fNIRS as a biomarker for individuals with subjective memory complaints and MCI.

INTRODUCTION: Identifying individuals at risk of developing dementia is crucial for early intervention. Mild cognitive impairment (MCI) and subjective memory complaints (SMCs) are considered its preceding stages. This study aimed to assess the utility of functional near-infrared spectroscopy (fNIRS) in identifying individuals with MCI and SMC. METHODS: One hundred fifty-one participants were categorized into normal cognition (NC); amnestic MCI (aMCI); non-amnestic MCI (naMCI); and mild, moderate, and severe SMC groups. Task-related prefrontal hemodynamics were measured using fNIRS during a visual memory span task. RESULTS: Results showed significantly lower oxyhemoglobin (HbO) levels in aMCI, but not in naMCI, compared to the NC. In addition, severe SMC had lower HbO levels than the NC, mild, and moderate SMC. Receiver operating characteristic analysis demonstrated 69.23% and 69.70% accuracy in differentiating aMCI and severe SMC from NC, respectively. DISCUSSION: FNIRS may serve as a potential non-invasive biomarker for early detection of dementia. HIGHLIGHTS: Only amnestic mild cognitive impairment (aMCI), but not non-amnestic MCI, showed lower oxyhemoglobin (HbO) than normal individuals. Reduced HbO was observed in those with severe subjective memory complaints (SMCs) compared to normal cognition (NC), mild, and moderate SMCs. Functional near-infrared spectroscopy measures were associated with performance in memory assessments. Prefrontal hemodynamics could distinguish aMCI and severe SMC from NC.

Prospective association between social isolation, loneliness and lung function among Chinese middle-aged and older adults.

OBJECTIVE: Previous research has highlighted a heightened occurrence of social isolation and loneliness in older adults diagnosed with chronic lung diseases. Nevertheless, there exists a dearth of studies that have explored the influence of impoverished social relationships on lung function. This study aimed to examine the longitudinal association between social isolation, loneliness and lung function over 4 years among middle-aged and older Chinese adults. METHODS: This study employed two waves (2011 and 2015) of data from the China Health and Retirement Longitudinal Study (CHARLS). The analysis was limited to participants aged 45 years and above and stratified based on gender (3325 men and 3794 women). The measurement of peak expiratory flow (PEF) served as an indicator for assessing lung function. Lagged dependent variable regression models, accounting for covariates, were employed to explore the relationship between baseline social isolation and loneliness and the subsequent PEF. RESULTS: For women, social isolation was significantly associated with the decline in PEF at follow-up (ß = -.06, p < .001) even after adjusting for all covariates; no significant correlation was observed between loneliness and PEF. Among men, there was no significant association found between either social isolation or loneliness and PEF. CONCLUSIONS: Social isolation is prospectively associated with worse lung function in middle-aged and older Chinese women but not men. The results highlight the importance of promoting social relationships in public health initiatives, especially in groups that are more vulnerable.

Pathophysiology characterization of Alzheimer's disease in South China's aging population: for the Greater-Bay-Area Healthy Aging Brain Study (GHABS).

INTRODUCTION: The Guangdong-Hong Kong-Macao Greater-Bay-Area of South China has an 86 million population and faces a significant challenge of Alzheimer's disease (AD). However, the characteristics and prevalence of AD in this area are still unclear due to the rarely available community-based neuroimaging AD cohort. METHODS: Following the standard protocols of the Alzheimer's Disease Neuroimaging Initiative, the Greater-Bay-Area Healthy Aging Brain Study (GHABS) was initiated in 2021. GHABS participants completed clinical assessments, plasma biomarkers, genotyping, magnetic resonance imaging (MRI), ß-amyloid (Aß) positron emission tomography (PET) imaging, and tau PET imaging. The GHABS cohort focuses on pathophysiology characterization and early AD detection in the Guangdong-Hong Kong-Macao Greater Bay Area. In this study, we analyzed plasma Aß42/Aß40 (A), p-Tau181 (T), neurofilament light, and GFAP by Simoa in 470 Chinese older adults, and 301, 195, and 70 had MRI, Aß PET, and tau PET, respectively. Plasma biomarkers, Aß PET, tau PET, hippocampal volume, and temporal-metaROI cortical thickness were compared between normal control (NC), subjective cognitive decline (SCD), mild cognitive impairment (MCI), and dementia groups, controlling for age, sex, and APOE-ε4. The prevalence of plasma A/T profiles and Aß PET positivity were also determined in different diagnostic groups. RESULTS: The aims, study design, data collection, and potential applications of GHABS are summarized. SCD individuals had significantly higher plasma p-Tau181 and plasma GFAP than the NC individuals. MCI and dementia patients showed more abnormal changes in all the plasma and neuroimaging biomarkers than NC and SCD individuals. The frequencies of plasma A+/T+ (NC; 5.9%, SCD: 8.2%, MCI: 25.3%, dementia: 64.9%) and Aß PET positivity (NC: 25.6%, SCD: 22.5%, MCI: 47.7%, dementia: 89.3%) were reported. DISCUSSION: The GHABS cohort may provide helpful guidance toward designing standard AD community cohorts in South China. This study, for the first time, reported the pathophysiology characterization of plasma biomarkers, Aß PET, tau PET, hippocampal atrophy, and AD-signature cortical thinning, as well as the prevalence of Aß PET positivity in the Guangdong-Hong Kong-Macao Greater Bay Area of China. These findings provide novel insights into understanding the characteristics of abnormal AD pathological changes in South China's older population.

Dyadic effects of cognitive function on depressive symptoms among middle-aged and older Chinese couples.

BACKGROUND: Although cognitive function and depressive symptoms have been suggested to be closely related, less attention has been paid to this association within married couples. This study explored the reciprocal dyadic relationship between cognitive function and depressive symptoms over time. METHODS: This study used four waves of data from the China Health and Retirement Longitudinal Study and analyses were restricted to middle-aged and older couples aged 45 or older. Actor-partner interdependence model adjusted for confounding factors was employed to examine the reciprocal association between cognitive function and depressive symptoms at both the individual and couple levels. Measures of cognitive function consisted of episodic memory and mental status. Depressive symptoms were measured by the Center for Epidemiological Studies Depression scale. RESULTS: For both husbands and wives, cognitive function was reciprocally associated with depressive symptoms at the individual level. Spouses' lower cognitive function was significantly linked to their partners' greater depressive symptoms. However, ones' depressive symptoms were not related to their partners' cognitive function. CONCLUSIONS: These findings expand our knowledge about the dyadic relationship between cognitive function and depressive symptoms in Chinese couples. Effects of interventions for depression in middle-aged and older adults may be enhanced by considering the marital context.

Too depressed to breathe: The longitudinal association between depressive symptoms and lung function among general middle-aged and older adults.

Objective Most previous studies focusing on the association between depressive symptoms and lung function were conducted in patients with chronic lung diseases. This study aims to investigate the association of depressive symptoms with lung function among general Chinese middle-aged and older adults. Participants This study used data from the China Health and Retirement Longitudinal Study (CHARLS). Analyses were conducted with data from three waves (2011, 2013, and 2015) and restricted to those respondents aged 45 and older. Finally, 9487 individuals [mean age (SD) = 58.47 (9.19); female, 53.1%] were included in analysis. Methods Depressive symptoms were measured by the Chinese version of 10-item Center for Epidemiological Studies Depression Scale (CESD-10). Lung function was assessed by peak expiratory flow (PEF). Two-level linear mixed growth models were used to evaluate the longitudinal association between depressive symptoms and PEF. Results Depressive symptoms were significantly associated with PEF among general middle-aged and older adults (b = -1.85, p < 0.001) after adjusting for multiple confounding factors. A significant interaction between depressive symptoms and gender was found (b = 1.29, p < 0.001). The association between depressive symptoms and PEF was greater for men (b = -2.36, p < 0.001) than for women (b = -1.46, p < 0.001). Conclusions This longitudinal study found that increased depressive symptoms were associated with reduced PEF in middle-aged and older adults in China. Compared with women, men with a higher level of depressive symptoms experienced a greater decrement in PEF. Our findings suggest that it is possible to reduce the effects of PEF by improving psychological health among general middle-aged and older populations.

Social isolation and cognitive decline among older adults with depressive symptoms: prospective findings from the China Health and Retirement Longitudinal Study.

OBJECTIVES: Identifying potentially modifiable risk factors of cognitive decline among people with depressive symptoms could provide insight into strategies for improving treatment effect of depression and prevention of dementia. Quite a few studies have examined the association between social isolation and cognitive function directly among depressed older adults and the results are still mixed. The aim is to examine the association of social isolation and cognitive decline among older adults with depressive symptoms in a non-Western country. METHODS: This study used data from the China Health and Retirement Longitudinal Study (CHARLS). Depressive symptoms were measured by the Chinese version of the 10-item Center for Epidemiological Studies Depression Scale (CESD-10) (elevated depressive symptom cutoff≥10). Social isolation was assessed based on responses to four items: marital status, residence, contact with children, and social activity. Lagged dependent variable regressions adjusted for confounding factors were used to evaluate the association between baseline social isolation and follow-up cognitive function. RESULTS: A number of 2,507 participants [mean age (SD)=61.37 (7.26); male, 41.0%] with increased depressive symptoms were available for the present study. Baseline social isolation was significantly associated with 4-year episodic memory (ß=-0.08, p<0.001) in depressed women, but not men (ß=-0.03, p=0.350). No significant association between baseline social isolation and follow-up mental status was found for women (ß=-0.04, p=0.097) or men (ß=0.01, p=0.741). DISCUSSION: This longitudinal study found that social isolation was significantly associated with memory decline over 4 years among depressed women (but not men) in China.

Social isolation and depression onset among middle-aged and older adults in China: Moderating effects of education and gender differences.

BACKGROUND: Most studies exploring the association between social isolation and depression tend to focus on Western countries. The primary aim of this longitudinal study was to examine the association between social isolation and depression onset among middle-aged and older adults in China. METHODS: Data on 6,817 participants (mean age = 57.91, SD = 8.77; men, 52.1%) from the first and fourth waves of the China Health and Retirement Longitudinal Study (CHARLS) were analyzed. Binary logistic regressions were used to evaluate the association between social isolation and depression onset. The moderating effects of socioeconomic status (education) and gender differences were also examined. RESULTS: Social isolation was significantly associated with depression onset (OR = 1.24, 95% CI = 1.10-1.41). Compared to men with lower education (OR = 0.97, 95% CI = 0.77-1.23), those with higher education (OR = 1.91, 95% CI = 1.40-2.60) exhibited a greater association between social isolation and depression onset. Moderating effect of education was not found for women. LIMITATIONS: Depression were self-reported, which might be less reliable than clinical interview. CONCLUSIONS: Our results suggested that high level of social isolation was significantly associated with a higher incidence of depression among middle-aged and older adults in China. Education played a moderating role in this association for men rather than women.

Social isolation, loneliness and functional disability in Chinese older women and men: a longitudinal study.

OBJECTIVE: This study investigated whether loneliness or social isolation is associated with the onset of functional disability over 4 years among Chinese older populations. SETTING AND SUBJECTS: This study used data from the China Health and Retirement Longitudinal Study (CHARLS). Functional status was assessed by activities of daily living (ADL) and instrumental activities of daily living (IADL). Analyses were conducted with data from two waves (2011 and 2015) and were restricted to those respondents aged 50 and older and free of functional disability at baseline [n = 5,154, mean age (SD) = 60.72 (7.51); male, 52.3%]. METHOD: Social isolation, loneliness and covariates were measured at baseline. Follow-up measures of new-onset ADL and IADL disability were obtained 4 years later. We stratified the sample by gender, and then used binary logistic regressions to evaluate the associations between baseline isolation, loneliness and new-onset ADL and IADL disability. RESULTS: For women, baseline social isolation was significantly associated with new-onset ADL (OR = 1.18, 95% CI = 1.07-1.30) and IADL (OR = 1.11, 95% CI = 1.01-1.21) disability; no significant association between loneliness and ADL or IADL disability was found. For men, neither social isolation nor loneliness was found to be significantly associated with ADL or IADL disability. CONCLUSION: This longitudinal study found that social isolation, rather than loneliness, was significantly associated with functional disability over 4 years among women (but not men) in China. These findings expand our knowledge about the association between social relationships and functional status among non-Western populations.

Preparation and characterization of a titanium bonding porcelain.

The titanium bonding porcelain was synthesized through normal melting-derived route using borate-silicate system. The porcelain was characterized by thermal expansion, X-ray diffraction, scanning electron microscope and cytotoxicity tests. The results of X-ray diffraction showed that the main phase of the bonding porcelain was SnO2. The SnO2 microcrystals precipitated from the glass matrix when the SnO2 content was increased. The thermal expansion coefficient of bonding porcelains decreased with the increasing concentration of SiO2. The thermal expansion coefficient of bonding porcelains first decreased slightly with the increasing of B2O3 concentration (from 0 wt% to 10 wt%) and then increased to about 9.4×10(-6)/°C(from 10 wt% to 12 wt%). As an intermediate, B2O3 can act as both network formers and modifiers, depending on the relationship between the concentration of basic oxides and intermediates. The Vickers hardness of bonding porcelains increased with the increase of SnO2 concentration. When SnO2 concentration was 6 wt%, only Si and Sn elements attended the reaction between titanium and porcelain and mainly adhesive fracture was found at Ti-porcelain interface. When SnO2 concentration was 12 wt%, failure of the titanium-porcelain predominantly occurred in the bonding porcelain and mainly cohesive fracture was found at Ti-porcelain interface. The methyl thiazolyl tetrazolium assay results demonstrated that the cytotoxicity of the titanium porcelain was ranked as 0.