Race and sex differences in bone mineral density and geometry at the femur

IntroductionDifferences in osteoporotic hip fracture incidence between American whites and blacks and between women and men are considered to result, in part, from differences in bone mineral density and geometry at the femur. The aim of this study was to quantify differences in femoral bone density and geometry between a large sample of healthy American white and black women and men.Subjects and methodsHealthy American white (n = 612) and black (n = 164) premenopausal women, aged 23 to 57 years, and healthy American white (n = 492) and black (n = 169) men, aged 20 to 63 years, had volumetric bone mineral density (vBMD) and geometry variables measured at the femur by computerized tomography (CT), and areal bone mineral density (aBMD) at femoral neck measured by dual X-ray absorptiometry (DXA).ResultsAmerican blacks had higher vBMD at the femoral neck and femoral shaft cortex than American whites whereas femoral axis length and femoral neck area were not different. Men had lower vBMD at the femoral neck and femoral cortex than women but had greater femoral axis length and femoral neck area than women. The higher aBMD in American blacks than whites persisted after correction for measured area whereas the higher aBMD in men than women disappeared.ConclusionsAt the femoral neck, American whites have lower bone density than American blacks but similar geometry. Women have higher bone density than men in both races but have smaller geometry variables. The differences in bone density may account in part for the differences in hip fracture incidence between American blacks and whites, whereas the differences in femur size may account for the differences in hip fracture rates between men and women.     

Challenges and implementation of a women's breast health initiative in rural Kashmir

The purpose of this study was to explore how to successfully collect demographic, lifestyle and health behavior data, followed by an educational intervention on a culturally sensitive topic, breast cancer, in the politically fragile Kashmir Valley. Survey results of 520 women identified challenges that impact the general health of women, including literacy, hygiene and water safety, as well as a dearth of breast health and educational resources and all cancer services. The study tested culturally sensitive approaches to obtain survey data and provide appropriate breast health education for Kashmiri women at risk for breast cancer, who live within this socially and politically challenging environment. This study provides a foundation for future development of research and clinical programs to identify women at high risk and implement an active health surveillance monitoring program with a focus on breast cancer in Kashmir.     

A correlative study of the geometry and anatomy of the distal femur

Sixteen knees were examined roentgenographically in the lateral plane. Ten knees were examined from autopsy subjects. The distal articular femur may be represented by three circular surfaces: (1) the floor of the patellar groove (articulating with the patella from 10 degrees to 100 degrees), (2) the posterior femoral condyles (articulating with the tibia from 10 degrees to 150 degrees), and (3) the distal condyles (articulating with the tibia from 0 degrees to 10 degrees). The radii of these surfaces, their angular arcs, and the distances between their centers varied with the size of the femur but fell within a narrow range. The radii of the patellar groove and the posterior femoral condyles averaged 24 mm and 21 mm, and the average angle subtended by these arcs was 90 degrees and 140 degrees, respectively. The average distance between the centers of these two circles was 20 mm. The femoral attachment of the synovial and patellar retinacular reflections was found in the area of the center of the patellar groove circle. The femoral attachments of the medial collateral and posterior cruciate ligaments and of the lateral collateral and anterior cruciate ligaments were found to be in the area of the center of the circle of the medial and lateral posterior femoral condylar circles, respectively.     

Young-elderly differences in bone density, geometry and strength indices depend on proximal femur sub-region: a cross sectional study in Caucasian-American women

Fragility fractures at the trochanter (TR) and the femoral neck (FN) have distinct etiologies, but the underlying age-related structural changes at these proximal femoral sub-regions are poorly understood. 28 young (41+/-3 years) and 124 elderly (74+/-3 years) healthy Caucasian women underwent volumetric quantitative computed tomography at the hip. Integral (i), cortical (c) and trabecular (t) bone mineral density and content (BMD, BMC) were measured. Geometric parameters included cross sectional area (CSA), and volumes of the integral, cortical and trabecular regions (VOL). Structural measures included indices of compressive (Compstr) and bending (BSI) strength. After adjusting for height and weight, an F-test was used to compare the TR and the FN mean values between young and elderly and to test for interaction to compare logarithmic difference of young and elderly (log(Young)-log(Elderly), Y/Ed) between the FN and the TR in an ANOCOVA model. All BMC, iBMD and tBMD values were significantly lower in elderly than in young women, with the largest Y/Ed in the FN tBMC and tBMD (P<0.0011 and P<0.0001). cBMD in young and elderly groups was not significantly different at the TR while at the FN it was greater (P=0.0075) in elderly than young women, showing significant Y/Ed (P=0.0003) dependence on skeletal site. Elderly women had significantly larger iVOL and CSA values (0.0001相似文献   

Risedronate improves proximal femur bone density and geometry in patients with osteoporosis or osteopenia and clinical risk factors of fractures: a practice-based observational study

The purpose of this practice-based observational study was to clarify the acute effect of risedronate on proximal femur bone mineral density (BMD) and structural geometry in patients with an increased risk of fractures. One hundred sixty-four patients (7 men and 157 postmenopausal women; mean age, 69.2 years) with osteoporosis or osteopenia and clinical risk factors of fractures were analyzed. All these patients were treated with risedronate for 1 year. Urinary levels of cross-linked N-terminal telopeptide of type I collagen (NTX) were measured at baseline and 4 months after the start of treatment. BMD of the lumbar spine and proximal femur and structural geometric parameters of the proximal femur were evaluated by dual-energy X-ray absorptiometry with advanced hip assessment (AHA) software at baseline and every 4 months. Urinary NTX levels significantly decreased after 4 months of treatment. BMD of the femoral neck and total hip significantly increased after 4, 8, and 12 months of treatment. Cross-sectional moment of inertia (CSMI) and cross-sectional area significantly increased after 4, 8, and 12 months of treatment. An increase in CSMI was apparently greater than those of proximal femur BMD after 4 months of treatment. These results suggest the acute (4 months) and sustained (12 months) effect of risedronate on proximal femur structural geometry as well as BMD as a result of suppression of bone resorption in patients with an increased risk of fractures.     

The geometry of the adult canine proximal femur

The canine is often used as a model to study functional bone adaptation after total hip replacement. To improve our understanding of the model, we defined the central tendencies and statistical variations in the cross-sectional geometry, angle of anteversion, and cervicodiaphyseal angle of the proximal femur in 15 adult male mongrel dogs and compared the results with published reports of the human femur. Numerous similarities in the cross-sectional geometry of the canine and the human femur were noted, supporting the use of the canine as a model. The two species differed in that the orientation of the principal axes in the proximal cross sections was not related to the angle of anteversion in the canine femur, whereas these angles are related in humans. In addition, the canine medullary canal is larger than the human medullary canal relative to the external dimensions of the femur, and hence the canine has relatively thinner cortical bone. This difference in femoral cross-sectional geometry may explain, in part, why the canine provides an accentuated model of bone loss in hip arthroplasty experiments.     

Gender differences in mortality following non-cardiovascular surgery: an observational study

Purpose

Although inequality between males and females in cardiovascular surgery is well recognized, few studies have examined the influence of sex on mortality following non-cardiovascular surgery. The objective of the study was to determine whether there are differences in mortality between males and females following non-cardiovascular surgery and to ascertain to what extent preoperative risk factors explain these differences.

Methods

This was an observational study of 39,433 consecutive non-cardiovascular inpatient surgical cases from non-sex-biased surgical services from 2003 to 2009. Data on the surgical procedure, patient risk factors, and outcomes was retrieved from the institutional Electronic Data Warehouse. The primary outcome was in-hospital mortality within 30?days of surgery. Multivariate analysis using logistic regression was conducted to determine the role of risk factors for mortality.

Results

The 30-day mortality was 2.76% for males and 1.89% for females (odds ratio, 1.47; 95% confidence interval [CI], 1.29 to 1.69). Logistic regression showed that age, number of Charlson comorbidities, American Society of Anesthesiologists (ASA) classification, and emergent/urgent status were independent predictors of mortality (receiver operating characteristic area, 0.90). After adjustment for these factors, the odds ratio for male mortality was reduced to 1.31 (95% CI, 1.14 to 1.52).

Conclusion

Males present for non-cardiovascular surgery with a higher ASA classification, with more comorbidities, and more often emergently than females, providing a partial explanation of the observed difference in mortality.     

Gender differences in the anatomy of the distal femur

Recently, gender-specific designs of total knee replacement have been developed to accommodate anatomical differences between males and females. We examined a group of male and female distal femora matched for age and height, to determine if there was a difference in the aspect ratio (mediolateral distance versus anteroposterior distance) and the height of the anterior flange between the genders. The Hamann-Todd Collection provided 1207 skeletally mature cadaver femora. The femoral length, the anteroposterior height, height of the lateral and medial flanges and the mediolateral width were measured in all the specimens. The mechanical axis of the femur, the cut articular width and the aspect ratio were assessed. Statistical analysis of the effect of gender upon the aspect ratio and the lateral and medial flanges was undertaken, controlling for age, height and race. The mean aspect ratio of male femora was 1.21 (SD 0.07) and of female femora it was 1.16 (SD 0.06) (p < 0.001). There was no significant difference between male and female specimens in the mean size of the lateral flange (6.57 mm (SD 2.57) and 7.02 mm (SD 2.36), respectively; p = 0.099) or of the medial flange (3.03 mm (SD 2.47) and 3.56 mm (SD 2.32), respectively; p = 0.67). Future work in the design of knee prostheses should take into account the overall variability of the anatomy of the distal femur.     

Sex differences in age-related remodeling of the femur and tibia

Changes with age in cross-sectional geometry of the lower limb bones were investigated in a large sample of cadaveric skeletal material from U.S. white adults. Section properties (areas and second moments of area) were determined at 11 locations by sectioning and direct measurement of 103 femora and 99 tibiae. All properties were standardized for body size differences by dividing by powers of bone length, and age trends were determined through linear regression analysis. Results indicate that while both men and women undergo endosteal resorption of bone and medullary expansion with aging, only men exhibit concurrent subperiosteal bone apposition and expansion. As a consequence, men show little change in cortical area and some increase in second moments of area with age, while women show decreases in both cortical area and second moments of area. Thus, only men appear to remodel bone in a way that would tend to compensate for loss of bone material strength with aging. In a previous study of a preindustrial sample with high activity levels, both men and women exhibited bone subperiosteal expansion and increase in second moments of area with aging. Together with observed differences in fracture incidence among living populations, these findings suggest that relatively low activity levels may not stimulate optimal bone remodeling throughout life and thus may contribute to higher risk of fracture in old age.     

Antiepileptic drug use,falls, fractures,and BMD in postmenopausal women: Findings from the women's health initiative (WHI)

Antiepileptic drugs (AEDs) are used increasingly in clinical practice to treat a number of conditions. However, the relationship between the use of these medications, particularly the newer AEDs, and fracture risk has not been well characterized. We used data from the Women's Health Initiative (WHI) to determine the relationship bewteen the use of AEDs and falls, fractures, and bone mineral density (BMD) over an average of 7.7 years of follow‐up. We included 138,667 women (1,385 users of AEDs and 137,282 nonusers) aged 50 to 79 years in this longitudinal cohort analyses. After adjustment for covariates, use of AEDs was positively associated with total fractures [hazard ratio (HR) = 1.44, 95% confidence interval (CI) 1.30–1.61], all site‐specific fractures including the hip (HR = 1.51, 95% CI 1.05–2.17), clinical vertebral fractures (HR = 1.60, 95% CI 1.20–2.12), lower arm or wrist fractures (HR = 1.40, 95% CI 1.11–1.76), and other clinical fractures (HR = 1.46, 95% CI 1.29–1.65) and two or more falls (HR = 1.62, 95% CI 1.50–1.74) but not with baseline BMD or changes in BMD (p ≥ .064 for all sites). Use of more than one and use of enzyme‐inducing AEDs were significantly associated with total fractures (HR = 1.55, 95% CI 1.15–2.09 and HR = 1.36, 95% CI 1.09–1.69, respectively). We conclude that in clinical practice, postmenopausal women who use AEDs should be considered at increased risk for fracture, and attention to fall prevention may be particularly important in these women. © 2010 American Society for Bone and Mineral Research.     

Vitamin E and risk of type 2 diabetes in the women's health study randomized controlled trial

We directly assessed the efficacy of vitamin E supplements for primary prevention of type 2 diabetes among apparently healthy women in the Women's Health Study randomized trial. Between 1992 and 2004, 38,716 apparently healthy U.S. women aged >or=45 years and free of diabetes, cancer, and cardiovascular disease were in two randomly assigned intervention groups and received 600 IU of vitamin E (alpha-tocopherol, n = 19,347) or placebo (n = 19,369) on alternate days. During a median 10-year follow-up, there were 827 cases of incident type 2 diabetes in the vitamin E group and 869 in the placebo group, a nonsignificant 5% risk reduction (relative risk [RR] 0.95 [95% CI 0.87-1.05], P = 0.31). There was no evidence that diabetes risk factors including age, BMI, postmenopausal hormone use, multivitamin use, physical activity, alcohol intake, and smoking status modified the effect of vitamin E on the risk of type 2 diabetes. In a sensitivity analysis taking compliance into account, women in the vitamin E group had an RR of 0.93 (95% CI 0.83-1.04) (P = 0.21) compared with those randomized to placebo. In this large trial with 10-year follow-up, alternate-day doses of 600 IU vitamin E provided no significant benefit for type 2 diabetes in initially healthy women.     

脆性股骨颈骨折的股骨近端几何结构分析

目的 研究脆性股骨颈骨折的股骨近端几何结构特点.方法 将57例患者分为两组.骨折组29例,平均年龄73.6±9.9岁,性别:男10例,女19例;非骨折组28例,平均年龄64.8±9.3岁,性别:男10例,女18例.对患者股骨近端CT扫描的定位像进行健侧股骨近端几何结构参数测量.结果 骨折组的股骨颈颈长较长、颈中段皮质厚度变薄、颈干角较大、颈中段皮质厚度比率下降、颈中段宽度与颈轴长比率下降、颈长与颈轴长比率升高、颈长与颈宽度比率升高,两组比较有统计学意义;颈轴长、颈中段宽度、颈中段髓腔宽度在两组比较中没有统计学意义.结论 在脆性股骨颈骨折中,股骨近端几何结构的参数在其绝对数值上有着重要性,而股骨近端各部分结构在比率上的合理配置对股骨近端的骨强度也起着重要的作用.     

Sex differences in clinical outcomes in Japanese incident dialysis patients: a prospective observational multicenter study

Clinical and Experimental Nephrology - A Dialysis Outcomes and Practice Patterns Study (DOPPS) has shown a one-to-one male-to-female mortality ratio, notwithstanding the statistically longer life...     

脆性股骨颈骨折的股骨近端几何结构分析

目的研究脆性股骨颈骨折的股骨近端几何结构特点。方法将57例患者分为两组。骨折组29例,平均年龄73.6±9.9岁,性别:男10例,女19例;非骨折组28例,平均年龄64.8±9.3岁,性别:男10例,女18例。对患者股骨近端CT扫描的定位像进行健侧股骨近端几何结构参数测量。结果骨折组的股骨颈颈长较长、颈中段皮质厚度变薄、颈干角较大、颈中段皮质厚度比率下降、颈中段宽度与颈轴长比率下降、颈长与颈轴长比率升高、颈长与颈宽度比率升高,两组比较有统计学意义;颈轴长、颈中段宽度、颈中段髓腔宽度在两组比较中没有统计学意义。结论在脆性股骨颈骨折中,股骨近端几何结构的参数在其绝对数值上有着重要性,而股骨近端各部分结构在比率上的合理配置对股骨近端的骨强度也起着重要的作用。