Ethnic differences in composite indices of femoral neck strength

Estimation of population affinity using proximal femoral measurements based on computed tomographic images in the Japanese and western Australian populations

The present study analyzes morphological differences femora of contemporary Japanese and Western Australian individuals and investigates the feasibility of population affinity estimation based on computed tomographic (CT) data. The latter is deemed to be of practical importance because most anthropological methods rely on the assessment of aspects of skull morphology, which when damaged and/or unavailable, often hampers attempts to estimate population affinity. The study sample comprised CT scans of 297 (146 females; 151 males) Japanese and 330 (145 females; 185 males) Western Australian adult individuals. A total of 10 measurements were acquired in two-dimensional CT images of the left and right femora; two machine learning methods (random forest modeling [RFM]) and support vector machine [SVM]) were then applied for population affinity classification. The accuracy of the two-way (sex-specific and sex-mixed) model was between 71.38 and 82.07% and 76.09-86.09% for RFM and SVM, respectively. Sex-specific (female and male) models were slightly more accurate compared to the sex-mixed models; there were no considerable differences in the correct classification rates between the female- and male-specific models. All the classification accuracies were higher in the Western Australian population, except for the male model using SVM. The four-way sex and population affinity model had an overall classification accuracy of 74.96% and 79.11% for RFM and SVM, respectively. The Western Australian females had the lowest correct classification rate followed by the Japanese males. Our data indicate that femoral measurements may be particularly useful for classification of Japanese and Western Australian individuals.

Osteoporosis and Fracture Risk among Older US Asian Adults

PURPOSE OF REVIEW

This review summarizes the current knowledge regarding osteoporosis and fracture among older US Asian adults.

RECENT FINDINGS

Asian adults have lower (areal) bone density than non-Hispanic White adults and thus are more likely to be diagnosed and treated for osteoporosis, despite their lower risk of hip fracture. The latter may relate to favorable characteristics in hip geometry, volumetric bone density, and bone microarchitecture; lower risk of falls; and other clinical factors. The fracture risk calculator FRAX accounts for the lower risk of hip fracture among US Asian adults. However, data on major osteoporotic fracture risk remain limited. Fracture rates also vary by Asian subgroup, which may have implications for fracture risk assessment. Furthermore, among women receiving bisphosphonate drugs, Asian race is a risk factor for atypical femur fracture, an uncommon complication associated with treatment duration. Recent clinical trial efficacy data pertaining to lower bisphosphonate doses and longer dosing intervals may be relevant for Asian adults. More research is needed to inform osteoporosis care of US Asian adults, including risk-benefit considerations and the optimal duration of bisphosphonate treatment. Greater evidence-based guidance for primary fracture prevention among US Asian adults will ensure health equity in the prevention of osteoporotic fractures.

The Effects of a 1-Year Recreational Kung Fu Protocol on Bone Health Parameters in a Group of Healthy Inactive Young Men

The main aim of the current study was to explore the effects of a 1-year recreational Kung Fu protocol on bone health parameters (bone mineral content (BMC), bone mineral density (BMD), femoral neck geometry and composite indices of femoral neck strength) in a group of healthy inactive young men. 54 young inactive men voluntarily participated in this study, but only 51 of them completed it. The participants were assigned to 2 different groups: control group (n=31) and Kung Fu group (n=20). The Kung Fu group performed two sessions of recreational Kung Fu per week; the duration of each session was 45 minutes. The current study has demonstrated that whole body (WB) BMC, ultra-distal (UD) radius BMD, 1/3 radius BMD, total radius BMD, total forearm BMD, maximal strength, maximum oxygen consumption and jumping performance increased in the Kung Fu group but not in the control group. The percentages of variations in WB BMC, forearm BMD and physical performance parameters were significantly different between the two groups. In conclusion, this study suggests that recreational Kung Fu is an effective method to improve WB BMC, forearm BMD and physical performance parameters in young inactive men.

The effects of a 1-year recreational football protocol on bone health parameters in a group of healthy inactive 50-year-old men

The main aim of the current study was to explore the effects of a 1-year recreational football protocol on bone health parameters (bone mineral content (BMC), bone mineral density (BMD), femoral neck geometry and composite indices of femoral neck strength) in a group of healthy inactive 50-year-old men. 51 middle-aged men voluntarily participated in this study, but only 41 of them completed it. Thus, the study population included 11 former football (FF) players and 30 inactive men. Inactive men were assigned to 3 different groups: controls (n=10), recreational football 30 (RF30; n=10) and recreational football 60 (RF60; n=10). The RF30 group performed two sessions of recreational football per week; the duration of each session was 30 minutes. The RF60 group performed two sessions of recreational football per week; the duration of each session was 60 minutes. The current study has demonstrated that whole body (WB) BMC, femoral neck BMD, cross-sectional moment of inertia, compression strength index, bending strength index and impact strength index increased in both experimental groups (RF30 and RF60) but not in the control group. The percentages of variations in bone health parameters were not significantly different between RF30 and RF60. In conclusion, this study suggests that recreational football is an effective method to improve bone health parameters in middle-aged men. In the studied population, most of the bone health benefits occurred after a low volume training protocol (2 * 30 minutes of recreational football per week).

Does hip structural analysis confer additional benefit to routine BMD assessment in postmenopausal women with hip fracture? A study from a tertiary center in southern India

This study from southern India showed that proximal hip geometry was significantly impaired in postmenopausal women with femoral neck fracture. The trabecular bone score (TBS), which is reflective of bone microarchitecture, was also significantly impaired in patients with fracture.

INTRODUCTION

There is limited information with regard to comprehensive bone health in Indian postmenopausal women with neck of femur fracture. We studied the bone mineral density (BMD), trabecular bone score (TBS), proximal hip geometry, and bone mineral biochemistry in postmenopausal women with and without femoral neck fractures.

METHODS

This was a cross-sectional study conducted at a tertiary care center in South India. BMD, TBS, and hip structural analysis (HSA) were assessed using a dual-energy X-ray absorptiometry (DXA) scanner. Bone mineral biochemical profiles were also studied.

RESULTS

A total of 90 postmenopausal women with acute femoral neck fracture with mean (SD) age of 63.2 (6.1) years and 90 age-matched controls were included. The prevalence of osteoporosis was higher among cases as compared to controls (83.3% vs 47.8%; P < 0.001). Degraded bone microarchitecture (TBS value < 1.200) was more frequent among women with hip fracture as compared to controls (46.7% vs 31.1%; P = 0.032). Cross-sectional moment of inertia (CSMI) was significantly lower at the narrow neck (NN) and inter-trochanteric (IT) region in cases (P < 0.05) and buckling ratio (BR) was significantly higher at all three sites in postmenopausal women with femoral neck fracture as compared controls. Multivariate logistic regression analysis showed that femoral neck osteoporosis, low CSMI at NN and high BR at NN and femoral shaft emerged as factors significantly associated with femoral neck fractures.

CONCLUSION

This study highlights that impaired parameters of proximal hip geometry and a low trabecular bone score may be significantly associated with femoral neck fractures in postmenopausal women.

Effect of vitamin D on bone strength in older African Americans: a randomized controlled trial

There is controversy over whether African Americans have higher vitamin D requirements than recommended by the Institute of Medicine. We previously reported that maintaining serum 25(OH)D above 30 ng/mL does not prevent age-related bone loss. Herein, we report that bone strength is also unaffected by maintaining this level in this population.

INTRODUCTION

The role of vitamin D in bone strength has not been investigated in the African American (AA) population.

METHODS

A 3-year randomized controlled trial was designed to examine the effect of vitamin D supplementation on physical performance, bone loss, and bone strength in healthy older AA women. A total of 260 postmenopausal AA women, ages ≥ 60 years were randomized to a vitamin D₃ or placebo arm. Vitamin D₃ dose was adjusted to maintain serum 25OHD > 30 ng/mL. Bone mineral density, femoral axis length, and femoral neck (FN) width were measured by dual-energy X-ray absorptiometry. Composite indices of FN strength [compression strength index (CSI), bending strength index (BSI), and impact strength index (ISI)] were computed.

RESULTS

The mean age of participants was 68.2 ± 4.9 years. Baseline characteristics between groups were similar. The average dose of vitamin D₃ was 3490 ± 1465 IU/day in the active group. The mean serum 25OHD was 46.8 ± 1.2 ng/mL versus 20.7 ± 1.1 ng/mL in the active versus placebo group. Serum 25OHD did not correlate with any composite indices. The longitudinal differences observed in FN width, CSI, BSI, and ISI in both groups were not statistically significant (all p values > 0.05). Further, there was no group × time interaction effect for any of the composite indices (all p values > 0.05).

CONCLUSION

Maintaining serum 25OHD > 30 ng/mL (75 nmol/L) does not affect bone strength in older AA women. There is no evidence to support vitamin D intake greater than the recommended RDA by the Institute of Medicine in this population for bone strength.

The menopause transition and women's health at midlife: a progress report from the Study of Women's Health Across the Nation (SWAN)

OBJECTIVE

Our initial understanding of the menopause transition (MT) has been framed by clinical samples of women seeking treatment rather than by population-based studies. The Study of Women's Health Across the Nation (SWAN) initiated in 1996 with an overall goal to define the MT, to characterize its biological and psychosocial antecedents and sequelae in an ethnically and racially diverse sample of midlife women.

METHODS

This review summarizes the central findings of SWAN to date that can inform women and their healthcare providers about the impact of the MT and midlife aging on overall health and well-being.

RESULTS

SWAN characterized changes in reproductive axis and menstrual cycle patterns that informed the development of the reproductive aging staging system Staging of Reproductive Aging Workshop+10; MT-related symptoms and mental health (vasomotor symptoms, sleep complaints, psychological symptoms, cognitive performance, and urogenital and sexual health); and physiological systems and functions (cardiovascular and cardiometabolic health, bone health, physical function performance) that are influenced by the MT. SWAN demonstrated substantial interrelations among these changes and significant racial/ethnic differences in the rate and magnitude of change in multiple health indictors in midlife women. The findings point to midlife as a critical stage for adopting healthy behavior and preventive strategies.

CONCLUSIONS

Over the past 23 years, SWAN has advanced our understanding of the impact of the MT and midlife aging on health and well-being in women. SWAN will be instrumental to determine whether MT-related changes during midlife are related to unfavorable health and well-being in early old age.

Bone Health During the Menopause Transition and Beyond

The menopause transition is a critical period for bone health, with rapid losses in bone mass and strength occurring in a 3-year window bracketing the date of the final menstrual period. Declines in bone mass are accompanied by deleterious changes in bone macrostructure and microarchitecture, which may be captured by changes in composite strength indices and indices of trabecular thickness and connectivity. The onset of the rapid bone loss phase is preceded by changes in sex steroid hormones and increases in markers of bone resorption, measurements of which may be clinically useful in predicting the onset of the rapid loss phase and in identifying the women who will lose the most bone strength over the menopause transition.

Inclusion of Regional Body Composition Parameters Improves Bone Mineral Density Cross-Calibration Between GE Lunar Prodigy and iDXA Densitometers

Since 1989, the Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE, n = 14220) Study has followed long-term changes of bone mineral density (BMD) and body composition in women with GE Lunar devices. During the course of OSTPRE, the dual-energy X-ray absorptiometry device had to be replaced by a newer model. Then, it was essential to determine whether systematic measurement differences in BMD and body composition will occur. As a part of the OSTPRE study, BMD was measured in 54 women, whereas body composition was determined in 55 women, aged 27-71, by using both the GE Healthcare Lunar Prodigy and iDXA narrow-angle fan beam densitometers during the same visit. The total body fat mass (FM) and lean body mass (LBM) results of these scanners showed a high linear correlation (r = 0.981-0.994, p < 0.0001). However, the mean total body FM and LBM values measured by iDXA were on average 2.3% (0.5 kg, 95% confidence interval: 0.3-0.7 kg) higher and 0.8% (0.3 kg, 95% confidence interval: 0.1-0.6 kg) lower, respectively, than those measured by Prodigy. Inclusion of local soft tissue measurements (total body LBM, legs/android FM) improved the agreement of total body, total hip, and lumbar spine BMD values between the devices but not femoral neck BMD agreement. Equations, based on linear regression analyses, were derived to minimize differences between the instruments. Then, the differences in BMD and body composition measurements were negligible between Prodigy and iDXA. Using correction equations enables an objective comparison of longitudinal BMD and body composition measurements.

Conjugated estrogens and bazedoxifene in minority populations: pooled analysis of four phase 3 trials

OBJECTIVE

The aim of the study was to compare efficacy of conjugated estrogens (CE)/bazedoxifene (BZA) for treatment of menopausal symptoms and prevention of postmenopausal osteoporosis in minorities (black/Hispanic) versus whites.

METHODS

In a post hoc analysis, data were pooled from 3,424 white or minority nonhysterectomized postmenopausal women randomized to CE 0.45 or 0.625 mg/BZA 20 mg or placebo in four double-blind, phase 3 Selective Estrogens, Menopause, and Response to Therapy (SMART) trials. Outcomes included hot flush frequency/severity (daily diary) in women with at least seven moderate-to-severe hot flushes per day (SMART-1, -2), vaginal cytology in women with at most 5% superficial cells (SMART-1, -3), lumbar spine and total hip bone mineral density (BMD) (SMART-1, -5), and the Menopause-Specific Quality of Life (MENQOL) questionnaire (SMART-1, -2, -3, -5).

RESULTS

The analysis included 2,907 white (84.9%), 315 black (9.2%), and 202 Hispanic (5.9%) women. The reduction in hot flush frequency/severity versus placebo (P < 0.05; week 12) was similar in white and minority women. In both populations, both doses significantly (P < 0.05 vs placebo) improved MENQOL vasomotor function, sexual function, and total scores at 3 months; decreased the percentage of parabasal cells at 2 years; and increased the percentage of BMD responders at 12 and 24 months. Significant differential treatment effects by race/ethnicity were observed only for effects on vaginal superficial cells at month 24 and vaginal pH at month 3.

CONCLUSIONS

Notwithstanding a limited sample size, CE/BZA had a similar and beneficial impact on hot flushes, MENQOL, and BMD in minorities and whites.

Moving toward a prevention strategy for osteoporosis by giving a voice to a silent disease

A major unmet challenge in developing preventative treatment programs for osteoporosis is that the optimal timing of treatment remains unknown. In this commentary we make the argument that the menopausal transition (MT) is a critical period in a woman's life for bone health, and that efforts aimed at reducing fracture risk later in life may benefit greatly from strategies that treat women earlier with the intent of keeping bones strong as long as possible. Bone strength is an important parameter to monitor during the MT because engineering principles can be applied to differentiate those women that maintain bone strength from those women that lose bone strength and are in need of early treatment. It is critical to understand the underlying mechanistic causes for reduced strength to inform treatment strategies. Combining measures of strength with data on how bone structure changes during the MT may help differentiate whether a woman is losing strength because of excessive bone resorption, insufficient compensatory bone formation, trabeculae loss, or some combination of these factors. Each of these biomechanical mechanisms may require a different treatment strategy to keep bones strong. The technologies that enable physicians to differentially diagnose and treat women in a preventive manner, however, have lagged behind the development of prophylactic treatments for osteoporosis. To take advantage of these treatment options, advances in preventive treatment strategies for osteoporosis may require developing new technologies with imaging resolutions that match the pace by which bone changes during the MT and supplementing a woman's bone mineral density (BMD)-status with information from engineering-based analyses that reveal the structural and material changes responsible for the decline in bone strength during the menopausal transition.

Incidence and characteristics of proximal femoral fractures in an Afro-Caribbean population

BACKGROUND

Although fractures of the proximal femur (FPF) are supposedly less frequent in Black populations (studies of incidence are rare) the life expectancy in Africa is low, which could partially explain this notion. There is only one retrospective study on the incidence of FPF in the islands of the Caribbean, thus we performed an incidence study in the insular, circumscribed, 90% Afro-Caribbean population of Martinique. The goals of this study were: (1) to estimate the incidence of FPF; (2) and to prospectively describe the main characteristics.

HYPOTHESIS

The incidence of fractures of the proximal femur in Martinique is lower than in Western countries.

PATIENTS AND METHODS

The raw and standardized incidence ratio of FPF in relation to the world population was estimated based on data from the Medical Information System Program (Programme de médicalisation des systèmes d'information [PMSI]) for all of Martinique for a period of 4 years (January 1, 2010 to December 31, 2013). Characteristics were based on all patients over the age of 60 who presented to the Fort-de-France University Hospital (CHU) for a FPF between December 1, 2011 and April 31, 2012. Patients with light-skin phenotype, high-energy fractures and secondary fractures were excluded from the study.

RESULTS

The standardized incidence ratio in relation to the world population was estimated (n=794) as 22.5/100,000 patient-years [20.6-24.4]: 22.6 and 22.4/100,000 in men and women respectively. The characteristics of eighty-seven patients (including 56 women), mean age 85.3 (±7.2) (62-100) years old were evaluated: 52 femoral neck fractures (60%) and 33 fractures of the greater trochanter (38%). The 2-month mortality rate was 21%, and 1/3 of the surviving patients could function independently. The risk of death increased in relation to the initial risk of moderate to severe dementia.

DISCUSSION

The incidence of FPF in Martinique is lower than in Western countries and includes, as expected, an elderly, female population. Unlike a previous study performed in Guadeloupe, there was a majority of femoral neck fractures. A Caribbean multi-insular study is needed to confirm these results and to obtain precise data on bone density.

LEVEL OF EVIDENCE

IV; descriptive prospective epidemiological study.

Cross-Calibration of GE Healthcare Lunar Prodigy and iDXA Dual-Energy X-Ray Densitometers for Bone Mineral Measurements

In long-term prospective studies, dual-energy X-ray absorptiometry (DXA) devices need to be inevitably changed. It is essential to assess whether systematic differences will exist between measurements with the new and old device. A group of female volunteers (21-72 years) underwent anteroposterior lumbar spine L2-L4 (n = 72), proximal femur (n = 72), and total body (n = 62) measurements with the Prodigy and the iDXA scanners at the same visit. The bone mineral density (BMD) measurements with these two scanners showed a high linear association at all tested sites (r = 0.962-0.995; p < 0.0001). The average iDXA BMD values were 1.5%, 0.5%, and 0.9% higher than those of Prodigy for lumbar spine (L2-L4) (p < 0.0001), femoral neck (p = 0.048), and total hip (p < 0.0001), respectively. Total body BMD values measured with the iDXA were -1.3% lower (p < 0.0001) than those measured with the Prodigy. For total body, lumbar spine, and femoral neck, the BMD differences as measured with these two devices were independent of subject height and weight. Linear correction equations were developed to ensure comparability of BMD measurements obtained with both DXA scanners. Importantly, use of equations from previous studies would have increased the discrepancy between these particular DXA scanners, especially at hip and at spine.

Bone health after menopause

PURPOSE OF REVIEW

This article reviews recent publications (January 2014-June 2015) on bone health and menopause.

RECENT FINDINGS

Recent articles suggest that simple instruments, such as the osteoporosis self-assessment tool based on age and weight may identify women age 50-64 for bone mineral density (BMD) testing. Rescreening of women age 50-64 is not recommended because their overall risk of fracture is quite low. A novel risk factor for hip fracture among non-Caucasian women is socioeconomic status. Midlife women with low serum 25-hydroxyvitamin D (<20 ng/ml) have an increased risk of fracture over the menopausal transition and vitamin D supplementation is warranted. Wrist fractures are the most common fracture in women age 50-64. Women who experience a wrist fracture have an increased risk of subsequent fracture and should have a BMD scan. Results of studies using composite measures of femoral neck strength relative to load emphasize the need for osteoporotic research to move beyond BMD.

SUMMARY

This recent research has provided new and important findings improving our understanding of osteoporosis during the menopausal transition.

Parity, lactation, bone strength, and 16-year fracture risk in adult women: findings from the Study of Women's Health Across the Nation (SWAN)

Our objective was to examine the associations of lifetime parity and accumulated length of lactation with bone strength in women prior to the menopause transition and fracture risk during and after the transition. Participants were 2239 pre- or early peri-menopausal women from the Study of Women's Health Across the Nation (SWAN), ages 42-53 years at baseline, who had no childbirths after age 42. Bone mineral density (BMD) was measured in the femoral neck and the lumbar spine at the baseline SWAN visit using dual-energy x-ray absorptiometry, and the composite indices of femoral neck strength relative to load (in three failure modes: compression, bending, and impact) were calculated from femoral neck BMD, femoral neck size, and body size. Data on fractures after age 42 were collected for a median follow-up of 15.7 years (interquartile range, 11.4-18.5 years). In multiple linear regressions adjusted for covariates, lifetime parity was associated positively with femoral neck strength relative to load (0.024 standard deviation (SD) increment in impact strength index per childbirth, p=0.049), but accumulated length of lactation was associated negatively with lumbar spine BMD (0.018 SD decrement per every additional 6 months of lactation, p=0.040). In Cox proportional hazards regressions adjusted for covariates, neither parity nor lactation was associated with fracture hazard after age 42. In conclusion, parity and lactation have little impact on peak bone strength prior to menopause, and do not affect fracture risk after age 42 over 16-year follow-up.

Adult bone strength of children from single-parent families: the Midlife in the United States Study

Bone health may be negatively impacted by childhood socio-environmental circumstances. We examined the independent associations of single-parent childhood and parental death or divorce in childhood with adult bone strength indices. Longer exposure to a single-parent household in childhood was associated with lower bone strength in adulthood.

INTRODUCTION

Because peak bone mass is acquired during childhood, bone health may be negatively impacted by childhood socio-environmental disadvantage. The goal of this study was to determine whether being raised in a single-parent household is associated with lower bone strength in adulthood.

METHODS

Using dual-energy X-ray absorptiometry data from 708 participants (mean age 57 years) in the Midlife in the United States Biomarker Project, we examined the independent associations of composite indices of femoral neck bone strength relative to load (in three failure modes: compression, bending, and impact) in adulthood with the experience of single-parent childhood and parental death or divorce in childhood.

RESULTS

After adjustment for gender, race, menopause transition stage, age, and body mass index, each additional year of single-parent childhood was associated with 0.02 to 0.03 SD lower indices of adult femoral neck strength. In those with 9-16 years of single-parent childhood, the compression strength index was 0.41 SD lower, bending strength index was 0.31 SD lower, and impact strength index was 0.25 SD lower (all p values < 0.05). In contrast, parental death or divorce during childhood was not by itself independently associated with adult bone strength indices. The magnitudes of these associations were unaltered by additional adjustment for lifestyle factors and socioeconomic status in childhood and adulthood.

CONCLUSIONS

Independent of parental death or divorce, growing up in a single-parent household is associated with lower femoral neck bone strength in adulthood, and this association is not entirely explained by childhood or adult socioeconomic conditions or lifestyle choices.

Multisystem dysregulation and bone strength: findings from the study of midlife in the United States

CONTEXT

Accumulated dysregulation across multiple physiological systems, or allostatic load (AL), has been proposed as the biological pathway from psychosocial adversity to poor health.

OBJECTIVE

The objective of the study was to examine whether AL, constructed using biomarkers and medication data from seven systems (sympathetic, parasympathetic, hypothalamic-pituitary-adrenal axis, cardiovascular regulation, inflammation, and lipid and glucose metabolism), is associated with lower bone strength in a national sample.

DESIGN

This was a cross-sectional study.

SETTING AND PARTICIPANTS

Seven hundred three community-dwelling men and women from the Study of Midlife in the United States participated in the study.

OUTCOME MEASURES

Bone mineral density (BMD) was measured in the femoral neck and lumbar spine. Femoral neck BMD was combined with bone size and body size to create composite indices of femoral neck strength relative to load in three failure modes: compression, bending, and impact.

RESULTS

In mixed-effects linear regression controlling for clustering within families and adjusted for age, gender, race/ethnicity, body mass index, menopausal transition stage, childhood socioeconomic status, adult finances, education level, and study center, each SD increment in AL score was associated with between 0.10 and 0.11 SD decrements in lumbar spine BMD and each of the three composite strength indices (all values of P < .05). Gender modified the association of AL only with femoral neck BMD; each SD increment in AL score was associated with 0.21 SD decrement in femoral neck BMD in men (P < .01) but not in women.

CONCLUSIONS

Accumulation of dysregulation across systems was modestly associated with lower bone strength. This study adds to the accumulating evidence that multisystem dysregulation, or AL, predicts a variety of adverse health outcomes.

Hip fractures in Hefei, China: the Hefei osteoporosis project

Hip fracture incidence rates in Hefei, China, over a period of 1 year (2010) were assessed. The aim of this study was to investigate the incidence and epidemiology of hip fracture in Hefei and compare it with other populations. All the hip fracture records were obtained from the Hefei Hospital Discharge Register for the entire population ≥50 years of age and restricted to cervical or trochanteric types. The incidence of hip fracture was standardized to the 2010 World population. A total of 1518 (aged ≥50) hip fractures (628 in men, 890 in women) were recorded during the study period. The age-adjusted incidence rate for 1 year was 144/100,000 (95 % CI = 135-153/100,000) for women and 97/100,000 (95 % CI = 85-109/100,000) for men. The standardized incidence rate against the 2010 World population was 151.7/100,000 for women and 98.2/100,000 for men. The mean age of patients with a hip fracture was 74.5 ± 10.1 years for women and 71.9 ± 11.9 years for men. The overall female to male ratio of hip fracture was 1.48:1 for hip fracture incidence and 1.54:1 for standardized incidence. Simple fall accounted for 85 % hip fractures in total cases. Hefei has a lower incidence of hip fracture compared with Beijing and other countries from the five continents in recent studies, but a higher incidence than those cities in north-east China in the early 1990s. The inequality incidence in different geographic areas could be due to the urbanization or life expectancy of the population, but further investigation needs to be done to confirm this hypothesis. We also found a higher incidence in women than in men. Simple fall may be the main mechanism of injury for hip fracture.

Race/ethnic differences in associations between bone mineral density and fracture history in older men

SUMMARY

To determine whether there are race/ethnic differences in bone mineral density (BMD) by fracture history in men aged 65 years and older, we performed cross-sectional analysis in five large independent cohorts. Low BMD was associated with a higher prevalence of fracture in all cohorts, and the magnitude of the BMD differences by fracture status was similar across groups.

INTRODUCTION

We aimed to determine whether there are race/ethnic and geographic differences in bone mineral density by fracture history in men aged 65 years and older.

METHOD

The datasets included the Osteoporotic Fractures in Men (MrOS) Study (5,342 White, 243 African-American, 190 Asian, and 126 Hispanic), MrOS Hong Kong (1,968 Hong Kong Chinese), Tobago Bone Health Study (641 Afro-Caribbean), Namwon Study (1,834 Korean), and Dong-gu Study (2,057 Korean). The two Korean cohorts were combined.

RESULTS

The prevalence of self-reported non-traumatic fracture was US white, 17.1 %; Afro-Caribbean, 5.5 %; US African-American, 15.1 %; US Hispanic, 13.7 %; US Asian, 10.5 %; Hong Kong Chinese, 5.6 %, and Korean, 5.1 %. The mean differences in hip and lumbar spine BMD between subjects with fracture and without fracture were statistically significant in all cohorts except US African American and US Asian men. There was a significant race/ethnic interaction for lumbar spine BMD by fracture status (p for interaction = 0.02), which was driven by the small number of Hispanic men. There was no interaction for femoral neck or total hip BMD. There were no significant race/ethnic differences in the odds ratio of fracture by BMD.

CONCLUSIONS

Low BMD was associated with a higher prevalence of fracture in all cohorts and the magnitude of the BMD differences by fracture status was similar across groups suggesting homogeneity in the BMD-fracture relationship among older men.

Physical activity as determinant of femoral neck strength relative to load in adult women: findings from the hip strength across the menopause transition study

Our objective was to examine associations of physical activity in different life domains with peak femoral neck strength relative to load in adult women. Greater physical activity in each of the domains of sport, active living, home, and work was associated with higher peak femoral neck strength relative to load.

INTRODUCTION

Our objective was to examine the associations of physical activity in different life domains with peak femoral neck strength relative to load in adult women. Composite indices of femoral neck strength integrate body size with femoral neck size and bone mineral density to gauge bone strength relative to load during a fall, and are inversely associated with incident fracture risk.

METHODS

Participants were 1,919 pre- and early perimenopausal women from the Study of Women's Health Across the Nation. Composite indices of femoral neck strength relative to load in three failure modes (compression, bending, and impact) were created from hip dual-energy X-ray absorption scans and body size. Usual physical activity within the past year was assessed with the Kaiser Physical Activity Survey in four domains: sport, home, active living, and work. We used multiple linear regression to examine the associations.

RESULTS

Greater physical activity in each of the four domains was independently associated with higher composite indices, adjusted for age, menopausal transition stage, race/ethnicity, Study of Women's Health Across the Nation study site, smoking status, smoking pack-years, alcohol consumption level, current use of supplementary calcium, current use of supplementary vitamin D, current use of bone-adverse medications, prior use of any sex steroid hormone pills or patch, prior use of depo-provera injections, history of hyperthyroidism, history of previous adult fracture, and employment status: standardized effect sizes ranged from 0.04 (p < 0.05) to 0.20 (p < 0.0001).

CONCLUSIONS

Physical activity in each domain examined was associated with higher peak femoral neck strength relative to load in pre- and early perimenopausal women.

The Chinese skeleton: insights into microstructure that help to explain the epidemiology of fracture

Osteoporotic fractures are a major public health problem worldwide, but incidence varies greatly across racial groups and geographic regions. Recent work suggests that the incidence of osteoporotic fracture is rising among Asian populations. Studies comparing areal bone mineral density and fracture across races generally indicate lower bone mineral density in Asian individuals including the Chinese, but this does not reflect their relatively low risk of non-vertebral fractures. In contrast, the Chinese have relatively high vertebral fracture rates similar to that of Caucasians. The paradoxically low risk for some types of fractures among the Chinese despite their low areal bone mineral density has been elucidated in part by recent advances in skeletal imaging. New techniques for assessing bone quality non-invasively demonstrate that the Chinese compensate for smaller bone size by differences in hip geometry and microstructural skeletal organization. Studies evaluating factors influencing racial differences in bone remodeling, as well as bone acquisition and loss, may further elucidate racial variation in bone microstructure. Advances in understanding the microstructure of the Chinese skeleton have not only helped to explain the epidemiology of fracture in the Chinese, but may also provide insight into the epidemiology of fracture in other races as well.

Childhood socioeconomic status and adult femoral neck bone strength: findings from the Midlife in the United States Study

PURPOSE

Bone acquisition in childhood impacts adult bone mass, and can be influenced by childhood socioeconomic conditions. Socioeconomic status is also associated with body weight which affects the load that bone is exposed to in a fall. We hypothesized that socioeconomic advantage in childhood is associated with greater bone strength relative to load in adulthood.

METHODS

Hip dual x-ray absorptiometry scans from 722 participants in the Midlife in the United States Study were used to measure femoral neck size and bone mineral density, and combined with body weight and height to create composite indices of femoral neck strength relative to load in different failure modes: compression, bending, and impact. A childhood socioeconomic advantage score was created for the same participants from parental education, self-rated financial status relative to others, and not being on welfare. Multiple linear regression was used to determine the association of childhood socioeconomic advantage with femoral neck composite strength indices, stratified by gender and race (white/non-white), and adjusted for study site, age, menopause status in women, education, and current financial advantage.

RESULTS

Childhood socioeconomic advantage was independently associated with higher indices of all three composite strength indices in white men (adjusted standardized effect sizes, 0.19 to 0.27, all p values<0.01), but not in the other three race/gender groups. Additional adjustment for adult obesity, physical activity in different life stages, smoking, and heavy drinking over the life-course significantly attenuated the associations in white men.

CONCLUSIONS

Socioeconomic disadvantage in childhood is associated with lower hip strength relative to load in white men, and these influences are dampened by healthy lifestyle choices.

Trajectories of femoral neck strength in relation to the final menstrual period in a multi-ethnic cohort

The purpose of this study was to describe the evolution of femoral neck strength relative to load across the menopause transition. It declined significantly over the 10 years bracketing the final menstrual period, and the rate of decline was modified by body mass index, race/ethnicity, and smoking status.

INTRODUCTION

Composite indices of femoral neck strength, which integrate dual energy X-ray absorptiometry (DXA)-derived bone mineral density and bone size with body size, are inversely associated with hip fracture risk. Our objective was to describe longitudinal trajectories of the strength indices across the menopausal transition.

METHODS

Data came from the Study of Women's Health Across the Nation; participants were pre- or early peri-menopausal, ages 42-53 at baseline, and were followed up for 9.1 ± 1.8 years. Composite indices of femoral neck strength in different failure modes (compression, bending, and impact) were created in 921 women who had three or more hip DXA scans and had definable final menstrual period (FMP) dates. We used mixed effects models to fit piecewise linear growth curves to the baseline-normalized strength indices as a function of time to/after the FMP.

RESULTS

Compression and impact strength indices did not decline until 1 year prior to the FMP, and declined rapidly thereafter, with some slowing of decline 1 year after the FMP. Bending strength index increased slightly until 2 years prior to the FMP, then plateaued, and began to decline at the FMP. Mean decline in strength indices over 10 years was 6.9 % (compression), 2.5 % (bending), and 6.8 % (impact). Women with higher body mass index had larger declines in two of the three indices. Other major modifiers of rates of decline were race/ethnicity and smoking status.

CONCLUSIONS

Femoral neck strength relative to load declines significantly during the menopausal transition, with declines commencing 1 to 2 years prior to the FMP.

Osteoporosis and treatments in Japan: management for preventing subsequent fractures

Prevalent fractures are major contributors to an increased risk of subsequent fractures, particularly in people with osteoporosis. While many studies have been conducted to assess the incidence of fracture in Japanese people with osteoporosis, far fewer have been conducted to assess the risk of subsequent fractures. This article reviews the morbidity, mortality, and risk of fracture in patients who are at high risk of subsequent fracture in Japan and the current treatment options available for these patients. Osteoporotic fractures in Japan are associated with high morbidity and mortality that result in significant financial and social costs. The rise in the proportion of elderly women in the Japanese population is contributing to a greater proportion of people with osteoporotic fractures and the high cost of osteoporosis. Although hip fractures have a significant effect on costs, a greater proportion of the Japanese population experience vertebral fractures. An increase in the incidence of vertebral fractures is concerning because preexisting vertebral fractures in older patients are associated with an increased risk of subsequent fractures. Hence, there is a clear rationale for pharmacological treatment of patients with prevalent vertebral fractures, or for those who are hospitalized or undergo surgery for osteoporotic fractures. Several pharmacological therapies are now available in Japan for the treatment of patients with osteoporosis. Understanding the consequences of subsequent fractures and the treatment options available for patients at high risk of subsequent fractures may contribute to clinical decision-making and improved outcomes for patients with osteoporosis.

C-reactive protein, bone strength, and nine-year fracture risk: data from the Study of Women's Health Across the Nation (SWAN)

Higher levels of C-reactive protein (CRP), an inflammatory marker, are associated with increased fracture risk, although previous studies on CRP and bone mineral density (BMD) have yielded conflicting results. We aimed to test the hypotheses that composite indices of femoral neck strength relative to load, which are inversely associated with fracture risk, would also be inversely associated with CRP, and would explain part of the association between CRP and fracture risk. We analyzed data from a multisite, multiethnic prospective cohort of 1872 community-dwelling women, premenopausal or early perimenopausal at baseline. Femoral neck composite strength indices in three failure modes were calculated using dual-energy X-ray absorptiometry (DXA)-derived femoral neck width (FNW), femoral neck axis length (FNAL), femoral neck BMD and body size at baseline, as BMD*FNW/weight for compression strength, BMD*(FNW)(2) /(FNAL*weight) for bending strength, and BMD*FNW*FNAL/(height*weight) for impact strength. Incident nondigital, noncraniofacial fractures were ascertained annually over a median follow-up of 9 years. In analyses adjusted for age, race/ethnicity, diabetes, menopause transition stage, body mass index, smoking, alcohol use, physical activity, medications, prior fracture, and study site, CRP was associated inversely with each composite strength index (0.035-0.041 SD decrement per doubling of CRP, all p < 0.001), but not associated with femoral neck or lumbar spine BMD. During the follow-up, 194 women (10.4%) had fractures. In Cox proportional hazards analyses, fracture hazard increased linearly with loge (CRP), only for CRP levels ≥ 3 mg/L. Addition of femoral neck or lumbar spine BMD to the model did not attenuate the CRP-fracture association. However, addition of any of the composite strength indices attenuated the CRP-fracture association and made it statistically nonsignificant. We conclude that fracture risk increases with increasing CRP, only above the threshold of 3 mg/L. Unlike BMD, composite strength indices are inversely related to CRP levels, and partially explain the increased fracture risk associated with inflammation.

Ethnic variability in bone geometry as assessed by hip structure analysis: findings from the hip strength across the menopausal transition study

Racial/ethnic origin plays an important role in fracture risk. Racial/ethnic differences in fracture rates cannot be fully explained by bone mineral density (BMD). Studies examining the influence of bone geometry and strength on fracture risk have focused primarily on older adults and have not included people from diverse racial/ethnic backgrounds. Our goal was to explore racial/ethnic differences in hip geometry and strength in a large sample of midlife women. We performed hip structure analysis (HSA) on hip dual-energy X-ray absorptiometry (DXA) scans from 1942 premenopausal and early perimenopausal women. The sample included white (50%), African American (27%), Chinese (11%), and Japanese (12%) women aged 42 to 52 years. HSA was performed using software developed at Johns Hopkins University. African American women had higher conventional (8.4% to 9.7%) and HSA BMD (5.4% to 19.8%) than other groups with the exception being Japanese women, who had the highest HSA BMD (9.7% to 31.4%). HSA indices associated with more favorable geometry and greater strength and resistance to fracture were more prevalent in African American and Japanese women. Femurs of African American women had a smaller outer diameter, a larger cross-sectional area and section modulus, and a lower buckling ratio. Japanese women presented a different pattern with a higher section modulus and lower buckling ratio, similar to African American women, but a wider outer diameter; this was offset by a greater cross-sectional area and a more centrally located centroid. Chinese women had similar conventional BMD as white women but a smaller neck region area and HSA BMD at both regions. They also had a smaller cross-sectional area and section modulus, a more medially located centroid, and a higher buckling ratio than white women. The observed biomechanical differences may help explain racial/ethnic variability in fracture rates. Future research should explore the contribution of hip geometry to fracture risk across all race/ethnicities.

Prediction of hip osteoporotic fractures from composite indices of femoral neck strength

OBJECTIVE

To clarify whether composite hip strength indices improve predictive ability for hip osteoporotic fractures independent of conventional bone mineral density (BMD).

SUBJECTS AND METHODS

Three hundred and eighty-two health controls and 43 women with hip fractures (aged 28.2-87.7 years, mean age 59.5 ± 9.2 years) were measured by dual energy X-ray absorptiometry for femoral neck bone mineral density (FN_BMD) and proximal femur geometry parameters of hip, and composite hip strength indices (Compression strength index, Bending strength index, and Impact strength index). The association between the studied parameters and the fractures was modelled using multiple logistic regression, including age, height, weight, and menopausal status. Fracture-predicted probability was calculated for each predictor tested. ROC curve areas (AUCs) were calculated for the fracture status, having the calculated fracture-predicted probability as a test variable. AUCs were compared by the Hanley-McNeil test.

RESULTS

Women with hip fractures had lower FN_BMD, composite hip strength indices, and longer hip axis length than controls, and no significant difference in femoral neck width. Logistic regression showed composite hip strength indices could predict hip fractures risk. To the same extent as FN BMD, Compression Strength Index (CSI) best predicted the risk for each fracture (AUC = 0.787 ± 0.028). When CSI was added to FN_BMD, there was a small but not statistically significant increase in AUC to 0.796 ± 0.027 (P = 0.9018).

CONCLUSION

Composite indices of femoral neck strength may be valuable in the assessment of the biomechanics of bone fragility; however, they do not appear to add diagnostic value to the simple measurement of BMD.

Clinical review: Ethnic differences in bone mass--clinical implications

CONTEXT

Differences in bone mineral density (BMD) as assessed with dual-energy x-ray absorptiometry are observed between geographic and ethnic groups, with important implications in clinical practice.

EVIDENCE ACQUISITION

PubMed was employed to identify relevant studies. A review of the literature was conducted, and data were summarized and integrated.

EVIDENCE SYNTHESIS

The available data highlight the complex ethnic variations in BMD, which only partially account for observed variations in fracture rates. Factors contributing to ethnic differences include genetics, skeletal size, body size and composition, lifestyle, and social determinants. Despite BMD differences, the gradient of risk for fracture from BMD and other clinical risk factors appears to be similar across ethnic groups. Furthermore, BMD variation is greater within an ethnic population than between ethnic populations. New imaging technologies have identified ethnic differences in bone geometry, volumetric density, microarchitecture, and estimated bone strength that may contribute to a better understanding of ethnic differences in fracture risk.

CONCLUSIONS

Factors associated with ethnicity affect BMD and fracture risk through direct and indirect mechanisms.

Bone resorption and fracture across the menopausal transition: the Study of Women's Health Across the Nation

OBJECTIVE

Bone turnover markers (BTMs) predict fracture in older women, whereas data on younger women are lacking. To test the hypothesis that BTMs measured before and after menopause predict fracture risk, we performed a cohort study of 2,305 women.

METHODS

Women attended up to nine clinic visits for an average of 7.6 ± 1.6 years; all were aged 42 to 52 years and were premenopausal or early perimenopausal at baseline. Incident fractures were self-reported. Serum osteocalcin and urinary cross-linked N-telopeptide of type I collagen (NTX) were measured at baseline. NTX was measured at each annual follow-up. Interval-censored survival models or generalized estimating equations were used to test whether baseline BTMs and changes in NTX, respectively, were associated with fracture risk. Hazard ratios (HRs) or odds ratios were calculated with 95% CIs.

RESULTS

Women who experienced fractures (n = 184) had about a 10% higher baseline median NTX (34.4 vs 31.5 nanomoles of bone collagen equivalents per liter per nanomole of creatinine per liter; P = 0.001), but there was no difference in osteocalcin. A 1-SD decrease in lumbar spine bone mineral density (BMD) measured premenopausally was associated with a higher fracture risk during menopause (HR, 1.50; 95% CI, 1.28-1.68). Women with a baseline NTX greater than the median had a 45% higher risk of fracture, multivariable-adjusted (HR, 1.46; 95% CI, 1.05-2.26). The HR of fracture among women with both the lowest spine BMD (quartile 1) and the highest NTX (quartile 4) at baseline was 2.87 (95% CI, 1.61-6.01), compared with women with lower NTX and higher BMD. Women whose NTX increased more than the median had a higher risk of fracture (odds ratio, 1.51; 95% CI, 1.08-2.10). Women who had baseline NTX greater than the median experienced greater loss of spine and hip BMD.

CONCLUSIONS

A higher urinary NTX excretion measured before menopause and across menopause is associated with a higher risk of fracture. Our results are consistent with the pathophysiology of transmenopausal changes in bone strength.

Fracture risk assessment without race/ethnicity information

CONTEXT

Dual-energy x-ray absorptiometry-derived bone mineral density (BMD) does not explain interracial differences in fracture risk; thus, BMD-based fracture risk assessment requires patient race/ethnicity information and ethnicity-specific BMD reference databases.

OBJECTIVE

The objective of the study was to investigate whether composite femoral neck strength indices, which integrate dual-energy x-ray absorptiometry-derived femoral neck size, femoral neck BMD, and body size, will allow fracture risk assessment without requiring race/ethnicity information.

DESIGN

This was a prospective cohort study.

SETTING AND PARTICIPANTS

A total of 1940 community-dwelling women aged 42-53 yr from four race/ethnicity groups (968 Caucasian, 512 African-American, 239 Japanese, and 221 Chinese) were followed up for 9 yr.

OUTCOME MEASUREMENTS

Self-reported, nondigital, noncraniofacial fractures were measured.

RESULTS

Two hundred and two women (10.4%) sustained fractures and 82 (4.3%) had minimum-trauma fractures. Each sd increment in any of the strength indices was associated with a 34-41% reduction in fracture hazard over 9 yr (each P<0.001). Race/ethnicity predicted fracture hazard independent of BMD (P=0.02) but did not predict fracture hazard independent of any of the composite indices (P=0.11-0.22). Addition of race/ethnicity did not improve risk discrimination ability of the strength indices, but did significantly improve the discrimination ability of BMD. The discrimination ability of BMD with race/ethnicity was not statistically different from that of any of the strength indices without race/ethnicity.

CONCLUSIONS

Composite strength indices of the femoral neck can predict fracture risk without race/ethnicity information as accurately as bone mineral density does in combination with race/ethnicity information and therefore would allow risk prediction in people of mixed race/ethnicity and in groups without a BMD reference database.

Health disparities in endocrine disorders: biological, clinical, and nonclinical factors--an Endocrine Society scientific statement

OBJECTIVE

The aim was to provide a scholarly review of the published literature on biological, clinical, and nonclinical contributors to race/ethnic and sex disparities in endocrine disorders and to identify current gaps in knowledge as a focus for future research needs. PARTICIPANTS IN DEVELOPMENT OF SCIENTIFIC STATEMENT: The Endocrine Society's Scientific Statement Task Force (SSTF) selected the leader of the statement development group (S.H.G.). She selected an eight-member writing group with expertise in endocrinology and health disparities, which was approved by the Society. All discussions regarding the scientific statement content occurred via teleconference or written correspondence. No funding was provided to any expert or peer reviewer, and all participants volunteered their time to prepare this Scientific Statement.

EVIDENCE

The primary sources of data on global disease prevalence are from the World Health Organization. A comprehensive literature search of PubMed identified U.S. population-based studies. Search strategies combining Medical Subject Headings terms and keyword terms and phrases defined two concepts: 1) racial, ethnic, and sex differences including specific populations; and 2) the specific endocrine disorder or condition. The search identified systematic reviews, meta-analyses, large cohort and population-based studies, and original studies focusing on the prevalence and determinants of disparities in endocrine disorders. consensus process: The writing group focused on population differences in the highly prevalent endocrine diseases of type 2 diabetes mellitus and related conditions (prediabetes and diabetic complications), gestational diabetes, metabolic syndrome with a focus on obesity and dyslipidemia, thyroid disorders, osteoporosis, and vitamin D deficiency. Authors reviewed and synthesized evidence in their areas of expertise. The final statement incorporated responses to several levels of review: 1) comments of the SSTF and the Advocacy and Public Outreach Core Committee; and 2) suggestions offered by the Council and members of The Endocrine Society.

CONCLUSIONS

Several themes emerged in the statement, including a need for basic science, population-based, translational and health services studies to explore underlying mechanisms contributing to endocrine health disparities. Compared to non-Hispanic whites, non-Hispanic blacks have worse outcomes and higher mortality from certain disorders despite having a lower (e.g. macrovascular complications of diabetes mellitus and osteoporotic fractures) or similar (e.g. thyroid cancer) incidence of these disorders. Obesity is an important contributor to diabetes risk in minority populations and to sex disparities in thyroid cancer, suggesting that population interventions targeting weight loss may favorably impact a number of endocrine disorders. There are important implications regarding the definition of obesity in different race/ethnic groups, including potential underestimation of disease risk in Asian-Americans and overestimation in non-Hispanic black women. Ethnic-specific cut-points for central obesity should be determined so that clinicians can adequately assess metabolic risk. There is little evidence that genetic differences contribute significantly to race/ethnic disparities in the endocrine disorders examined. Multilevel interventions have reduced disparities in diabetes care, and these successes can be modeled to design similar interventions for other endocrine diseases.

Diabetes and femoral neck strength: findings from the Hip Strength Across the Menopausal Transition Study

CONTEXT

Diabetes mellitus is associated with increased hip fracture risk, despite being associated with higher bone mineral density in the femoral neck.

OBJECTIVE

The objective of the study was to test the hypothesis that composite indices of femoral neck strength, which integrate dual-energy x-ray absorptiometry derived femoral neck size, femoral neck areal bone mineral density, and body size and are inversely associated with hip fracture risk, would be lower in diabetics than in nondiabetics and be inversely related to insulin resistance, the primary pathology in type 2 diabetes.

DESIGN

This was a cross-sectional analysis.

SETTING AND PARTICIPANTS

The study consisted of a multisite, multiethnic, community-dwelling sample of 1887 women in pre- or early perimenopause.

OUTCOME MEASUREMENTS

Composite indices for femoral neck strength in different failure modes (axial compression, bending, and impact) were measured.

RESULTS

Adjusted for age, race/ethnicity, menopausal stage, body mass index, smoking, physical activity, calcium and vitamin D supplementation, and study site, diabetic women had higher femoral neck areal bone mineral density [+0.25 sd, 95% confidence interval (CI) (+0.06, +0.44) sd] but lower composite strength indices [-0.20 sd, 95% CI (-0.38, -0.03) sd for compression, -0.19 sd, 95% CI (-0.38, -0.003) sd for bending, -0.19 sd, 95% CI (-0.37, -0.02) sd for impact] than nondiabetic women. There were graded inverse relationships between homeostasis model-assessed insulin resistance and all three strength indices, adjusted for the same covariates.

CONCLUSIONS

Despite having higher bone density, diabetic women have lower indices of femoral neck strength relative to load, consistent with their documented higher fracture risk. Insulin resistance appears to play an important role in bone strength reduction in diabetes.