Femoral neck geometry in overweight and normal weight adolescent girls

Comparison of trabecular bone score and hip structural analysis with FRAX® in postmenopausal women with type 2 diabetes mellitus

PURPOSE

To evaluate (a) the performance in predicting the presence of bone fractures of trabecular bone score (TBS) and hip structural analysis (HSA) in type 2 diabetic postmenopausal women compared to a control group and (b) the fracture prediction ability of TBS versus Fracture Risk Calculator (FRAX^®) as well as whether TBS can improve the fracture prediction ability of FRAX^® in diabetic women.

METHODS

Eighty diabetic postmenopausal women were matched with 88 controls without major diseases for age and body mass index. The individual 10-year fracture risk was assessed by FRAX^® tool for Europe-Italy; bone mineral density (BMD) at lumbar spine, femoral neck and total hip was evaluated through dual-energy X-ray absorptiometry; TBS measurements were taken using the same region of interest as the BMD measurements; HSA was performed at proximal femur with the HSA software.

RESULTS

Regarding variables of interest, the only significant difference between diabetic and control groups was observed for the value of TBS (median value: 1.215; IQR 1.138-1.285 in controls vs. 1.173; IQR 1.082-1.217 in diabetic; p = 0.002). The prevalence of fractures in diabetic women was almost tripled than in controls (13.8 vs. 3.4 %; p = 0.02). The receiver operator characteristic curve analysis showed that TBS alone (AUC = 0.71) had no significantly lower discriminative power for fracture prediction in diabetic women than FRAX major adjusted for TBS (AUC = 0.74; p = 0.65).

CONCLUSION

In diabetic postmenopausal women TBS is an excellent tool in identifying fragility fractures.

Effect of vitamin D replacement on hip structural geometry in adolescents: a randomized controlled trial

BACKGROUND

We have shown in a randomized controlled trial that vitamin D increases bone mass, lean mass and bone area in adolescent girls, but not boys. These increments may translate into improvements in bone geometry and therefore bone strength. This study investigated the impact of vitamin D on hip geometric dimensions from DXA-derived hip structural analyses in adolescents who participated in the trial.

METHODS

167 girls (mean age 13.1 years) and 171 boys (mean age 12.7 years) were randomly assigned to receive weekly placebo oil or vitamin D3, at doses of 1400 IU or 14,000 IU, in a double blind placebo-controlled 1-year trial. DXA images were obtained at baseline and one year, and hip images were analyzed using the hip structural analysis (HSA) software to derive parameters of bone geometry. These include outer diameter (OD), cross sectional area (CSA), section modulus (Z), and buckling ratio (BR) at the narrow neck (NN), intertrochanteric (IT), and shaft (S) regions. Analysis of Covariance (ANCOVA) was used to examine group differences for changes of bone structural parameters.

RESULTS

In the overall group of girls, vitamin D supplementation increased aBMD (7.9% and 6.8% in low and high doses, versus 4.2% in placebo) and reduced the BR of NN (6.1% and 2.4% in low and high doses, versus 1.9% in placebo). It also improved aBMD (7.9% and 5.2% versus 3.6%) and CSA (7.5% and 5.1% versus 4.1%) of the IT and OD of the S (2.4% and 2.5% versus 0.8% respectively). Significant changes in the OD and BR of the NN, in the overall group of girls remained, after adjusting for lean mass, and were unaffected with further adjustments for lifestyle, pubertal status, and height measures. Conversely, boys did not exhibit any significant changes in any parameters of interest. A dose effect was not detected and subgroup analyses revealed no beneficial effect of vitamin D by pubertal stage.

CONCLUSIONS

Vitamin D supplementation improved bone mass and several DXA-derived structural bone parameters, in adolescent girls, but not boys. This occurred at a critical site, the femoral neck, and if maintained through adulthood could improve bone strength and lower the risk of hip fractures.

Geometric indices of hip bone strength in obese, overweight, and normal-weight adolescent girls

The aim of this study was to compare hip bone strength indices in obese, overweight, and normal-weight adolescent girls using hip structure analysis (HSA). This study included 64 postmenarcheal adolescent girls (14 obese, 21 overweight, and 29 normal weight). The 3 groups (obese, overweight, and normal weight) were matched for maturity (years since menarche). Body composition and bone mineral density (BMD) of whole body, lumbar spine, and proximal femur were assessed by dual-energy X-ray absorptiometry (DXA). To evaluate hip bone strength, DXA scans were analyzed at the femoral neck (FN) at its narrow neck (NN) region, the intertrochanteric (IT), and the femoral shaft (FS) by the HSA program. Cross-sectional area and section modulus were measured from hip BMD profiles. Total hip BMD and FN BMD were significantly higher in obese and overweight girls in comparison with normal-weight girls (p < 0.05). However, after adjusting for weight, using a one-way analysis of covariance, there were no significant differences among the 3 groups regarding HSA variables. This study suggests that in obese and overweight adolescent girls, axial strength and bending strength indices of the NN, IT, and FS are adapted to the increased body weight.

Bone mineral density, hip bone geometry, and calcaneus trabecular bone texture in obese and normal-weight children

Our study aimed at comparing bone mineral density (BMD), geometric indices of hip bone strength, and indices of trabecular bone texture at the calcaneus in obese and normal-weight children. Fifty-three obese children (10.3 ± 1.4 yr) and 24 normal-weight children (10.4 ± 1.5 yr) participated in this study. Body composition, bone mineral content, and BMD at whole body (WB), lumbar spine (L2-L4), total forearm, and proximal femur (total hip [TH] and femoral neck [FN]) were measured by dual-energy X-ray absorptiometry (DXA). Bone geometry of the hip was evaluated by the hip structure analysis (HSA) program. DXA scans were analyzed at the FN at its narrowest region and the femoral shaft (FS) by the HSA program. Cross-sectional area (CSA) and section modulus (Z) were measured from hip BMD profiles. Texture analysis was performed on digitized radiographs of the calcaneus to assess trabecular bone microarchitecture, and the result was expressed as Hmean. WB BMD, L2-L4 BMD, TH BMD, and FN BMD were significantly higher in obese children compared with normal-weight peers (p < 0.05). FN Z and FS Z were not significantly different between the 2 groups, whereas Hmean parameter was significantly lower in obese children compared with normal-weight peers (p < 0.001). After adjustment for body weight, obese children displayed lower WB BMD, FN CSA, FN Z, FS CSA, and FS Z compared with normal-weight children. This study suggests that BMD of WB and geometric indices of hip bone strength are not adapted to the increased body weight in obese children.

Geometric indices of hip bone strength in obese, overweight, and normal-weight adolescent boys

The aim of this study was to compare hip bone strength indices in obese, overweight, and normal-weight adolescent boys using hip structure analysis. After adjusting for weight, obese boys displayed lower intertrochanteric cross-sectional moment of inertia and femoral shaft cross-sectional moment of inertia and section modulus in comparison to normal-weight and overweight boys. This study suggests that in obese adolescent boys, femoral shaft bending strength is not adapted to the increased body weight.

INTRODUCTION

The influence of being obese or overweight on bone strength in adolescents remains controversial. The main aim of this study was to compare hip bone strength indices in obese, overweight, and normal-weight adolescent boys using hip structure analysis. The second aim of this study was to explore the influence of lean mass and fat mass on hip bone strength indices in the same population.

METHODS

This study included 70 adolescent boys (25 obese, 25 normal weight, and 20 overweight). The three groups (obese, overweight, and normal weight) were matched for maturity (Tanner stage) and age. Body composition and bone mineral density (BMD) were assessed by dual-energy X-ray absorptiometry (DXA). To evaluate hip bone strength, DXA scans were analyzed at the femoral neck (FN), the intertochanteric (IT), and the femoral shaft (FS) by the Hip Structure Analysis (HSA) program. Cross-sectional area (CSA), an index of axial compression strength, section modulus (Z), an index of bending strength, and cross-sectional moment of inertia (CSMI), an index of structural rigidity were measured from bone mass profiles.

RESULTS

Body weight, lean mass, fat mass and BMI were significantly higher in obese and overweight boys in comparison to normal-weight boys (P < 0.05). Total hip (TH) BMD and femoral neck (FN) BMD were significantly higher in obese and overweight boys in comparison to normal-weight boys (P < 0.05). After adjusting for age or maturation index, obese and overweight boys displayed significantly higher TH and FN BMD, CSA, CSMI, and Z of the three sites (FN, IT, and FS) in comparison to normal-weight boys (P < 0.05). However, after adjusting for weight, obese boys displayed significantly lower IT CSMI and FS CSMI and Z in comparison to normal-weight and overweight boys (P < 0.05).

CONCLUSIONS

This study suggests that in obese adolescent boys, intertrochanteric structural rigidity and femoral shaft structural rigidity and bending strength are not adapted to the increased body weight.

Association between weight changes and changes in hip geometric indices in the Japanese female population during 10-year follow-up: Japanese Population-based Osteoporosis (JPOS) Cohort Study

During a 10-year follow-up of 893 women of various ages from the Japanese Population-based Osteoporosis Cohort Study, we evaluated the relationship between weight changes and hip geometric strength assessed by hip structure analysis. Our findings suggest that maintaining weight may help retain geometric strength and reduce hip fracture risk.

INTRODUCTION

The effects of changes in anthropometric indices on hip geometry in women of various ages are unclear. We evaluated these effects by analyzing 10-year longitudinal data from a representative sample of Japanese women.

METHODS

Dual-energy X-ray absorptiometry scans of the proximal femur were performed at baseline and at the 10-year follow-up. Data were analyzed with the Hip Structure Analysis (HSA) program, which yields geometric strength indices including cross-sectional area (CSA), section modulus (SM) and subperiosteal diameter (PD) at regions of interest (ROIs) in the narrow neck (NN), intertrochanter, and femoral shaft (FS) regions. Annual percent change of each HSA index was determined. Height and weight were measured at baseline and follow-up.

RESULTS

After excluding subjects with factors affecting bone metabolism, we evaluated 893 women (18-79 years old at baseline). The greatest changes in most HSA indices during the follow-up were observed in subjects aged ≥ 70 years at all ROIs. PD modestly but significantly expanded with age, but this change was not significant in subjects aged ≥ 70 years or those who had entered menopause ≥ 20 years before baseline. An increasing trend in weight was associated with an increase or smaller decline in CSA and SM at the NN and FS regions regardless of menopausal status after adjusting for age, height, and weight at baseline and change of estimated volumetric bone mineral density. Changes in height showed a much weaker association with HSA indices.

CONCLUSIONS

Maintaining weight may help retain hip geometric strength and reduce the risk of hip fracture.

DXA femoral neck strength analysis in Chinese overweight and normal weight adolescents

The aim of this study was to compare femoral neck (FN) strength in Chinese overweight adolescents with gender-matched normal weight controls and investigate the relationship of total body soft tissue composition (lean and fat masses) to indices of FN strength. Dual-energy X-ray absorptiometry (DXA) measurements of the proximal femur and total body were made in 65 Chinese overweight adolescents and 89 gender-matched normal weight controls using Lunar Prodigy DXA bone densitometer (GE Healthcare, Madison, WI). FN bone mineral density (BMD), total body lean mass, fat mass, and bone mineral content (BMC) were measured. Using FN BMD values derived from DXA measurements, hip structural analysis (HSA) was performed using Lunar enCORE (GE Healthcare), version 10.5 software. Structural parameters derived by HSA were bone cross-sectional area (CSA), cross-sectional moment of inertia (CSMI), and the section modulus (Z). Data were analyzed by Student's t-test, Pearson correlation coefficients (r), and one-way analysis of covariance (ANCOVA). Overweight boys and girls had higher body weight, lean mass, fat mass, and body mass index (p<0.001) than normal controls. CSA, CSMI, and Z were higher in overweight groups compared with controls (p<0.05). Lean mass correlated well with all HSA parameters (range of r: 0.501--0.714) for both genders. ANCOVA test showed no significant differences between overweight and normal weight groups regarding HSA variables in both genders after adjustment for lean mass. However, the differences remain significant after adjustment for fat mass in boys but not in girls. This study supports the conclusion that overweight individuals have greater hip neck strength in comparison with normal weight controls in Chinese adolescents. Lean mass is a major determinant for FN strength.

Anthropometric predictors of geometric indices of hip bone strength in a group of Lebanese postmenopausal women

The effects of anthropometric characteristics on hip bone strength in postmenopausal women are not completely elucidated. The aim of this study was to investigate the influence of anthropometric characteristics on geometric indices of hip bone strength using the hip structure analysis (HSA) program in a group of Lebanese postmenopausal women. This study included 109 postmenopausal women (aged 64--84yr). Age and years since menopause were recorded. Body composition and bone mineral density were assessed by dual-energy X-ray absorptiometry (DXA). To evaluate hip bone strength, DXA scans were analyzed at the femoral neck (FN), the intertrochanteric (IT), and the femoral shaft (FS) by the HSA program. Cross-sectional area (CSA), an index of axial compression strength, section modulus (Z), an index of bending strength, and buckling ratio (BR), an estimate of cortical stability in buckling, were measured from bone mass profiles. Using univariate analysis, weight, height, body mass index (BMI), lean mass, and fat mass were positively correlated to CSA and Z of the FN, IT, and FS. Weight, BMI, fat mass, and fat mass percentage were negatively correlated to BR of the FN, IT, and FS. Multiple linear regression analysis showed that lean mass was a stronger determinant of FN CSA, FN Z, IT Z, and FS Z than fat mass, whereas fat mass was a stronger determinant of IT CSA, FS CSA, IT BR, and FS BR than lean mass. This study suggests that, in postmenopausal women, fat mass is a strong predictor of hip axial compression strength and cortical stability in buckling, and lean mass is a strong predictor of hip bending strength.

Hip bone strength indices in overweight and control adolescent boys

The influence of being overweight on bone strength in adolescents remains controversial. The aim of this study was to compare hip bone strength indices in overweight and control adolescent boys using hip structure analysis (HSA). This study included 25 overweight adolescent boys [body mass index (BMI) >25 kg/m(2)] and 31 maturation-matched controls (BMI <25 kg/m(2)). Body composition and bone mineral density were assessed by dual-energy X-ray absorptiometry (DXA). To evaluate hip bone strength, DXA scans were analyzed at femoral neck, intertrochanteric, and femoral shaft by the HSA program. Cross-sectional area (CSA), an index of axial compression strength, section modulus (Z), an index of bending strength, cross-sectional moment of inertia (CSMI), cortical thickness (CT), and buckling ratio (BR) were measured from bone mass profiles. Body weight, lean mass, fat mass, and BMI were higher in overweight boys compared to controls (P < 0.001). CSA, CSMI, and Z of the three sites (femoral neck, intertrochanteric, and femoral shaft) were higher in overweight boys compared to controls (P < 0.01). BR was not significantly different between the two groups at the three sites. After adjustment for either body weight, BMI, or fat mass, using a one-way analysis of covariance, there were no differences between the two groups regarding the HSA variables (CSA, Z, CSMI, CT, and BR). After adjusting for lean mass, overweight boys displayed higher values of femoral shaft CSA, CSMI, and Z in comparison to controls (P < 0.05). In conclusion, this study suggests that overweight adolescent boys have greater indices of bone axial and bending strength in comparison to controls at the femoral neck, the intertrochanteric, and the femoral shaft.

Bone mineral density in healthy female adolescents according to age, bone age and pubertal breast stage

Objectives:

This study was designed to evaluate bone mineral density (BMD) in healthy female Brazilian adolescents in five groups looking at chronological age, bone age, and pubertal breast stage, and determining BMD behavior for each classification.

Methods:

Seventy-two healthy female adolescents aged between 10 to 20 incomplete years were divided into five groups and evaluated for calcium intake, weight, height, body mass index (BMI), pubertal breast stage, bone age, and BMD. Bone mass was measured by bone densitometry (DXA) in lumbar spine and proximal femur regions, and the total body. BMI was estimated by Quetelet index. Breast development was assessed by Tanner’s criteria and skeletal maturity by bone age. BMD comparison according to chronologic and bone age, and breast development were analyzed by Anova, with Scheffe’s test used to find significant differences between groups at P≤0.05.

Results:

BMD (g·cm^-2) increased in all studied regions as age advanced, indicating differences from the ages of 13 to 14 years. This group differed to the 10 and 11 to 12 years old groups for lumbar spine BMD (0.865±0.127 vs 0.672±0.082 and 0.689±0.083, respectively) and in girls at pubertal development stage B3, lumbar spine BMD differed from B5 (0.709±0.073 vs 0.936±0.130) and whole body BMD differed from B4 and B5 (0.867±0.056 vs 0.977±0.086 and 1.040±0.080, respectively).

Conclusion:

Bone mineralization increased in the B3 breast maturity group, and the critical years for bone mass acquisition were between 13 and 14 years of age for all sites evaluated by densitometry.

Lean mass predicts hip geometry in men and women with non-insulin-requiring type 2 diabetes mellitus

Persons with type 2 diabetes mellitus (T2DM) are at increased risk for hip fracture despite normal bone mineral density (BMD). The contribution of body composition to hip geometry, a measure of hip strength, has not been studied in T2DM. We hypothesized that lean mass would predict hip geometry. Subjects (n=134) for this cross-sectional analysis were men and women aged 56 ± 6yr with non-insulin-requiring T2DM. Fat and lean mass were measured with dual-energy X-ray absorptiometry (DXA). Abdominal fat was measured with magnetic resonance imaging. Hip geometry parameters including section modulus, cross-sectional area, and buckling ratio were estimated from DXA using validated formulae. Subjects had normal BMD, elevated body mass indices (29-41 kg/m(2)), and controlled T2DM (hemoglobin A1c: 5.1-8.3%). In bivariate analysis, lean mass was positively associated with section modulus and cross-sectional area in both sexes (r=0.36-0.55, p<0.05). In multivariate analyses, lean mass remained a significant predictor of all hip strength estimates in both sexes. In women alone, fat mass predicted parameters of hip strength. These data demonstrate that lean mass is significantly associated with hip strength in subjects with non-insulin-requiring T2DM. Resistance exercises that build lean mass may be an intervention for hip fracture prevention in T2DM, although additional research is needed.