMD were maximum non-pregnant lifetime weight, age at menarche, ratio of ∑central-to-peripheral skinfold thicknesses, calcium intake from milk and usual alcohol intake. Although serum 25(OH)D3 and urinary N-telopeptide concentrations did not contribute to femoral BMD in the regression models, the lower (p<0.0001) serum 25(OH)D3 (33.1 ± 16.5 vs 64.0 ± 22.0 nmol/l) and higher (p= 0.0004) urinary N-telopeptide (45.9 ± 43.3 vs 18.9 ± 18.7 nmol BCE/mmol) values in Indian/Pakistani versus American Caucasians, respectively, coupled with their lower BMD, places the Indian/Pakistani women at greater osteoporotic risk. These results suggest that a clinical trial to increase BMD and reduce osteoporotic risk is warranted in this ethnic group of premenopausal women. Received: 29 April 1998 / Accepted: 12 August 1998  相似文献   

9.
Low serum 25‐hydroxy vitamin D (25(OH)D) concentrations are associated with increased hip fracture risk and decreased femoral areal bone mineral density (BMD) among elderly men. Structural dimensions of the proximal femur and volumetric BMD in cortical and trabecular compartments are also associated with hip fracture risk. However, associations of volumetric BMD or structural dimensions with serum 25(OH)D concentrations among older men remain unclear. In a random sample of 1608 men aged ≥65 years from the Osteoporotic Fractures in Men Study (MrOS), baseline serum 25(OH)D concentrations were measured by liquid chromatography/mass spectrometry assays. Femoral neck geometry and volumetric BMD derived from quantitative computed tomography included integral, cortical, and trabecular volumetric BMD; cross‐sectional area; integral and cortical volume; and cortical volume as a percent of integral volume. We studied 888 men with vitamin D, parathyroid hormone (PTH), femoral neck geometry, and BMD measures. Whole‐bone femoral strength and load‐strength ratio from finite element (FE) analysis were also available for 356 men from this sample. Multivariable linear regression was used to estimate least square means of each femoral measure within quartiles of 25(OH)D adjusted for age, race, body mass index, height, latitude, and season of blood draw. Tests of linear trend in the means were performed across increasing quartile of serum 25(OH)D levels. Mean cortical volume (p trend = 0.006) and cortical volume as a percent of integral volume (p trend < 0.001) increased across increasing quartile of 25(OH)D level. However, overall femoral neck size (area and integral volume) did not vary by 25(OH)D level. Femoral neck volumetric BMD measures increased in a graded manner with higher 25(OH)D levels (p trend < 0.001). Femoral strength, but not load‐strength ratio, increased with increasing 25(OH)D. Adjustment for PTH did not materially change these associations. We conclude that in older men, higher levels of endogenous 25(OH)D may increase whole‐bone strength by increasing femoral volumetric BMD and cortical volume. © 2014 American Society for Bone and Mineral Research.  相似文献   

10.
The Canadian Multicentre Osteoporosis Study (CaMos) is a prospective cohort study which will measure the incidence and prevalence of osteoporosis and fractures, and the effect of putative risk factors, in a random sample of 10 061 women and men aged ≥25 years recruited in approximately equal numbers in nine centers across Canada. In this paper we report the results of studies to establish peak bone mass (PBM) which would be appropriate reference data for use in Canada. These reference data are used to estimate the prevalence of osteoporosis and osteopenia in Canadian women and men aged ≥50 years. Participants were recruited via randomly selected household telephone listings. Bone mineral density (BMD) of the lumbar spine and femoral neck were measured by dual-energy X-ray absorptiometry using Hologic QDR 1000 or 2000 or Lunar DPX densitometers. BMD results for lumbar spine and femoral neck were converted to a Hologic base. BMD of the lumbar spine in 578 women and 467 men was constant to age 39 years giving a PBM of 1.042 ± 0.121 g/cm2 for women and 1.058 ± 0.127 g/cm2 for men. BMD at the femoral neck declined from age 29 years. The mean femoral neck BMD between 25 and 29 years was taken as PBM and was found to be 0.857 ± 0.125 g/cm2 for women and 0.910 ± 0.125 g/cm2 for men. Prevalence of osteoporosis, as defined by WHO criteria, in Canadian women aged ≥50 years was 12.1% at the lumbar spine and 7.9% at the femoral neck with a combined prevalence of 15.8%. In men it was 2.9% at the lumbar spine and 4.8% at the femoral neck with a combined prevalence of 6.6%. Received: 23 April 1999 / Accepted: 14 April 2000  相似文献   

11.
目的研究人体内25羟维生素D2(25-OH-D2)、25羟维生素D3(25-OH-D3)含量与股骨颈骨密度的相关性。方法利用双能X线骨密度测量法检测205例患者股骨颈骨密度,同时用高效液相色谱法检测其血清中25-OH-D2及25-OH-D3的含量,并根据维生素D(VitD)含量分析VitD与骨密度的关系。结果人体内VitD(25-OH-D2+25-OH-D3)含量与50岁以下者的股骨颈骨矿含量无相关性(P0.05),与50岁以上者呈正向直线相关(P0.05或P0.01),男女性别均一致。结论对于50岁以上者,随着年龄的增长,其体内血清VitD的含量降低很可能会导致其股骨颈骨矿含量下降。  相似文献   

12.
The purpose of this study was to determine if differences exist in premenopausal women between z-scores for lumbar spine and proximal femoral bone mineral densities (BMD). Participants were 237 women ranging in age from 20 to 45 years. BMDs of the lumbar spine and proximal femur (femoral neck, Ward's area, and trochanter) were assessed using dual-energy X-ray absorptiometry (Lunar DPX). Mean (±SD) age, height, and weight of the participants were 29.4 ± 6.9 years, 164.4 ± 6.1 cm, and 64.9 ± 12.1 kg, respectively. Lumbar spine BMD and BMD at the femoral neck, Ward's area, and trochanter were significantly correlated with large SEEs (r = 0.59–0.65; SEE = 0.09–0.11). No positive correlation with age and BMD at any site was seen in this population but a significant negative correlation with age was seen in the proximal femur beginning at age 30. Twenty to 24% of the 20–29-year-olds exhibited a difference in z-scores of greater than 1 between the spine and sites in the proximal femur. This percentage increased to 32–46% in the 30–45-year-olds but the nature of the observed differences changed. The differences in spine and proximal femoral z-scores that are seen in the older age group appear to be the result of the earlier onset of bone loss in the proximal femur rather than an initial difference in peak bone mass which has been maintained. Received: 28 August 1996 / Accepted: 25 April 1997  相似文献   

13.
Little has been understood about vitamin D status in relation to bone health in Asian women. The purpose of this study was to identify how the serum 25-hydroxyvitamin D (25[OH]D) concentration is associated with bone mass and bone metabolism. This cross-sectional, community-based epidemiologic study was conducted among 600 ambulatory postmenopausal women. The serum 25(OH)D concentration was measured with radioimmunoassay. Other blood biochemical measurements were intact parathyroid hormone and markers of bone turnover, including osteocalcin and type I collagen cross-linked N-telopeptides. Bone mineral density (BMD) of the lumbar spine and right femoral neck were measured with the dual-energy X-ray absorptiometry method using a QDR4500a. The mean serum 25(OH)D concentration was 55.6 nmol/L (SD 14.6). Serum 25(OH)D concentration was linearly associated with BMD of the femoral neck (R(2)=0.020, P=0.003), but not with BMD of the lumbar spine. Odds ratios (ORs) for low BMD (defined as t score < or =-2.5 SD) were calculated for strata defined by 25(OH)D concentration. The prevalence of low BMD of the lumbar spine was significantly higher in the 40- to 50-nmol/L 25(OH)D group (adjusted OR=3.0, 95% CI: 1.3-7.0) compared to the reference group (> or =70 nmol/L). Prevalence of low BMD for the femoral neck was significantly higher in the 30- to 40-nmol/L (adjusted OR=3.6, 95% CI: 1.1-12.1) and the 40- to 50-nmol/L (adjusted OR=7.6, 95% CI: 2.5-23.2) groups compared to the reference group (> or =70 nmol/L). The mean serum concentration of intact PTH was significantly higher in subjects with serum 25(OH)D <50 nmol/L compared to those with serum 25(OH)D > or =50 nmol/L. The present study suggests that higher serum 25(OH)D concentrations are associated with increased BMD of the femoral neck, and that a serum 25(OH)D concentration of at least 70 nmol/L is needed to obtain high BMD of the femoral neck, and that of at least 50 nmol/L is needed to achieve normal PTH levels and prevent low BMD in home-dwelling postmenopausal Japanese women.  相似文献   

14.
The aim of the study was to establish population ranges of bone mineral density (BMD) for Hong Kong Chinese men and women for the Hologic QDR 2000 bone densitometer, to compare these values with the manufacturer’s reference ranges, to compare these values with population ranges for women obtained for the Norland X26 bone densitometer, and to examine variations between the two densitometers. The subjects were 164 men aged 40–79 years and 436 women aged 20–89 years, who were all ethnic Chinese, recruited from volunteers, social centers for the elderly and general practice clinics. BMD in women began to decline rapidly between ages 50 and 79 years, averaging about 10% loss per decade from the young adult (20–29 years) mean. The percentage losses from young adult mean values in the spine, femroal neck, trochanter and total femur were 23%, 30%, 31% and 33%, respectively, from 20 to 79 years. In the ninth decade no further decrease in BMD occurred with the exception of a further 4% at the hip sites. In men, no decrease in spine BMD occurred between 40 and 70 years. Compared with BMD in the fourth decade, 10%, 13%, and 11% of BMD was lost at the femoral neck, trochanter and total femur, respectively, by the seventh decade. These values show differences compared with the manufacturer’s reference ranges for Caucasians and Japanese. BMD values for the spine were comparable between Hologic and Norland densitometers, but Hologic values for femoral neck and trochanteric regions were lower than the Norland values. Data provided by this study may thus be used as normative values for the Hologic QDR2000 bone densitometer, instead of values provided by the manufacturer. BMD values at the hip sites are not interchangeable between Norland and Hologic bone densitometers, and estimation of numbers of the population with osteoporosis will depend on the model of densitometer used. Received: 31 May 2000 / Accepted: 31 October 2000  相似文献   

15.
Although only few postmenopausal women exhibit biochemical signs of hypovitaminosis D, vitamin D insufficiency has been shown to have adverse effects on bone metabolism and could be an important risk factor for osteoporosis and fracture. We determined serum levels of 25-hydroxyvitamin D [25(OH)D], intact parathyroid hormone (iPTH), bone turnover markers, dietary calcium intake, and bone mineral density (BMD; measured by dual X-ray absorptiometry) in 161 consecutive ambulatory women, healthy except for osteoporosis, referred to a bone metabolic unit. The prevalence of vitamin D insufficiency [25(OH)D < or = 15 ng/ml] was 39.1%. 25(OH)D was lower in the osteoporotic subjects (15.7 +/- 5.3 ng/ml vs. 21.8 +/- 9.7 ng/ml; p < 0.001). After controlling for all other variables, lumbar spine (LS) BMD was found to be significantly associated with 25(OH)D, body mass index (BMI), and years after menopause (YSM) (R2 = 0.253; p < 0.001). For femoral neck (FN), significant independent predictors of BMD were YSM, BMI, iPTH, and 25(OH)D (R2 = 0.368; p < 0.001). The probability of meeting osteoporosis densitometric criteria was higher in the vitamin D insufficiency group (odds ratio [OR], 4.17, 1.83-9.48) after adjusting by YSM, BMI, iPTH, and dietary calcium intake. Our study shows that vitamin D insufficiency in an otherwise healthy postmenopausal population is a common risk factor for osteoporosis associated with increased bone remodeling and low bone mass.  相似文献   

16.
A higher calcium intake is still the primary recommendation for the prevention of osteoporosis, whereas vitamin D deficiency is often not addressed. To study the relative importance of dietary calcium intake and serum 25‐hydroxyvitamin D [25(OH)D] status in regard to hip BMD, 4958 community‐dwelling women and 5003 men ≥20 yr of age from the U.S. NHANES III population‐based survey were studied. Calcium supplement users and individuals with a prior radius or hip fracture were excluded. We calculated standardized means for BMD by quartiles of sex‐specific calcium intake for three 25(OH)D categories (<50, 50–74, and 75+ nM) among men and women, separately controlling for other important predictors of BMD. A higher calcium intake was significantly associated with higher BMD (p value for trend: p = 0.005) only for women with 25(OH)D status <50 nM, whereas calcium intake beyond the upper end of the lowest quartile (>566 mg/d) was not significantly associated with BMD at 25(OH)D concentrations >50 nM. Among men, there was no significant association between a higher calcium intake beyond the upper end of the lowest quartile (626 mg/d) and BMD within all 25(OH)D categories. Among both sexes, BMD increased stepwise and significantly with higher 25(OH)D concentrations (<50, 50–74, 75+ nM; p value for trend: women < 0.0001; men = 0.0001). Among men and women, 25(OH)D status seems to be the dominant predictor of BMD relative to calcium intake. Only women with 25(OH)D concentrations <50 nM seem to benefit from a higher calcium intake.  相似文献   

17.

Summary

The relationship between serum 25(OH)D and intact parathyroid hormone (iPTH) was evaluated in the Multicenter Osteoarthritis Study (MOST). No further change in iPTH was observed for African Americans with 25(OH)D levels above 20?ng/ml, suggesting that compared to Caucasians, lower vitamin D targets for sufficiency may be appropriate for African Americans.

Introduction

Vitamin D levels ≥30?ng/ml are commonly considered “normal” based upon maximal suppression of iPTH; however, this has recently been challenged and the optimal 25(OH)D level among non-Caucasians is unclear. We evaluated the cross-sectional relationship between serum 25(OH)D and iPTH in a sample of Caucasian and African American adults.

Methods

We used baseline serum samples of participants from the Multicenter Osteoarthritis Study (MOST) for this analysis and used three methods to model the relationship between 25(OH)D and iPTH: ordinary least squares regression (OLS), segmented regression and Helmert contrasts.

Results

Among Caucasians (n?=?1,258), 25(OH)D and iPTH ranged from 4 to 51?ng/ml and 2 to 120?pg/ml and from 3 to 32?ng/ml and 3 to 119?pg/ml in African Americans (n?=?423). We observed different thresholds between African Americans and Caucasians using each analytic technique. Using 25(OH)D as a categorical variable in OLS, iPTH was statistically higher at lower 25(OH)D categories than the 24–32?ng/ml referent group among Caucasians. However, in African Americans, the mean iPTH was only significantly higher at 25(OH)D levels below 15?ng/ml. Using segmented regression, iPTH appeared to stabilize at a lower 25(OH)D level in African Americans (19–23?ng/ml) compared to in Caucasians (>32?ng/ml). Helmert contrasts also revealed a lower threshold in African Americans than Caucasians.

Conclusion

Among MOST participants, the 25(OH)D thresholds at which no further change in iPTH was observed was approximately 20?ng/ml in African Americans versus approximately 30?ng/ml in Caucasians, suggesting optimal vitamin D levels in Caucasians may not be applicable to African Americans.  相似文献   

18.
Summary A cross-sectional study of 351 healthy Finnish women aged 20–76 years was done to establish reference values of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DEXA). The effects of age and of several physical and lifestyle factors on BMD of the lumbar spine and proximal femur (femoral neck, trochanter, and Ward's triangle area) were investigated. Altogether 58 women were excluded from the final analysis due to significant spinal osteoarthritis or other diseases or drugs known to influence calcium or bone metabolism. The precision of the method was 0.9, 1.2, 2.7, and 2.4% in the lumbar, femoral neck, Ward's triangle and trochanter area, respectively. Lumbar BMD was increased by 30% (P<0.001) in 15 patients with osteoarthritis (21% of women 50 years or older), but it was apparently unaffected in 5 cases with aortic calcification. Except for the trochanter area, BMD diminished along with age, and this was significant after the menopause. The peak of mean BMD was observed at the age of 31–35 years in the spine and at the age of 20–25 years in the femoral neck and Ward's triangle. BMD was in a positive relationship to weight both in premenopausal and postmenopausal women and to the use of oral contraceptives in premenopausal women and to that of estrogen replacement therapy in postmenopausal women. Labors and pregnancies had a weak positive effect on BMD in premenopausal women. As compared with nonusers premenopausal women who had used alcohol showed a slightly decreased BMD of Ward's triangle. In postmenopausal women there was a positive correlation between alcohol intake and BMD.  相似文献   

19.
Several authors have found a relationship between vitamin D status and bone mineral density (BMD). To our knowledge, no previous studies on this topic have been carried out on the Italian postmenopausal population. We studied this relationship retrospectively in 156 Italian postmenopausal women. We also investigated the relationship between parathyroid hormone (PTH) and BMD. Measurements of BMD were taken at the lumbar spine and upper femur by dual X-ray absorptiometry. Serum 25(OH)D (calcidiol), 1,25(OH)2D (calcitriol), PTH, calcium, phosphorus, creatinine, osteocalcin and urinary calcium and phosphorus were measured according to the current laboratory methods of analysis. We found a positive statistically significant correlation between BMD, both at the spine and hip, and 25(OH)D, and a negative statistically significant correlation between BMD and PTH. No statistically significant correlation was found between BMD and 1,25(OH)2D. Crude logistic regression showed age, 25(OH)D and PTH were significant predictors of low BMD, while 1,25(OH)2D was not. Backward logistic regression showed 25(OH)D was the best predictive model for spine osteoporosis together with age, and on its own it was the best predictive model for femoral neck osteoporosis.No funding sources supported this publication.  相似文献   

20.
In the past it was usual to interpret bone mineral density (BMD) scans of the femur using the femoral neck, trochanter, or Ward's triangle sites. Recently, a study by the International Committee for Standards in Bone Measurement recommended that the total hip should be the preferred site for the interpretation of femur BMD, and another study described a new central hip site that may offer improved precision. This article compares the longitudinal sensitivities of the different femur BMD sites for monitoring patient response to treatment. The study population was 152 postmenopausal women enrolled in a trial of a bisphosphonate therapy. Spine and hip BMD scans were performed at 0, 1, and 2 yr. The mean percentage change at 2 yr was calculated for six sites in the hip, and the spine was also included for comparison. Treatment effect was defined as the difference in the BMD change between the treated and placebo groups. Although the data analysis incorporated a term for a calibration change caused by a repair of the dual X-ray absorptiometry scanner, the effect of this event on the estimation of treatment effect was negligible. Longitudinal sensitivity was derived by dividing the treatment effect by the root mean square error (RMSE) of the statistical model. Results (and standard errors) normalized to the ratio of treatment effect: RMSE for femoral neck BMD were as follows: femoral neck: 1.00; trochanter: 1.33 (0.38); intertrochanteric: 0.84 (0.41); total hip: 1.20 (0.38); Ward's triangle: 1.03 (0.27); central hip: 1.09 (0.30); spine: 2.08 (0. 45). At none of the femur sites was the change in BMD large enough to allow monitoring of response to treatment in individual patients. However, for studies involving the follow-up of a group of subjects, the longitudinal sensitivities of the different femur sites were equal within the statistical errors of the study. In particular, total hip BMD appears to be as effective as femoral neck BMD for detecting response to treatment in the femur in the setting of a clinical trial or similar research study.  相似文献   

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