Serum albumin to globulin ratio is related to cognitive decline via reflection of homeostasis: a nested case-control study

Non-linear relationship of serum albumin-to-globulin ratio and cognitive function in American older people: a cross-sectional national health and nutrition examination survey 2011-2014 (NHANES) study

Background

Inflammation and liver function are associated with cognitive decline and dementia. Little is known about the serum albumin-to-globulin ratio on cognitive function.

Objective

The objective of this study was to investigate the association between albumin-to-globulin ratio and cognitive function among the American older people.

Methods

The public data available on the US National Health and Nutrition Examination Survey (NHANES) from 2011 to 2014 was used for this cross-sectional study. Participants aged ≥60 years completed the cognitive function assessments, including word learning and recall modules from the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), the animal fluency (AF) test, and the digit symbol substitution test (DSST). A composite cognition score was calculated to evaluate global cognition. The univariate and multivariate linear regression analysis, curve fitting, a threshold effect, along with a subgroup analysis and interaction tests were conducted.

Results

Serum albumin-to-globulin ratio (per 0.1 unit) was positively associated DSST score (β = 0.36, 95% CI: 0.21, 0.51), AF score (β = 0.1, 95% CI: 0.04, 0.16) and global cognition score (β = 0.05, 95% CI: 0.02, 0.07), after being fully adjusted, while albumin-to-globulin ratio was not related to CERAD score (β = 0.05, 95% CI: -0.02, 0.12). A non-linear was observed in the dose-response relationship between albumin-to-globulin ratio and global cognition (P for non-linearity < 0.001). The subgroup analysis was overall stable, yet the interaction test was significant for age on global cognition (P for interaction = 0.036).

Conclusion

The findings of this cross-sectional study suggested a positive and non-linear association between albumin-to-globulin ratio and cognitive function in the American older people. Maintaining albumin-to-globulin ratio with an appropriate range may be one of the therapeutic strategies to limit the progression of cognitive decline for the older people.

Associations between liver function and cerebrospinal fluid biomarkers of Alzheimer's disease pathology in non-demented adults: The CABLE study

Liver function has been suggested as a possible factor in the progression of Alzheimer's disease (AD) development. However, the association between liver function and cerebrospinal fluid (CSF) levels of AD biomarkers remains unclear. In this study, we analyzed the data from 1687 adults without dementia from the Chinese Alzheimer's Biomarker and LifestylE study to investigate differences in liver function between pathological and clinical AD groups, as defined by the 2018 National Institute on Aging-Alzheimer's Association Research Framework. We also examined the linear relationship between liver function, CSF AD biomarkers, and cognition using linear regression models. Furthermore, mediation analyses were applied to explore the potential mediation effects of AD pathological biomarkers on cognition. Our findings indicated that, with AD pathological and clinical progression, the concentrations of total protein (TP), globulin (GLO), and aspartate aminotransferase/alanine transaminase (ALT) increased, while albumin/globulin (A/G), adenosine deaminase, alpha-L-fucosidase, albumin, prealbumin, ALT, and glutamate dehydrogenase (GLDH) concentrations decreased. Furthermore, we also identified significant relationships between TP (β = -0.115, pFDR  < 0.001), GLO (β = -0.184, pFDR  < 0.001), and A/G (β = 0.182, pFDR  < 0.001) and CSF β-amyloid1-42 (Aβ1-42 ) (and its related CSF AD biomarkers). Moreover, after 10 000 bootstrapped iterations, we identified a potential mechanism by which TP and GLDH may affect cognition by mediating CSF AD biomarkers, with mediation effect sizes ranging from 3.91% to 16.44%. Overall, our results suggested that abnormal liver function might be involved in the clinical and pathological progression of AD. Amyloid and tau pathologies also might partially mediate the relationship between liver function and cognition. Future research is needed to fully understand the underlying mechanisms and causality to develop an approach to AD prevention and treatment approach.

Association between serum globulin and cognitive impairment in older American adults

Background and aims

Cognitive impairment is on the rise around the world, with profound economic and social consequences. Serum globulin, a marker of liver function, may also play a role in cognitive function. Unfortunately, no consistent conclusion exists regarding the association between serum globulin and cognitive function.

Methods

Data from the 2011 to 2014 National Health and Nutrition Examination Survey were used to assess the association between serum globulin and cognitive impairment. Cognitive function was assessed by three tests: Consortium to Establish a Registry for Alzheimer's Disease (CERAD), Animal Fluency (AF), and Digit Symbol Substitution Test (DSST). Furthermore, the breakthrough point of cognitive impairment correlated with CERAD < 5, AF < 14, and DSST < 34. A weighted multiple logistics regression model was used to verify the association between serum globulin and cognitive impairment. Generalized additive models (GAMs) and a smooth curve fit (penalty spline method) were used to determine a non-linear relationship between serum globulin and cognitive impairment. Finally, subgroup analysis and interaction tests were conducted to further verify the association between serum globulin and cognitive impairment.

Results

Data from 2,768 participants aged ≥60 (in accordance with the study design) were collected for the final analysis. Data suggested that serum globulin levels were associated with an elevated cognitive impairment based on the AF [full adjustment, OR = 1.05, 95% CI: 1.01-1.08] and DSST [full adjustment, OR = 1.06, 95% CI: 1.02-1.10] tests. Eventually, the GAM and smooth curve fit model was conducted to confirm that the association between serum globulin and cognitive impairment was non-linear. Moreover, the inflection point was 27 g/L serum globulin based on the CERAD test and 35 g/L serum globulin based on the AF test. Finally, the interaction term between serum globulin and cognitive impairment based on the AF test indicated no significant interactions among all variables (all p for interaction >0.05).

Conclusion

The association between serum globulin levels and cognitive impairment is non-linear. A threshold effect exists between serum globulin and cognitive impairment. Large-scale prospective clinical trials are needed to validate our findings.

Focusing on Helicobacter pylori infection in the elderly

As a confirmed carcinogen, Helicobacter pylori (H. pylori) is the main cause of inflammatory diseases of the upper digestive tract and even gastric cancer. There is a high prevalence of H. pylori infection among the elderly population, which may cause adverse clinical outcomes. Particularly noteworthy is that guidelines or expert consensus presently available on H. pylori infection overlook the management of the elderly population as a special group. A brief overview of H. pylori in the elderly is as follows. The detection of H. pylori infection can be divided into invasive and non-invasive techniques, and each technique has its advantages and shortcomings. There may be more side effects associated with eradication treatment in elderly individuals, especially for the frail population. Physical conditions and risk-benefit assessments of the elderly should be considered when selecting therapeutic strategies for H. pylori eradication. Unless there are competing factors, elderly patients should receive H. pylori eradication regimens to finally reduce the formation of gastric cancer. In this review, we summarize the latest understanding of H. pylori in the elderly population to provide effective managements and treatment measures.

Left ventricular hypertrophy, carotid atherosclerosis, and cognitive impairment in peritoneal dialysis patients

BACKGROUND

Left ventricular hypertrophy (LVH) and carotid atherosclerosis (CAS) have been identified as factors associated with cognitive impairment (CI) but have not been studied in patients undergoing peritoneal dialysis (PD). This study investigated the relationship between LVH and CAS and cognitive function in patients undergoing PD.

METHODS

In this single-center cross-sectional study, the clinically stable patients who were over 18 years of age and had undergone PD for at least 3 months were enrolled. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA), which included seven areas: visuospatial/executive function, naming, attention, language, abstraction, delayed recall, and orientation. LVH was defined as LVMI > 46.7 g/m^2.7 in women and LVMI > 49.2 g/m^2.7 in men. CAS was defined as carotid intima-media thickness ≥ 1.0 mm and/or the presence of plaque.

RESULTS

A total of 207 patients undergoing PD were recruited, with an average age of 52.14 ± 14.93 years and a median PD duration of 8 months (5-19 months). The CI rate was 56%, and the prevalence of CAS was 53.6%. LVH occurred in 110 patients (53.1%). Patients in the LVH group tended to be older, and had a higher body mass index, a higher pulse pressure, a higher male proportion, a lower ejection fraction, a higher prevalence of cardiovascular disease and CI, and a lower MoCA scores.Multivariate logistic regression analysis was conducted to analyze the association between LVH and CI (OR, 10.087; 95% confidence interval, 2.966-34.307). And the association between LVH and CI was still supported after propensity matching scores. CAS was not significantly associated with CI.

CONCLUSION

LVH is independently associated with CI in patients undergoing PD, while CAS is not significantly associated with CI.

Association of serum albumin to globulin ratio with outcomes in acute ischemic stroke

BACKGROUND

Serum albumin to globulin ratio (A/G) has been widely used as a representative biomarker for assessing inflammation and nutrition status. However, in patients with acute ischemic stroke (AIS), the predictive value of serum A/G has rarely been reported. We aimed to evaluate whether serum A/G is associated with prognosis in stroke.

METHODS

We analyzed data from the Third China National Stroke Registry. The patients were categorized into quartile groups according to the serum A/G at admission. Clinical outcomes included poor functional outcomes (modified Rankin Scale [mRS] score of 3-6 or 2-6) and all-cause mortality at 3 months and1 year. Multivariable logistic regressions and Cox proportional hazards regressions were used to evaluate the association of serum A/G with the risk of poor functional outcomes and all-cause mortality.

RESULTS

A total of 11, 298 patients were included in this study. After adjustment for confounding factors, patients in the highest serum A/G quartile had a lower proportion of mRS score 2-6 (odds ratio [OR], 0.87; 95% confidence interval [CI], 0.76-1.00) and mRS score 3-6 (OR, 0.87; 95% CI, 0.73-1.03) at 3 months follow-up. At 1 year follow-up, there was a significant association between higher serum A/G and mRS score 3-6 (OR, 0.68; 95% CI, 0.57-0.81). We also found that the highest serum A/G was related to decreased risk of all-cause mortality (hazard ratio [HR], 0.58; 95% CI, 0.36-0.94) at 3 months follow-up. Similar results were found at 1-year follow-up.

CONCLUSIONS

Lower serum A/G levels were associated with poor functional outcomes and all-cause mortality at 3 months and 1-year follow-up in patients with acute ischemic stroke.

Effect modification by aging on the associations of nicotine exposure with cognitive impairment among Chinese elderly

Active and passive exposure to tobacco smoke may increase risk of cognitive decline. However, effects of enhanced the aging process on the association of urinary nicotine metabolites with cognitive impairment remain unclear. In this study, 6657 Chinese older adults completed the physical examinations and cognitive tests. We measured urinary nicotine metabolite levels, mitochondrial DNA copy number (mtDNA-CN), and relative telomere length (RTL) and analyzed effects of urinary nicotine metabolites and their interaction with mtDNA-CN or RTL on cognitive impairment by generalized linear models and qg-computation, respectively. Each 1-unit increase in urinary 3-OHCot, 3-OHCotGluc, CotGluc, or NicGluc levels corresponded to a 1.05-, 1.09-, 1.04-, and 0.90-fold increased risk of cognitive impairment. Each 1-quantile increment in the mixture level of 8 nicotine metabolites corresponded to an increment of 1.40- and 1.34-fold risk of cognitive impairment in individuals with longer RTL or low mtDNA-CN. Urinary 3-OHCotGluc and RTL or mtDNA-CN exhibited an additive effect on cognitive impairment in addition to the mixture of 8 nicotine metabolites and mtDNA-CN. The findings suggested that aging process may increase the risk of tobacco-related cognitive impairment.

Cannabidiol-enriched cannabis extraction product in Parkinson's disease: A randomized, double-blind, and placebo-controlled trial in Buriram Hospital

Objectives

The objective of this study was to assess cannabidiol-enriched cannabis extraction product (CBDEP) efficacy in patients with Parkinson's disease (PD).

Materials and Methods

Forty patients with PD were randomly assigned to the sublingual CBDEP (n = 20) or placebo (n = 20) group. All patients were prescribed a low initial dose with gradual titration within 2 weeks based on individual response - including side effects - followed by 6 weeks of stable dosing. The primary outcome was the Unified Parkinson's Disease Rating Scale (UPDRS) score. The secondary outcomes were as follows: Quality of life (QOL) evaluated by the EQ-5D-5L, timed up and go (TUG) test, 5 times sit to stand (FTSTS) test, gait velocity, hospital anxiety and depression scale (HADS), renal and liver function indices, and adverse events. All outcomes were measured at baseline and at 8 weeks. The generalized estimating equation adjusted for baseline scores was used to compare the values at baseline and at 8 weeks, and between the groups.

Results

Four patients were lost to follow-up (CBDEP group, n = 1; placebo group, n = 3) and 36 were included in the analysis (CBDEP group, n = 19; placebo group, n = 17). The CBDEP group received mean cannabidiol and tetrahydrocannabinol dosages of 15.59 ± 5.04 mg/day and 0.61 ± 0.19 mg/day, respectively. No significant differences were found between the groups in terms of the UPDRS, TUG test, FTSTS test, gait velocity, HADS-anxiety, and HADS-depression. The placebo group had significantly improved EQ-5D-5L scores for QOL (P = 0.004). The CBDEP group showed significantly improved blood urea nitrogen (BUN), serum albumin, serum globulin levels, and albumin/globulin ratio (P = 0.037, P < 0.001, P = 0.011, and P = 0.002, respectively) compared with the placebo group. Neither group had serious side effects.

Conclusion

No evidence was found that CBDEP can reduce disease severity or improve functional performance, anxiety, or depression in PD. However, CBDEP is safe and can improve the levels of BUN, serum albumin, serum globulin, and albumin/globulin ratio in patients with PD.

Trial Registration

Thai Clinical Trials Registry (registration number: TCTR 20210303005).

Albumin to Globulin Ratio was associated with in-stent restenosis and revascularization events after percutaneous coronary intervention

In-stent restenosis is a common complication after percutaneous coronary intervention (PCI) for coronary heart disease requiring revascularization. We performed a retrospective analysis to assess the value of inflammatory biomarker Albumin to Globulin Ratio (AGR) in clinical prognosis of percutaneous coronary intervention (PCI). In total, 992 coronary heart disease (CHD) patients who underwent the first drug-eluting stent implantation and reexamination angiography in our hospital were enrolled in this study. Albumin to Globulin Ratio was measured. At mean follow-up of 11.2 ± 4 months, the in-stent restenosis (ISR) and revascularization events (including target lesion revascularization, target vessel revascularization, and revascularization of de novo lesions) occurred in 127 and 284 patients respectively. Compared with the non-ISR or non-event group, AGR was significantly lower in the ISR group and events group. Beyond that, albumin was significantly lower, while urea nitrogen, glucose and gensini score, as well as the proportions of a history of diabetes and peripheral vascular diseases, were significantly higher in the ISR group and events group. Age, heart rate, white blood cell, neutrophils, lymphocyte, monocyte and incidence of ischemic stroke were significantly higher in the events group. Multivariate cox regression analysis showed that AGR was independently associated with ISR (P = 0.032) and events (P = 0.024). Besides, Kaplan-Meier analysis indicated that the higher quartile of AGR had a lower rate of ISR (P = 0.038) and events (p ≤ 0.001). Finally, the receiver operating characteristic (ROC) curve for AGR in diagnosing ISR and events indicated that the area under the curve (AUC) were 0.56 and 0.57 respectively. Therefore, AGR is one of the most important factors that independently associate with the ISR and revascularization events after PCI.

Olfactory dysfunction predicts the development of dementia in older patients with type 2 diabetes

AIMS

Olfactory dysfunction is associated with the transition from normal cognition to dementia in persons without type 2 diabetes. This study aimed to investigate whether olfactory dysfunction could be an early marker of future dementia in older patients with type 2 diabetes.

METHODS

This exploratory study included 151 older Japanese outpatients with type 2 diabetes who did not have a diagnosis of probable dementia at baseline. A multivariate logistic regression model was used to determine whether Open Essence (OE) test score at baseline is associated with the development of probable dementia.

RESULTS

Over 3 years, approximately 9% of the study subjects developed probable dementia. Subjects with olfactory dysfunction at baseline developed probable dementia more frequently than those without. Multivariate logistic regression showed that lower OE test score, higher age, lower Mini-Mental State Examination (MMSE) score, higher total protein concentration, and more frequent use of a sulfonylurea are significantly associated with the development of probable dementia. Stepwise multivariate regression analysis demonstrated that change in OE test score over 3 years is significantly associated with change in MMSE score.

CONCLUSIONS

Our study suggested that olfactory dysfunction precedes the development of probable dementia in older patients with type 2 diabetes.

Associations of Serum Liver Function Markers With Brain Structure, Function, and Perfusion in Healthy Young Adults

Background: Previous neuroimaging studies have demonstrated brain abnormalities in patients with hepatic diseases. However, the identified liver-brain associations are largely limited to disease-affected populations, and the nature and extent of such relations in healthy subjects remain unclear. We hypothesized that serum liver function markers within a normal level would affect brain properties. Method: One hundred fifty-seven healthy young adults underwent structural, resting-state functional, and arterial spin labeling MRI scans. Gray matter volume (GMV), regional homogeneity (ReHo), and cerebral blood flow (CBF) analyses were performed to assess brain structure, function, and perfusion, respectively. Peripheral venous blood samples were collected to measure serum liver function markers. Correlation analyses were conducted to test potential associations between liver function markers and brain imaging parameters. Results: First, serum proteins showed relations to brain structure characterized by higher albumin associated with increased GMV in the parahippocampal gyrus and amygdala and lower globulin and a higher albumin/globulin ratio with increased GMV in the olfactory cortex and parahippocampal gyrus. Second, serum bilirubin was linked to brain function characterized by higher bilirubin associated with increased ReHo in the precuneus, middle cingulate gyrus, inferior parietal lobule, and supramarginal gyrus and decreased ReHo in the caudate nucleus. Third, serum alanine transaminase (ALT) was related to brain perfusion characterized by higher ALT associated with increased CBF in the superior frontal gyrus and decreased CBF in the middle occipital gyrus, angular gyrus, precuneus, and middle temporal gyrus. More importantly, we found that CBF in the superior frontal gyrus was a significant mediator of the association between serum ALT level and working memory performance. Conclusion: These findings may not only expand existing knowledge about the relationship between the liver and the brain but also have clinical implications for studying brain impairments secondary to liver diseases as well as providing potential neural targets for their diagnosis and treatment.

Cognitive impairment is associated with mitochondrial dysfunction in peripheral blood mononuclear cells of elderly population

Cognitive impairment is commonly found in the elderly population. Evidence suggests that mitochondrial function in lymphocytes are potential biomarkers in the progression of neurodegeneration, as peripheral mitochondrial function is associated with mild cognitive impairment (MCI) in the elderly population. Therefore, we hypothesize that impaired mitochondrial ATP production and oxidative stress in peripheral blood mononuclear cells (PBMCs) are associated with cognitive impairment in the elderly population. Data were collected from 897 participants from the EGAT (The Electricity Generating Authority of Thailand) cohort. The participants were classified to be in the normal cognition group (n = 428) or mild cognitive impairment group (n = 469), according to their MoCA score. The association of mitochondrial function and cognitive status was analyzed by binary logistic regression analysis. MCI participants had higher age, systolic blood pressure, waist/hip ratio, and lower plasma high- and low-density lipoprotein cholesterol levels, when compared to the normal cognition group. In addition, estimated glomerular filtration rate were lower in the MCI group than those in the normal cognition group. Collectively, MCI is associated with mitochondrial dysfunction in PBMCs as indicated by decreasing mitochondrial ATP production, increasing proton leak, and oxidative stress, in the elderly population, independently of the possible confounding factors in this study.

High Dose of Intravenous Allogeneic Umbilical Cord-Derived Mesenchymal Stem Cells (CLV-100) Infusion Displays Better Immunomodulatory Effect among Healthy Volunteers: A Phase 1 Clinical Study

Background

Mesenchymal stem cells (MSCs) express growth factors and other cytokines that stimulate repair and control the immune response. MSCs are also immunoprivileged with low risk of rejection. Umbilical cord-derived MSCs (UCMSCs) are particularly attractive as an off-the-shelf allogeneic treatment in emergency medical conditions. We aim to determine the safety and efficacy of intravenous allogeneic infusion of UCMSCs (CLV-100) by Cytopeutics® (Selangor, Malaysia) in healthy volunteers, and to determine the effective dose at which an immunomodulatory effect is observed. Methodology. Umbilical cord samples were collected after delivery of full-term, healthy babies with written consent from both parents. All 3 generations (newborn, parents, and grandparents) were screened for genetic mutations, infections, cancers, and other inherited diseases. Samples were transferred to a certified Good Manufacturing Practice laboratory for processing. Subjects were infused with either low dose (LD, 65 million cells) or high dose (HD, 130 million cells) of CLV-100 and followed up for 6 months. We measured cytokines using ELISA including anti-inflammatory cytokines interleukin 1 receptor antagonist (IL-1RA), interleukin 10 (IL-10), pro-/anti-inflammatory cytokine interleukin 6 (IL-6), and the proinflammatory cytokine tumor necrosis factor-alpha (TNF-α).

Results

11 healthy subjects (LD, n = 5; HD, n = 6; mean age of 55 ± 13 years) were recruited. All subjects tolerated the CLV-100 infusion well with no adverse reaction throughout the study especially in vital parameters and routine blood tests. At 6 months, the HD group had significantly higher levels of anti-inflammatory markers IL1-RA (705 ± 160 vs. 306 ± 36 pg/mL; p = 0.02) and IL-10 (321 ± 27 vs. 251 ± 28 pg/mL; p = 0.02); and lower levels of proinflammatory marker TNF-α (74 ± 23 vs. 115 ± 15 pg/mL; p = 0.04) compared to LD group.

Conclusion

Allogeneic UCMSCs CLV-100 infusion is safe and well-tolerated in low and high doses. Anti-inflammatory effect is observed with a high-dose infusion.

Methamphetamine-Induced Cognitive Deficits and Psychiatric Symptoms Are Associated with Serum Markers of Liver Damage

Cognitive deficits and psychiatric disorders have been regarded as the most common clinical symptoms of methamphetamine (MA) users. Accumulating evidence has shown that liver disease may be involved in cognitive deficits and psychiatric disorders. This study examines whether cognitive deficits and psychiatric symptoms are associated with serum levels of liver biomarkers in MA users. Cognition was assessed by the Repeatable Battery for the Assessment of neuropsychological Status (RBANS). Psychiatric symptoms were assessed by the Symptom Checklist-90 (SCL-90). Liver function was assessed by serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total protein, albumin, globulin, Apolipoprotein B (ApoB), triglyceride, total cholesterol, and glucose concentrations in 106 MA addicts and 76 controls. Compared to control subjects, MA users had greater severity of psychotic symptoms on the dimension of somatization, depression, anxiety, psychoticism, addiction, and global severity index in SCL-90, and lower scores of cognition, including the total RBANS score and all five subscales. The globulin levels were increased, while the albumin, albumin/globulin, and ApoB levels were decreased. ApoB levels were positively correlated with immediate memory, attention, and total RBANS score. Furthermore, stepwise multivariate regression analysis indicated that ApoB levels were associated with immediate memory, attention, and total RBANS score. The findings of this study suggest that MA addicts might experience cognitive deficits, psychiatric disorders, and liver damage. Serum ApoB levels may be involved in cognitive deficits; thus, improving liver function may help to treat cognitive deficits and psychiatric disorders in MA addicts.

Serum albumin/globulin ratio is associated with cognitive function in community-dwelling older people: The Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study

AIM

The objective of this study was to clarify the relationship between cognitive function and the serum albumin/globulin ratio (A/G ratio) in community-dwelling Japanese older adults.

METHODS

Randomly extracted residents in both urban and rural parts of Japan were enrolled in this study. A total of 1827 participants with a mean age of 70 or 80 years were recruited. A venue survey method was carried out with comprehensive studies, including interviews, blood collection, physical examination and cognitive function tests.

RESULTS

Univariate analysis showed a significant positive correlation between the total Japanese version of the Montreal Cognitive Assessment score and the serum A/G ratio at the age of 70 and 80 years, in which better cognitive function was associated with a high serum A/G ratio. Multiple regression analysis with the total Japanese version of the Montreal Cognitive Assessment score as the dependent variable showed that the serum albumin level, serum globulin level, serum A/G ratio, C-reactive protein, years of formal education and sex were related to the Japanese version of the Montreal Cognitive Assessment total score at the age of 70 years, and that the serum albumin level, serum globulin level, serum A/G ratio, C-reactive protein, years of formal education and stroke were related at the age of 80 years. The serum A/G ratio showed a better correlation than the serum globulin levels at the age of 70 and 80 years (70 years: β = 0.131 vs -0.111, 80 years: β = 0.108 vs -0.071).

CONCLUSIONS

We found a correlation between cognitive function and the serum A/G ratio in community-dwelling older people, suggesting that nutritional status and chronic inflammation might influence cognitive function. Geriatr Gerontol Int 2019; 19: 967-971.

Measuring proteins in H2O with 2D-IR spectroscopy

The amide I infrared band of proteins is highly sensitive to secondary structure, but studies under physiological conditions are prevented by strong, overlapping water absorptions, motivating the widespread use of deuterated solutions. H/D exchange raises fundamental questions regarding the impact of increased mass on protein dynamics, while deuteration is impractical for biomedical or commercial applications of protein IR spectroscopy. We show that 2D-IR spectroscopy can avoid this problem because the 2D-IR amide I signature of proteins dominates that of water even at sub-millimolar protein concentrations. Using equine blood serum as a test system, we investigate the significant implications of being able to measure the spectroscopy and dynamics of proteins in water, demonstrating relevance in areas ranging from fundamental science to the clinic. Measurements of vibrational relaxation dynamics of serum proteins reveals that deuteration slows down the rate of amide I vibrational relaxation by >10%, indicating a dynamic impact of isotopic exchange in some proteins. The unique link between protein secondary structure and 2D-IR amide I lineshape allows differentiation of signals due to albumin and globulin protein fractions in serum leading to measurements of the biomedically-important albumin to globulin ratio (AGR) with an accuracy of ±4% across a clinically-relevant range. Furthermore, we demonstrate that 2D-IR spectroscopy enables differentiation of the structurally similar globulin proteins IgG, IgA and IgM, opening up a straightforward spectroscopic approach to measuring levels of serum proteins that are currently only accessible via biomedical laboratory testing.

Systemic Inflammation Is Associated With Longitudinal Changes in Cognitive Performance Among Urban Adults

Objectives/Background: Systemic inflammation can affect cognitive performance over time. The current study examined associations between systemic inflammation and cognitive performance among African Americans and Whites urban adults, stratifying by sex, and age group and by race. Patients/Methods: Among 1,555-1,719 White and African-American urban adults [Age_base: 30-64y, 2004-2013, mean±SD follow-up time(y): 4.64 ± 0.93y], conducted linear mixed-effects regression models were conducted to test associations of inflammatory markers [C-reactive protein, Erythrocyte Sedimentation Rate (ESR), albumin, iron, and an inflammation composite score (ICS)] with longitudinal cognitive performance. Results: Among key findings, CRP was linked to poorer baseline mental status among younger women (≤50y, γ₀₁ = -0.03 ± 0.01, p = 0.002) and poorer attention in older women (>50y, γ₀₁ = -0.024 ± 0.007, p < 0.004) and African-Americans (γ₀₁ = -0.029 ± 0.008, p < 0.001). ESR was related to faster decline on verbal memory among older men (>50y, γ₁₁ = -0.008 ± 0.003, P = 0.009); with poorer performance on attention tests overall (γ₀₁ = -0.010 ± 0.003, P = 0.003) and among African-Americans (γ₀₁ = -0.013 ± 0.004, P = 0.002); on verbal fluency among older women (>50y,γ₀₁ = -0.037 ± 0.013, P = 0.004) and on executive function: overall (γ₀₁ = +0.62 ± 0.21, P = 0.004), older men (>50y, γ₀₁ = +1.69 ± 0.53, P = 0.001) and African-Americans (γ₀₁ = +0.84 ± 0.28, P = 0.002). Albumin was linked to slower attention decline among older men (>50y, γ₁₁ = +0.329 ± 0.103, P = 0.009), over-time improvement in executive function overall (γ₁₁ = -6.00 ± 2.26, P = 0.008), and better baseline psychomotor speed among African-Americans (γ₀₁ = +0.56 ± 0.19, P = 0.003). Finally, ICS predicted faster decline on visual memory/visuo-constructive abilities among older men (>50y, γ₁₁ = +0.17 ± 0.06, p = 0.003). Conclusion: In sum, strong associations between systemic inflammation and longitudinal cognitive performance were detected, largely among older individuals (>50y) and African-Americans. Randomized trials targeting inflammation are warranted.

Albumin-to-globulin ratio as an independent predictor of mortality in chronic heart failure

AIM

Albumin-to-globulin ratio (AGR) is emerged as a marker of impaired prognosis. We determined the predictive value of AGR in patients with heart failure with reduced ejection fraction (HFrEF).

METHODOLOGY

999 patients with HFrEF were enrolled. Rates of 1-year all-cause mortality were compared between AGR quartiles (Q). Moreover, multivariate survival analysis in Cox's regression model and receiver operating characteristic analyses were performed.

RESULTS

90-day and 1-year mortality was the highest in AGR Q1. AGR was an independent predictor of 90-day and 1-year mortality. Receiver operating characteristic analysis revealed moderate diagnostic value in predicting 90-day (AGR cutoff <1.2) and 1-year (AGR cutoff <1.38) mortality.

CONCLUSION

AGR had a good prognostic value and remained an independent predictor of mortality in HFrEF patients.