Association of Female Reproductive Factors With Incidence of Fracture Among Postmenopausal Women in Korea

Increased Risk of Fracture after Traumatic Amputation: A Nationwide Retrospective Cohort Study

The physiological changes and alterations in gait following amputation may increase the risk of fractures. However, there is insufficient research on fracture risk in amputees. Therefore, this study intended to analyze whether the risk of new fractures increases after traumatic amputations. This population-based, retrospective cohort study used data from the Korean National Health Insurance System database. The study included 19,586 participants who had undergone an amputation and 76,645 matched controls. The incidence of any fracture and site-specific fractures (vertebral, hip, and others) according to amputation site(s) and severity of disability due to amputation were evaluated using Cox proportional hazard regression analysis. During the mean follow-up of 4.2 years, amputees had a higher incidence rate (IR) of any fracture (adjusted HR [aHR] 1.47, 95% CI 1.36-1.60), vertebral fracture (aHR 1.63, 95% CI 1.44-1.85), hip fracture (aHR 1.85, 95% CI 1.39-2.46), and other fracture (aHR 1.34, 95% CI 1.20-1.49) compared to that of controls. In the presence of disability, the risks were further increased and were highest among amputees with severe disabilities. All fracture risks were higher in amputees than they were in controls, regardless of lower limb or upper limb amputation. This cohort study demonstrated that traumatic amputees experienced higher incidence of all fractures than did individuals without amputations, and this risk increases with severity of disability. This finding underscores the importance of early screening and lifestyle interventions to address fracture risk in traumatic amputees.

Risk of fracture among patients with spinal cord injury: A nationwide cohort study in South Korea

BACKGROUND

Clinical concerns about preventing and managing fractures after spinal cord injury (SCI) have been growing.

OBJECTIVE

This study investigates the risk of fractures among SCI patients according to the presence of disability, disease severity, and level of injury.

METHODS

We performed a retrospective cohort study using the Korean National Health Insurance Service (KNHIS 2010-2018) database. We included 5190 SCI patients and 1:3 age- and sex-matched control participants. The primary outcome was fracture, and the cohort was followed until December 31, 2019.

RESULTS

SCI patients had a higher fracture risk than the matched controls (adjusted hazard ratio [aHR] 1.33, 95 % CI 1.16-1.54). The risk of fracture was higher in the presence of disability (aHR 1.57, 95 % CI 1.19-2.07), especially among patients with severe disability (aHR 1.65, 95 % CI 1.05-2.60). Higher fracture risks were observed among SCI patients regardless of injury level, but statistical significance was found only with cervical-level injury. When we considered site-specific fractures, vertebral (aHR 1.31, 95 % CI 1.04-1.64) and hip fracture risks (aHR 2.04, 95 % CI 1.39-2.98) were both higher among SCI patients than the controls. SCI patients with disability and cervical-level injury showed the highest hip fracture risk (aHR 3.67, 95 % CI 1.90-7.07).

CONCLUSIONS

Compared with the controls, SCI patients were at higher risk of any fracture, particularly hip fracture, especially those with disability and cervical-level injury. Clinicians should be aware of the fracture risk among SCI patients to provide proper management.

Fracture Risk Among Stroke Survivors According to Poststroke Disability Status and Stroke Type

BACKGROUND

Stroke survivors face physical and cognitive challenges, leading to an increased dependency and a higher fall risk. We aimed to investigate the impact of poststroke disability and stroke type on fracture risk at various sites compared with matched controls.

METHODS

This retrospective cohort study used data from the Korean National Health Insurance System database (2010-2018), including patients with stroke and 1:1 matched controls. Stroke survivors were grouped based on the presence and severity of their poststroke disability and stroke type. The primary outcome was a newly diagnosed fracture, analyzed by Cox proportional hazard regression analyses adjusting for potential confounders.

RESULTS

Among 223 358 stroke survivors (mean age, 64.8±10.9 years; 61.2% men), 16 344 fractures occurred during a mean follow-up of 3.7±2.5 years. In matched controls (n=322 161; mean age, 65.4±11.2 years; 61.3% men), 20 398 fractures were identified. Stroke survivors had increased overall fracture risk compared with matched controls (adjusted hazard ratio [aHR], 1.40 [95% CI, 1.37-1.43]). Specifically, hip fracture risk was even greater in stroke survivors (incidence rate per 1000 person-years, 4.7 [95% CI, 4.5-4.8]; aHR, 2.42 [95% CI, 2.30-2.55]) than controls (incidence rate, 2.2 [95% CI, 2.1-2.3]). The risk of vertebral fractures (aHR, 1.29 [95% CI, 1.25-1.34]) and other fractures (aHR, 1.19 [95% CI, 1.15-1.23]) was also higher than that of the control group. Hip fracture risk was the highest among stroke survivors with severe poststroke disability (aHR, 4.82 [95% CI, 4.28-5.42]), although vertebral or other fracture risk was the highest among those with mild poststroke disability. No significant difference in fracture risk was found between hemorrhagic and ischemic stroke survivors when stratified by disability status.

CONCLUSIONS

Our findings showed increased subsequent fracture risk among stroke survivors, particularly those with poststroke disability and for hip fracture. Bone health assessment and treatment should be emphasized as an essential part of stroke management.

Contrasting bone profiles in PCOS are related to BMI: a systematic review and meta-analysis

CONTEXT

Controversial results have emerged regarding whether PCOS is protective or increases the risk of bone frailty.

OBJECTIVE

This study investigated whether the PCOS condition affects bone parameters of premenopausal women. This is an update for a previous meta-analysis published in 2019.

DATA SOURCES

We searched MEDLINE and Embase.

STUDY SELECTION

Studies were considered eligible for the update if published in English between the 1st of October 2018 and the 31st of December 2023. The diagnosis of PCOS should be based on NIH criteria, the Rotterdam Consensus, AE-PCOS society criteria, or ICD codes in women over 18 years old. Only records with the Newcastle-Ottawa Scale > 6 were selected for data extraction.

DATA EXTRACTION

Data were extracted by two independent reviewers.

DATA SYNTHESIS

We identified 31 studies that met the inclusion criteria for qualitative analysis from 3322 studies in the whole period (1990-2023). Overall, cross-sectional studies included 1822 individuals with PCOS and 1374 controls, while cohort studies incorporated 30305 women with PCOS and 101907 controls. Contrasting profiles emerged after stratification using a BMI cutoff of 27 kg/m2. Individuals with PCOS and a BMI <27 kg/m2 exhibited lower vertebral and non-vertebral bone density, reduced bone turnover marker (osteocalcin), and increased bone resorption marker (CTX) levels. Conversely, individuals with PCOS and a BMI >27 kg/m2 exhibited increased vertebral and non-vertebral BMD, with no significant changes in bone formation and resorption markers (except osteocalcin).

CONCLUSIONS

The findings of this study alert for a low bone mass, low bone formation, and increased bone resorption PCOS with a BMI <27 kg/m2.

Neferine alleviates ovariectomy-induced osteoporosis by enhancing osteogenic differentiation of bone marrow mesenchymal stem cells via regulation of the p38MAPK pathway

OBJECTIVE

Osteoporosis, a skeletal ailment marked by bone metabolism imbalance and disruption of bone microarchitecture, Neferine, a bisbenzylisoquinoline alkaloid with diverse pharmacological activities, has received limited attention in the context of osteoporosis treatment.

METHODS

We employed a bilateral ovariectomy (OVX) rat model to induce osteoporosis and subsequently administered Neferine treatment for four weeks following successful model establishment. Throughout the modeling and treatment phases, we closely monitored rat body weights. We assessed alterations in bone tissue microstructure through micro-CT, HE staining, and safranin O-fast green staining. Levels of bone formation and resorption markers in serum were evaluated using ELISA assay. Western blot analysis was employed to determine the expression levels of p38MAPK, p-p38MAPK, and bone formation-related genes in bone tissue. We isolated and cultured OVX rat BMSCs (OVX-BMSCs) and induced osteogenic differentiation while simultaneously introducing Neferine and the p38MAPK inhibitor SB203580 for intervention.

RESULTS

Neferine treatment effectively curbed the rapid weight gain in OVX rats, ameliorated bone loss, and decreased serum levels of TRAP, CTX-I, PINP, and BALP. Most notably, Neferine promoted the expression of bone formation-related factors in bone tissue of OVX rats, while concurrently activating the p38MAPK signaling pathway. In in vitro experiments, Neferine facilitated the expression of bone formation-related factors in OVX-BMSCs, increased the osteogenic differentiation potential of OVX-BMSCs, and activated the p38MAPK signaling pathway. Nevertheless, SB203580 partially reversed Neferine's promotive effect.

CONCLUSION

Neferine can boost the osteoblastic differentiation of BMSCs and alleviate OVX-induced osteoporosis in rats by activating the p38MAPK signaling pathway.

Osteoporosis, Osteoarthritis, and Subchondral Insufficiency Fracture: Recent Insights

The increased incidence of osteoarthritis (OA), particularly knee and hip OA, and osteoporosis (OP), owing to population aging, have escalated the medical expense burden. Osteoarthritis is more prevalent in older women, and the involvement of subchondral bone fragility spotlights its association with OP. Notably, subchondral insufficiency fracture (SIF) may represent a more pronounced condition of OA pathophysiology. This review summarizes the relationship between OA and OP, incorporating recent insights into SIF. Progressive SIF leads to joint collapse and secondary OA and is associated with OP. Furthermore, the thinning and fragility of subchondral bone in early-stage OA suggest that SIF may be a subtype of OA (osteoporosis-related OA, OPOA) characterized by significant subchondral bone damage. The high bone mineral density observed in OA may be overestimated due to osteophytes and sclerosis and can potentially contribute to OPOA. The incidence of OPOA is expected to increase along with population aging. Therefore, prioritizing OP screening, early interventions for patients with early-stage OA, and fracture prevention measures such as rehabilitation, fracture liaison services, nutritional management, and medication guidance are essential.

The risk of fracture in age-related macular degeneration according to the presence of visual disability: a nationwide cohort study

PURPOSE

To evaluate the association between age-related macular degeneration (AMD) with or without visual disability (VD) and the risk of fracture using the National Health Insurance data in South Korea.

METHODS

In total, 3,894,702 individuals who had taken part in health-screening programs between January 1, 2009, and December 31, 2009, were included in the cohort and followed until December 31, 2019. The participants with VD, which could be related to the severity of AMD, were defined as those with a loss of vision or visual field defect as certified by the Korean government's Ministry of Health and Welfare. The hazard ratio was calculated for groups (control and AMD with/without VD) using the multivariable-adjusted cox regression analysis.

RESULTS

In total, 466,890 participants (11.99%) were diagnosed with fractures during the study period. An increased risk of fracture was observed in individuals with AMD compared with the control (adjusted hazard ratio (aHR), 1.09, 95% confidence interval (CI), 1.06-1.11). Furthermore, among the AMD individuals, an increased risk of fracture was prominent in individuals with VD (aHR 1.17, 95% CI 1.08-1.27) than those without VD (aHR 1.08, 95% CI 1.06-1.11) compared with the reference group (control).

CONCLUSIONS

AMD was associated with an increased risk of fracture even without VD. Prevention for fracture should be considered in AMD patients, especially when accompanied by VD.

Effect of SGLT2 inhibitors versus DPP4 inhibitors on major and non-major osteoporotic fracture risks among general and high-risk type 2 diabetes patients: A nationwide retrospective cohort study

AIMS

To retrospectively analyze the association of sodium-glucose cotransporter-2 inhibitors (SGLT2is) versus dipeptidyl peptidase-4 inhibitors (DPP4is) with a range of major and non-major fracture events, and explore heterogeneous treatment effect among high-risk patient subgroups.

METHODS

Newly stable SGLT2i or DPP4i users in 2017 were identified in Taiwan's National Health Insurance Research Database and followed up until a fracture occurred, loss of follow-up, death, or December 31, 2018, whichever came first. Outcomes included composite major and non-major fractures and individual components in major fractures. Cox model and restricted mean survival time (RMST) analyses were utilized to assess the treatment effect on fractures.

RESULTS

21,155 propensity-score-matched SGLT2i and DPP4i users were obtained. Over 2 years, the hazard ratio and RMST difference for major fracture with SGLT2i versus DPP4i use were 0.89 (95% CI, 0.80, 1.00) and 1.51 (-0.17, 3.17) days, respectively, and those for non-major fracture with SGLT2i versus DPP4i use were 0.89 (0.81, 0.98) and 2.44 (0.47, 4.37) days, respectively. A 180-day lag time analysis for fracture outcomes showed consistent results with primary findings. A SGLT2is-associated harmful effect on major fractures (but not on non-major fractures) was observed among female patients and those with a diabetes duration of ≥ 8 years, prior fractures, and established osteoporosis.

CONCLUSION

This study adds supporting real-world evidence for SGLT2is-associated bone safety for a wide range of fractures, which promotes the rational use of SGLT2is in routine care and highlights the importance of the close monitoring of patients with high fracture risks to maximize treatment benefits while reducing undesirable effects.

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.

Combined hormonal contraceptive use is not protective against musculoskeletal conditions or injuries: a systematic review with data from 5 million females

OBJECTIVE

Assess the association between combined hormonal contraceptives (CHC) use and musculoskeletal tissue pathophysiology, injuries or conditions.

DESIGN

Systematic review with semiquantitative analyses and certainty of evidence assessment, guided by the Grading of Recommendations Assessment, Development and Evaluation approach.

DATA SOURCES

MEDLINE, EMBASE, CENTRAL, SPORTDiscus, CINAHL searched from inception to April 2022.

ELIGIBILITY

Intervention and cohort studies that assessed the association between new or ongoing use of CHC and an outcome of musculoskeletal tissue pathophysiology, injury or condition in postpubertal premenopausal females.

RESULTS

Across 50 included studies, we assessed the effect of CHC use on 30 unique musculoskeletal outcomes (75% bone related). Serious risk of bias was judged present in 82% of studies, with 52% adequately adjusting for confounding. Meta-analyses were not possible due to poor outcome reporting, and heterogeneity in estimate statistics and comparison conditions. Based on semiquantitative synthesis, there is low certainty evidence that CHC use was associated with elevated future fracture risk (risk ratio 1.02-1.20) and total knee arthroplasty (risk ratio 1.00-1.36). There is very low certainty evidence of unclear relationships between CHC use and a wide range of bone turnover and bone health outcomes. Evidence about the effect of CHC use on musculoskeletal tissues beyond bone, and the influence of CHC use in adolescence versus adulthood, is limited.

CONCLUSION

Given a paucity of high certainty evidence that CHC use is protective against musculoskeletal pathophysiology, injury or conditions, it is premature and inappropriate to advocate, or prescribe CHC for these purposes.

PROSPERO REGISTRATION NUMBER

This review was registered on PROSPERO CRD42021224582 on 8 January 2021.

Predictors of osteoporotic fracture in postmenopausal women: a meta-analysis

Osteoporosis affects more than 200 million women worldwide, with postmenopausal women being particularly susceptible to this condition and its severe sequelae disproportionately, such as osteoporotic fractures. To date, the current focus has been more on symptomatic treatment, rather than preventive measures. To address this, we performed a meta-analysis aiming to identify potential predictors of osteoporotic fractures in postmenopausal women, with the ultimate goal of identifying high-risk patients and exploring potential therapeutic approaches. We searched Embase, MEDLINE and Cochrane with search terms (postmenopausal AND fracture) AND ("risk factor" OR "predictive factor") in May 2022 for cohort and case-control studies on the predictors of osteoporotic fracture in postmenopausal women. Ten studies with 1,287,021 postmenopausal women were found eligible for analyses, in which the sample size ranged from 311 to 1,272,115. The surveyed date spanned from 1993 to 2021. Our results suggested that age, BMI, senior high school and above, parity ≥ 3, history of hypertension, history of diabetes mellitus, history of alcohol intake, age at menarche ≥ 15, age at menopause < 40, age at menopause > 50, estrogen use and vitamin D supplements were significantly associated with osteoporotic fracture in postmenopausal women. Our findings facilitate the early prediction of osteoporotic fracture in postmenopausal women and may contribute to potential therapeutic approaches. By focusing on preventive strategies and identifying high-risk individuals, we can work toward reducing the burden of osteoporosis-related fractures in this vulnerable population.

Association between the fatty liver index and the risk of fracture among individuals over the age of 50 years: a nationwide population-based study

Background and purpose

The association between fatty liver and fracture risk has not been firmly established. In this study, we investigated the relationship between the fatty liver index (FLI) and the incidence of fractures among individuals ≥50 years of age, using a nationwide population-based cohort.

Methods

Data from the Korean National Health Insurance System between January 2009 and December 2019 were analyzed using the Cox proportional hazards model. Fatty liver status was defined using FLI. Newly diagnosed fractures were identified based on insurance claim data.

Results

Among the 3,384,457 individuals who met our inclusion criteria over the study period, 444,203 cases of incident fractures were identified over a median follow-up of 10.3 years. On multivariate analysis, the risk of fracture was significantly higher among individuals with a higher FLI score compared to those with an FLI<30, with adjusted hazard ratio [aHR] and 95% confidence interval [CI] as follows: FLI 30-59 group, aHR 1.04 and 95% CI 1.03-1.05; and FLI ≥60 group, aHR 1.12 and 95% CI 1.10-1.13. A higher FLI was associated with a greater risk of hip (aHR 1.23 and 1.52 for the FLI 30-59 and FLI ≥60 group, respectively) and vertebral fracture (aHR 1.08 and 1.16 for the FLI 30-59 and FLI≥60 group, respectively). The association between the risk for fracture and FLI ≥60 was prominent for non-obese than obese individuals (aHR 1.25 and 95% CI, 1.22-1.27 versus 1.06 and 1.05-1.08, respectively).

Conclusions

A high FLI is associated with an increased risk of hip and vertebral fractures among individuals ≥50 years of age, suggestive of an association between a higher FLI and osteoporotic fractures.

Bridging the Gap: Pregnancy-And Lactation-Associated Osteoporosis

Early diagnosis of pregnancy- and lactation-associated osteoporosis (PLO) is mandatory for a good outcome. Standard care is not a matter of conventional guidelines, rather it requires an individualized strategy while true overall incidence and pathogeny remain open issues. This is a narrative review based on full-length English articles, published between January 2021 and March 2023 and accessed via PubMed (no traumatic fractures or secondary osteoporosis are included). Our case-sample-based analysis included 836 females with PLO (the largest cohort based on published cases so far) through 12 studies and 24 single case reports. Except for one survey, these involved retrospective cohorts of small size (6-10 females/study) to medium size (23-47 women/study), and large cohorts with >50 subjects per study (a maximum of 379). Age of diagnosis: from 24 to 40 years for case reports (most subjects being over 30 and primigravida), while original studies indicated an average age between 31 and 34.18 years. Type of fractures underlined a most frequent vertebral phenotype (a mean of 2 to 5.8 vertebral fractures per patient) versus a most severe non-vertebral phenotype (hip and femoral neck fractures mostly requiring surgery). Potential contributors varied: smoking (1/3-1/2 of subjects), family history of osteoporosis (1/3), heparin and glucocorticoid use in pregnancy, low body mass index (majority of cases), hypovitaminosis D; and (with a low level of statistical significance) anti-psychotic medication, gestational diabetes, lupus, thrombophilia, anemia, in vitro fertilization (1/3 in one study), twin pregnancy, tocolysis with MgSO4, and postpartum thyroiditis. Most remarkably, up to 50% of PLO patients harbor mutations of LRP5, WNT1, and COL1A1/A2 (more damaged form with potential benefits from osteoanabolic drugs); gene testing might become the new norm in PLO. The low index of clinical suspicion should be supported by performing magnetic resonance imaging (gold standard in pregnancy) with DXA (in lactation). Low bone mineral density is expected (Z-score varying from -2.2 SD to -4 SD, unless normal which does not exclude PLO). Bone turnover markers might be useful in individuals with normal DXA, in pregnancy when DXA cannot be performed, and in following the response to anti-osteoporosis drugs. Alternatively, microarchitecture damage might be reflected by DXA-trabecular bone score and high-resolution peripheral quantitative computed tomography. Specific medical interventions are currently focused on teriparatide (TPT) use (3 studies; n = 99 females treated with TPT and an additional subgroup of 18 patients from the gene-analysis-based study, thus a total of 117 females) which seems to be the therapy of choice as reflected by these new data: 6-24 months, 20 µg/day, no sequential therapy needed; case selection based on high fracture risk is necessary). The first case using romosozumab was reported in 2022. PAO/LAO remains a challenging condition which is a battle for the wellbeing of two individuals, on one hand, considering maternal-fetal outcomes and taking care of the offspring, but it is a battle for a multidisciplinary team, on the other hand, since a standardized approach is lacking.

Risk of fracture in neuromyelitis optica spectrum disorder and multiple sclerosis: a nationwide cohort study in South Korea

PURPOSE

Interest in fractures in patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) has considerably increased in the last decade. However, few studies have compared the incidence of fractures between patients with MS and NMOSD using a nationwide database. This study aimed to evaluate the differences in the risk of fracture between patients with NMOSD and MS compared to that in healthy controls using cohort data from a Korean nationwide database.

METHODS

In this retrospective cohort study, data from the National Health Insurance Service (NHIS) database from January 2010 to December 2017 were analyzed. A total of 1,217/1,329 patients with MS/NMOSD free of fractures at the index date were included. Matched controls were selected based on age, sex, and the presence of hypertension, diabetes mellitus, and dyslipidemia. The mean follow-up durations after the index date were 4.40/4.08 years for patients with MS/NMOSD and 4.73/4.28 for their matched controls.

RESULTS

The adjusted hazard ratios (aHRs) with 95% confidence intervals of any, hip, and vertebral fractures were 1.81 (1.43-2.28), 3.36 (1.81-6.24), and 2.01 (1.42-2.99) times higher for patients with MS than for controls, respectively, and they were 1.85 (1.47-2.34), 3.82 (2.05-7.11), and 2.84 (1.92-4.21) times higher for patients with NMOSD than for controls, respectively. No significant differences were observed in the incidence of fractures between the MS and NMOSD groups. Patients with MS/NMOSD had a 1.8-fold higher risk of fracture than matched controls, and the risk of hip fracture was especially high (3- to 4-fold higher).

CONCLUSIONS

Clinicians need to regularly assess patients with MS/NMOSD for the risk of fractures and take preventative measures to reduce it.

Associations of reproductive factors with incidence of myocardial infarction and ischemic stroke in postmenopausal women: a cohort study

BACKGROUND

To assess the association between the reproductive factors of age at menarche, age at menopause, and reproductive span and the incidence of myocardial infarction (MI) and ischemic stroke (IS).

METHODS

We used a population-based retrospective cohort study from the National Health Insurance Service database of Korea including a total of 1,224,547 postmenopausal women. Associations between age at menarche (≤ 12, 13-14 [reference], 15, 16, and ≥ 17 years), age at menopause (< 40, 40-45, 46-50, 51-54 [reference], and ≥ 55 years), and reproductive span (< 30, 30-33, 34-36, 37-40 [reference], and ≥ 41 years) and the incidence of MI and IS were assessed by Cox proportional hazard models with adjustment for traditional cardiovascular risk factors and various reproductive factors.

RESULTS

During a median follow-up of 8.4 years, 25,181 MI and 38,996 IS cases were identified. Late menarche (≥ 16 years), early menopause (≤ 50 years), and short reproductive span (≤ 36 years) were linearly associated with a 6%, 12-40%, and 12-32% higher risk of MI, respectively. Meanwhile, a U-shaped association between age at menarche and risk of IS was found, with a 16% higher risk in early menarche (≤ 12 years) and a 7-9% higher risk in late menarche (≥ 16 years). Short reproductive span was linearly associated with an increased risk of MI, whereas both shorter and longer reproductive spans were associated with an increased risk of IS.

CONCLUSIONS

This study demonstrated different patterns of association between age at menarche and incidence of MI and IS: a linear association for MI versus a U-shaped association for IS. Female reproductive factors in addition to traditional cardiovascular risk factors should be considered when assessing overall cardiovascular risk in postmenopausal women.

Association Between Reproductive Health Factors and Musculoskeletal Injuries in Female Canadian Armed Forces Members

Background: Musculoskeletal injuries (MSKi) play a role in member retention in the military. In general, female military members have higher rates of MSKi than males and female reproductive health characteristics may be contributing to these disparities. This study seeks to characterize reproductive health factors in female Canadian Armed Forces (CAF) members and their relationship with MSKi. Materials and Methods: An electronic survey (SurveyMonkey^®) was made available to present and former CAF members 18-65 years of age. Responses were collected between September 2020 and February 2021. Seven female reproductive characteristics were assessed: age of menarche, menstrual cycle regularity, birth control use, having given birth while serving, endometriosis, early menopause, and secondary oligomenorrhea/amenorrhea. Binary logistic regressions were used to analyze associations between reproductive characteristics with repetitive strain (RSI) and acute injuries. Results: A total of 2,001 participants consented to the survey with 855 respondents being female. Females reporting menstrual cycles as never regular, irregular for a few months, who never had a period, and whose periods stopped while serving presented a greater likelihood of reporting RSI compared to their peers who reported regular menstrual cycles (adjusted odds ratio [aOR]: 1.898, confidence interval [CI]: 1.138-3.166). Participants who have experienced endometriosis presented a higher likelihood of reporting acute injuries than those who did not (aOR: 2.426, CI: 1.030-5.709). Conclusion: This examination of females within the CAF suggests that irregular menstrual cycles or absent periods increase the likelihood of experiencing MSKi, namely those categorized as RSI injuries and reporting endometriosis were associated with greater rates of acute injuries.

Risk factors for the development of idiopathic macular hole: a nationwide population-based cohort study

This nationwide population-based cohort study searched for demographic, comorbid, behavioral, and reproductive risk factors for idiopathic macular hole (MH) development using data provided by the Korean National Health Insurance Service. A total of 4,496,867 individuals aged 50-79 years who participated in the Korean National Health Screening Program in 2013 or 2014 were included. Participants were followed up until December 2018, and incident cases of idiopathic MH were identified. Prospective associations between incident idiopathic MH and various covariates were investigated using multivariable-adjusted Cox proportional hazard models. During an average follow-up period of 4.91 years, 3054 patients were newly diagnosed with idiopathic MHs. Women showed greater risk (hazard ratio of 1.71) and earlier presentation of idiopathic MH than men. Compared to the normal body mass index group, the obese group (≥ 25 kg/m²) showed a significantly lower risk of idiopathic MH. Among postmenopausal women, those with two or more children showed a greater risk of idiopathic MH than those who had not been pregnant, with a hazard ratio of 1.80. In conclusion, idiopathic MH occurred earlier and greater in women. Childbirth were associated with an increased risk of MH development, and obesity was associated with a lower risk of MH.

Alzheimer's disease-associated inflammatory pathways might contribute to osteoporosis through the interaction between PROK2 and CSF3

This study aimed to explore the potential molecular pathways and targets of Alzheimer's disease leading to osteoporosis using bioinformatics tools. The Alzheimer's and osteoporosis microarray gene expression data were retrieved from the Gene Expression Omnibus, and differentially expressed genes in the blood microenvironment related to Alzheimer's disease and osteoporosis were identified. The intersection of the three datasets (GSE97760, GSE168813, and GSE62402) was used to obtain 21 co-expressed targets in the peripheral blood samples in patients with Alzheimer's disease and osteoporosis. Based on the degree algorithm, the top 10 potential core target genes related to these diseases were identified, which included CLEC4D, PROK2, SIGLEC7, PDGFB, PTCRA, ECH1, etc. Two differentially expressed mRNAs, Prokineticin 2 (PROK2) and three colony-stimulating factor 3 (CSF3), were screened in the GSE62402 dataset associated with osteoporosis. Protein–protein rigid docking with ZDOCK revealed that PROK2 and CSF3 could form a stable protein docking model. The interaction of PROK2 and CSF3, core genes related to osteoporosis inflammation, plays an important role in the mechanism of osteoporosis in patients with Alzheimer's. Therefore, abnormalities or alterations in the inflammatory pathways in the peripheral blood samples of Alzheimer's patients may affect the course of osteoporosis.

Early menopause and weight loss are significant factors associated with risk of future fracture in middle-aged women

BACKGROUND

To identify factors related to reproductive history and weight change associated with first incident fracture in middle-aged women.

METHODS

In total, 18,326 women from the Malmö Diet and Cancer study were included in this prospective population-based cohort study. Participants were included 1991-1996 and followed to 2016. Using data from the National Patient Registry, linked with every participants' unique personal identification number, any first fracture affecting spine, thoracic cage, upper and lower extremities was identified. The association of baseline factors with incident fracture risk was analyzed using Cox regression models.

RESULTS

For participating women, median age 56.0 years, the multivariable Cox regression analysis observed that early menopause (40-44 years) (hazard ratio (HR) 1.14, 95% confidence interval (CI) 1.03-1.27) but not premature menopause < 40 years (HR 1.06, 95% CI 0.91-1.24) was associated with future fracture risk. Self-reported weight loss since age 20 was also associated with future fracture risk (HR 1.39, 95% CI 1.17-1.65) whereas a daily alcohol consumption in the third quartile (5.36-11.42 g/day) compared to the lowest quartile (0-0.80 g/day) was associated with decreased future fracture risk (HR 0.88, 95% CI 0.81-0.96). The multivariable Cox regression analysis also observed that increasing age and weight at baseline, current smoking, a positive history of previous fracture and family history of fractures were associated with increased fracture risk whereas an increasing BMI was associated with a decreased fracture risk. No association to parity or period of lactation was observed nor ever-use of oral contraceptives and menopausal hormone therapy.

CONCLUSION

This study shows that early menopause between 40 to 45 years and self-reported weight loss since age of 20 are relevant factors associated with increased fracture risk in middle-aged women. These factors were independent of traditional predictors of fracture risk among women and may be considered in preventive initiatives.

TRIAL REGISTRATION

Clinicaltrials.gov with identifier: NCT04151732, since Nov 5th 2018.

The Impact of Endogenous Estrogen Exposure Duration on Fracture Incidence: a Longitudinal Cohort Study

CONTEXT

Although it is well documented that estrogen hormone is positively associated with bone mineral density and lower risk of fracture, there are limited studies on the association between duration of endogenous estrogen exposure (EEE) and fracture, especially by longitudinal design.

OBJECTIVE

This study aimed to investigate the relationship between EEE with fracture incidence by longitudinal design in a community-based study.

METHODS

A total of 5269 eligible postmenarcheal women, including 2411 premenopausal and 2858 menopausal women, were recruited from among the Tehran Lipid and Glucose Study. Cox proportional hazards regression model with adjustment of potential confounders was performed to assess the relationship between duration of EEE and incident of any hospitalized fractures.

RESULTS

A total of 26.7% (1409/5269) women were menopausal at the baseline, and 2858 of the remaining participants reached menopause at the end of follow-up. Results of the unadjusted model demonstrated that the EEE z-score was negatively associated with fracture incidence [unadjusted hazard ratio (HR) 0.81, 95% CI 0.68-0.96] in postmenarchal women, indicating that per 1-SD increase of EEE z-score, the hazard of fracture reduced by 19%. Results remained statistically unchanged after adjustment for potential confounders (adjusted HR 0.70, 95% CI 0.58-0.86).

CONCLUSION

The findings of this cohort study suggest that a longer duration of EEE has a protective effect on fracture incidence; a point that needs to be considered in fracture risk assessment.

Crosstalk between the gut microbiota and postmenopausal osteoporosis: Mechanisms and applications

Postmenopausal osteoporosis (PMO) results from a reduction in bone mass and microarchitectural deterioration in bone tissue due to estrogen deficiency, which may increase the incidence of fragility fractures. The number of people suffering from PMO has increased over the years because of the rapidly aging population worldwide. However, several pharmacological agents for the treatment of PMO have many safety risks and impose a heavy financial burden to patients and society. In recent years, the "gut-bone" axis has been proposed as a new approach in the prevention and treatment of PMO. This paper reviews the relationship between the gut microbiota and PMO, which mainly includes the underlying mechanisms between hormones, immunity, nutrient metabolism, metabolites of the gut microbiota and intestinal permeability, and explores the possible role of the gut microbiota in these processes. Finally, we discuss the therapeutic effects of diet, prebiotics, probiotics, and fecal microbiota transplantation on the gut microbiota.

Reproductive Life Span and Severe Hypoglycemia Risk in Postmenopausal Women with Type 2 Diabetes Mellitus

BACKGROUND

Estrogen promotes glucose homeostasis, enhances insulin sensitivity, and maintains counterregulatory responses in recurrent hypoglycemia in women of reproductive age. Postmenopausal women with type 2 diabetes mellitus (T2DM) might be more vulnerable to severe hypoglycemia (SH) events. However, the relationship between reproductive factors and SH occurrence in T2DM remains unelucidated.

METHODS

This study included data on 181,263 women with postmenopausal T2DM who participated in a national health screening program from January 1 to December 31, 2009, obtained using the Korean National Health Insurance System database. Outcome data were obtained until December 31, 2018. Associations between reproductive factors and SH incidence were assessed using Cox proportional hazards models.

RESULTS

During the mean follow-up of 7.9 years, 11,279 (6.22%) postmenopausal women with T2DM experienced SH episodes. A longer reproductive life span (RLS) (≥40 years) was associated with a lower SH risk compared to a shorter RLS (<30 years) (adjusted hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.69 to 0.80; P for trend <0.001) after multivariable adjustment. SH risk decreased with every 5-year increment of RLS (with <30 years as a reference [adjusted HR, 0.91; 95% CI, 0.86 to 0.95; P=0.0001 for 30-34 years], [adjusted HR, 0.80; 95% CI, 0.76 to 0.84; P<0.001 for 35-39 years], [adjusted HR, 0.74; 95% CI, 0.68 to 0.81; P<0.001 for ≥40 years]). The use of hormone replacement therapy (HRT) was associated with a lower SH risk than HRT nonuse.

CONCLUSION

Extended exposure to endogenous ovarian hormone during lifetime may decrease the number of SH events in women with T2DM after menopause.

Severity of underweight and risk of fracture: a Korean nationwide population-based cohort study

Underweight is an important modifiable risk factor for fractures. However, there have been few large cohort studies regarding the relationship between underweight and fracture in the general population. We investigated the risk of fracture development according to underweight severity in a large population cohort. This nationwide cohort study included 2,896,320 people aged ≥ 40 years who underwent national health checkups in 2009 and were followed up to identify the incidence of fracture until December 31, 2018. After applying the exclusion criteria that included overweight and obese individuals, the study population was divided according to body mass index (BMI) into normal weight (18.5 ≤ BMI < 23.0), mild underweight (17.5 ≤ BMI < 18.5), moderate underweight (16.5 ≤ BMI < 17.5), and severe underweight (BMI < 16.5) groups. Cox proportional hazards regression analyses were performed to calculate the hazard ratios for risk of fracture according to underweight severity. Severely underweight participants had a 28% increased fracture risk (adjusted hazard ratio [HR] 1.28, 95% confidence interval [CI] 1.20-1.37) compared with those of normal weight. In addition, fracture risk was increased by 14% in individuals with moderate underweight (adjusted HR 1.14, 95% CI 1.08-1.19) and 9% in those with mild underweight (adjusted HR 1.09, 95% CI 1.06-1.13). The severity of underweight was significantly associated with risk of fracture.

Early menopause is associated with increased risk of retinal vascular occlusions: a nationwide cohort study

This nationwide population-based cohort study evaluated the association between female reproductive factors and the incidence of retinal vein occlusion (RVO) and retinal artery occlusion (RAO) using data provided by the Korea National Health Insurance Service. A total of 2,289,347 postmenopausal women over 50 years of age who participated in both national health screening and cancer screening in 2013 or 2014 were included. Data on female reproductive factors, including age at menarche, age at menopause, parity, history of hormone replacement therapy, and oral contraceptive pill usage, were collected. Patients were followed up until December 2018, and incident cases of RVO and RAO were identified using registered diagnostic codes from claim data. During an average follow-up period of 4.90 years, 7461 and 1603 patients were newly diagnosed with RVO and RAO, respectively. In the multivariable-adjusted Cox proportional hazard model, patients who experienced menopause after 55 years of age had a lower risk of RVO and RAO development compared to those who had menopause before 45 years of age, with a hazard ratio (95% confidence interval) of 0.83 (0.76–0.95) for RVO and 0.80 (0.66‒0.98) for RAO. In conclusion, early menopause was an independent risk factor for future development of RVO and RAO.

Blood Pressure Variability and the Risk of Fracture: A Nationwide Cohort Study

CONTEXT

Although blood pressure variability (BPV) is associated with various health outcomes, only 1 study suggested that BPV is correlated with hip fractures. As cardiovascular disease and fractures share similar pathophysiology, there might be a link between BPV and fractures.

OBJECTIVE

To investigate the association between BPV and the incident fractures.

DESIGN

Retrospective cohort study.

SETTING

Population-based, using the Korean National Health Insurance System database.

PATIENTS OR OTHER PARTICIPANTS

A total of 3 256 070 participants aged ≥50 who participated in ≥3 health examinations within the previous 5 years, including the index year (2009-2010), were included. Outcome data were obtained through the end of 2016.

EXPOSURE

BPV was calculated using variability independent of the mean. High variability was defined as the highest quartile of variability.

MAIN OUTCOME MEASURES

Newly diagnosed fractures.

RESULTS

During the median follow-up of 7.0 years, there were 337 045 cases of any fracture (10.4%). After adjusting for age, sex, income, lifestyle factors, and comorbidities, a higher risk of fracture was observed with higher quartiles of BPV than the lowest quartile group: the adjusted hazard ratios (95% CIs) for incident any fracture were 1.07 (1.06-1.08) in the higher quartile of systolic BPV, 1.06 (1.05-1.07) in that of diastolic BPV, and 1.07 (1.06-1.08) in that of both systolic and diastolic BPV. Consistent results were noted for vertebral fractures and hip fractures, as well as in various subgroup analyses.

CONCLUSIONS

A positive association was noted between higher BPV and fracture incidence. BPV is an independent predictor for developing fracture.

Femoral Neck Stress Fractures in Athletes and the Military

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Femoral neck stress fractures (FNSFs) are an infrequent condition in athletic and military populations.

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A high index of suspicion with liberal use of magnetic resonance imaging (MRI) is vital for early recognition and treatment initiation.

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An associated hip effusion on MRI is a risk factor for an evolving stress injury and requires close assessment and consideration for repeat MRI.

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Stress reactions and stable, incomplete FNSFs (<50% of femoral neck width) can be treated nonsurgically.

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Surgical intervention is accepted for high-risk, incomplete (≥50% of femoral neck width), and complete FNSFs.

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Overall, there is a paucity of high-quality literature on the rates of return to activity following FNSF.

Does the risk of chronic low back pain depend on age at menarche or menopause? A population-based cross-sectional and cohort study: the Trøndelag Health Study

OBJECTIVE

In most population-based studies of low back pain (LBP), women have a higher risk than men, possibly reflecting hormonal influences. The aim of this study was to explore associations between age at menarche and menopause and risk of chronic LBP.

DESIGN

Population-based cross-sectional and cohort study designs.

SETTING

The HUNT2 and HUNT3 medical surveys of the entire population of Nord-Trøndelag County in Norway.

MAIN OUTCOME MEASURE

Prevalence or risk of chronic LBP, defined as LBP persisting at least 3 months continuously during last year.

PARTICIPANTS

Associations between age at menarche and prevalence of chronic LBP were examined in cross-sectional data from HUNT2, comprising 27 697 women aged 20-69 years, with 7300 women reporting LBP. The corresponding cohort data included 11 659 women without LBP at baseline in HUNT2, with 2353 women reporting LBP at follow-up 11 years later in HUNT3. Cross-sectional data on age at menopause or premenopausal status included 11 332 women aged 40-69 years, with 3439 women reporting chronic LBP. Corresponding cohort data included 7893 women without LBP at baseline, of whom 1100 developed LBP.

METHODS

Associations between age at menarche or menopause and risk of chronic LBP were examined by generalised linear modelling.

RESULTS

A U-shaped association was indicated between age at menarche and risk of chronic LBP, both in the cross-sectional and cohort studies. Age at menarche ≤11 years was associated with an increased risk of chronic LBP, with a relative risk of 1.32 (95% CI 1.15 to 1.52), compared with age 14 years at menarche, after relevant adjustments. Corresponding cross-sectional crude absolute risks were 32% and 25%, respectively. No association was established between age at menopause and risk of LBP. Being premenopausal had no influence on risk.

CONCLUSIONS

In contrast to results for age at menopause, the association with age at menarche suggests that hormonal factors affect the risk of LBP.

Female Reproductive Factors and the Risk of Bronchiectasis: A Nationwide Population-Based Longitudinal Study

Although the oestrogen level is thought to be involved in the occurrence of bronchiectasis, limited data are available on the relationship between female reproductive factors and the risk of bronchiectasis. We performed a population-based retrospective cohort study of 959,523 premenopausal women and 1,362,401 postmenopausal women without a previous history of bronchiectasis who participated in a health screening exam in 2009 in South Korea. In premenopausal women, compared with a later age at menarche (≥16 years), an earlier menarche (<12 years) was associated with a reduced risk of bronchiectasis with an adjusted hazard ratio (aHR) (95% confidence interval (CI)) of 0.74 (0.67–0.81). However, there were no significant associations between other reproductive factors (breastfeeding, parity, or oral contraceptive use) and the risk of bronchiectasis. In postmenopausal women, the risk of bronchiectasis (aHR (95% CI)) was lower in those with an earlier menarche (0.79 (0.72–0.87) for <12 years vs. ≥16 years), a later menopause (0.90 (0.84–0.96) ≥55 years vs. <40 years), and a longer reproductive period (0.90 (0.86–0.94) for ≥40 years vs. <30 years). There was no significant relationship between parity and the risk of bronchiectasis. Although breastfeeding <1 year (aHR (95% CI) = 0.92 (0.87–0.97) for <0.5 years and 0.93 (0.88–0.97) for 0.5–1 years) and oral contraceptive use <1 year (0.97 (0.94–0.99)) reduced the risk of bronchiectasis, hormone replacement therapy ≥5 years increased the risk of bronchiectasis (1.24 (1.18–1.30)). Female reproductive factors are risk factors for developing bronchiectasis, showing a higher risk associated with shorter endogenous oestrogen exposure regardless of the menopausal status.

Female reproductive factors and risk of joint replacement arthroplasty of the knee and hip due to osteoarthritis in postmenopausal women: a nationwide cohort study of 1.13 million women

OBJECTIVES

Previous studies of the relationships between female reproductive factors and osteoarthritis (OA) have shown conflicting results. In this study, we aimed to explore the relationships between reproductive factors and joint replacement arthroplasty of the knee (TKRA) and hip (THRA) in a large nationwide population-based cohort of postmenopausal Korean women.

METHODS

We included 1,134,680 subjects who participated in national health examinations in 2009 in the study. The study outcomes were incident THRA or TKRA due to severe hip or knee OA. The relationships between reproductive factors and THRA or TKRA were evaluated using a multivariable-adjusted proportional hazards model.

RESULTS

During a mean follow-up duration of 8.2 years, 1,610 incident THRA cases and 60,670 incident TKRA cases were observed. Later age at menarche, longer breastfeeding, HRT and OC use were associated with increased risk of TKRA for severe knee OA, while later age at menopause and longer reproductive span were associated with decreased risk. With regard to THRA for severe hip OA, later menarche, longer breastfeeding, HRT more than 5 years, and OC use more than 1 year were associated with higher risk. The associations between reproductive factors and severe OA were more pronounced in underweight and younger subjects.

CONCLUSION

We found that shorter estrogen exposure was associated with higher risk of TKRA due to severe knee OA, and such associations were more pronounced in underweight and younger subjects. The association between shorter estrogen exposure and THRA was not robust.

Risk of fracture in antidepressant users with concurrent use of benzodiazepines: A self-controlled case-series analysis

OBJECTIVE

Despite the fracture risk associated with both antidepressant (AD) medication and benzodiazepines (BDZs), they are commonly prescribed simultaneously. However, studies elucidating the effects of concurrent use of BDZs and ADs on the risk fracture are scant. The objective of this study was to evaluate the risk of fracture associated with concurrent use of BDZs in AD users, using a self-controlled case-series analysis.

METHODS

A self-controlled case-series analysis, in which the participants act as their own control, was conducted using the Korean National Health Insurance Service-National Sample Cohort database (2002-2015). We studied AD users who were prescribed BDZs and diagnosed with a fracture. The risk periods were subdivided into consecutive periods (1-30, 31-60, and > 60 days) after receiving a BDZ. A 2-week pre-exposure period and a 2-week post-exposure period were also included. The incidence rate ratio (IRR) was estimated after adjusting for age and use of co-medications.

RESULTS

A total of 3020 patients were identified during the study period. There was an increased fracture risk in the first 30 days following BDZ use (IRR: 1.88, 95% confidence interval [CI] 1.66-2.12), in the 31-60-day period (1.73, 95% CI 1.48-2.02), and beyond the 60-day period (IRR: 1.68, 95% CI 1.47-1.91). The risks of fracture were greater in men and older patients.

CONCLUSION

The concomitant use of BDZs and ADs was related to a significant increase in fracture risk. AD users should be aware of the fracture risk with concomitant BDZ use, especially for first-time BDZ users and for elderly patients.

Breastfeeding and Allergic Diseases: What's New?

Asthma and other allergic disorders, such as atopic dermatitis and food allergies, are common chronic health problems in childhood. The rapid rise in the prevalence of these conditions registered over the last few decades has stressed the need to identify the modifiable risk factors associated with the development of these diseases. Breast milk, recognized as the gold standard for healthy growth and development of the newborn, is one of the major factors associated with a lower incidence of allergic and infectious diseases in childhood and young adulthood. Although the underlying mechanisms for these effects are not well understood, breastfeeding leads to immune system maturation. In this narrative review, we summarize existing evidence on breastfeeding and human milk composition in relation to allergic disease prevention or development.