Glycemic control, inflammation, and cognitive function in older patients with type 2 diabetes

Cognitive decline in elderly patients with type 2 diabetes is associated with glycated albumin, ratio of Glycated Albumin to glycated hemoglobin, and concentrations of inflammatory and oxidative stress markers

Objective

To investigate the correlations of cognitive function with glycated albumin (GA), the ratio of GA to glycated hemoglobin (GA/HbA1c), and the concentrations of interleukin-6 (IL-6) and superoxide dismutase (SOD) in elderly patients with type 2 diabetes mellitus (T2DM).

Methods

A total of 44 elderly T2DM patients were evaluated for cognitive function using the mini-mental state examination (MMSE) and the Montreal cognitive assessment (MoCA). Patients were then divided into two groups based on the MMSE and MoCA scores: a cognitive dysfunction group and a normal cognitive function group. The correlations of the MMSE and MoCA scores with GA/HbA1c, GA, IL-6, and SOD were analyzed. Logistic regression analysis was used to identify independent influential factors for cognitive dysfunction. The predictive value of GA and GA/HbA1c for cognitive dysfunction in elderly T2DM patients was evaluated by receiver operating characteristic (ROC) curve analysis.

Results

Among these patients, 28 had cognitive impairment. They had significantly higher GA/HbA1c, increased GA and IL-6 levels, and lower SOD concentrations than the normal cognitive function group (all P < 0.05). GA/HbA1c was negatively correlated with the MMSE (r = -0.430, P = 0.007) and MoCA (r = -0.432, P = 0.007) scores. SOD was positively correlated with the MMSE (r = 0.585, P=0.014) and MoCA (r = 0.635, P=0.006) scores. IL-6 was negatively correlated with the MoCA score (r = -0.421, P=0.015). Age and GA/HbA1c were independent factors contributing to cognitive dysfunction. The areas under the ROC curves of GA and GA/HbA1c for the diagnosis of cognitive dysfunction were 0.712 and 0.720, respectively.

Conclusions

GA and GA/HbA1c are related to cognitive dysfunction in elderly patients with T2DM.

Correlation between inflammatory biomarkers, cognitive function and glycemic and lipid profiles in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

This study aimed to quantitatively estimate the correlation between systemic inflammation with cognitive function, as well as glycemic and lipid profiles in patients with type 2 diabetes mellitus (T2DM). The PubMed, Web of Science, EMBASE, SCOPUS, CNKI, Wanfang, VIP, and CBM databases were searched from its inception until June 2023 (PROSPERO registration: CRD42022356889). We analyzed data extracted from observational studies to quantify the correlations (r) as the pooled effect size and further performed subgroup analyses and sensitivity analyses. A total of 32 studies involving 7,483 patients with T2DM were included. The findings revealed a significant moderate negative correlation between interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) levels with Montreal Cognitive Assessment scores. TNF-α levels also had moderate negative correlation with Mini-Mental State Examination scores. For glycemic and lipid profiles, there was a significant moderate positive correlation between CRP and TNF-α levels and glycated hemoglobin (HbA1c), and TNF-α levels were also found to be lowly positively correlated with fasting blood glucose (FBG). CRP levels were found to have a low positive correlation with total cholesterol (TC), and IL-6 levels were found to be lowly positively correlated with triglycerides. The results indicate that elevated levels of IL-6, CRP, and TNF-α are significantly associated with cognitive impairment in patients with T2DM and may serve as inflammatory markers for T2DM with mild cognitive impairment. The CRP and TNF-α levels were more strongly correlated with HbA1c than with FBG and TC. Further research is needed to determine the clinical value of these inflammatory biomarkers and to investigate potential causal mechanisms underlying this association.

HbA1c Variability and Cardiovascular Events in Patients with Prostate Cancer Receiving Androgen Deprivation Therapy

Background

Androgen deprivation therapy (ADT) worsens glycaemic control and cardiovascular outcomes. The prognostic value of visit-to-visit HbA1c variability (VVHV) has been unexplored in prostate cancer (PCa) patients receiving ADT.

Objective

To explore the effect of ADT on VVHV and the cardiovascular prognostic value of VVHV.

Design setting and participants

PCa patients receiving ADT in Hong Kong between January 1, 1993 and March 31, 2021 were included in this retrospective cohort study. Those with fewer than three HbA1c results available within 3 yr after ADT initiation, <6 mo of ADT, missing baseline HbA1c, prior diagnosis of any component of major adverse cardiovascular events (MACEs), and MACEs occurring within 3 yr were excluded. Patients were followed up until September 31, 2021.

Outcome measurements and statistical analysis

The outcome was MACEs (composite of heart failure, myocardial infarction, stroke, and cardiovascular mortality). VVHV was calculated from HbA1c levels within 3 yr after and, separately where available, before ADT initiation using coefficient of variation (CV; standard deviation [SD] divided by mean) and average real variability (ARV; average difference between consecutive measurements).

Results and limitations

Altogether, 1065 patients were analysed (median age 74.4 yr old [interquartile range 68.3-79.5 yr]). In 709 patients with VVHV available before and after ADT initiation, VVHV increased after ADT initiation (p < 0.001), with 473 (66.2%) and 474 (66.9%) having increased CV and ARV, respectively. Over a median follow-up of 4.3 yr (2.8-6.7 yr), higher VVHV was associated with a higher risk of MACEs (adjusted hazard ratio [per SD] for CV 1.21 [95% confidence interval: 1.02, 1.43], p = 0.029; ARV 1.25 [1.06, 1.48], p = 0.008). Limitations included residual confounding and selection bias.

Conclusions

In PCa patients receiving ADT, VVHV increased after ADT initiation. Higher VVHV was associated with an increased risk of MACEs.

Patient summary

In prostate cancer patients receiving androgen deprivation therapy (ADT), glycaemic control is less stable after initiating ADT, which was associated with an increased cardiovascular risk.

Glycemic and lipid variability for predicting complications and mortality in diabetes mellitus using machine learning

INTRODUCTION

Recent studies have reported that HbA1c and lipid variability is useful for risk stratification in diabetes mellitus. The present study evaluated the predictive value of the baseline, subsequent mean of at least three measurements and variability of HbA1c and lipids for adverse outcomes.

METHODS

This retrospective cohort study consists of type 1 and type 2 diabetic patients who were prescribed insulin at outpatient clinics of Hong Kong public hospitals, from 1st January to 31st December 2009. Standard deviation (SD) and coefficient of variation were used to measure the variability of HbA1c, total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglyceride. The primary outcome is all-cause mortality. Secondary outcomes were diabetes-related complications.

RESULT

The study consists of 25,186 patients (mean age = 63.0, interquartile range [IQR] of age = 15.1 years, male = 50%). HbA1c and lipid value and variability were significant predictors of all-cause mortality. Higher HbA1c and lipid variability measures were associated with increased risks of neurological, ophthalmological and renal complications, as well as incident dementia, osteoporosis, peripheral vascular disease, ischemic heart disease, atrial fibrillation and heart failure (p <  0.05). Significant association was found between hypoglycemic frequency (p <  0.0001), HbA1c (p <  0.0001) and lipid variability against baseline neutrophil-lymphocyte ratio (NLR).

CONCLUSION

Raised variability in HbA1c and lipid parameters are associated with an elevated risk in both diabetic complications and all-cause mortality. The association between hypoglycemic frequency, baseline NLR, and both HbA1c and lipid variability implicate a role for inflammation in mediating adverse outcomes in diabetes, but this should be explored further in future studies.

The Association between Hepatic Encephalopathy and Diabetic Encephalopathy: The Brain-Liver Axis

Hepatic encephalopathy (HE) is one of the main consequences of liver disease and is observed in severe liver failure and cirrhosis. Recent studies have provided significant evidence that HE shows several neurological symptoms including depressive mood, cognitive dysfunction, impaired circadian rhythm, and attention deficits as well as motor disturbance. Liver disease is also a risk factor for the development of diabetes mellitus. Diabetic encephalopathy (DE) is characterized by cognitive dysfunction and motor impairment. Recent research investigated the relationship between metabolic changes and the pathogenesis of neurological disease, indicating the importance between metabolic organs and the brain. Given that a diverse number of metabolites and changes in the brain contribute to neurologic dysfunction, HE and DE are emerging types of neurologic disease. Here, we review significant evidence of the association between HE and DE, and summarise the common risk factors. This review may provide promising therapeutic information and help to design a future metabolic organ-related study in relation to HE and DE.

Glycemic Variability and CNS Inflammation: Reviewing the Connection

Glucose is the primary energy source for the brain, and exposure to both high and low levels of glucose has been associated with numerous adverse central nervous system (CNS) outcomes. While a large body of work has highlighted the impact of hyperglycemia on peripheral and central measures of oxidative stress, cognitive deficits, and vascular complications in Type 1 and Type 2 diabetes, there is growing evidence that glycemic variability significantly drives increased oxidative stress, leading to neuroinflammation and cognitive dysfunction. In this review, the latest data on the impact of glycemic variability on brain function and neuroinflammation will be presented. Because high levels of oxidative stress have been linked to dysfunction of the blood-brain barrier (BBB), special emphasis will be placed on studies investigating the impact of glycemic variability on endothelial and vascular inflammation. The latest clinical and preclinical/in vitro data will be reviewed, and clinical/therapeutic implications will be discussed.

Diabetic Cognitive Dysfunction: From Bench to Clinic

Type 2 diabetes increases the risk of developing cognitive dysfunction in the elderly in the form of short-term memory and executive function impairment. Genetic and diet-induced models of type 2 diabetes further support this link, displaying deficits in working memory, learning, and memory performance. The risk factors for diabetic cognitive dysfunction include vascular disease, hypoglycaemia, hyperlipidaemia, adiposity, insulin resistance, lifestyle factors, and genetic factors. Using neuronal imaging technologies, diabetic patients with cognitive dysfunction show atrophy of the whole brain, particularly the grey matter, hippocampus and amygdala; increased volume of the ventricular and white matter; brain infarcts; impaired network integrity; abnormal microstructure; and reduced cerebral blood flow and amplitude of low-frequency fluctuations. The pathogenesis of type 2 diabetes with cognitive dysfunction involves hyperglycaemia, macrovascular and microvascular diseases, insulin resistance, inflammation, apoptosis, and disorders of neurotransmitters. Large clinical trials may offer further proof of biomarkers and risk factors for diabetic cognitive dysfunction. Advanced neuronal imaging technologies and novel disease animal models will assist in elucidating the precise pathogenesis and to provide better therapeutic interventions and treatment.

Personality traits and cognitive function in old-adults with type-2 diabetes

Objectives: Personality may constitute an important domain of influence on cognitive function in old-adults. We assessed the relationship of personality traits and cognitive performance in individuals with Type-2 Diabetes (T2D), and explored possible mediators. Method: The sample includes 377 dementia-free subjects with T2D participating in the Israel Diabetes and Cognitive Decline study who underwent assessment of cognition and personality (mean age 72 ± 4y; 42% females). We assessed the relationships of personality traits with episodic memory, semantic categorization, attention/working memory, executive function and overall cognition using linear regression models adjusting for age, education, sex, BMI, T2D duration, Hemoglobin A1C (HbA1C), hypertension, c-reactive protein, total- to HDL-cholesterol ratio and ApoEɛ4 genotype. A post-hoc mediation analysis was conducted with HbA1C, proportion of days covered (PDC) by T2D prescription claims and depressive symptoms. Results: After adjustment for multiple covariates, high neuroticism levels were associated with poorer performance overall (β= -0.16 ± 0.05; p = 0.001) and with poorer episodic memory, attention/working memory, and semantic categorization (β= -0.14 ± 0.05; p = 0.007, β= -0.12 ± 0.05; p = 0.017 and β= -0.12 ± 0.05; p = 0.018, respectively). High scores on openness to experience were associated with better global cognition (β = 0.11 ± 0.05; p = 0.026), executive functions (β = 0.13 ± 0.05; p = 0.013) and semantic categorization (β = 0.17 ± 0.05; p = 0.001, respectively). Depressive symptoms mediated the association of neuroticism with executive function, and the association of openness with executive function and overall cognition. Conclusion: Personality may play an important role in cognitive health among elderly subjects with T2D. Future studies should address the mechanisms underlying these relationships and specifically the potential role of depressive symptoms which may be in the causal pathway between personality traits and cognitive outcomes.

Integrating Frailty and Cognitive Phenotypes: Why, How, Now What?

PURPOSE OF REVIEW

This review elucidates the concept of frailty in relationship to reserve and resilience, the relationships and shared pathophysiology between physical frailty and cognitive impairment, the theoretical underpinnings of three integrated phenotypes of physical and cognitive impairments, and the potential of incorporating biomarkers into phenotype refinement and validation.

RECENT FINDINGS

The fact that frailty and cognitive impairment are associated and often coexist in older adults has led to the popular view of expanding the definition of frailty to include cognitive impairment. However, there is great variability in approaches to and assumptions regarding the integrated phenotypes of physical frailty and cognitive impairment.

SUMMARY

The development of integrated frailty and cognitive phenotypes should explicate the types of frailty and cognitive impairment they intend to capture and prioritize the incorporation of biological theories that help determine shared and distinct pathways in the progression to physical and cognitive impairments.

Day-to-day fasting glycaemic variability in DEVOTE: associations with severe hypoglycaemia and cardiovascular outcomes (DEVOTE 2)

AIMS/HYPOTHESIS

The Trial Comparing Cardiovascular Safety of Insulin Degludec vs Insulin Glargine in Patients with Type 2 Diabetes at High Risk of Cardiovascular Events (DEVOTE) was a double-blind, randomised, event-driven, treat-to-target prospective trial comparing the cardiovascular safety of insulin degludec with that of insulin glargine U100 (100 units/ml) in patients with type 2 diabetes at high risk of cardiovascular events. This paper reports a secondary analysis investigating associations of day-to-day fasting glycaemic variability (pre-breakfast self-measured blood glucose [SMBG]) with severe hypoglycaemia and cardiovascular outcomes.

METHODS

In DEVOTE, patients with type 2 diabetes were randomised to receive insulin degludec or insulin glargine U100 once daily. The primary outcome was the first occurrence of an adjudicated major adverse cardiovascular event (MACE). Adjudicated severe hypoglycaemia was the pre-specified secondary outcome. In this article, day-to-day fasting glycaemic variability was based on the standard deviation of the pre-breakfast SMBG measurements. The variability measure was calculated as follows. Each month, only the three pre-breakfast SMBG measurements recorded before contact with the site were used to determine a day-to-day fasting glycaemic variability measure for each patient. For each patient, the variance of the three log-transformed pre-breakfast SMBG measurements each month was determined. The standard deviation was determined as the square root of the mean of these monthly variances and was defined as day-to-day fasting glycaemic variability. The associations between day-to-day fasting glycaemic variability and severe hypoglycaemia, MACE and all-cause mortality were analysed for the pooled trial population with Cox proportional hazards models. Several sensitivity analyses were conducted, including adjustments for baseline characteristics and most recent HbA_1c.

RESULTS

Day-to-day fasting glycaemic variability was significantly associated with severe hypoglycaemia (HR 4.11, 95% CI 3.15, 5.35), MACE (HR 1.36, 95% CI 1.12, 1.65) and all-cause mortality (HR 1.58, 95% CI 1.23, 2.03) before adjustments. The increased risks of severe hypoglycaemia, MACE and all-cause mortality translate into 2.7-, 1.2- and 1.4-fold risk, respectively, when a patient's day-to-day fasting glycaemic variability measure is doubled. The significant relationships of day-to-day fasting glycaemic variability with severe hypoglycaemia and all-cause mortality were maintained after adjustments. However, the significant association with MACE was not maintained following adjustment for baseline characteristics with either baseline HbA_1c (HR 1.19, 95% CI 0.96, 1.47) or the most recent HbA_1c measurement throughout the trial (HR 1.21, 95% CI 0.98, 1.49).

CONCLUSIONS/INTERPRETATION

Higher day-to-day fasting glycaemic variability is associated with increased risks of severe hypoglycaemia and all-cause mortality.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01959529.

Dopamine Adaptations as a Common Pathway for Neurocognitive Impairment in Diabetes and Obesity: A Neuropsychological Perspective

Evidence accumulates linking obesity and diabetes with cognitive dysfunction. At present the mechanism(s) underlying these associations and the relative contribution of diet, adiposity, and metabolic dysfunction are unknown. In this perspective key gaps in knowledge are outlined and an initial sketch of a neuropsychological profile is developed that points toward a critical role for dopamine (DA) adaptations in neurocognitive impairment secondary to diabetes and obesity. The precise mechanisms by which diet, metabolic dysfunction, and adiposity influence the DA system to impact cognition remains unclear and is an important direction for future research.

Chronic Peripheral Inflammation is Associated With Cognitive Impairment in Schizophrenia: Results From the Multicentric FACE-SZ Dataset

OBJECTIVES

Inflammation, measured by abnormal blood C-reactive protein (CRP) level, has been described in schizophrenia (SZ), being inconsistently related to impaired cognitive functions. The aim of the present study is to investigate cognitive impairment associated with abnormal CRP levels in a large multi-centric sample of community-dwelling SZ patients, using a comprehensive neuropsychological battery.

METHOD

Three hundred sixty-nine community-dwelling stable SZ subjects (76.2% men, mean age 32.7 y) were included and tested with a comprehensive battery of neuropsychological tests. Abnormal CRP level was defined as >3mg/L.

RESULTS

Multiple factor analysis revealed that abnormal CRP levels, found in 104 patients (28.2%), were associated with impaired General Intellectual Ability and Abstract Reasoning (aOR = 0.56, 95% CI 0.35-0.90, P = .014), independently of age, sex, education level, psychotic symptomatology, treatments, and addiction comorbidities. Abnormal CRP levels were also associated with the decline of all components of working memory (respectively effect size [ES] = 0.25, P = .033; ES = 0.27, P = .04; ES = 0.33, P = .006; and ES = 0.38, P = .004) and a wide range of other impaired cognitive functions, including memory (ES = 0.26, P = .026), learning abilities (ES = 0.28, P = .035), semantic memory (ES = 0.26, P = .026), mental flexibility (ES = 0.26, P = .044), visual attention (ES = 0.23, P = .004) and speed of processing (ES = 0.23, P = .043).

CONCLUSION

Our results suggest that abnormal CRP level is associated with cognitive impairment in SZ. Evaluating the effectiveness of neuroprotective anti-inflammatory strategies is needed in order to prevent cognitive impairment in SZ.

Parthenolide, an NF-κB Inhibitor Ameliorates Diabetes-Induced Behavioural Deficit, Neurotransmitter Imbalance and Neuroinflammation in Type 2 Diabetes Rat Model

Diabetes is associated with behavioural and neurochemical alterations. In this manuscript, we are reporting the beneficial effects of parthenolide, an NF-κB inhibitor on behavioural and neurochemical deficits in type 2 diabetic rat model. Diabetes was induced by high-fat diet followed by low dose of streptozotocin (35 mg/kg). Elevated plus maze, open-field, MWM and passive avoidance test paradigm were used to assess behavioural and cognitive deficits. Three-week treatment of parthenolide (0.25 and 0.50 mg/kg; i.p.) attenuated diabetes-induced alteration in cognitive function in Morris water maze and passive avoidance test. Anxiety-like behaviour was also reduced by parthenolide treatment. Moreover, TNF-α and IL-6 levels were significantly decreased in cortex and hippocampus of parthenolide-treated rats. Three-week parthenolide treatment also toned down the alteration of GABA and glutamate homoeostasis. Results of this study corroborate the involvement of neuroinflammation in the development of behavioural and neurochemical deficits in diabetic animals and point towards the therapeutic potential of parthenolide in diabetes-induced alteration of learning, memory and anxiety behaviour.