Association between bone mineral density and cognitive decline in older women

From the Mind to the Spine: The Intersecting World of Alzheimer's and Osteoporosis

PURPOSE OF REVIEW

This comprehensive review delves into the intricate interplay between Alzheimer's disease (AD) and osteoporosis, two prevalent conditions with significant implications for individuals' quality of life. The purpose is to explore their bidirectional association, underpinned by common pathological processes such as aging, genetic factors, inflammation, and estrogen deficiency.

RECENT FINDINGS

Recent advances have shown promise in treating both Alzheimer's disease (AD) and osteoporosis by targeting disease-specific proteins and bone metabolism regulators. Monoclonal antibodies against beta-amyloid and tau for AD, as well as RANKL and sclerostin for osteoporosis, have displayed therapeutic potential. Additionally, ongoing research has identified neuroinflammatory genes shared between AD and osteoporosis, offering insight into the interconnected inflammatory mechanisms. This knowledge opens avenues for innovative dual-purpose therapies that could address both conditions, potentially revolutionizing treatment approaches for AD and osteoporosis simultaneously. This review underscores the potential for groundbreaking advancements in early diagnosis and treatment by unraveling the intricate connection between AD and bone health. It advocates for a holistic, patient-centered approach to medical care that considers both cognitive and bone health, ultimately aiming to enhance the overall well-being of individuals affected by these conditions. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.

Mind Gaps and Bone Snaps: Exploring the Connection Between Alzheimer's Disease and Osteoporosis

PURPOSE OF REVIEW

This comprehensive review discusses the complex relationship between Alzheimer's disease (AD) and osteoporosis, two conditions that are prevalent in the aging population and result in adverse complications on quality of life. The purpose of this review is to succinctly elucidate the many commonalities between the two conditions, including shared pathways, inflammatory and oxidative mechanisms, and hormonal deficiencies.

RECENT FINDINGS

AD and osteoporosis share many aspects of their respective disease-defining pathophysiology. These commonalities include amyloid beta deposition, the Wnt/β-catenin signaling pathway, and estrogen deficiency. The shared mechanisms and risk factors associated with AD and osteoporosis result in a large percentage of patients that develop both diseases. Previous literature has established that the progression of AD increases the risk of sustaining a fracture. Recent findings demonstrate that the reverse may also be true, suggesting that a fracture early in the life course can predispose one to developing AD due to the activation of these shared mechanisms. The discovery of these commonalities further guides the development of novel therapeutics in which both conditions are targeted. This detailed review delves into the commonalities between AD and osteoporosis to uncover the shared players that bring these two seemingly unrelated conditions together. The discussion throughout this review ultimately posits that the occurrence of fractures and the mechanism behind fracture healing can predispose one to developing AD later on in life, similar to how AD patients are at an increased risk of developing fractures. By focusing on the shared mechanisms between AD and osteoporosis, one can better understand the conditions individually and as a unit, thus informing therapeutic approaches and further research. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.

Bone mineral density and the risk of incident dementia: A meta-analysis

BACKGROUND

It is not known whether bone mineral density (BMD) measured at baseline or as the rate of decline prior to baseline (prior bone loss) is a stronger predictor of incident dementia or Alzheimer's disease (AD).

METHODS

We performed a meta-analysis of three longitudinal studies, the Framingham Heart Study (FHS), the Rotterdam Study (RS), and the Rush Memory and Aging Project (MAP), modeling the time to diagnosis of dementia as a function of BMD measures accounting for covariates. We included individuals with one or two BMD assessments, aged ≥60 years, and free of dementia at baseline with follow-up available. BMD was measured at the hip femoral neck using dual-energy X-ray absorptiometry (DXA), or at the heel calcaneus using quantitative ultrasound to calculate estimated BMD (eBMD). BMD at study baseline ("baseline BMD") and annualized percentage change in BMD prior to baseline ("prior bone loss") were included as continuous measures. The primary outcome was incident dementia diagnosis within 10 years of baseline, and incident AD was a secondary outcome. Baseline covariates included age, sex, body mass index, ApoE4 genotype, and education.

RESULTS

The combined sample size across all three studies was 4431 with 606 incident dementia diagnoses, 498 of which were AD. A meta-analysis of baseline BMD across three studies showed higher BMD to have a significant protective association with incident dementia with a hazard ratio of 0.47 (95% CI: 0.23-0.96; p = 0.038) per increase in g/cm2 , or 0.91 (95% CI: 0.84-0.995) per standard deviation increase. We observed a significant association between prior bone loss and incident dementia with a hazard ratio of 1.30 (95% CI: 1.12-1.51; p < 0.001) per percent increase in prior bone loss only in the FHS cohort.

CONCLUSIONS

Baseline BMD but not prior bone loss was associated with incident dementia in a meta-analysis across three studies.

Total shoulder arthroplasty in patients with dementia or mild cognitive impairment

Background

Anatomic total shoulder arthroplasty (ATSA) and reverse total shoulder arthroplasty (RTSA) reliably alleviate pain and restore shoulder function for a variety of indications. However, these procedures are not well-studied in patients with neurocognitive impairment. Therefore, the purpose of this study was to investigate whether patients with dementia or mild cognitive impairment (MCI) have increased odds of surgical or medical complications following arthroplasty.

Methods

The PearlDiver database was queried from 2010 through October 2021 to identify a cohort of patients who underwent either ATSA or RTSA and had a minimum 2-year follow-up. Current Procedural Terminology and International Classification of Diseases codes were used to stratify this cohort into three groups: (1) patients with dementia, (2) patients with MCI, and (3) patients with neither condition. Surgical and medical complication rates were compared among these three groups.

Results

The overall prevalence of neurocognitive impairment among patients undergoing total shoulder arthroplasty was 3.0% in a cohort of 92,022 patients. Patients with dementia had increased odds of sustaining a periprosthetic humerus fracture (odds ratio [OR] = 1.46, P < .001), developing prosthesis instability (OR = 1.72, P < .001), and undergoing revision arthroplasty (OR = 1.55, P = .003) after RTSA compared to patients with normal cognition. ATSA patients with dementia did not have an elevated risk of surgical complications or revision. Conversely, RTSA patients with MCI did not have an elevated risk of complications or revision, although ATSA patients with MCI had greater odds of prosthesis instability (OR = 2.51, P = .008). Additionally, patients with neurocognitive impairment had elevated odds of medical complications compared to patients with normal cognition, including acute myocardial infarction and cerebrovascular accident.

Conclusion

Compared to patients with normal cognition, RTSA patients with preoperative dementia and ATSA patients with preoperative MCI are at increased risk for surgical complications. Moreover, both ATSA and RTSA patients with either preoperative MCI or dementia are at increased risk for medical complications. As the mean age in the U.S. continues to rise, special attention should be directed towards patients with neurocognitive impairment to minimize postoperative complications aftertotal shoulder arthroplasty, and the risks of this surgery more carefully discussed with patients and their families and caretakers.

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.

Positive associations between sex hormones, bone metabolism and cognitive impairment in Chinese oldest-old females

PURPOSE

With a rapid increase in older adults, progressive impairment in cognitive function has become an increasing concern owing to high social and economic burdens. The current study was designed to investigate the associations of sex hormones and bone metabolism with cognitive impairment (CI) in Chinese oldest-old females.

METHODS

There were 396 oldest-old females from the China Hainan Oldest-old Cohort Study (CHOCS). Following standardized procedures, Mini Mental State Examination was effectively completed, and sex hormones and bone metabolism were assessed in these females.

RESULTS

The median age of all females was 101 years (range: from 80 to 116). There were 340 females (86%) with CI. Participants with CI had significantly higher levels of age, progesterone, prolactin and estradiol than those without CI (P < 0.05 for all). Total type I collagen N-terminal elongation peptide [hazard ratio (HR): 1.018, 95%CI: 1.001-1.035] and prolactin (HR: 1.065, 95%CI: 1.005-1.129) levels were positively and significantly associated with CI (P < 0.05 for all).

CONCLUSIONS

Prolactin and total type I collagen N-terminal elongation peptide had positive associations with CI in Chinese oldest-old females. Thus, a balance in sex hormones and bone metabolism may have significant effects on cognitive function during the aging process.

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

OBJECTIVE

To systematically assess the association between osteoporosis and cognitive impairment, and to provide new light on the prevention of cognitive impairment in patients with osteoporosis.

METHOD

A comprehensive research of Embase, Cochrane Library, PubMed, Web of Science, CNKI, Wangfang Data and VIP was performed from inception to January 2022, using the search term 'osteoporosis' and 'cognitive impairment'. Literature screening, data extraction and quality evaluation were conducted by two reviewers independently, and meta-analysis was performed by RevMan 5.4 software.

RESULTS

A total of 8 studies (136222 participants) were included. Meta-analysis showed that patients with osteoporosis had an increased risk of cognitive impairment [OR=2.01, 95% CI(1.63-2.48), P<0.01]. This initial meta-analysis had significant heterogeneity, and subgroup analysis suggested that potential heterogeneity in different study types, age and outcome indicators.

CONCLUSION

Patients with osteoporosis are at increased risk of cognitive impairment, and osteoporosis intervention could prevent or delay the onset of cognitive impairment for those at risk.

Degradation of Bone Quality in a Transgenic Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) patients present with symptoms such as impairment of insulin signaling, chronic inflammation, and oxidative stress. Furthermore, there are comorbidities associated with AD progression. For example, osteoporosis is common with AD wherein patients exhibit reduced mineralization and a risk for fragility fractures. However, there is a lack of understanding on the effects of AD on bone beyond loss of bone density. To this end, we investigated the effects of AD on bone quality using the 5XFAD transgenic mouse model in which 12-month-old 5XFAD mice showed accumulation of amyloid-beta (Aβ42) compared with wild-type (WT) littermates (n = 10/group; 50% female, 50% male). Here, we observed changes in cortical bone but not in cancellous bone quality. Both bone mass and bone quality, measured in femoral samples using imaging (micro-CT, confocal Raman spectroscopy, X-ray diffraction [XRD]), mechanical (fracture tests), and chemical analyses (biochemical assays), were altered in the 5XFAD mice compared with WT. Micro-CT results showed 5XFAD mice had lower volumetric bone mineral density (BMD) and increased endocortical bone loss. XRD results showed decreased mineralization with smaller mineral crystals. Bone matrix compositional properties, from Raman, showed decreased crystallinity along with higher accumulation of glycoxidation products and glycation products, measured biochemically. 5XFAD mice also demonstrated loss of initiation and maximum toughness. We observed that carboxymethyl-lysine (CML) and mineralization correlated with initiation toughness, whereas crystal size and pentosidine (PEN) correlated with maximum toughness, suggesting bone matrix changes predominated by advanced glycation end products (AGEs) and altered/poor mineral quality explained loss of fracture toughness. Our findings highlight two pathways to skeletal fragility in AD through alteration of bone quality: (i) accumulation of AGEs; and (ii) loss of crystallinity, decreased crystal size, and loss of mineralization. We observed that the accumulation of amyloidosis in brain correlated with an increase in several AGEs, consistent with a mechanistic link between elevated Aβ42 levels in the brain and AGE accumulation in bone. © 2022 American Society for Bone and Mineral Research (ASBMR).

Osteoporosis is associated with elevated baseline cerebrospinal fluid biomarkers and accelerated brain structural atrophy among older people

Objective

The aim of this study was to examine whether osteoporosis (OP) is associated with Alzheimer’s disease-related cerebrospinal fluid (CSF) biomarkers and brain structures among older people.

Methods

From the Alzheimer’s disease Neuroimaging Initiative database, we grouped participants according to the OP status (OP+/OP−) and compared the Alzheimer’s disease (AD)-related CSF biomarker levels and the regional brain structural volumes between the two groups using multivariable models. These models were adjusted for covariates including age, education, gender, diagnosis of Alzheimer’s disease, and apolipoprotein E4 carrier status.

Results

In the cross-sectional analyses at baseline, OP was related to higher CSF t-tau (total tau) and p-tau₁₈₁ (tau phosphorylated at threonine-181) but not to CSF amyloid-beta (1–42) or the volumes of entorhinal cortex and hippocampus. In the longitudinal analyses, OP was not associated with the change in the three CSF biomarkers over time but was linked to a faster decline in the size of the entorhinal cortex and hippocampus.

Conclusion

OP was associated with elevated levels of CSF t-tau and p-tau₁₈₁ at baseline, and accelerated entorhinal cortex and hippocampal atrophies over time among older people.

Comorbidity of osteoporosis and Alzheimer's disease: Is `AKT `-ing on cellular glucose uptake the missing link?

Osteoporosis and Alzheimer's disease (AD) are both degenerative diseases. Osteoporosis often proceeds cognitive deficits, and multiple studies have revealed common triggers that lead to energy deficits in brain and bone. Risk factors for osteoporosis and AD, such as obesity, type 2 diabetes, aging, chemotherapy, vitamin deficiency, alcohol abuse, and apolipoprotein Eε4 and/or Il-6 gene variants, reduce cellular glucose uptake, and protective factors, such as estrogen, insulin, exercise, mammalian target of rapamycin inhibitors, hydrogen sulfide, and most phytochemicals, increase uptake. Glucose uptake is a fine-tuned process that depends on an abundance of glucose transporters (Gluts) on the cell surface. Gluts are stored in vesicles under the plasma membrane, and protective factors cause these vesicles to fuse with the membrane, resulting in presentation of Gluts on the cell surface. This translocation depends mainly on AKT kinase signaling and can be affected by a range of factors. Reduced AKT kinase signaling results in intracellular glucose deprivation, which causes endoplasmic reticulum stress and iron depletion, leading to activation of HIF-1α, the transcription factor necessary for higher Glut expression. The link between diseases and aging is a topic of growing interest. Here, we show that diseases that affect the same biochemical pathways tend to co-occur, which may explain why osteoporosis and/or diabetes are often associated with AD.

Depression and bone loss as risk factors for cognitive decline: A systematic review and meta-analysis

BACKGROUND

Depression is linked to Alzheimer's disease (AD) but it is unclear whether depression is also associated with cognitive decline in the preclinical phase and mild cognitive impairment (MCI). Previous meta-analyses have only investigated AD as an outcome without accounting for individuals showing cognitive decline that does not meet the diagnostic criteria for AD. Other potentially modifiable risk factors such as bone loss have also been less explored and there remains uncertainty around their temporal relationship with cognitive decline.

AIMS

To conduct a systematic review and meta-analysis investigating depression and bone loss as risk factors for subsequent cognitive decline.

METHODS

A comprehensive search strategy was developed and applied using four databases; MEDLINE Complete, Embase, PsycINFO and CINAHL Complete. The pooled summary effects were estimated as odds ratios with 95% confidence intervals using a random-effects model. The study protocol was registered with PROSPERO (ID: CRD42020159369).

RESULTS

A total of 75 longitudinal cohort studies were identified for meta-analysis, of which 70 examined the impact of depression on cognitive decline and five examined the impact of bone loss. Prior exposure to depression was found to be associated with cognitive score reduction (OR 1.33 95% CI 1.17, 1.51), MCI incidence (OR 1.52 95% CI 1.28, 1.79) and AD incidence (OR 1.79 95% CI 1.46, 2.2). Bone loss was also associated with the incidence of AD (OR=1.81 95% CI 1.28, 2.55).

CONCLUSIONS

Overall, the results support the hypothesis that depression is associated with subsequent cognitive decline. Bone loss was also found to be associated with AD incidence; however, due to the small number of studies, the results should be viewed with caution.

Systemic effects of abnormal bone resorption on muscle, metabolism, and cognition

Skeletal tissue is dynamic, undergoing constant remodeling to maintain musculoskeletal integrity and balance in the human body. Recent evidence shows that apart from maintaining homeostasis in the local microenvironment, the skeleton systemically affects other tissues. Several cancer-associated and noncancer-associated bone disorders can disrupt the physiological homeostasis locally in the bone microenvironment and indirectly contribute to dysregulation of systemic body function. The systemic effects of bone on the regulation of distant organ function have not been widely explored. Recent evidence suggests that bone can interact with skeletal muscle, pancreas, and brain by releasing factors from mineralized bone matrix. Currently available bone-targeting therapies such as bisphosphonates and denosumab inhibit bone resorption, decrease morbidity associated with bone destruction, and improve survival. Bisphosphonates have been a standard treatment for bone metastases, osteoporosis, and cancer treatment-induced bone diseases. The extraskeletal effects of bisphosphonates on inhibition of tumor growth are known. However, our knowledge of the effects of bisphosphonates on muscle weakness, hyperglycemia, and cognitive defects is currently evolving. To be able to identify the molecular link between bone and distant organs during abnormal bone resorption and then treat these abnormalities and prevent their systemic effects could improve survival benefits. The current review highlights the link between bone resorption and its systemic effects on muscle, pancreas, and brain.

The Occurrence of Alzheimer's Disease and Parkinson's Disease in Individuals With Osteoporosis: A Longitudinal Follow-Up Study Using a National Health Screening Database in Korea

Background: Public health concerns regarding the potential link between osteoporosis and the increased occurrence of Alzheimer’s disease (AD) and Parkinson’s disease (PD) have been raised, but the results remain inconsistent and require further validation. Here, we investigated the long-term relationship of osteoporosis with the occurrence of AD/PD using data from a large-scale nationwide cohort.

Methods: This longitudinal follow-up study included 78,994 patients with osteoporosis and 78,994 controls from the Korean National Health Insurance Service-Health Screening Cohort database (2002–2015) who were matched using propensity score matching at a 1:1 ratio based on age, sex, income, and residential area. A Cox proportional hazard model was used to assess the association between osteoporosis and the occurrence of AD/PD after adjusting for multiple covariates.

Results: During the follow-up period, AD occurred in 5,856 patients with osteoporosis and 3,761 controls (incidence rates: 10.4 and 6.8 per 1,000 person-years, respectively), and PD occurred in 1,397 patients and 790 controls (incidence rates: 2.4 and 1.4 per 1,000 person-years, respectively). The incidences of AD and PD were significantly higher in the osteoporosis group than in the matched control group. After adjustment, the osteoporosis group exhibited 1.27-fold and 1.49-fold higher occurrences of AD (95% confidence interval (CI) = 1.22–1.32) and PD (95% CI = 1.36–1.63) than the controls, respectively. The results of subgroup analyses supported the increased occurrence of AD and PD in patients with osteoporosis, independent of income, residential area, obesity, smoking, alcohol consumption, hyperlipidemia, hypertension, or blood glucose level.

Conclusion: Our results indicate that the presence of osteoporosis may increase the likelihood of developing two common neurodegenerative diseases in adults aged ≥40 years.

Osteoporosis and cognitive impairment interwoven warning signs: community-based study on older adults-Bushehr Elderly Health (BEH) Program

Cognitive impairment and osteoporosis are frequently seen to coincide in clinical practice. Osteoporosis was higher in elderly populations with cognitive impairment, especially in postmenopausal women. Thus, prophylaxis for osteoporosis, falls, and fractures should be considered as part of the treatment of patients with cognitive impairment.

INTRODUCTION

Cognitive impairment and osteoporosis are two important health concerns among older adults that their possible relationship, concurrent occurrence, and linking mechanism have recently been highlighted. The purpose of this study was to assess the sex-independent association of these two conditions.

MATERIALS AND METHODS

From among 2331 individuals aged ≥ 60 years selected in Bushehr Elderly Health (BEH) Program, Iran; data of 1508 participants were analyzed. Cognitive status was assessed using Category Fluency Test and Mini-cog assessment instrument. Association between osteopenia-osteoporosis and cognitive impairment were assessed using uni- and multivariable logistic regression models.

RESULTS

Osteoporosis was diagnosed in 598 (39.6%) of the participants (58.3% female and 21.9% male, P < 0.001). From among them, 677 (44.9%) had evidence of cognitive impairment (64.5% female and 31.0% male, P < 0.001). Multivariate logistic regressions showed spinal and total hip osteoporosis was associated with 1.83 (CI 95% 1.13-2.96) and 2.24-fold (CI 95% 1.28-3.89) increase in the risk of cognitive impairment among female subjects, respectively. Ordinal logistic regression, on the other hand, revealed cognitive impairment to be associated with 1.42-fold (CI 95% 1.04-1.92) increase in the risk of spinal osteopenia-osteoporosis, 1.5-fold increase in total hip osteoporosis (CI 95% 1.09-2.05), and 1.48-fold increase in general osteoporosis (CI 95% 1.06-2.0).

CONCLUSION

Different degrees of bone loss and cognitive impairment may be a risk factor for each other among women but not in men. It is suggested that the screening, adopting preventive measures for the other condition and regular follow-ups, if needed, could be of utmost importance.

Voxel-Based Morphometry Reveals a Correlation Between Bone Mineral Density Loss and Reduced Cortical Gray Matter Volume in Alzheimer's Disease

Background: Decreased bone mineral density (BMD) was associated with poorer cognitive function and increased risk of Alzheimer's disease (AD). However, objective evidence for the relationship between osteoporosis and AD in humans has not been extensively described. Objectives: We aimed to evaluate the relationships between BMD and the cortical volumes of brain regions vulnerable to AD; hippocampus, parahippocampal gyrus, precuneus, posterior cingulate, and angular gyrus, using voxel-based morphometry (VBM), to investigate the association between bone loss and AD. Methods: A cohort of 149 consecutive elderly participants who complained of memory disturbance underwent high-resolution structural brain magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry (DXA). We used SPM12 software to conduct a voxel-based multiple regression analysis to examine the association between femoral neck BMD values and regional gray matter volume (rGMV) on structural T1-weighted MRI. Results: After adjusting for subject age, gender, total brain volume (TBV), and mini-mental state examination (MMSE) scores, the multiple regression analysis showed significant correlations between BMD loss and rGMV decline in the left precuneus, which is an important neural network hub vulnerable to AD. Conclusion: These data suggest that the bone and brain communicate with each other, as in "bone-brain crosstalk," and that control of BMD factors could contribute to cognitive function and help prevent AD.

Low bone density and osteoporosis among older adults with Alzheimer's disease, vascular dementia, and mixed dementia: A Cross-sectional Study With Prospective Enrollment

OBJECTIVES

This study aims to examine bone mineral density (BMD) and osteoporosis in older adults with dementia compared to those with a normal cognitive status and to evaluate the type, severity, and duration of dementia.

PATIENTS AND METHODS

Between May 2013 and May 2017, a total of 363 participants aged ≥65 years (136 males, 227 females; mean age 78.4±5.4 years; range 66 to 99 years) with and without Alzheimer's disease (AD), vascular dementia (VaD), or mixed dementia (AD-VaD) were included in this single-center, prospective, cross-sectional study. The dementia group included 93 patients with dementia and the control group included 270 age- and sex-matched healthy individuals. We used dual-energy X-ray absorptiometry (DXA) to measure BMD of the lumbar spine, total hip, and femoral neck.

RESULTS

Controlled for age and sex, demented and non-demented participants had a similar BMD (g/cm2) at lumbar spine [F (1, 358):0.83, p=363], but lower BMD values of total hip [F (1, 359):10.26, p=0.001] and femoral neck [F (1, 359):15.21, p<0.001] in the patients with dementia. Adjusted percentage of osteoporosis and low bone mass based on total hip and femoral neck T-scores were also significantly higher in the patient group. The mean BMD values, frequency of osteoporosis, and low bone mass did not significantly differ according to the subtype of dementia, sex, and disease duration or severity.

CONCLUSION

Our study results show that demented elders have a lower BMD and higher frequency of osteoporosis at the hip, but not at the lumbar spine, irrespective of sex and type of dementia. Based on these results, we can speculate that not only AD, but also VaD and AD-VaD may be associated with bone loss at the hip.

Associations of Bone Turnover Markers with Cognitive Function in Patients Undergoing Hemodialysis

BACKGROUND

Patients undergoing hemodialysis experience a greater risk of cognitive impairment than the general population, but limited data elucidates the biomarkers on this. We evaluated the association of bone turnover markers on cognitive function among 251 prevalent hemodialysis enrollees in a cross-sectional study.

METHODS

251 hemodialysis patients (median age = 57.8, 55% men) and 37 control subjects (mean age = 61.2, 56% men) without a prior stroke or dementia diagnosis were enrolled. Serum concentrations of 8 bone markers were analyzed as the association of cognitive function (Montreal Cognitive Assessment (MoCA) and Cognitive Abilities Screening Instrument (CASI)) using linear regression analysis.

RESULTS

A lower cognitive function was noted in hemodialysis patients compared to control subjects. The receptor activator of nuclear factor kappa-B ligand (RANKL) was the only bone marker found to be associated with cognitive function (MoCA and CASI tests) in hemodialysis patients without a prior stroke or dementia diagnosis. In stepwise multiple linear regression analysis, the association remained significant in MoCA (β = 1.14, 95% CI 0.17 to 2.11) and CASI (β = 3.06, 95% CI 0.24 to 5.88). Short-term memory (β = 0.52, 95% CI 0.01 to 1.02), mental manipulation (β = 0.51, 95% CI 0.05 to 0.96), and abstract thinking (β = 0.57, 95% CI 0.06 to 1.09) were the significant subdomains in the CASI score related to RANKL.

CONCLUSIONS

Serum RANKL levels were potentially associated with better cognitive function in hemodialysis patients. Further large-scale and prospective studies are needed to confirm our findings.

Systemic Exposure to Lipopolysaccharide from Porphyromonas gingivalis Induces Bone Loss-Correlated Alzheimer's Disease-Like Pathologies in Middle-Aged Mice

BACKGROUND

Alzheimer's disease (AD) and bone loss are clinically exacerbated. However, the mechanism of exacerbation remains understood.

OBJECTIVE

We tested our hypothesis that periodontitis is involved in the exacerbation, contributing to AD pathologies.

METHODS

The bone, memory, and inflammation in bone and brain were examined in 12-month-old mice after systemic exposure to lipopolysaccharide from Porphyromonas gingivalis (P gLPS) for 3 consecutive weeks.

RESULTS

Compared with control mice, bone loss in tibia (26% decrease) and memory decline (47% decrease) were induced in mice with a positive correlation after exposure to P gLPS (r = 0.7378, p = 0.0011). The IL-6 and IL-17 expression in tibia was negatively correlated with the bone volume/total tissue volume (r = -0.6619, p = 0.0052; r = -0.7129, p = 0.0019), while that in the cortex was negatively correlated with the memory test latency (r = -0.7198, p = 0.0017; p = 0.0351, r = -0.5291). Furthermore, the IL-17 expression in microglia was positively correlated with Aβ42 accumulation in neurons (r = 0.8635, p < 0.0001). In cultured MG6 microglia, the P gLPS-increased IL-6 expression was inhibited by a PI3K-specific inhibitor (68% decrease), and that of IL-17 was inhibited by IL-6 antibody (41% decrease). In cultured N2a neurons, conditioned medium from P gLPS-stimulated microglia (MCM) but not P gLPS increased the productions of AβPP, CatB, and Aβ42, which were significantly inhibited by pre-treatment with IL-17 antibody (67%, 51%, and 41% decrease).

CONCLUSION

These findings demonstrated that chronic systemic exposure to P gLPS simultaneously induces inflammation-dependent bone loss and AD-like pathologies by elevating IL-6 and IL-17 from middle age, suggesting that periodontal bacteria induce exacerbation of bone loss and memory decline, resulting in AD progression.

Medical Comorbidities of Dementia: Links to Caregivers' Emotional Difficulties and Gains

OBJECTIVES

To evaluate how eight major medical comorbidities of dementia (arthritis, cancer, diabetes, heart disease, hypertension, lung disease, osteoporosis, and stroke) are associated with caregivers' perceptions of emotional caregiving difficulties and caregiving gains (ie, benefits or rewards from the care role).

DESIGN

Nationally representative cross-sectional surveys of community-dwelling persons living with dementia (PLWDs) and their co-resident family caregivers in the United States.

SETTING

The 2011 National Health and Aging Trends Study and National Study of Caregiving.

PARTICIPANTS

Total of 356 co-resident family caregivers of community-dwelling PLWDs.

MEASUREMENTS

Caregivers' sociodemographic and health characteristics, caregiving stressors, emotional caregiving difficulties, caregiving gains, and chronic health conditions of PLWDs.

RESULTS

Caregivers most commonly cared for a PLWD with arthritis (65.5%), followed by hypertension (64.9%), diabetes (30.1%), stroke (28.8%), osteoporosis (27.1%), heart disease (23.3%), cancer (21.5%), and lung disease (17.2%). Logistic regressions revealed that caregivers were 2.63 and 2.32 times more likely to report higher than median emotional caregiving difficulties when PLWDs had diagnoses of diabetes and osteoporosis, respectively, controlling for caregiver sex, relationship to the PLWD (spouse vs non-spouse), educational attainment, self-rated health, and assistance with activities of daily living and medical care activities. Caregivers were also 2.10 times more likely to report lower than median caregiving gains when PLWDs had a diagnosis of osteoporosis.

CONCLUSION

Comorbid health conditions among PLWDs have distinct implications for caregiving outcomes. Clinical care and interventions to improve the well-being of both care dyad members should support caregivers in managing medical comorbidities of dementia. J Am Geriatr Soc 68:609-613, 2020.

Circulating Dkk1 and TRAIL Are Associated With Cognitive Decline in Community-Dwelling, Older Adults With Cognitive Concerns

Background

Osteoporosis and Alzheimer's disease are common diseases of aging that would seem to be unrelated, but may be linked through the influence of bone-derived signals on brain function. The aim of the current study is to investigate the relationship between circulating levels of bone-related biomarkers and cognition.

Methods

The population included 103 community-dwelling older individuals with memory concerns but without cognitive impairment. A global cognition summary measure was collected at baseline and 6, 12, and 18 months post-enrollment by converting raw scores from 19 cognitive function tests to z-scores and averaging. Baseline plasma concentrations of bone-related biomarkers, including undercarboxylated, carboxylated, and total osteocalcin, parathyroid hormone, C-terminal telopeptide of collagen 1 (CTX-1), procollagen type 1 amino-terminal propeptide, osteoprotegrin, osteopontin, Dickkopf WNT signaling pathway inhibitor 1 (Dkk1), sclerostin, and amyloid β peptides (Aβ40 and Aβ42), were measured.

Results

Using sex, age, and education-adjusted mixed-effects models, we found that baseline levels of TNF-related apoptosis-inducing ligand (TRAIL; p < .001), Dkk1 (p = .014), and CTX-1 (p = .046) were related to the annual rate of change of global cognition over the 18 month follow-up. In cognitive domain-specific analysis, baseline TRAIL was found to be positively related to the annual rate of change in episodic (p < .001) and working memory (p = .016), and baseline Dkk1 was positively related to semantic memory (p = .027) and negatively related to working memory (p = .016).

Conclusions

These results further confirm the link between bone and brain health and suggest that circulating levels of bone-related biomarkers may have diagnostic potential to predict worsening cognition.

The cause-effect relationship between bone loss and Alzheimer's disease using statistical modeling

BACKGROUND

Animal studies provide strong evidence that the CNS directly regulates bone remodeling through the actions of the hypothalamus via two distinct pathways, the neural (mediated by leptin) arm and neurohumoral (mediated by neurohormones and growth factors) arm. The impact of AD on central regulatory mechanisms of bone mass is not known.

OBJECTIVES

To test a model that assesses the relationship between hypothalamic atrophy and bone loss in Alzheimer's disease (AD) and potential mediation through neural (leptin) and neurohumoral (insulin-like growth factor -1, IGF-1) mechanisms.

HYPOTHESES

AD-related hypothalamic structural change alters neural and neurohumoral regulatory systems of bone remodeling and contributes to bone loss in early AD.

DESIGN

A secondary data analysis of data obtained in a two-year longitudinal study with path analysis and longitudinal mediation modeling.

PARTICIPANTS

The data were collected as a part of the University of Kansas Brain Aging Project, a two-year observational study of 71 older adults with early stage AD and 69 non-demented controls.

MEASUREMENTS

Demographic characteristics and measures of bone density, body composition, and hypothalamic volume, serum levels of leptin, growth hormone, and IGF-1 were collected.

RESULTS

Hypothalamic atrophy and bone loss were observed in AD group and were associated. Data modeling suggests that bone loss may precede measurable changes in the brain. Leptin increased over two years in AD and the increase in leptin was associated with hypothalamic atrophy. However, changes in leptin or IGF-1 levels did not mediate the relationship between hypothalamic atrophy and bone loss.

CONCLUSIONS

This study extends previous findings by suggesting that bone loss in AD may be related to neurodegenerative changes (atrophy) in the hypothalamus. Further studies are needed to explore the role of brain atrophy and mediating mechanisms in bone loss. Further exploring temporal relationship between bone loss and AD may have an important diagnostic value.

Bone mineral loss and cognitive impairment: The PRESENT project

Low bone mineral density (BMD) is correlated with Alzheimer's disease and its severity, but the association remains unclear in adults (≥50 years) without a history of stroke or dementia.We assessed BMD and cognitive function using the Mini-Mental Status Examination (MMSE) in 650 stroke- and dementia-free subjects (≥50 years) who were recruited for an early health check-up program between January 2009 and December 2010.The mean age was 62.9 ± 8.0 years and mean MMSE score was 27.6 ± 3.6. A total of 361 subjects had reduced BMD: 197 (30.3%) had osteopenia and 154 (23.6%) had osteoporosis, based on criteria of world health organization. A total of 5.4% of the male subjects had osteoporosis, versus 19.8% of the female subjects. After adjusting for age, sex, education, and other possible confounding factors such as hypertension, diabetes mellitus, and smoking, the estimated odds ratio for cognitive impairment was 1.72 for the osteopenia group (95% confidence interval [CI] 1.09-2.14, P = .019) and 2.81 for the osteoporosis group (95% CI 1.78-4.45, P < .001).Low BMD is correlated with cognitive impairment in community-dwelling adults aged 50 years and above without any medical history of stroke or dementia, especially in women. A community-based, early life, preventive osteoporosis education campaign might decrease the incidence of dementia.

Risk factors for cognitive decline following osteoporotic vertebral fractures: A multicenter cohort study

BACKGROUND

Osteoporotic vertebral fractures (OVFs) are the most common cause of intractable back pain and reduced activities of daily living (ADL), which may affect cognitive function. However, no previous studies have reported a change in cognitive function after OVFs. The purpose was to reveal cognitive function changes after OVFs and investigate the risk factors for cognitive decline.

METHODS

Consecutive patients with symptomatic OVFs were enrolled in a prospective multicenter cohort study. The inclusion criteria were age >65 years, diagnosis of acute or subacute OVF, and back pain onset within 2 months prior to presentation. Cognitive function was assessed with the mini-mental state examination. Medical history, radiological findings, and ADL were investigated as risk factors for cognitive decline.

RESULTS

We recruited a sample of 339 patients (58 men and 281 women) who met the inclusion criteria. Patients underwent examinations and completed questionnaires at both the time of enrollment and at 6-month follow-up. At 6-month follow-up, cognitive decline was observed in 26 (7.7%) patients. Medical history, including comorbidities and sports activities, did not affect odds ratios (ORs). However, elevated ORs were associated with delayed union (OR: 4.67, 95% Confidence interval: 1.22-17.87). In addition, significantly increased ORs were associated with reduced ADL at 6-month follow-up.

CONCLUSIONS

The current results revealed the incidence of cognitive decline after the onset of OVF. Delayed union and reduced ADL at 6-month follow-up were associated with cognitive decline. Patients with cognitive decline experienced significantly reduced quality of life. These results highlight the importance of preventing cognitive impairment in patients with symptomatic OVF. Physical treatment or early surgical treatment may provide appropriate options, particularly for patients with suspected delayed union.

Associations of Childhood and Adulthood Cognition with Bone Mineral Density in Later Adulthood: A Population-Based Longitudinal Study

This study explores the association between cognitive ability in childhood and midlife and bone health outcomes in early old age; and the relationships of these bone measures with contemporaneous and subsequent cognitive ability in the MRC National Survey of Health and Development (NSHD). This British birth cohort assessed areal and volumetric bone mineral density (aBMD and vBMD) at age 60-64, derived from peripheral quantitative computed tomography and dual-energy X-ray absorptiometry, and cognitive performance from childhood to age 69, among 866 women and 792 men. Cognitive performance at age 15 was assessed using tests of verbal and non-verbal ability, and mathematics; and memory and search speed tasks were administered at ages 53, 60-64, and 69. Covariates included body size, pubertal timing, smoking, leisure time physical activity, socioeconomic circumstances and menopause timing. Multiple linear regression analyses showed that higher childhood cognitive ability was associated with higher hip aBMD, in women, and greater cortical and trabecular vBMD, in men. For women, there were positive associations between hip aBMD and total vBMD, and contemporaneous cognitive ability with associations also extending to subsequent cognitive ability for total vBMD. For men, some associations with trabecular and total vBMD emerged at ages 60-64 and 69 but only after adjusting for education, occupational class and health behaviors. Our findings highlight that higher cognitive ability in childhood is associated with BMD in early old age and these associations might be explained by social and behavioral pathways. The results suggest that individuals with greater cognitive ability in early life are more likely to engage in healthy behaviors (e.g., leisure time physical activity) in adulthood, which in turn are associated with greater BMD later in life. Associations between bone health and cognitive performance should be considered within a life course framework; and the potential role of smoking and physical activity should be addressed when advising adults at high future risk of osteoporosis and fracture.

Multimodal population brain imaging in the UK Biobank prospective epidemiological study

Medical imaging has enormous potential for early disease prediction, but is impeded by the difficulty and expense of acquiring data sets before symptom onset. UK Biobank aims to address this problem directly by acquiring high-quality, consistently acquired imaging data from 100,000 predominantly healthy participants, with health outcomes being tracked over the coming decades. The brain imaging includes structural, diffusion and functional modalities. Along with body and cardiac imaging, genetics, lifestyle measures, biological phenotyping and health records, this imaging is expected to enable discovery of imaging markers of a broad range of diseases at their earliest stages, as well as provide unique insight into disease mechanisms. We describe UK Biobank brain imaging and present results derived from the first 5,000 participants' data release. Although this covers just 5% of the ultimate cohort, it has already yielded a rich range of associations between brain imaging and other measures collected by UK Biobank.

Metabolic and Non-Cognitive Manifestations of Alzheimer's Disease: The Hypothalamus as Both Culprit and Target of Pathology

Alzheimer's disease (AD) is increasingly recognized as a complex neurodegenerative disease beginning decades prior to the cognitive decline. While cognitive deficits remain the cardinal manifestation of AD, metabolic and non-cognitive abnormalities, such as alterations in body weight and neuroendocrine functions, are also present, often preceding the cognitive decline. Furthermore, hypothalamic dysfunction can also be a driver of AD pathology. Here we offer a brief appraisal of hypothalamic dysfunction in AD and provide insight into an underappreciated dual role of the hypothalamus as both a culprit and target of AD pathology, as well as into new opportunities for therapeutic interventions and biomarker development.

Bone mineral density, adiposity, and cognitive functions

Cognitive decline and dementia due to Alzheimer's disease (AD) have been associated with genetic, lifestyle, and environmental factors. A number of potentially modifiable risk factors should be taken into account when preventive or ameliorative interventions targeting dementia and its preclinical stages are investigated. Bone mineral density (BMD) and body composition are two such potentially modifiable risk factors, and their association with cognitive decline was investigated in this study. 164 participants, aged 34–87 years old (62.78 ± 9.27), were recruited for this longitudinal study and underwent cognitive and clinical examinations at baseline and after 3 years. Blood samples were collected for apolipoprotein E (APOE) genotyping and dual energy x-ray absorptiometry (DXA) was conducted at the same day as cognitive assessment. Using hierarchical regression analysis, we found that BMD and lean body mass, as measured using DXA were significant predictors of episodic memory. Age, gender, APOE status, and premorbid IQ were controlled for. Specifically, the List A learning from California Verbal Learning Test was significantly associated with BMD and lean mass both at baseline and at follow up assessment. Our findings indicate that there is a significant association between BMD and lean body mass and episodic verbal learning. While the involvement of modifiable lifestyle factors in human cognitive function has been examined in different studies, there is a need for further research to understand the potential underlying mechanisms.

Increased risk of dementia in patients with osteoporosis: a population-based retrospective cohort analysis

Osteoporosis is a common systemic skeletal disease that predominantly affects people older than 50 years and often co-occurs with dementia. The purpose of this study was to evaluate the risk of dementia in osteoporosis patients in Taiwan. Using data from Taiwan's National Health Insurance Research Database (NHIRD), we identified 23,941 patients with osteoporosis from 2000 to 2010 and 47,579 nonosteoporosis control patients, frequency-matched for age, sex, and index year, excluding patients with dementia at the baseline. We conducted univariate and multiple Cox proportional-hazards regression analyses to calculate the hazard ratios (HRs) and 95 % confidence intervals (CIs) of the association between osteoporosis and risk of dementia. After adjustment for potential risk factors, the osteoporosis patients exhibited 1.46-fold and 1.39-fold higher risk of dementia (95 % CI = 1.37-1.56) and Alzheimer's disease (95 % CI = 0.95-2.02), respectively, compared with the matched nonosteoporosis patients. We observed increased risk of dementia in both men and women with osteoporosis. The osteoporosis patients receiving bisphosphonate treatment or estrogen supplementation were associated with significantly lower risk of dementia compared with the osteoporosis patients who did not receive any treatment. Overall, our results suggest higher risks of dementia in osteoporosis patients than in nonosteoporosis patients. Osteoporosis could thus be considered an early risk factor for dementia. Future large-scale double-blind randomized clinical trials are required to clarify the role of medication in osteoporosis-related dementia.

The Implications of Body Fat Mass and Fat Distribution for Cognitive Function in Elderly Women

OBJECTIVE

To investigate how body fat mass, an established source of endogenous estrogen after menopause, influences cognitive impairment in elderly women.

RESEARCH METHODS AND PROCEDURES

Study participants were 5607 generally healthy postmenopausal women with mean age of 63.8 years at baseline followed for an average of 7.3 years. Cognitive function assessed at follow-up using the short Blessed test was related to baseline body weight, the yearly change in weight, and follow-up measures of body fat depots assessed by DXA. Cognitive function was also related to various surrogates of lifetime estrogen exposure.

RESULTS

Women with the worst cognitive performance (score >or= 9) at follow-up were the ones who lost the most body weight and revealed the lowest central fat mass (CFM). The association of weight loss with worse cognitive performance was apparent across all age groups except for those more than 80 years old. In the multivariate logistic model, the risk of cognitive impairment was 18% lower in women in the second quartile of CFM (p = 0.14), 32% lower in the third (p = 0.01), and 48% lower in the fourth (p < 0.001) compared with those in the first quartile. CFM showed significant correlation with the simultaneously measured serum estradiol (r = 0.25; p < 0.001). Cognitive score showed an inverse linear relationship with the duration of reproductive period and bone mineral density assessed at follow-up.

DISCUSSION

These findings argue for a protective association of body fat mass with cognitive impairment in elderly women. This association seems to involve a more prominent exposure to endogenous estrogens.

Osteoporosis piece of multi-morbidity puzzle in geriatric care

Osteoporosis frequently coexists with other chronic diseases and syndromes of aging, and therefore multimorbidity interactions can potentially complicate its evaluation and treatment. This article reviews osteoporosis comorbidity interactions with select common diseases of aging including cardiovascular, neurologic, and geriatric syndromes, and select commonly used medications by older adults. Using depression as a case example, we describe the complex relationship between osteoporosis, mood, and antidepressant medications, and the implications of these interactions for patients and clinicians.

Non-psychiatric comorbidity associated with Alzheimer's disease

The burden of medical comorbidity in individuals with Alzheimer's disease is greater than that observed in matched individuals without dementia. This has important implications for all clinicians and healthcare providers who deal with this common condition. The prevalence of vascular risk factors and vascular disease is particularly high. Additionally, associations with a number of other chronic medical conditions have been described, including thyroid disorders, sleep apnoea, osteoporosis and glaucoma. This review gives an overview of evidenced medical (non-psychiatric) comorbidity associated with Alzheimer's disease and briefly explores the underlying mechanisms that may account for these associations.

Prevalence of dementia and cognitive impairment among older adults with hip fractures

BACKGROUND

Dementia and cognitive impairment are known to be risk factors for hip fractures and are associated with increased postoperative morbidity and mortality. Little is known of the prevalence of dementia and cognitive impairment among older adults with hip fractures.

METHODS

We completed searches of the electronic databases for observational studies and report the prevalence of either dementia or cognitive impairment among individuals with hip fractures. We included studies that reported the prevalence of dementia using standard diagnostic criteria or cognitive impairment as measured on cognitive screening tests. We used random-effects meta-analysis to arrive at pooled estimates of the prevalence of dementia and cognitive impairment.

RESULTS

Five studies reported the prevalence of dementia and 34 studies reported the prevalence of cognitive impairment in older adults with hip fractures. The estimated prevalence of dementia among older adults with hip fractures was 19.2% (95% confidence interval [CI]: 11.4% to 30.6%), whereas the prevalence of cognitive impairment was 41.8% (95% CI: 37.0% to 46.8%). In subgroup analyses, individuals admitted from long-term care were more likely to have dementia when compared with individuals admitted from the community, whereas there were no significant differences in the prevalence of cognitive impairment according to gender or study setting.

CONCLUSIONS

We conclude that dementia and cognitive impairment are common among older adults with hip fractures. Clinicians providing care for individuals with hip fractures should be aware of the high prevalence of cognitive impairment in this population. Effective strategies to prevent hip fractures and improve postoperative outcomes for older adults with dementia are needed.

Fall prevention and vitamin D in the elderly: an overview of the key role of the non-bone effects

Preventing falls and fall-related fractures in the elderly is an objective yet to be reached. There is increasing evidence that a supplementation of vitamin D and/or of calcium may reduce the fall and fracture rates. A vitamin D-calcium supplement appears to have a high potential due to its simple application and its low cost. However, published studies have shown conflicting results as some studies failed to show any effect, while others reported a significant decrease of falls and fractures. Through a 15-year literature overview, and after a brief reminder on mechanism of falls in older adults, we reported evidences for a vitamin D action on postural adaptations - i.e., muscles and central nervous system - which may explain the decreased fall and bone fracture rates and we underlined the reasons for differences and controversies between published data. Vitamin D supplementation should thus be integrated into primary and secondary fall prevention strategies in older adults.

Bone density and brain atrophy in early Alzheimer's disease

Studies suggest a link between bone loss and Alzheimer's disease. To examine bone mineral density (BMD) in early Alzheimer's disease (AD) and its relationship to brain structure and cognition, we evaluated 71 patients with early stage AD (Clinical Dementia Rating (CDR) 0.5 and 1) and 69 non-demented elderly control participants (CDR 0). Measures included whole body BMD by dual energy x-ray absorptiometry (DXA) and normalized whole brain volumes computed from structural MRI scans. Cognition was assessed with a standard neuropsychological test battery. Mean BMD was lower in the early AD group (1.11 +/- 0.13) compared to the non-demented control group (1.16 +/- 0.12, p = 0.02), independent of age, gender, habitual physical activity, smoking, depression, estrogen replacement, and apolipoprotein E4 carrier status. In the early AD group, BMD was related to whole brain volume (b = 0.18, p = 0.03). BMD was also associated with cognitive performance, primarily in tests of memory (logical memory [b = 0.15, p = 0.04], delayed logical memory [b = 0.16, p = 0.02], and the selective reminding task - free recall [b = 0.18, p = 0.009]). BMD is reduced in the earliest clinical stages of AD and associated with brain atrophy and memory decline, suggesting that central mechanisms may contribute to bone loss in early AD.

Reduced limbic and hypothalamic volumes correlate with bone density in early Alzheimer's disease

Accelerated bone loss is associated with Alzheimer's disease (AD). Although the central nervous system plays a direct role in regulating bone mass, primarily through the actions of the hypothalamus, there is little work investigating the possible role of neurodegeneration in bone loss. In this cross-sectional study, we examined the association between bone mineral density (BMD) and neuroimaging markers of neurodegeneration (i.e., global and regional measures of brain volume) in early AD and non-demented aging. Fifty-five non-demented and 63 early AD participants underwent standard neurological and neuropsychological assessment, structural MRI scanning, and dual energy x-ray absorptiometry. In early AD, voxel-based morphometry analyses demonstrated that low BMD was associated with low volume in limbic grey matter (GM) including the hypothalamus, cingulate, and parahippocampal gyri and in the left superior temporal gyrus and left inferior parietal cortex. No relationship between BMD and regional GM volume was found in non-demented controls. The hypothesis-driven region of interest analysis further isolating the hypothalamus demonstrated a positive relationship between BMD and hypothalamic volume after controlling for age and gender in the early AD group but not in non-demented controls. These results demonstrate that lower BMD is associated with lower hypothalamic volume in early AD, suggesting that central mechanisms of bone remodeling may be disrupted by neurodegeneration.

The NIH Cognitive and Emotional Health Project. Report of the Critical Evaluation Study Committee

BACKGROUND

The Cognitive and Emotional Health Project (CEHP) seeks to identify the demographic, social, and biological determinants of cognitive and emotional health in the older adult. As part of the CEHP, a critical evaluation study committee was formed to assess the state of epidemiological research on demographic, social, and biological determinants of cognitive and emotional health.

METHODS

Criteria for inclusion in the survey were large cohort studies, longitudinal in design, participants predominantly 65 years or older, with measurements of both cognition and emotion, and information on a wide variety of demographic, psychosocial, and biological factors. North American and European studies, which met these criteria, were selected for the review. Outcome measures included cognition, cognitive decline, and cognitive function. For emotion, symptoms included depression and anxiety, positive and negative affect, subjective well being, mastery, and resilience.

RESULTS

Ninety-six papers were identified that addressed cognitive and emotional outcomes. A large variety of risk factors were consistently identified with cognitive outcomes, particularly those previously associated with increased risk of cardiovascular disease. There was considerable overlap between risk factors for cognitive and emotional outcomes.

CONCLUSION

This review identifies a large number of lifestyle and health behaviors that alter the risk for maintenance of cognitive and emotional health. Large longitudinal cohort studies are a unique source to explore factors associated with cognitive and emotional health. Secondary analyses of these studies should be encouraged as should the development of standardized questionnaires to measure cognitive and emotional health. Future research in this field should study cognitive and emotional health simultaneously.

Endogenous and exogenous estrogen, cognitive function, and dementia in postmenopausal women: evidence from epidemiologic studies and clinical trials

There are more than 200 published scientific papers showing that estrogen has favorable effects on brain tissue and physiology in cell culture and animal models including non-human primates. The biological plausibility for a neuroprotective estrogen effect is overwhelming. However, most studies of endogenous estrogen and cognitive decline or dementia in women fail to show protection, and some suggest harm. Failure to find any consistent association might reflect the limitations of a single time of estrogen assay or poor assay sensitivity. More than half of the observational studies of hormone therapy suggest benefit. Nearly all long-term clinical trials fail to show benefit, and the longer trials tend to show harm. Failure to adequately adjust for self-selection of healthier and wealthier women and publication bias could account for some, or all, of the protective effect attributed to estrogen in observational studies. Overall, the evidence does not convincingly support the prescription of early or late postmenopausal estrogen therapy to preserve cognitive function or prevent dementia.

Psychological state, quality of life, and body composition in postmenopausal women with osteoporosis in Lithuania

SUMMARY: The objective of this study was to determine body composition, physical activity, and psychological state in postmenopausal women with osteoporosis. Fat mass, lean mass, water mass, and basal metabolic rate are lower, self-reported physical activity and risk factors of fractures are higher, and cognitive functions were worse in osteoporotic patients than in controls. Significant correlations were found between physical activity and emotional state parameters. INTRODUCTION: This study aims to determine peculiarities of body composition, physical activity, risk factors predicting fractures, psychological state and quality of life, and possible relations between them in postmenopausal women with osteoporosis in Lithuania. METHODS: Thirty-one postmenopausal women with osteoporosis and 29 healthy age- and sex-matched controls were included in the study. Profile of Mood State and Hospital Anxiety and Depression Scale were used for the assessment of emotional state. Trail Making Test and Digit Symbol Test of Wechsler Adult Intelligence Scale were used to evaluate cognitive functioning. Quality of life was evaluated using the World Health Organization Brief Quality of Life Questionnaire. Risk of fractures was assessed by the Risk Factors Predicting Questionnaire. RESULTS: Fat mass (22.4 +/- 4.7 vs. 40.6 +/- 14.2 kg, p < 0.001), lean mass (37.3 +/- 6.0 vs. 48.1 +/- 7.6 kg, p < 0.001), water mass (31.6 +/- 2.9 vs. 38.3 +/- 5.3 kg, p < 0.001), and basal metabolic rate (1,253 +/- 132 vs. 1,456 +/- 126 kcal, p < 0.001) were lower in osteoporotic patients than in controls. Self-reported physical activity (2.35 +/- 0.6 vs. 1.69 +/- 0.5, p < 0.001) and risk factors of fractures (5.9 +/- 2.1 vs. 2.6 +/- 2.4, p < 0.001) were higher in women with osteoporosis than in healthy age- and sex-matched controls (2.35 +/- 0.6 vs. 69 +/- 0.5, p < 0.001). Trail making A and B scores were higher in patients than in age- and sex-matched controls (55.8 +/- 19.9 vs. 45.1 +/- 19.9, p = 0.07 and 118.2 +/- 34.6 vs. 92.8 +/- 48.7, p = 0.006). Some significant correlations were detected between physical activity and emotional state and quality of life parameters. CONCLUSION: In postmenopausal women with osteoporosis, fat body mass, lean body mass, water body mass, basal metabolic rate, and waist-to-hip ratio are lower, physical activity and risk of fractures are higher, and cognitive functions are worse than in age- and sex-matched controls. Some psychological peculiarities could be related to physical activity in women with osteoporosis.

Successful skeletal aging: a marker of low fracture risk and longevity. The Study of Osteoporotic Fractures (SOF)

Successful aging is multidimensional, and many phenotypes have been proposed. We examined a biomarker of aging based on repeated measures of BMD for up to 15 yr and hypothesized that maintenance of BMD will be associated with low fracture risk and disability and improved survival. We studied 9704 women recruited at four U.S. clinical centers and enrolled in the Study of Osteoporotic Fractures, a longitudinal cohort study. Of these, 8224 women had at least one hip BMD measurement. Hip BMD was measured a maximum of five times over 15 yr. Random effects regression was used to determine a BMD slope for each subject. Three groups were formed-"maintained" BMD: slope >or=0, n = 724 (9%); "expected" BMD loss: slope <0 to <1 SD below mean, n = 6478 (79%); and "accelerated" BMD loss: slope >or=1 SD below mean, n = 1022 (12%). Cox proportional hazards models were used to compare the relative hazard (RH; 95% CI) of fracture, incident mobility disability, and mortality in the maintained and accelerated groups compared with the expected. A 1 SD decrease in the BMD slope was associated with an increased risk of all outcomes. In multivariate models, the RH of nonspine fracture was 0.81 (0.71-0.93) and of hip fracture was 0.36 (0.25-0.53) for women in the maintained compared with the expected group. The incidence of mobility disability was lower in the maintained versus expected group (RH = 0.70; 95% CI = 0.59-0.83), but this was largely explained by other factors. Women who experienced accelerated bone loss were more likely to develop disability (RH = 1.56; 95% CI: 1.33-1.84). Mortality risks were lower in the maintained compared with the expected group (RH = 0.49; 95% CI: 0.42-0.58). In conclusion, a subset of older women maintained their BMD up to 15 yr, suggesting that bone loss is not an inevitable consequence of aging. These women experienced a lower risk of fractures, disability, and mortality, suggesting that this phenotype may be a marker of successful aging.

Item response theory facilitated cocalibrating cognitive tests and reduced bias in estimated rates of decline

OBJECTIVE

To cocalibrate the Mini-Mental State Examination, the Modified Mini-Mental State, the Cognitive Abilities Screening Instrument, and the Community Screening Instrument for Dementia using item response theory (IRT) to compare screening cut points used to identify cases of dementia from different studies, to compare measurement properties of the tests, and to explore the implications of these measurement properties on longitudinal studies of cognitive functioning over time.

STUDY DESIGN AND SETTING

We used cross-sectional data from three large (n>1000) community-based studies of cognitive functioning in the elderly. We used IRT to cocalibrate the scales and performed simulations of longitudinal studies.

RESULTS

Screening cut points varied quite widely across studies. The four tests have curvilinear scaling and varied levels of measurement precision, with more measurement error at higher levels of cognitive functioning. In longitudinal simulations, IRT scores always performed better than standard scoring, whereas a strategy to account for varying measurement precision had mixed results.

CONCLUSION

Cocalibration allows direct comparison of cognitive functioning in studies using any of these four tests. Standard scoring appears to be a poor choice for analysis of longitudinal cognitive testing data. More research is needed into the implications of varying levels of measurement precision.

Cognitive decline and dementia in diabetes--systematic overview of prospective observational studies

AIMS/HYPOTHESIS

We systematically reviewed and summarised prospective data relating diabetes status to changes in cognitive function over time.

METHODS

Published reports of longitudinal studies that described assessment of cognitive function in people with diabetes were sought. Studies were included if they assessed cognitive function in participants with diabetes at the beginning and at follow-up. Studies were excluded if they had (1) a follow-up period of less than 1 year, (2) a rate of loss to follow-up in excess of 30%, or (3) described selected subgroups. Change in cognitive function was recorded as either the mean change in score and/or the proportion of individuals developing various degrees of change in cognitive function. A pooled estimate was calculated for the latter.

RESULTS

Of 1,165 abstracts and titles initially identified, 25 articles met the inclusion and exclusion criteria. Individuals with diabetes had a 1.2- to 1.5-fold greater change over time in measures of cognitive function than those without diabetes. When assessed by the Mini-Mental State Exam and the Digit Symbol Span tests, a diagnosis of diabetes increased the odds of cognitive decline 1.2-fold (95% CI 1.05-1.4) and 1.7-fold (95% CI 1.3-2.3), respectively . The odds of future dementia increased 1.6-fold (95% CI 1.4-1.8).

CONCLUSIONS/INTERPRETATION

Compared to people without diabetes, people with diabetes have a greater rate of decline in cognitive function and a greater risk of cognitive decline. Cognitive dysfunction should therefore be added to the list of chronic complications of diabetes.

Endogenous and exogenous hormone exposure and risk of cognitive impairment in Swedish twins: a preliminary study

PURPOSE

To analyze the risk of cognitive impairment among female Swedish Twins with regard to endogenous and exogenous hormone exposure.

DESIGN AND SETTING

A cross-sectional analysis of data from the HARMONY Study, a population-based cohort study of cognitive impairment in the Swedish Twin Registry.

METHODS

Information regarding age at menarche and menopause, parity, and length and type of hormone therapy (HT) was collected via a telephone interview from 6604 women, aged 65-84. Cognitive impairment was assessed with the TELE, a brief telephone cognitive screen.

RESULTS

Length of reproductive period was inversely associated with risk of cognitive impairment (p<0.01). The OR was 1.15 (CI 95% 0.96-1.36) for women with reproductive periods <35 years and 0.82 (CI 95% 0.66-1.00) for women with reproductive periods >39 years. Age at menopause was inversely associated with risk of cognitive impairment. Use of HT was associated with average 40% decline in the risk of cognitive impairment, independent of type and timing of treatment.

CONCLUSION

Our results suggest that both increased length of reproductive period and HT are associated with reduced risk of cognitive impairment.