Analysis of Combined Indicators for Risk of Osteoporotic Hip Fracture in Elderly Women

Assessing the Interaction Effects of Mitochondrial DNA Polymorphisms and Lifestyle on Heel Bone Mineral Density

BACKGROUND

Bone mineral density (BMD) is a major predictor of osteoporotic fractures, and previous studies have reported the effects of mitochondrial dysfunction and lifestyle on BMD, respectively. However, their interaction effects on BMD are still unclear.

OBJECTIVE

We aimed to investigate the possible interaction of mitochondrial DNA (mtDNA) and common lifestyles contributing to osteoporosis.

METHODS

Our analysis included 119 120 white participants (Nfemale = 65 949 and Nmale = 53 171) from the UK Biobank with heel BMD phenotype data. A generalized linear regression model of PLINK was performed to assess the interaction effects of mtDNA and 5 life environmental factors on heel BMD, including smoking, drinking, physical activity, dietary diversity score, and vitamin D. In addition, we also performed linear regression analysis for total body BMD. Finally, we assessed the potential causal relationships between mtDNA copy number (mtDNA-CN) and life environmental factors using Mendelian randomization (MR) analysis.

RESULTS

Our study identified 4 mtDNA loci showing suggestive evidence of heel BMD, such as m.16356T>C (MT-DLOOP; P = 1.50 × 10-3) in total samples. Multiple candidate mtDNA × lifestyle interactions were also detected for heel BMD, such as MT-ND2 × physical activity (P = 2.88 × 10-3) in total samples and MT-ND1 × smoking (P = 8.54 × 10-4) in males. Notably, MT-CYB was a common candidate mtDNA loci for heel BMD to interact with 5 life environmental factors. Multivariable MR analysis indicated a causal effect of physical activity on heel BMD when mtDNA-CN was considered (P = 1.13 × 10-3).

CONCLUSION

Our study suggests the candidate interaction between mtDNA and lifestyles on heel BMD, providing novel clues for exploring the pathogenesis of osteoporosis.

Correlation between bone mineral density and bone metabolic markers in postmenopausal women with osteoporotic fractures at different C-terminal telopeptide of type 1 collagen levels: a retrospective analysis study

OBJECTIVE

This study aimed to analyze the correlation between bone mineral density (BMD) and bone resorption markers in postmenopausal women with osteoporosis fractures and identify risk factors for second fractures.

METHODS

This retrospective analysis of 1,239 older women with fractures with a median age of 70 years who attended Shanghai General Hospital from January 2007 to December 2016, included a first fracture group (1,008 cases) and a second fractures group (231 cases). The risk factors for fractures were analyzed by comparing these groups on clinical characteristics, BMD, and bone metabolism markers stratified by quartiles of serum C-terminal telopeptide of type 1 collagen (CTX). Binary logistic regression analysis was used to identify risk factors for second fractures.

RESULTS

In the whole sample, BMD was negatively correlated with age and serum osteocalcin and positively correlated with body mass index (BMI). In women with first fractures, those in the highest quartile of serum CTX had the lowest spine and hip BMD. Second fractures were significantly associated with BMI, lower spine and hip BMD, and higher serum osteocalcin but not CTX. Binary logistic regression analysis showed that high BMI (odds ratio [OR], 1.08 [95% CI, 1.03-1.14]; P = 0.001), low lumbar BMD (OR, 0.24 [95% CI, 0.07-0.82]; P = 0.023), low total hip BMD (OR, 0.05 [95% CI, 0.00-0.88]; P = 0.041), and lack of antiosteoporosis treatment (OR, 2.71 [95% CI, 2.71-4.08]; P < 0.001) were independent risk factors for second fractures.

CONCLUSIONS

In older women with fractures, BMD was significantly lower in women with second fractures than in those with first fractures. Higher levels of serum CTX and osteocalcin, which indicates increased bone resorption, were negatively correlated with BMD. In women with a first fracture, serum CTX higher than 605 pg/mL was negatively correlated with BMD, whereas no correlation was found between different CTX and BMD in women with second fractures. High BMI and low BMD as well as not receiving antiosteoporosis treatment were independent risk factors for second fractures.

Proportion and Risk Factors of Silent Vertebral Fractures Among Egyptian Females With Fragility Hip Fracture Presenting to the Emergency Room of Ain Shams University Hospitals

Background Fragility fractures caused by osteoporosis are known to increase the risk of further fragility fractures. Also, several factors have been associated with an increasing risk of fracture in postmenopausal women with osteoporosis, as prior fracture, advancing age, low bone mineral density (BMD), greater risk or history of falls certain, pharmacologic therapies such as glucocorticoids, and medical conditions increase the risk of secondary osteoporosis and related fractures through their direct impact on bone density or structure. Menstrual history including age at menarche menopause and a history of amenorrhea is documented as a predicting osteoporotic fracture. Objective The aim of the current study is to find the proportion of hidden vertebral fractures among Egyptian females with fragility hip fracture. Patients and methods A cross-sectional study was conducted on patients who presented to the orthopedic emergency room (ER) of Ain Shams University Hospitals in Cairo, Egypt, from September 2020 to September 2021. Our inclusion criteria include females aged 40 years or older, who presented to the ER with fragility hip fractures. A simple random sample of females fulfilling our inclusion criteria for osteoporotic hip fracture was thoroughly investigated. Conventional lateral and anteroposterior radiographs of the dorsolumbar spine were obtained excluding those with high-impact fractures or pathological fractures. Results During the study period, a total of 43,935 persons presented to the orthopedic ER, of whom 30,901 were females, comprising 70.03% of total orthopedic ER visits. A sample of 150 females met our inclusion criteria. Results showed that 16 of our 150 cases had concomitant vertebral fracture, meaning that 10.7% of cases had hidden vertebral fracture at the time of osteoporotic hip fracture, as diagnosed by the screening lumbosacral plain X-rays. Older age at menarche, younger age at menopause, and amenorrhea are shown to be risk factors for hidden vertebral fracture in Egyptian females. Conclusion Osteoporosis is a complex and costly disease. Osteoporotic fractures may be largely preventable, as environmental factors are open to intervention, and effective pharmacological agents are available. Concomitant hidden vertebral fracture is prevalent among females with osteoporotic hip fractures, and those who had later menarche, earlier menopause, and menstrual irregularities have a higher incidence of developing associated vertebral fracture, which warrants identification and management to evade complications and mortality.

Establishment of Reference Intervals for Bone Turnover Markers in Healthy Chinese Older Adults

BACKGROUND

Reference ranges for bone turnover markers (BTMs) are still lacking in the healthy Chinese population.

AIM

To establish reference intervals for BTMs and to investigate the correlations between BTMs and BMD in Chinese older adults.

SUBJECTS AND METHODS

A community-based cross-sectional study was conducted among 2,511 Chinese subjects aged over 50 yrs residing in Zhenjiang, Southeast China. Reference intervals for BTMs (i.e., procollagen type I N-terminal propeptide, P1NP; β cross-linked C-terminal telopeptide of type I collagen, β-CTX) were calculated as the central 95% range of all measurements in Chinese older adults.

RESULTS

The reference intervals of P1NP, β-CTX and P1NP/β-CTX were 15.8-119.9 ng/mL, 0.041-0.675 ng/mL and 49.9-1261.5 for females and 13.6-111.4 ng/mL, 0.038-0.627 ng/mL and 41.0-1269.1 for males, respectively. In the multiple linear regression analysis, only β-CTX was negatively associated with BMD after adjusting for age and body mass index (BMI) in both sex-stratified groups (all P < 0.05).

CONCLUSION

This study established age- and sex-specific reference intervals for BTMs in a large sample of healthy Chinese participants ≥ 50 and < 80 years of age and explored the correlations between BTMs and BMD, which provides an effective reference for the assessment of bone turnover in the clinical practice of osteoporosis.

The Impact of Coronal Configuration of the Proximal Femur on its Mechanical Properties and the Validation of a New Theoretical Model: Finite Element Analysis and Biomechanical Examination

OBJECTIVE

This study aims to establish the coronal configuration of the proximal femur as an independent factor for its mechanical properties and provide validation for the theoretical model "fulcrum-balance-reconstruction."

METHODS

The digital 3D femur model constructed with the lower extremity high-resolution computed tomography of a senior subject was applied with the axial compression of 2100N under 5 different α angles of 10°, 5°, 0°, -5°, -10°. The equivalent stress distribution of the femoral geometric model under each angle were calculated. Under the same five α angles, fatigue test was performed on 15 composite artificial left femurs (three specimens in each angle group) to obtain the failure cycle and fracture site. The statistical analysis was accomplished using One-Way ANOVA.

RESULTS

The maximum stress of the entire femur in physiological angle (α = 10°) occurred below femoral neck with a value of 63.91 MPa. When the proximal femur is in extreme abducted angle (α = -10°), the maximum stress shift to the lower medial cortex of femoral shaft with a value of 105.2 MPa. As the α angle changed from 10° to -10°, the greater trochanteric region had the largest increment in maximum stress (2.78 times for cortex and 1.67 times for cancellous bone) locally at the proximal femur. The failure cycles of the artificial femurs with a variety of abduction angle were averagely 9126 ± 2453.87 (α = -10°), 58,112.33 ± 1293.84 (α = -5°), 92,879.67 ± 2398.54 (α = 0°), 172,045.3 ± 11011.11 (α = 5°), and 264,949.3 ± 35,067.26 (α = 10°), and the statistical analysis revealed that the α angle of the group of concern is proportional to the P value of the corresponding group compared to the 10° group(α = 5° & α = 10°, P = 0.01; α = 0 & α = 10°, P = 0.001; α = -5°, -10° & α = 10°, P < 0.001). In fatigue test, the fracture appeared on femoral neck for the α angles of 10° (three subcapital), 5° (two basal; one transcervical), and 0° (one transcervical). Fracture sites located at trochanteric region were observed with the more abducted angles including 0° (two subtrochanteric) and -5° (two intertrochanteric; one subtrochanteric). The fracture line was only found on femoral shaft in the -10° group.

CONCLUSION

With increasing hip abduction, the proximal femur shows declining mechanical properties, which suggests higher risk of hip fracture and increasement in the fraction of trochanteric fracture subtype. Furthermore, the hypothesis of "fulcrum-balance-reconstruction" was validated by our study to a certain extent.

Risk factors of primary and recurrent fractures in postmenopausal osteoporotic Chinese patients: A retrospective analysis study

BACKGROUND

As postmenopausal osteoporotic fractures can cause higher rates of disability and mortality in women; it is essential to analyze the factors associated with primary and recurrent fractures in postmenopausal osteoporosis (PMOP) patients.

METHODS

Retrospective analysis of 2478 PMOP patients aged ≥ 50 years who attended the Shanghai General Hospital from January 2007 to December 2016, including 1239 patients with no fractures and 1239 patients with histories of fractures (1008 in the primary fracture group and 231 in the re-fracture group). All patients' basic clinical data, serum biochemical and bone metabolic markers, bone mineral density (BMD), and other indicators were recorded uniformly. Comparing the differences between the clinical characteristics of patients with primary and recurrent fractures, as well as the differences in the clinical characteristics of patients with primary and recurrent fractures in combination with different diseases, further analyses the risk factors for primary and recurrent fractures in PMOP patients. SPSS.26 was used for statistical analysis.

RESULTS

Compared to the unfractured group, the fractured group was older and had lower height and bone mineral density (all P < 0.01), with the re-fractured group having lower BMD at each key site than the primary fracture group (all P < 0.01). Analysis of the combined disease subgroups showed that serum BGP levels were lower in the primary and re-fracture patients with diabetes than in the non-diabetic subgroup (P < 0.05), and serum CTX levels were lower in the re-fracture group with diabetes than in the primary fracture group with diabetes (P < 0.05). Patients with recurrent fractures with cardio-vascular diseases had lower BMD than the subgroup without cardio-vascular diseases (P < 0.05) and also had lower BMD than the group with primary fractures with cardio-vascular diseases (P < 0.05). Multiple logistic regression analysis showed that advanced age, overweight, low lumbar spine and total hip BMD were risk factors for primary and recurrent fractures; and comorbid chronic liver and kidney diseases were risk factors for primary fractures.

CONCLUSION

PMOP patients with advanced age, overweight, low bone mineral density, and comorbid chronic liver and kidney diseases are at greater risk of fractures and require early intervention to reduce fractures occurrence. Moreover, those who are elderly, overweight, and have low bone density should also be aware of the risk of re-fractures.