Association between parity and bone mineral density in postmenopausal women

Gynoid lean muscle mass as mediator between menarche age, hand grip and bone mineral density in postmenopausal women

Numerous clinical studies indicate that reproductive factors and physical performance levels are significant predictors of bone mineral density (BMD) in postmenopausal women. However, research on the relationship between these factors and body composition remains limited, and the mediating role of body composition in the impact of these factors on BMD remains unclear. This cross-sectional study aims to explore the correlation between reproductive factors, physical performance levels, BMD, and body composition in postmenopausal women, and to further investigate the mediating role of body composition in these relationships. This study enrolled 102 postmenopausal women meeting predetermined criteria from the osteoporosis outpatient clinic of Huzhou Central Hospital, China. Data were collected through surveys, assessments of physical performance function, and dual-energy X-ray absorptiometry (DXA) measurements. Correlation analysis and multiple linear regression analysis were used to determine the relationships among factors. Mediation analysis was conducted to explore the mediating role of body composition, followed by logistic regression analysis to investigate risk factors for osteoporosis. Gynoid Lean Muscle Mass (GLM) emerged as an independent predictive factor for BMD of spine, hip, and total body, and a protective factor against osteoporosis. Hand grip and 6-meter gait speed were positively correlated with BMD at these skeletal sites and GLM, also serving as protective factors against osteoporosis. Conversely, menarche age and Time taken for 5 sit-ups exhibited negative correlations with BMD and GLM, concurrently representing risk factors for osteoporosis. GLM mediated the relationship between menarche age, hand grip, and hip BMD. Prolonged reproductive periods and enhanced physical performance appear beneficial in mitigating Lean Mass loss, particularly GLM, in postmenopausal women, thereby protecting BMD and effectively preventing osteoporosis.

Femoral Fracture in Pregnancy: A Case Report and Review of Data from the Literature

BACKGROUND

Orthopedic trauma during pregnancy is a rare yet complex medical challenge, impacting both maternal and fetal health. Among these, femoral fractures are particularly uncommon but require careful management to minimize maternal and fetal risks.

METHODS

We report the case of a 28-year-old woman, gravida 4, para 3, at 40 weeks of gestation, who sustained a left mid-femoral diaphyseal fracture following a low-energy fall. A multidisciplinary team approach, including obstetric, orthopedic, anesthetic, and neonatal specialists, was employed. Preoperative imaging by X-ray was performed under lead-apron protection. The patient underwent an emergency C-section, followed by closed reduction and internal fixation with an intramedullary nail.

RESULTS

The surgical intervention was successful, with minimal radiation exposure. Postoperative management included thromboprophylaxis, calcium, vitamin D supplementation, and physiotherapy. The patient recovered well, achieving fracture healing within three months. Postpartum bone density assessment was recommended, suspecting pregnancy- and lactation-associated osteoporosis.

CONCLUSIONS

Managing femoral fractures during pregnancy necessitates a balance between maternal and fetal well-being. A collaborative, multidisciplinary approach ensures optimal outcomes. Early surgical intervention, proper radiation precautions, and postpartum bone health assessment are crucial in these cases. Further research is needed to understand risk factors and preventive strategies for pregnancy-associated osteoporosis.

'Bone Health-Across a Woman's Lifespan'

Despite a high burden of osteoporosis and minimal trauma fractures worldwide, there is still a treatment gap in timely diagnosis and optimal treatment. There is also a lack of international consensus and guidelines on the management of bone fragility in premenopausal women. This review article provides an overview of the current understanding of factors impacting women's bone health across the adult lifespan, as well as dilemmas in the diagnosis, assessment and management of osteoporosis in premenopausal and postmenopausal women, premature ovarian insufficiency and bone health following breast cancer.

Association between visceral fat and bone mineral density in perimenopausal women

Background

The effects of visceral fat and body fat on osteoporosis (OP) have long been controversial. This study investigated the correlation between visceral fat and bone mineral density (BMD) in perimenopausal women aged 40-60. The goal was to evaluate the current state of BMD and its influencing factors, with the specific objective of establishing a foundation for preventing and treating osteoporosis in this demographic.

Methods

This case-control study included female participants (n = 330), aged 40-60 years, from the Health Management Center of Guilin Medical College Affiliated Hospital, China, between January 2020 to August 2023. Their BMD was assessed using an ultrasound bone mineral density meter, and the visceral fat area was determined utilizing a body composition analyzer. Furthermore, past medical history, dietary habits, and lifestyle factors were collected through a telephonic questionnaire survey. Additionally, we analyzed the baseline characteristics of the population, bone status and visceral fat status, and the relationship between these variables.

Results

Among perimenopausal women with varying bone mineral density statuses, there was no significant difference regarding body fat percentage (p = 0.359). In contrast, a statistically significant difference was observed regarding visceral fat area (p < 0.001) and vitamin D (p < 0.001). The visceral fat area exhibited an inverse correlation with bone density (r = -0.313, p < 0.001). Additionally, mediation analysis outcomes did not support the hypothesis that visceral fat affects bone density through its influence on vitamin D levels (p = 0.92).

Conclusions

Among perimenopausal women, visceral fat is negatively associated with bone density, suggesting that the distribution of body fat rather than the total amount plays a pivotal role in the development of osteoporosis. These findings suggest the significance of regular physical exercise and the abdominal fat distribution for perimenopausal women.

Potential impact of obstetric history on postmenopausal fragility fracture risk: A reassessment of the Fracture Risk Assessment Tool

OBJECTIVES

This study aimed to evaluate the impact of integrating obstetric parameters into the Fracture Risk Assessment Tool (FRAX) on the precision of risk assessment.

PATIENTS AND METHODS

In this retrospective study, patients who experienced postmenopausal fragility fractures of the distal radius, proximal femur, or lumbar vertebrae between January 1, 2021, and December 31, 2023, were included. Obstetric histories, along with standard FRAX parameters, were obtained by phone interviews. Based on the FRAX major osteoporotic fracture risk score calculated without bone mineral density, patients were classified into high-, intermediate-, and low-risk group categories. Differences in age at menarche, age at menopause, lactation duration, gravidity, and parity were analyzed across risk categories.

RESULTS

A total of 328 patients (mean age: 64.5±5.8 years; range, 55 to 75 years) were included. The mean FRAX score was 16±8.8 (range, 3 to 58), and 85, 191, and 52 patients were classified as high-, intermediate-, and low-risk, respectively. A positive correlation was observed between FRAX scores and both later age at menarche and earlier menopause (p<0.001 and p=0.008, respectively). The mean age at menopause was significantly different between the high- and low-risk groups (46.4 vs. 49.3 years, p=0.016). The intermediate-risk group was also evaluated, showing no significant differences in obstetric parameters compared to the low-risk group (p>0.05).

CONCLUSION

Although late menarche is not explicitly included in FRAX, its association with higher fracture risk was evident. The established influence of early menopause on FRAX scores supports its role in fracture risk estimation. However, the inclusion of additional obstetric parameters did not enhance the predictive accuracy of FRAX in this cohort.

Associations of PFAS concentrations during pregnancy and midlife with bone health in midlife: Cross-sectional and prospective findings from Project Viva

BACKGROUND

PFAS may impair bone health, but effects of PFAS exposure assessed during pregnancy and the perimenopause-life stages marked by rapidly changing bone metabolism-on later life bone health are unknown.

METHODS

We studied 531 women in the Boston-area Project Viva cohort. We used multivariable linear, generalized additive, and mixture models to examine associations of plasma PFAS concentrations during early pregnancy [median (IQR) maternal age 32.9 (6.2) years] and midlife [age 51.2 (6.3)] with lumbar spine, total hip, and femoral neck areal bone mineral density (aBMD) and bone turnover biomarkersassessed in midlife. We examined effect modification by diet and physical activity measured at the time of PFAS exposure assessment and by menopausal status in midlife.

RESULTS

Participants had higher PFAS concentrations during pregnancy [1999-2000; e.g., PFOA median (IQR) 5.4 (3.8) ng/mL] than in midlife [2017-2021; e.g.

, PFOA

1.5 (1.2) ng/mL]. Women with higher PFOA, PFOS and PFNA during pregnancy had higher midlife aBMD, especially of the spine [e.g., 0.28 (95% CI: 0.07, 0.48) higher spine aBMD T-score, per doubling of PFOA], with stronger associations observed among those with higher diet quality. In contrast, higher concentrations of all PFAS measured in midlife were associated with lower concurrent aBMD at all sites [e.g., -0.21 (-0.35, -0.07) lower spine aBMD T-score, per doubling of PFOA]; associations were stronger among those who were postmenopausal. The associations of several PFAS with bone resorption (loss) were also stronger among postmenopausal versus premenopausal women.

DISCUSSION

Plasma PFAS measured during pregnancy versus in midlife had different associations with midlife aBMD. We found an adverse association of PFAS measured in midlife with midlife aBMD, particularly among postmenopausal women. Future studies with longer follow-up are needed to elucidate the effect of PFAS on bone health during the peri- and postmenopausal years.

Electroacupuncture on GB acupoints improves osteoporosis via the estradiol-PI3K-Akt signaling pathway

Recent studies have reported that electroacupuncture (EA) can treat osteoporosis, but most of which were based on the "kidney governing bones" theory. However, the ancient Chinese medical textbook Huangdi Neijing pointed out that "Gallbladder Meridian of Foot Shaoyang" correlates with bone diseases, including osteoporosis, although the therapeutic regimens were lost after the Tang Dynasty. Here, we explored whether EA at GB points improves osteoporosis and its underlying mechanism. We constructed ovariectomized mice and treated them with EA at GB30 (Huantiao), GB34 (Yanglingquan), and GB39 (Xuanzhong) acupoints. EA treatment significantly improved bone parameters in osteoporotic mice, as evidenced by micro-computed tomography and histological assessment. Additionally, EA treatment elevated the serum levels of estradiol and SOD that were downregulated in osteoporotic mice. Transcriptome and qPCR results verified that EA treatment upregulated the expression of genes associated with bone formation. Moreover, transcriptome analysis revealed differential enrichment of the PI3K-Akt pathway. Furthermore, Western blot analysis demonstrated that estradiol partially counteracted a reduction in p-AKT expression induced by hydrogen peroxide. These findings indicate that EA treatment increases serum estradiol levels in mice, thus inhibiting osteoporosis induced by oxidative stress. This effect is achieved by activating the PI3K-Akt signaling pathway.

Nonlinear relationship between cardiometabolic index and bone mineral density in U.S. adults: the mediating role of percent body fat

BACKGROUND

Both lipid metabolism and obesity are crucial factors in osteoporosis, influencing the relevance of the cardiometabolic index (CMI), a new body fat index incorporating obesity and lipid metrics. Our study aims to explore the relationship between CMI and lumbar spine bone mineral density (BMD) and the mediating role of body fat percentage.

METHODS

Utilizing the National Health and Nutrition Examination Survey (NHANES) data from 2011 to 2018, we conducted a cross-sectional analysis. We employed multiple linear regression models, subgroup analyses, generalized additive models (GAM), smooth curve fitting, and mediation analysis to evaluate the linear and nonlinear relationships between CMI and lumbar spine BMD.

RESULTS

The study involved 5,124 participants with an average lumbar spine BMD of 1.03 ± 0.15 g/cm2. We identified a negative correlation between CMI and lumbar spine BMD (β = -0.015; 95% CI: -0.023, -0.008). Nonlinear associations were evident, with inflection points at CMI values of 1.12 and 2.86. Subgroup analyses showed consistent negative correlations across all categories without significant differences (p for interaction > 0.05). Moreover, body fat percentage negatively correlated with BMD (β = -0.005; 95% CI: -0.006, -0.004) and mediated 9.41% of the relationship between CMI and BMD.

CONCLUSION

Increased CMI levels are associated with lower lumbar spine BMD, with body fat percentage significantly mediating this relationship. This underscores the importance of managing body composition in the context of bone health, highlighting CMI's potential utility in osteoporosis risk assessment.

The different association between fat mass distribution and intake of three major nutrients in pre- and postmenopausal women

BACKGROUND

Obesity, characterized by excessive body fat accumulation, is associated with various chronic health conditions. Body fat plays a crucial role in health outcomes, and nutrient intake is a contributing factor. Menopause further influences body fat, but the precise relationships between nutrients and fat mass distribution in pre- and post-menopausal women are unclear.

METHODS

Data from 4751 adult women aged ≥18 years old (3855 pre-menopausal, 896 post-menopausal) with completed information were obtained from the National Health and Examination Survey (NHANES) from 2011 to 2018. Multivariate linear regression models were used to examine the associations between protein, carbohydrate, fat intake and total percent fat (TPF), android percent fat (APF), gynoid percent fat (GPF), android to gynoid ratio (A/G), subcutaneous adipose tissue mass (SAT), visceral adipose tissue mass (VAT). Subgroup analyses, stratified by menopausal status, were also conducted. Additionally, we employed smoothing curve fitting techniques to investigate potential non-linear relationships between fat mass distribution and nutrient intake.

RESULTS

Compared with pre-menopausal women, post-menopausal women had higher body fat, BMI, and metabolic indicators but lower nutrient intake (All p<0.05). In the overall analysis, we found significant correlations between nutrient intake and fat mass. Specifically, protein intake was negatively correlated with TPF (β = -0.017, 95% CI: -0.030, -0.005), APF (β = -0.028, 95% CI: -0.044, -0.012), GPF (β = -0.019, 95% CI: -0.030, -0.008), while fat intake showed positive correlations with these measures (SAT: β = 2.769, 95% CI: 0.860, 4.678). Carbohydrate intake exhibited mixed associations. Notably, body fat mass-nutrient intake correlations differed by menopausal status. Generally speaking, protein intake showed negative correlations with body fat distribution in pre-menopausal women but positive correlations in post-menopausal women. Carbohydrate intake revealed significant negative associations with abdominal and visceral fat in post-menopausal women, while fat intake was consistently positive across all fat distribution indices, especially impacting visceral fat in post-menopausal women.

CONCLUSION

Dietary intake plays a crucial role in body fat distribution, with menopausal status significantly influencing the impact of nutrients on specific fat distribution metrics. The study emphasizes the need for dietary guidelines to consider the nutritional needs and health challenges unique to women at different life stages, particularly concerning menopausal status, to effectively manage obesity.

The Heterogeneity of Post-Menopausal Disease Risk: Could the Basis for Why Only Subsets of Females Are Affected Be Due to a Reversible Epigenetic Modification System Associated with Puberty, Menstrual Cycles, Pregnancy and Lactation, and, Ultimately, Menopause?

For much of human evolution, the average lifespan was <40 years, due in part to disease, infant mortality, predators, food insecurity, and, for females, complications of childbirth. Thus, for much of evolution, many females did not reach the age of menopause (45-50 years of age) and it is mainly in the past several hundred years that the lifespan has been extended to >75 years, primarily due to public health advances, medical interventions, antibiotics, and nutrition. Therefore, the underlying biological mechanisms responsible for disease risk following menopause must have evolved during the complex processes leading to Homo sapiens to serve functions in the pre-menopausal state. Furthermore, as a primary function for the survival of the species is effective reproduction, it is likely that most of the advantages of having such post-menopausal risks relate to reproduction and the ability to address environmental stresses. This opinion/perspective will be discussed in the context of how such post-menopausal risks could enhance reproduction, with improved survival of offspring, and perhaps why such risks are preserved. Not all post-menopausal females exhibit risk for this set of diseases, and those who do develop such diseases do not have all of the conditions. The diseases of the post-menopausal state do not operate as a unified complex, but as independent variables, with the potential for some overlap. The how and why there would be such heterogeneity if the risk factors serve essential functions during the reproductive years is also discussed and the concept of sets of reversible epigenetic changes associated with puberty, pregnancy, and lactation is offered to explain the observations regarding the distribution of post-menopausal conditions and their potential roles in reproduction. While the involvement of an epigenetic system with a dynamic "modification-demodification-remodification" paradigm contributing to disease risk is a hypothesis at this point, validation of it could lead to a better understanding of post-menopausal disease risk in the context of reproduction with commonalities may also lead to future improved interventions to control such risk after menopause.

The impact of diabetes, anemia, and renal function in the relationship between osteoporosis and fasting blood glucose among Taiwanese women: a cross-sectional study

BACKGROUND

The aim of this study was to investigate the association between fasting blood glucose and osteoporosis in women with diabetes, anemia, and renal function.

METHODS

The medical records of women who underwent a general health examination at a regional hospital in southern Taiwan were retrospectively reviewed. Logistic regression analysis was performed to assess the association between osteoporosis and fasting blood glucose separately for the eight subgroups (diabetes or non-diabetes, anemia or non-anemia, normal or decreased renal function), adjusting for other clinical characteristics and laboratory findings.

RESULTS

A total of 11,872 women were included in the study. Among women with diabetes, anemia, and decreased renal function, an increment of 10 mg/dL in fasting blood glucose was associated with an increased risk of osteoporosis (adjusted odds ratio [aOR] = 1.57, p = 0.004). Among women without diabetes, fasting blood glucose was significantly associated with an increased risk of osteoporosis in those with anemia and normal renal function (OR = 1.14, p = 0.023) and those without anemia and normal renal function (OR = 1.04, p = 0.015), but these associations were not significant after adjusting for other covariates.

CONCLUSIONS

Higher fasting blood glucose levels in women with diabetes, anemia, and decreased renal function were associated with an increased risk of osteoporosis. Clinicians should be vigilant about glucose control in patients with diabetes to reduce the risk of fracture.

Mechanistic advances in osteoporosis and anti-osteoporosis therapies

Osteoporosis is a type of bone loss disease characterized by a reduction in bone mass and microarchitectural deterioration of bone tissue. With the intensification of global aging, this disease is now regarded as one of the major public health problems that often leads to unbearable pain, risk of bone fractures, and even death, causing an enormous burden at both the human and socioeconomic layers. Classic anti-osteoporosis pharmacological options include anti-resorptive and anabolic agents, whose ability to improve bone mineral density and resist bone fracture is being gradually confirmed. However, long-term or high-frequency use of these drugs may bring some side effects and adverse reactions. Therefore, an increasing number of studies are devoted to finding new pathogenesis or potential therapeutic targets of osteoporosis, and it is of great importance to comprehensively recognize osteoporosis and develop viable and efficient therapeutic approaches. In this study, we systematically reviewed literatures and clinical evidences to both mechanistically and clinically demonstrate the state-of-art advances in osteoporosis. This work will endow readers with the mechanistical advances and clinical knowledge of osteoporosis and furthermore present the most updated anti-osteoporosis therapies.

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.