Cognitive impairment and risks of osteoporosis: A systematic review and meta-analysis

Association of serum neurofilament light chain and bone mineral density in adults

BACKGROUND

Serum neurofilament light chain (sNFL) is a blood-based marker of neuroaxonal damage increasingly used in neurological research. Although sNFL has been linked to systemic aging and chronic disease, its relationship with bone mineral density (BMD) remains unclear.

METHODS

We analyzed data from 1,344 participants aged ≥ 20 years in the 2013-2014 National Health and Nutrition Examination Survey (NHANES). Serum sNFL concentrations were measured using a high-sensitivity immunoassay. Lumbar BMD was assessed by dual-energy X-ray absorptiometry. Multivariable linear regression models were used to evaluate associations between log-transformed sNFL and BMD, adjusting for demographic, lifestyle, metabolic, renal, cognitive, and bone-related covariates. Sensitivity analyses examined osteoporosis, defined as physician diagnosis or T-score ≤ - 2.5, as a binary outcome.

RESULTS

Higher sNFL levels were significantly associated with lower lumbar BMD (fully adjusted β = - 0.02 g/cm² per 1-unit increase in ln-sNFL; 95% CI: - 0.04, - 0.01; P = 0.0089). Compared with the lowest quartile, participants in the highest quartile had a 0.04 g/cm² lower BMD (P for trend = 0.011). Sensitivity analyses confirmed higher odds of osteoporosis with increasing sNFL levels (Q4 vs. Q1 OR = 2.70, 95% CI: 1.69, 4.31, P < 0.001).

CONCLUSION

Elevated serum sNFL concentrations are independently associated with lower lumbar spine BMD in U.S. adults. These findings suggest that sNFL may serve as an exploratory marker of systemic vulnerability relevant to bone health, warranting further longitudinal and mechanistic investigation.

Association between multimorbidity and the risk of dementia: A systematic review and meta-analysis

BACKGROUND

Multimorbidity has become increasingly prevalent and poses challenges in managing cognitive function. This study aimed to (1) systematically review and perform a meta-analysis to understand the relationship between multimorbidity and the risk of dementia and (2) examine the impact of different multimorbidity patterns on this relationship.

METHOD

A systematic review was conducted using PubMed, Embase, PsychINFO, CINAHL, and Cochrane Central to gather studies published up to December 16, 2023. For the meta-analysis, studies with consistent study designs, multimorbidity definitions, and stages of dementia were included. Heterogeneity was assessed using the I2 statistic, and Egger's and Begg's tests were used to evaluate publication bias.

RESULTS

Of the 12,074 studies identified, 11 were deemed suitable for systematic review, and eight were included in the meta-analysis. Meta-analysis of the longitudinal studies revealed that baseline multimorbidity was significantly associated with an increased risk of dementia compared with individuals without multimorbidity (HR: 1.34, 95 % CI: 1.08-1.68). Meta-analysis of the cross-sectional studies indicated that multimorbidity was significantly associated with a higher risk of being in the prodromal stages of dementia than in individuals without multimorbidity (OR: 1.32, 95 % CI: 1.16-1.51). The risk of dementia varied according to diverse multimorbidity patterns, and the cardiovascular-metabolic condition-related patterns were the most common and associated with high dementia risk.

CONCLUSIONS

Our findings provide quantitative evidence of a significant association between multimorbidity and the risk of dementia. To develop effective dementia prevention strategies, an in-depth understanding of specific multimorbidity patterns is invaluable for managing cognitive function.

The potential link between the development of Alzheimer's disease and osteoporosis

Alzheimer's disease (AD) and osteoporosis (OP) pose distinct but interconnected health challenges, both significantly impacting the aging population. AD, a neurodegenerative disorder characterized by memory impairment and cognitive decline, is primarily associated with the accumulation of abnormally folded amyloid beta (Aβ) peptides and neurofibrillary tangles in the brain. OP, a skeletal disorder marked by low bone mineral density, involves dysregulation of bone remodeling and is associated with an increased risk of fractures. Recent studies have revealed an intriguing link between AD and OP, highlighting shared pathological features indicative of common regulatory pathophysiological pathways. In this article, we elucidate the signaling mechanisms that regulate the pathology of AD and OP and offer insights into the intricate network of factors contributing to these conditions. We also examine the role of bone-derived factors in the progression of AD, underscoring the plausibility of bidirectional communication between the brain and the skeletal system. The presence of amyloid plaques in the brain of individuals with AD is akin to the accumulation of brain Aβ in vascular dementia, pointing towards the need for further investigation of shared molecular mechanisms. Moreover, we discuss the role of bone-derived microRNAs that may regulate the pathological progression of AD, providing a novel perspective on the role of skeletal factors in neurodegenerative diseases. The insights presented here should help researchers engaged in exploring innovative therapeutic approaches targeting both neurodegenerative and skeletal disorders in aging populations.

Unraveling the impact of blood RANKL and OPG levels on Alzheimer's disease: Independent of bone mineral density and inflammation

INTRODUCTION

Observational studies have revealed a close relationship between reduced bone mineral density (BMD) and Alzheimer's disease (AD) risk. The receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) system, pivotal in regulating bone metabolism, has been implicated in brain function, but the causal impact on AD risk remains unclear.

METHODS

We employed bi-directional Mendelian randomization (MR) and multivariable MR (MVMR) approaches to elucidate the effect of blood soluble RANKL (sRANKL) and OPG levels on AD, assessing whether this influence was independent of BMD and inflammation. Three distinct AD genome-wide association study (GWAS) data sets from the International Genomics of Alzheimer's Project (IGAP), UK Biobank (UKB), and FinnGen were utilized. Summary-level data on blood sRANKL and OPG were sourced from deCODE Genetics.

RESULTS

Genetically predicted per standard deviation (SD) increase in blood sRANKL levels was significantly associated with a reduced risk of AD across all three AD GWAS data sets (IGAP: odds ratio [OR] = 0.82, 95% confidence interval [CI] = 0.72-0.94, p = 0.004; UKB: OR = 0.85, 95% CI = 0.78-0.91, p < 0.001; FinnGen: OR = 0.83, 95% CI = 0.73-0.94, p = 0.004). No significant causal relationship was observed between OPG levels and AD. In addition, there was no causal impact of AD on the blood levels of sRANKL and OPG. MVMR results showed that the inverse association between sRANKL and AD risk persisted after adjusting for BMD and interleukin-1α and chemoattractant protein-1.

DISCUSSION

Our study provides evidence that elevated sRANKL levels are causally linked to a reduced risk of AD, independent of BMD and inflammation. These findings enhance our understanding of the complex interactions between bone metabolism and AD.

Highlights

Blood soluble receptor activator of nuclear factor kappa-B ligand (sRANKL) levels are linked to a reduced risk of Alzheimer's disease (AD).The association between sRANKL levels and AD is independent of bone mineral density (BMD) and inflammation.No causal link exists between blood osteoprotegerin levels and AD.AD does not affect blood levels of sRANKL or osteoprotegerin.

Diet and Nutraceuticals for treatment and prevention of primary and secondary stroke: Emphasis on nutritional antiplatelet and antithrombotic agents

Ischemic stroke is a devastating disease that causes morbidity and mortality. Malnutrition following ischemic stroke is common in stroke patients. During the rehabilitation, the death rates of stroke patients are significantly increased due to malnutrition. Nutritional supplements such as protein, vitamins, fish, fish oils, moderate wine or alcohol consumption, nuts, minerals, herbal products, food colorants, marine products, fiber, probiotics and Mediterranean diets have improved neurological functions in stroke patients as well as their quality of life. Platelets and their mediators contribute to the development of clots leading to stroke. Ischemic stroke patients are treated with thrombolytics, antiplatelets, and antithrombotic agents. Several systematic reviews, meta-analyses, and clinical trials recommended that consumption of these nutrients and diets mitigated the vascular, peripheral, and central complications associated with ischemic stroke (Fig. 2). Particularly, these nutraceuticals mitigated the platelet adhesion, activation, and aggregation that intended to reduce the risks of primary and secondary stroke. Although these nutraceuticals mitigate platelet dysfunction, there is a greater risk of bleeding if consumed excessively. Moreover, malnutrition must be evaluated and adequate amounts of nutrients must be provided to stroke patients during intensive care units and rehabilitation periods. In this review, we have summarized the importance of diet and nutraceuticals in ameliorating neurological complications and platelet dysfunction with an emphasis on primary and secondary prevention of ischemic stroke.

Clinical characteristics and risk factors of osteoporosis among older Asian men with type-2 diabetes mellitus, hypertension, or hyperlipidaemia

This study investigated osteoporosis risk factors among older Asian men with type-2 diabetes mellitus, hypertension, or hyperlipidaemia in primary care. Advanced age, dementia, depression, and polypharmacy were associated with higher risks for osteoporosis. Screening strategies targeting these factors are crucial for improving bone health as part of comprehensive preventive care.

PURPOSE

Asian patients with type-2 diabetes mellitus (T2DM), hypertension, or hyperlipidaemia (DHL) are predominantly managed in primary care. They are also at risk of osteoporosis, but men are often under-screened and under-treated for this preventable bone disorder. This study aimed to identify the clinical characteristics and risk factors of osteoporosis among older men with DHL in primary care for early intervention.

METHODS

This retrospective study included men aged 65 years and older managed in public primary care clinics for their DHL between 1st July 2017 and 30th June 2018. Demographic, clinical, laboratory, and imaging data were extracted from their electronic medical records based on their International Classification of Diseases-10 (ICD-10) diagnosis codes. Descriptive statistical analyses, with statistical significance set at p < 0.05, were conducted, followed by generalized estimating equation (GEE) modelling.

RESULTS

Medical records of 17,644 men (83.1% Chinese, 16.9% minority ethnic groups, median age 71 years) were analysed. 2.3% of them had diagnosis of osteoporosis, 0.15% had fragility fracture, and 26.0% of those diagnosed with osteoporosis were treated with bisphosphonates. Their mean HbA1c was 6.9%; mean systolic and diastolic blood pressure were 133 and 69 mmHg. The GEE model showed that age (OR = 1.07, 95%CI = 1.05-1.09, p < 0.001), dementia (OR = 2.24, 95%CI = 1.33-3.77, p = 0.002), depression (OR = 2.38, 95%CI = 1.03-5.50, p = 0.043), and polypharmacy (OR = 6.85, 95%CI = 3.07-15.26, p < 0.001) were significantly associated with higher risks for osteoporosis.

CONCLUSION

Age, dementia, depression, and polypharmacy are associated with osteoporosis risks in men with DHL. Strategies to incorporate osteoporosis screening among older men with these risk factors are needed to improve their bone health.

Body Composition and Alzheimer's Disease: A Holistic Review

Alzheimer's disease (AD) represents a significant global health challenge and affects approximately 50 million people worldwide. This overview of published reviews provides a comprehensive understanding of the intricate correlations between AD and body composition, focusing particularly on obesity. We used a systematic approach to collect and analyze relevant reviews on the topic of obesity and Alzheimer's disease. A comprehensive search of electronic databases, including PubMed, MEDLINE, and Google Scholar, was conducted. We searched keywords such as "Alzheimer's disease", "body composition", "lean mass", "bone mass", and "fat mass". We considered only reviews written within the past 5 years and in English. Fifty-six relevant reviews were identified that shed light on the multiple connections between AD and body composition. The review involves several aspects, including the impact of lean mass, bone mass, and endocrinological factors related to obesity, as well as inflammation, neuroinflammation, and molecular/genetic factors. The findings highlight the complex interplay of these elements in the development of AD, underscoring the need for holistic approaches to reduce the risk of AD and to explore innovative strategies for diagnosis, prevention, and treatment.

Roles of osteocalcin in the central nervous system

BACKGROUND

Bone-derived protein osteocalcin, which has beneficial effects on brain function, may be a future research direction for neurological disorders. A growing body of evidence suggests a link between osteocalcin and neurological disorders, but the exact relationship is contradictory and unclear.

SCOPE OF REVIEW

The aim of this review is to summarize the current research on the interaction between osteocalcin and the central nervous system and to propose some speculative future research directions.

MAJOR CONCLUSIONS

In the normal central nervous system, osteocalcin is involved in neuronal structure, neuroprotection, and the regulation of cognition and anxiety. Studies on osteocalcin-related abnormalities in the central nervous system are divided into animal model studies and human studies, depending on the subject. In humans, the link between osteocalcin and brain function is inconsistent. These conflicting data may be due to methodological inconsistencies. By reviewing the related literature on osteocalcin, some comorbidities of the bone and nervous system and future research directions related to osteocalcin are proposed.

Crosstalk between bone and brain in Alzheimer's disease: Mechanisms, applications, and perspectives

Alzheimer's disease (AD) is a neurodegenerative disease that involves multiple systems in the body. Numerous recent studies have revealed bidirectional crosstalk between the brain and bone, but the interaction between bone and brain in AD remains unclear. In this review, we summarize human studies of the association between bone and brain and provide an overview of their interactions and the underlying mechanisms in AD. We review the effects of AD on bone from the aspects of AD pathogenic proteins, AD risk genes, neurohormones, neuropeptides, neurotransmitters, brain-derived extracellular vesicles (EVs), and the autonomic nervous system. Correspondingly, we elucidate the underlying mechanisms of the involvement of bone in the pathogenesis of AD, including bone-derived hormones, bone marrow-derived cells, bone-derived EVs, and inflammation. On the basis of the crosstalk between bone and the brain, we propose potential strategies for the management of AD with the hope of offering novel perspectives on its prevention and treatment. HIGHLIGHTS: The pathogenesis of AD, along with its consequent changes in the brain, may involve disturbing bone homeostasis. Degenerative bone disorders may influence the progression of AD through a series of pathophysiological mechanisms. Therefore, relevant bone intervention strategies may be beneficial for the comprehensive management of AD.

Changes in Rehmanniae Radix processing and their impact on ovarian hypofunction: potential mechanisms of action

Objective

This study evaluates the research developments concerning Rehmanniae Radix in ovarian hypofunction diseases. It explores the processing methods of Rehmanniae Radix, the variations in its compounds before and after processing, the mechanism of Rehmanniae Radix and its active compounds in improving ovarian function, and the advancements in clinical applications of traditional Chinese medicine (TCM) compound that include Rehmanniae Radix.

Methods

Comprehensive literature search was conducted using databases such as China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database, National Science and Technology Library, the Pharmacopoeia of the People's Republic of China, Pubmed, and the Web of Science Database. The search utilized the following Medical Subject Headings (MeSH) and keywords: "Rehmanniae Radix," "Drying Rehmannia Root," "Rehmannia glutinosa," "Rehmanniae Radix Praeparata," "Traditional Chinese Medicine Processing," "Pharmacological Effects," "Ovarian Aging," "Diminished ovarian reserve," "Premature ovarian insufficiency," "Premature Ovarian Failure," "Ovarian hypofunction diseases".

Results

The ancient Chinese medical books document various processing techniques for Rehmanniae Radix. Contemporary research has identified changes in its compounds processing and the resultant diverse therapeutic effects. When processed into Rehmanniae Radix Praeparata, it is noted for its ability to invigorate the kidney. TCM compound containing Rehmanniae Radix is frequently used to treat ovarian hypofunction diseases, demonstrating significant clinical effectiveness. The key changes in its compounds processing include cyclic dilute ether terpene glycosides, phenylethanol glycosides, sugars, and 5-hydroxymethylfurfural. Its pharmacological action is primarily linked to the improvement of granulosa cell proliferation, antioxidative and anti-aging properties, and modulation of the immune and inflammatory microenvironment. Furthermore, Rehmanniae Radix also offers therapeutic benefits for cardiovascular and cerebrovascular diseases, osteoporosis and cognitive dysfunction caused by low estrogen levels. Thereby Rehmanniae Radix mitigates both the short-term and long-term health risks associated with ovarian hypofunction diseases.

Conclusion

Processed Rehmanniae Radix has shown potential to improve ovarian function, and its compound prescriptions have a definite effect on ovarian dysfunction diseases. Therefore Rehmanniae Radix was garnering interest for both basic and clinical research, with promising application prospects as a future therapeutic agent for ovarian hypofunction diseases. However, further studies on its toxicology and the design of standardized clinical trials are necessary to fully establish its efficacy and safety.

Correlation between hearing loss and mild cognitive impairment in the elderly population: Mendelian randomization and cross-sectional study

Background

Hearing loss and tinnitus have been linked to mild cognitive impairment (MCI); however, the evidence is constrained by ethical and temporal constraints, and few prospective studies have definitively established causation. This study aims to utilize Mendelian randomization (MR) and cross-sectional studies to validate and analyze this association.

Methods

This study employs a two-step approach. Initially, the genetic data of the European population from the Genome-wide association studies (GWAS) database is utilized to establish the causal relationship between hearing loss and cognitive impairment through Mendelian randomization using the inverse variance weighted (IVW) method. This is achieved by identifying strongly correlated single nucleotide polymorphisms (SNPs), eliminating linkage disequilibrium, and excluding weak instrumental variables. In the second step, 363 elderly individuals from 10 communities in Qingdao, China are assessed and examined using methods questionnaire survey and pure tone audiology (PTA). Logistic regression and multiple linear regression were used to analyze the risk factors of MCI in the elderly and to calculate the cutoff values.

Results

Mendelian randomization studies have shown that hearing loss is a risk factor for MCI in European populations, with a risk ratio of hearing loss to MCI loss of 1. 23. The findings of this cross-sectional study indicate that age, tinnitus, and hearing loss emerged as significant risk factors for MCI in univariate logistic regression analysis. Furthermore, multivariate logistic regression analysis identified hearing loss and tinnitus as potential risk factors for MCI. Consistent results were observed in multiple linear regression analysis, revealing that hearing loss and age significantly influenced the development of MCI. Additionally, a notable finding was that the likelihood of MCI occurrence increased by 9% when the hearing threshold exceeded 20 decibels.

Conclusion

This study provides evidence from genomic and epidemiological investigations indicating that hearing loss may serve as a risk factor for cognitive impairment. While our epidemiological study has found both hearing loss and tinnitus as potential risk factors for cognitive decline, additional research is required to establish a causal relationship, particularly given that tinnitus can manifest as a symptom of various underlying medical conditions.

Investigation of causal relationships between cortical structure and osteoporosis using two-sample Mendelian randomization

The mutual interaction between bone characteristics and brain had been reported previously, yet whether the cortical structure has any relevance to osteoporosis is questionable. Therefore, we applied a two-sample bidirectional Mendelian randomization analysis to investigate this relationship. We utilized the bone mineral density measurements of femoral neck (n = 32,735) and lumbar spine (n = 28,498) and data on osteoporosis (7300 cases and 358,014 controls). The global surficial area and thickness and 34 specific functional regions of 51,665 patients were screened by magnetic resonance imaging. For the primary estimate, we utilized the inverse-variance weighted method. The Mendelian randomization-Egger intercept test, MR-PRESSO, Cochran's Q test, and "leave-one-out" sensitivity analysis were conducted to assess heterogeneity and pleiotropy. We observed suggestive associations between decreased thickness in the precentral region (OR = 0.034, P = 0.003) and increased chance of having osteoporosis. The results also revealed suggestive causality of decreased bone mineral density in femoral neck to declined total cortical surface area (β = 1400.230 mm2, P = 0.003), as well as the vulnerability to osteoporosis and reduced thickness in the Parstriangularis region (β = -0.006 mm, P = 0.002). Our study supports that the brain and skeleton exhibit bidirectional crosstalk, indicating the presence of a mutual brain-bone interaction.

Dementia, osteoporosis and fragility fractures: Intricate epidemiological relationships, plausible biological connections, and twisted clinical practices

Dementia, osteoporosis, and fragility fractures are chronic diseases, often co-existing in older adults. These conditions pose severe morbidity, long-term disability, and mortality, with relevant socioeconomic implications. While in the research arena, the discussion remains on whether dementia is the cause or the consequence of fragility fractures, healthcare professionals need a better understanding of the interplay between such conditions from epidemiological and physiological standpoints. With this review, we summarized the available literature surrounding the relationship between cognitive impairment, dementia, and both low bone mineral density (BMD) and fragility fractures. Given the strength of the bi-directional associations and their impact on the quality of life, we shed light on the biological connections between brain and bone systems, presenting the main mediators, including gut microbioma, and pathological pathways leading to the dysregulation of bone and brain metabolism. Ultimately, we synthesized the evidence about the impact of available pharmacological treatments for the prevention of fragility fractures on cognitive functions and individuals' outcomes when dementia coexists. Vice versa, the effects of symptomatic treatments for dementia on the risk of falls and fragility fractures are explored. Combining evidence alongside clinical practice, we discuss challenges and opportunities related to the management of older adults affected by cognitive impairment or dementia and at high risk for fragility fracture prevention, which leads to not only an improvement in patient health-related outcomes and survival but also a reduction in healthcare cost and socio-economic burden.

Increased risk of osteoporosis in patients with cognitive impairment: a systematic review and meta-analysis

BACKGROUND

Both osteoporosis and cognitive impairment affect overall health in elderly individuals. This study aimed to investigate the association between cognitive impairment and the risk of osteoporosis.

METHODS

PubMed, Web of Science, and the Cochrane Library were searched for studies on the association between osteoporosis and cognitive impairment from their inception until August 2023. The random-effects model was used to calculate the pooled risk ratio (RR) of osteoporosis in patients with cognitive impairment. Subgroup analysis was used to detect the sources of heterogeneity. Sensitivity analysis was used to test the robustness of the pooled results. Funnel plots, Egger's test, and Begg's test were used to test publication bias.

RESULTS

Ten studies involving 9,872 patients were included in this meta-analysis. The pooled results showed that patients with cognitive impairment had an increased risk of osteoporosis (RR = 1.56, 95% confidence interval [CI]: 1.30-1.87, p < 0.001). Subgroup analysis showed that patients with Alzheimer's disease (AD) are at 1.7-fold risk of osteoporosis compared with the control group (RR = 1.70, 95% CI: 1.23-2.37, p = 0.001), and sex, cognitive classification, study region, study design, and study quality might be the sources of heterogeneity. Sensitivity analysis showed robustness of the pooled results. No significant publication bias was found (Begg's test, p = 0.474; Egger's test, p = 0.065).

CONCLUSION

Current evidence suggests that patients with cognitive impairment are at increased risk of osteoporosis, especially patients with AD.

Neuropsychiatric adverse reactions in patients treated with denosumab: two case reports and a review of data from the FDA Adverse Event Reporting System (FAERS)

Denosumab is a human monoclonal antibody indicated for patients with osteoporosis and a high risk of fractures. It targets RANKL, the receptor activator of NF-κB (RANK) ligand, blocking RANKL-RANK interaction and leading to rapid osteoclast-mediated bone resorption inhibition. But RANK is widely expressed in neurons, microglia, and astrocytes. RANKL/RANK/NF-κB system can play an important role in the neuroinflammatory response, depressive behavior, memory impairments, and neurotrophism. We present two well-documented case reports of recurrent neuropsychiatric manifestations in patients treated with denosumab and a descriptive review of similar cases reported to the Food and Drug Administration Adverse Event Reporting System (FAERS) database between 2012 and 2022. Only those reported by healthcare professionals, coding denosumab as the only suspected drug, were retained. An 81-year-old woman with pre-existing mild cognitive impairment suffered two acute confusional episodes and another 81-year-old woman with depression in remission suffered two depressive recurrences with anxiety and psychomotor inhibition, in both cases following sequential administrations of denosumab without underlying calcium/phosphate imbalance. Scores on Naranjo Adverse Drug Reaction Probability Scale were 6 and 7, respectively, suggesting a probable causal relationship. Of the 91,151 cases with denosumab exposure reported to FAERS, 5.7% were related to psychiatric/neurological disorders and 23.8% of these corresponded to cognitive impairment, depressive/mood disturbances, or psychomotor retardation. Denosumab may cause transient but severe neuropsychiatric symptoms by several mechanisms involving RANKL blockade and subsequent immuno-inflammatory changes, at least in subjects with pre-existing neurobiological vulnerability. We recommend caution and careful monitoring of these patients following denosumab administrations.

Effects of Donepezil on the Musculoskeletal System in Female Rats

The extension of human life makes it more and more important to prevent and treat diseases of the elderly, including Alzheimer's disease (AD) and osteoporosis. Little is known about the effects of drugs used in the treatment of AD on the musculoskeletal system. The aim of the present study was to investigate the effects of donepezil, an acetylcholinesterase inhibitor, on the musculoskeletal system in rats with normal and reduced estrogen levels. The study was carried out on four groups of mature female rats: non-ovariectomized (NOVX) control rats, NOVX rats treated with donepezil, ovariectomized (OVX) control rats and OVX rats treated with donepezil. Donepezil (1 mg/kg p.o.) was administered for four weeks, starting one week after the ovariectomy. The serum concentrations of CTX-I, osteocalcin and other biochemical parameters, bone mass, density, mineralization, histomorphometric parameters and mechanical properties, and skeletal muscle mass and strength were examined. Estrogen deficiency increased bone resorption and formation and worsened cancellous bone mechanical properties and histomorphometric parameters. In NOVX rats, donepezil decreased bone volume to tissue volume ratio in the distal femoral metaphysis, increased the serum phosphorus concentration and tended to decrease skeletal muscle strength. No significant bone effects of donepezil were observed in OVX rats. The results of the present study indicate slightly unfavorable effects of donepezil on the musculoskeletal system in rats with normal estrogen levels.