Indices Of Femoral Neck Strength Research Articles

Effects of Two Types of Resistance Training Modalities (Hypertrophy vs. Contrast Training) on Bone Parameters in a Group of Healthy Elderly Women

The aim of the present study was to explore the effects of two types of resistance training modalities (hypertrophy training vs. contrast training) on bone health parameters in a group of healthy elderly women. Forty-nine healthy elderly women whose ages range between 60 and 70 years were included in this study. The study population was randomly divided into three groups: hypertrophy training group (HTG; n=16), contrast training group (CTG; n=16) and control group (CG; n=17). Bone mineral density (BMD) values at the whole body (WB), lumbar spine (L1-L4), total hip (TH) and femoral neck (FN) were measured by DXA before and after 12 months of resistance training. Composite indices of femoral neck strength were calculated. WB BMD, L1-L4 BMD, TH BMD and FN BMD increased in the contrast training group. WB BMD and L1-L4 BMD increased in the hypertrophy training group, while TH BMD and FN BMD remained unchanged. Significant decreases in WB BMD, L1-L4 BMD, TH BMD and FN BMD were observed in the control group. The contrast training group showed the highest improvements in BMD values compared to the two other groups. Both experimental groups (HTG and CTG) showed similar significant improvements in composite indices of femoral neck strength and muscular strength. In conclusion, contrast training and hypertrophy training can stimulate bone gain at clinically important sites of osteoporotic fractures in elderly women.

Association between composite indices of femoral neck strength and odds of hip fracture.

With the increased incidence of hip fractures worldwide, numerous studies have reported that composite indices of femoral neck strength can improve hip fracture risk assessment. This study aimed to assess the association between composite indices of femoral neck strength and the odds of hip fracture in Chinese adults. This retrospective cross-sectional study conducted at Changzhou Second People's Hospital included 937 Chinese adults (248 with hip fractures). After overnight fasting for ≥ 8h, blood samples were collected from all participants within 24h of admission. Composite indices of femoral neck strength were derived by combining bone mineral density, weight, and height with femoral axis length and width, which were measured by dual-energy X-ray absorptiometry. In total, 937 participants (293 men and 644 women) were enrolled. The mean age was 68.3years (SD 10.5). After adjusting for confounders, higher values of CSI and ISI were associated with a lower odd of hip fracture. Increase in CSI (per 1g/m·kg) was associated with a 46% decrease in the odd of hip fracture (OR = 0.54; 95% CI, 0.39-0.74), and increase in ISI (per 0.1g/m·kg) was associated with an 82% decrease (OR, 0.18; 95% CI, 0.11-0.30). Effect sizes of CSI and ISI on the odds of hip fracture remained robust and reliable in subgroup analyses. Increased CSI and ISI were associated with a lower odd of hip fracture, especially in women, suggesting that composite indices of femoral neck strength may provide useful information for improving hip fracture risk assessment.

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.

Lower limbs relative strength and composite indices of femoral neck strength in a group of young adult men

The aim of the current study was to investigate the relationships between relative strength of the lower limbs and composite indices of femoral neck strength (compression strength index [CSI], bending strength index [BSI] and impact strength index [ISI]) in a group of young adult men. In all, 54 Lebanese young men whose ages range from 20 to 30 years (24.4 ± 3.1 years) participated in our study. Body composition and hip bone mineral density were assessed by DXA. CSI, BSI and ISI were calculated. One-repetition maximum (1-RM) half-squat, 1-RM deadlift and 1-RM bench-press were measured. 1-RM half-squat/body mass was positively correlated to CSI (r = 0.35; P < 0.01), BSI (r = 0.33; P < 0.05) and ISI (r = 0.32; P < 0.05), but negatively correlated to fat mass percentage (r = −0.37; P < 0.01). The current study suggests that relative muscular strength of lower limbs is positively correlated to composite indices of femoral neck strength in young men. L’objectif de cette étude est d’explorer les relations entre la force relative des membres inférieurs et les indices de résistance osseuse du col fémoral (CSI, BSI et ISI) chez des jeunes hommes. Cinquante quatre jeunes hommes libanais âgés de 20 à 30 ans (24,4 ± 3,1 ans) ont participé à cette étude. La composition corporelle et la densité minérale osseuse ont été mesurées par DXA. Les indices de résistance osseuse du col fémoral (indice de résistance osseuse en compression [CSI], indice de résistance osseuse en flexion [BSI] et indice de résistance osseuse à l’impact [ISI]) ont été calculés. La force maximale (1-RM) en demi-squat, la force maximale en soulevé de terre et la force maximale en développé-couché ont été mesurées. Le rapport force maximale en demi-squat/poids corporel était positivement corrélé au CSI (r = 0,35 ; p < 0,01), au BSI (r = 0,33 ; p < 0,05), à l’ISI (r = 0,32 ; p < 0,05) mais négativement corrélé au pourcentage de masse grasse (r = −0,37 ; p < 0,01). Cette étude suggère que la force relative des membres inférieurs est positivement corrélée aux indices de résistance osseuse du col fémoral chez des hommes jeunes.

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).

Composite indices of femoral neck strength predicts the collapse of steroid-associated osteonecrosis of the femoral head: a retrospective study

PurposesThe purpose of this study was to investigate the predictive effect exerted by composite indices of femoral neck strength (compressive strength index (CSI), bending strength index (BSI) and impact strength index (ISI) on the femoral head collapse in steroid-associated ONFH patients.MethodsNonoperative steroid-associated osteonecrosis of the femoral head (ONFH) patients from 2017 to 2019 were selected. The patients fell into the collapsed group and the non-collapsed group according to whether the femoral head collapsed. CSI, BSI and ISI were calculated. Moreover, bone turnover markers were measured. The statistical analysis was conducted on the predictive effects of composite indices of femoral neck strength and bone turnover index on ONFH collapse.ResultsA total of 62 patients were included. The mean CSI, BSI and ISI were significantly lower in the collapsed group than those in the non-collapsed group (P < 0.05). CSI, ISI,t-P1NP and β-CTx were suggested as the protective risk factors for the femoral head collapse in ONFH patients. The ISI area under the curve values was 0. 878.The mean survival time of the hips of patients with ISI greater than 0.435 was greater (P < 0.05) than that of patients with ISI less than 0.435.ConclusionThe composite indices of femoral neck strength can predict steroid-associated ONFH femoral head collapse more effectively than the bone turnover markers. The ISI value of 0.435 is a potential cut-off value, lower than this value can predict the early collapse of steroid-associated ONFH.

Relationships Between Pulmonary Function and Composite Indices of Femoral Neck Strength in Korean Men (KNHANES IV).

BackgroundDespite the close relationship between osteoporosis and chronic pulmonary diseases, few studies have evaluated relationships between pulmonary functions and bone quality. We investigated associations between pulmonary function test results and femoral neck strength indices (SIs) in Korean men.MethodsThis population-based, cross-sectional study was conducted using data from the Korea National Health and Nutrition Examination Survey IV on 936 men aged ≥ 19 years. Pulmonary functions (forced vital capacity [FVC] and forced expiratory volume in one second [FEV1]) were measured using a dry rolling seal spirometer. Femoral neck SIs, relative to load, were calculated by hip dual-energy X-ray absorptiometry for compression strength index (CSI), bending strength index (BSI), and impact strength index (ISI).ResultsThe 443 (47.3%) of the 936 men were current smokers. FVC, FVC percentage with respect to the expected normal value, FEV1, and FEV1 percentage with respect to the expected normal value (FEV1p) were positively associated with CSI and BSI after adjusting for confounders, including smoking history (β = 0.003–0.223, P = 0.005–0.036). FEV1 and FEV1p were positively associated with ISI (β = 0.000–0.014, P = 0.010–0.025). Of components of femoral neck SIs, bone mineral density was correlated with FEV1 and FEV1p (β = 0.001–0.037, P = 0.017–0.019). After adjusting for all confounders, all femoral neck SIs increased with FVC quintiles (P for trends = 0.001–0.012), and CSI and BSI increased with FEV1 quintiles (P for trends = 0.034–0.043).ConclusionReduced pulmonary function was correlated with reduced femoral neck strength, even after adjusting for smoking history in Korean men. Femoral neck SIs might be useful tools for evaluating bone health in men with reduced pulmonary function.

Association of Visceral and Subcutaneous Fat Mass With Bone Density and Vertebral Fractures in Women With Severe Obesity

Introduction: The aim of this study was to evaluate the association of visceral and subcutaneous adipose tissue with bone mineral density (BMD), geometric indices of femoral neck strength and vertebral fractures in pre- and postmenopausal women with severe obesity. Methods: A cross-sectional study was conducted with pre- (n = 37) and postmenopausal (n = 21) women with body mass index higher than 40 kg/cm2. BMD at total body, lumbar spine, hip and forearm, presence of vertebral fractures, lean mass, visceral, and subcutaneous adipose tissue were assessed by DXA. Geometric indices of femoral neck strength were calculated by DXA. Serum bone turnover markers (CTX and osteocalcin) and 25(OH)D were also measured. Results: BMD at all studied sites was similar in pre- and postmenopausal women. In postmenopausal women, total subcutaneous adipose tissue was inversely associated with BMD at total femur (β = −0.009; 95% confidence interval [CI] −0.017; −0.002) and with strength index (β = −0.03; 95% CI −0.04; −0.01). In premenopausal women, visceral adipose tissue was inversely associated with cross-sectional moment of inertia (β = −0.95; 95%CI −1.89; −0.01). Vertebral fractures were highly prevalent in premenopausal (32%), and even more frequent among postmenopausal women (55%). Conclusion: Taken together, our results suggest that both visceral and subcutaneous fat may be detrimental for bone health in pre- and postmenopausal women, and that severe obesity may increase the risk of vertebral fractures, even in young women.

Positive correlations between physical activity level and composite indices of femoral neck strength in a group of young overweight and obese men

Summary Objective The aim of this study was to examine the associations between physical activity level and composite indices of femoral neck strength in a group of young overweight and obese Lebanese men. Methods Eighty overweight and obese (body mass index (BMI) > 25 kg/m2) young men whose ages range between 18 and 35 years participated in this study. Weight and height were measured, and BMI was calculated. Body composition and femoral neck (FN) bone mineral density were measured by dual-energy X-ray absorptiometry (DXA). Compressive strength index (CSI), bending strength index (BSI) and impact strength index (ISI) were calculated. Physical activity level was evaluated by the global physical activity questionnaire (GPAQ). Maximum oxygen consumption (VO2 max, in L/min) was measured using a valid device. Results Weight, BMI, fat mass and fat mass percentage were negatively correlated to CSI, BSI and ISI. Physical activity level (h/week) was positively correlated to CSI, BSI and ISI while VO2 max (mL/min/kg) was positively correlated to CSI and ISI. The positive associations between physical activity and composite indices of femoral neck strength (CSI, BSI and ISI) remained significant after adjustment for body weight. Conclusion Our study conducted on overweight and obese men shows that physical activity level is a positive determinant of composite indices of femoral neck strength. In overweight men, increasing physical activity level may help to prevent osteoporotic fractures later in life.

Composite Indices of Femoral Neck Strength in Middle-Aged Inactive Subjects Vs Former Football Players

The purpose of this study was to compare composite indices of femoral neck strength ((compression strength index [CSI], bending strength index [BSI], and impact strength index [ISI]) in inactive middle-aged men (n = 20) and middle-aged former football players (n = 15). 35 middle-aged men participated in this study. Body composition and bone variables were evaluated by dual-energy X-ray absorptiometry. Composite indices of femoral neck strength (CSI, BSI, and ISI) were calculated. Handgrip strength, vertical jump, maximum power of the lower limbs (watts), horizontal jump, maximal half-squat strength, maximal bench-press strength, sprint performance (10 meters), and maximum oxygen consumption (VO2 max, ml/min/kg) were evaluated using validated tests. CSI, BSI, and ISI were significantly higher in football players compared to inactive men. Vertical jump, horizontal jump, maximal half-squat strength, VO2 max and sprint performance were significantly different between the 2 groups. CSI, BSI, and ISI remained significantly higher in football players compared to inactive men after adjusting for physical activity level. The current study suggests that former football practice is associated with higher composite indices of femoral neck strength in middle-aged men.

SUN-369 Different Association of Dietary Fat Intake with Femoral Neck Strength According to Gender: A Nationwide Population-Based Study

Purpose: Despite the general belief that higher fat intake may be harmful for bone health, its impact on bone strength has not been thoroughly studied. Methods: We conducted a population-based cross-sectional study derived from the Korea National Health and Nutrition Examination Surveys, including 2,590 participants. Composite indices of femoral neck strength, such as the compression strength index (CSI), bending strength index (BSI), and impact strength index (ISI), were generated by combining bone mineral density, body mass, and height with the femoral axis length and width. Results: Dietary fat intake (%) was inversely related to CSI and ISI in men, but not in women. Men in the highest three fat intake quintiles had lower CSI, BSI, and/or ISI than those in the lowest quintile (P=0.003–0.024). In women, compared with participants in the third fat intake quintile, those in the other four quintiles had lower CSI, BSI, and/or ISI (P=0.004–0.049). When the participants were allocated to three groups according to the dietary reference intake of fat in Koreans [low (<15%), moderate (15–30%), or high (≥30%)], men with a moderate or high fat intake had significantly lower ISIs than those with a low fat intake (P=0.046 and 0.039, respectively). By contrast, compared with women consuming a moderate amount of fat, those with a high intake had lower CSI, BSI, and ISI (P = 0.025–0.047). Conclusion: These findings suggest that higher fat intake in men and low or high fat intake in women may contribute to deteriorations in bone strength.

Influence of Physical Activity Level on Composite Indices of Femoral Neck Strength in a Group of Young Overweight Men

The aim of the present study was to explore the influence of physical activity level on composite indices of femoral neck strength (compression strength index [CSI], bending strength index, and impact strength index) in a group of young overweight men. To do so, we compared composite indices of femoral neck strength in active overweight men and insufficiently active overweight men. They were divided into 2 groups based on their physical activity level: 70 active overweight men (engaging in more than 150 minutes of physical activity per week; 8.7 ± 4.8 h/wk) and 26 insufficiently active overweight men (engaging in less than 150 minutes of physical activity per week; 1.2 ± 0.7 h/wk). Height (m) and weight (kg) were measured, and body mass index (kg/m2) was calculated. Bone mineral density was measured by dual-energy X-ray absorptiometry at whole body, lumbar spine, total hip, and femoral neck. Body weight, lean mass, fat mass, and body mass index were not significantly different between the 2 groups. CSI, bending strength index, and impact strength index were significantly higher in active overweight men compared to insufficiently active overweight men. After adjustment for age, physical activity (h/wk) and lean mass, only CSI remained higher in active overweight men compared to insufficiently active overweight men. This study suggests that, in young overweight men, being active (engaging in more than 150 minutes of physical activity per week) is associated with greater composite indices of femoral neck strength. To our knowledge, this is the first study that finds a significant difference regarding composite indices of femoral neck strength between 2 groups of young overweight men with different levels of physical activity.

The positive association of total protein intake with femoral neck strength (KNHANES IV).

Despite the general belief that higher protein intake may be helpful for bone homeostasis, its impact on human bone health is still debated. Furthermore, the association of dietary protein intake with femoral neck (FN) strength, which can predict fracture risk independently of bone mineral density (BMD), has not been thoroughly studied. This is a population-based, cross-sectional study from Korea National Health and Nutrition Examination Surveys, including 592 men aged 50years or older and 590 postmenopausal women. The composite indices of FN strength, such as the compression strength index (CSI), bending strength index (BSI), and impact strength index (ISI), were generated by combining BMD, body weight, and height with the femoral axis length and width, which were measured by dual-energy X-ray absorptiometry. After adjustment for confounders, total protein intake (g/kg/day) positively correlated with all three FN composite indices in both genders (P= 0.006 to 0.035), except for BSI showing marginal significance in postmenopausal women (P= 0.093). Consistently, compared with subjects in lowest total protein intake quartile, those in the highest quartile showed markedly higher CSI, BSI, and ISI values (P= 0.043 to < 0.001), with a dose-response manner across increasing total protein intake quartile categories in both men and women (P for trend = 0.028 to < 0.001). These findings provide the clinical evidence that higher dietary protein intake can play a beneficial role on bone health through the increase of FN strength relative to load in adults.

Insulin resistance and composite indices of femoral neck strength in Asians: the fourth Korea National Health and Nutrition Examination Survey (KNHANES IV).

Fracture risk in type 2 diabetes mellitus with insulin resistance is increased, despite relatively preserved bone mineral density (BMD). In this study, we investigated the relationship between insulin resistance and composite indices of femoral neck strength in Koreans. A population-based, cross-sectional study from the Korea National Health and Nutrition Examination Survey PARTICIPANTS: About 1243 men and 1433 women MEASUREMENTS: Insulin resistance was evaluated using the homoeostasis model assessment-estimated insulin resistance (HOMA-IR) index. Femoral neck width and axis length were measured from hip dual-energy X-ray absorptiometry scans and combined with BMD, weight and height to calculate composite indices of femoral neck strength relative to load: compression (CSI), bending (BSI) and impact strength indices (ISI). HOMA-IR showed an inverse relationship with CSI, BSI and ISI in both genders before and after adjusting for confounders (P < 0·001-0·029). CSI was more strongly associated with HOMA-IR than BSI and/or ISI in both genders (P < 0·001-0·013). When men were stratified according to HOMA-IR quartiles, all strength indices decreased as the quartile increased, after adjusting for all potential confounders (P for trend <0·001-0·001), whereas CSI and ISI did in women (P for trend = 0·012 and 0·002, respectively). Fasting insulin levels, but not glucose levels, were negatively associated with all strength indices regardless of confounders (P < 0·001-0·044). Insulin resistance is associated with low femoral neck strength, particularly against the compressive load. These findings suggest a better approach to evaluate bone health in insulin-resistant individuals.

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

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

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

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

Erratum to: Ethnic differences in composite indices of femoral neck strength

The scale factors provided by Hologic, Inc. to compute femoral neck axis length (FNAL) from the midline endpoint coordinates were off by a factor of 2; thus absolute values reported in Tables 1–4 of the paper for FNAL, bending strength index (BSI), and impact strength index (ISI) were scaled incorrectly. Corrected absolute values for FNAL and ISI are 0.5 times the reported FNAL and ISI values, and corrected absolute values for BSI are 2 times the reported BSI values. Thus, the FNAL rows in Tables 1 and 3 should be as shown below. The BSI and ISI cells in Tables 2 and 4 also need to be scaled by 2 and 0.5 respectively. For example, BSI in Caucasians (reference) in Table 2 (model 3) is 0.98; in US-born Chinese (reference) in Table 4 (model 3) is 1.14; and in US-born Japanese (reference) in Table 4 (model 3) is 1.24. Similarly, for example, ISI in Caucasians (reference) in Table 2 (model 3) is 0.18; in US-born Chinese (reference) in Table 4 (model 3) is 0.20; and in US-born Japanese (reference) in Table 4 (model 3) is 0.23. Note that effect sizes (and confidence intervals) for BSI and ISI in tables 2 and 4 are also similarly scaled.

Diabetes and Femoral Neck Strength: Findings from The Hip Strength Across the Menopausal Transition Study

Diabetes mellitus is associated with increased hip fracture risk, despite being associated with higher bone mineral density in the femoral neck. 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. This was a cross-sectional analysis. The study consisted of a multisite, multiethnic, community-dwelling sample of 1887 women in pre- or early perimenopause. Composite indices for femoral neck strength in different failure modes (axial compression, bending, and impact) were measured. 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. 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.

Ethnic differences in composite indices of femoral neck strength

Bone mineral density does not explain race/ethnicity differences in hip fracture risk. In this study, we demonstrated that race/ethnicity differences in composite hip strength indices were consistent with documented race/ethnicity differences in hip fracture risk, suggesting that unlike bone density, the composite indices may represent ethnicity-independent measures of bone strength. African-American and Asian women have lower risks of hip fracture than Caucasian women, but such racial/ethnic variation in hip fracture risk cannot be explained by bone mineral density (BMD). The composite indices of femoral neck strength integrate femoral neck and body size with BMD and predict hip fracture risk in Caucasian women. We hypothesize that unlike race/ethnic differences in BMD, race/ethnic differences in the composite strength indices would be consistent with race/ethnic differences in hip fracture risk. We studied a community-based sample of Caucasian (n = 968), African-American (n = 512), Chinese (n = 221), and Japanese (n = 239) women, premenopausal or in early perimenopause, from the Study of Women's Health Across the Nation. Unadjusted indices were similar in Caucasian and African-American women but higher in Asian women. After adjusting for age, body mass index, and menopause status, all three minority groups had higher composite strength indices than Caucasian women. Foreign-born Japanese women had higher unadjusted and adjusted composite strength indices than US-born Japanese women, but such differences by nativity were not observed in Chinese women. We concluded that composite strength indices have the potential to explain racial/ethnic differences in hip fracture risk, suggesting that composite strength indices may represent ethnicity-independent measures of bone strength. This contention needs to be verified by further research on the fracture predictive ability of composite strength indices in multi-ethnic longitudinal cohorts.