Biomedical risk factors for decreased cognitive functioning in type 1 diabetes: an 18 year follow-up of the Diabetes Control and Complications Trial (DCCT) cohort

Risk factors associated with cognitive performance and cognitive impairment in older adults with type 1 diabetes: Data from the Wireless Innovation for Seniors with Diabetes Mellitus (WISDM) study

BACKGROUND

Adults with type 1 diabetes (T1D) are considered at increased risk for cognitive impairment and accelerated brain aging. However, longitudinal data on cognitive impairment and dementia in this population are scarce.

OBJECTIVE

To identify risk factors associated with cognitive performance and cognitive impairment in a longitudinal sample of older adults with T1D.

METHODS

We analyzed data collected as part of the Wireless Innovation for Seniors with Diabetes Mellitus (WISDM) Study, in which 22 endocrinology practices participated. Randomized participants with T1D ≥60 years of age who completed at least one cognitive assessment were included in this study (n = 203). Cognitive impairment was classified using published recommendations.

RESULTS

Older age, male sex, non-private health insurance, worse daily functioning, diagnosis of neuropathy, and longer duration of diabetes were associated with worse cognitive performance, but not cognitive impairment. 49 % and 39 % of the sample met criteria for cognitive impairment at baseline and 52 weeks respectively. Of the participants that had data at both time points, 10 % were normal at baseline and impaired at 52 weeks and 22 % of participants (44 % of those classified with cognitive impairment at baseline) reverted to normal over 52 weeks.

CONCLUSION

This study indicated that several demographic and clinical characteristics are associated with worse cognitive performance in older adults with T1D, but there were no associations between these characteristics and cognitive impairment defined by NIH Toolbox cognitive impairment criteria. Caution is warranted when assessing cognition in older adults with T1D, as a large percentage of those identified as having cognitive impairment at baseline reverted to normal after 52 weeks. There is need for future studies on the interrelationship of cognition and aging to better understand the effects of T1D on cognitive health, to improve clinical monitoring and help mitigate the risk of dementia in this population.

5. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Diabetic Encephalopathy: Role of Oxidative and Nitrosative Factors in Type 2 Diabetes

Diabetes mellitus is a set of complex metabolic disorders characterized by chronic hyperglycaemic condition due to defective insulin secretion (Type 1) and action (Type 2), which leads to serious micro and macro-vascular damage, inflammation, oxidative and nitrosative stress and a deranged energy homeostasis due to imbalance in the glucose and lipid metabolism. Moreover, patient with diabetes mellitus often showed the nervous system disorders known as diabetic encephalopathy. The precise pathological mechanism of diabetic encephalopathy by which it effects the central nervous system directly or indirectly causing the cognitive and motor impairment, is not completely understood. However, it has been speculated that like other extracerebellar tissues, oxidative and nitrosative stress may play significant role in the pathogenesis of diabetic encephalopathy. Therefore, the present review aimed to explain the possible association of the oxidative and nitrosative stress caused by the chronic hyperglycaemic condition with the central nervous system complications of the type 2 diabetes mellitus induced diabetic encephalopathy.

CKD Associates with Cognitive Decline in Middle-Aged and Older Adults with Long-Standing Type 1 Diabetes

Key Points

We found that development of both albuminuria and reduced eGFR was associated with clinically significant cognitive decline, particularly in the psychomotor and mental efficiency domain. There was also a significant interaction between worsened albuminuria and eGFR, the combination of which augmented cognitive deficits. A more comprehensive longitudinal phenotype of albuminuria showed that regressed albuminuria did not associate with worsened cognitive decline, as opposed to persistent albuminuria.

Background

Individuals with CKD or type 1 diabetes (T1D) are at risk for cognitive decline, but it is unclear whether these associations are with albuminuria, eGFR, or both.

Methods

We examined the longitudinal relationships between CKD and change in cognition in 1051 participants with T1D in the Diabetes Control and Complications Trial and its follow-up, the Epidemiology of Diabetes Interventions and Complications study. Albumin excretion rate and eGFR were measured every 1–2 years. Three cognitive domains were assessed repeatedly over a 32-year period: immediate memory, delayed memory, and psychomotor and mental efficiency. Associations between cognitive function and CKD were assessed: (1 ) longitudinally and (2 ) in models using eGFR and albuminuria measurements over the first 15–20 years with subsequent change in cognitive function over the ensuing 14 years (when decline in cognition was greatest).

Results

In fully adjusted longitudinal analyses, the magnitude of decline in the psychomotor and mental efficiency domain score was associated with eGFR <60 ml/min per 1.73 m2 (β −0.449; 95% confidence interval [CI], −0.640 to −0.259) and sustained albumin excretion rate 30 to <300 mg/24 hours (β −0.148; 95% CI, −0.270 to −0.026). This was equivalent to a decrease associated with approximately 11 and 4 years of aging, respectively. In analyses focused on changes in cognition between study years 18 and 32, eGFR <60 ml/min per 1.73 m2 was associated with reduced psychomotor and mental efficiency (β −0.915; 95% CI, −1.613 to −0.217).

Conclusions

In T1D, development of CKD was associated with a subsequent reduction on cognitive tasks requiring psychomotor and mental efficiency. These data highlight the need for increased recognition of risk factors for neurologic sequelae in patients with T1D, as well as preventive and treatment strategies to ameliorate cognitive decline.

Socioeconomic Deprivation, Sleep Duration, and Mental Health during the First Year of the COVID-19 Pandemic

The coronavirus disease 2019 (COVID-19) has had a rapid and sustained negative impact on sleep and mental health in the United States with disproportionate morbidity and mortality among socioeconomically deprived populations. We used multivariable and logistic regression to evaluate the associations among sleep duration, mental health, and socioeconomic deprivation (social deprivation index) in 14,676 Ohio residents from 1101 zip code tabulation areas from the 2020 Behavioral Risk Factor Surveillance System (BRFSS) survey. Higher socioeconomic deprivation was associated with shorter sleep and poorer mental health after adjusting for covariates (age, sex, race, education, income, and body mass index) in the multivariable linear regression models. Those in the highest socioeconomically deprived areas had 1.6 and 1.5 times higher odds of short sleep (duration < 6 h) and poor mental health (>14 poor mental health days), respectively, in the logistic regression models. Previous researchers have focused on limited socio-environmental factors such as crowding and income. We examined the role of a composite area based measure of socioeconomic deprivation in sleep duration and mental health during the first year of COVID-19. Our results suggest the need for a broader framework to understand the associations among socioeconomic deprivation, sleep duration, and mental health during a catastrophic event.

Association of consumption of sugar-sweetened beverages with cognitive function among the adolescents aged 12-16 years in US, NHANES III, 1988-1994

Objective

As a major source of added sugar, the consumption of sugar-sweetened beverages (SSBs) continues to increase worldwide. The adverse health effects associated with SSBs are also risk factors for cognitive development, but studies on the relationship between SSBs and adolescents' cognitive function are limited. We used data released by the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) to explore the association between the consumption of SSBs and cognitive function among children and adolescents aged 12-16 years in the United States.

Methods and procedures

A nationally representative population sample included 1,809 adolescents aged 12-16 years who participated in the United States NHANES from 1988 to 1994 and provided samples for the dietary intake frequency questionnaire and measures of cognitive function. Binary logistic regression was used to estimate the association between the frequency of SSB consumption and scores on cognitive function tests.

Results

This study of 1,809 adolescents aged 12-16 years comprised 963 girls (weighted proportion, 48.17%) and 846 boys (weighted, 51.83%), with a weighted mean (SE) age of 13.99 (0.05) years. Compared with adolescents who intake SSBs 0-1 times per week, those who drank 4-7 times per week had better scores in arithmetic, reading, and digit span tests, with odds ratios (ORs) of 0.36 (95% CI = 0.16-0.82), 0.35 (95% CI = 0.18-0.70), and 0.19 (95% CI = 0.08-0.44), respectively. The ORs for abnormal block design scores increase with the frequency of SSB intake after being adjusted for potential confounders (P for trend 0.02). Stratified analyses showed that compared with normal or below BMI, among overweight or obese individuals, the frequency of SSB intake had significant ORs for abnormal digit span scores (OR = 4.76, 95% CI = 1.19-18.96 vs. 0.35, 95% CI = 0.10-1.25; P for interaction = 0.01).

Conclusion

The positive associations of SSBs at moderate level intake with better scores in arithmetic, reading, and digit span were observed, but no dose-response relationship was identified at the overall level. Additionally, with the increasing frequency of SSB consumption, the risk of anomalous block design scores increased among US adolescents. Further investigation is warranted to confirm the association and mechanism between SSBs and cognitive function among adolescents.

A single injection of pregabalin induces short- and long-term beneficial effects on fear memory and anxiety-like behavior in rats with experimental type-1 diabetes mellitus

Anxiety Disorders and Posttraumatic Stress Disorders (PTSD) associated with type-1 diabetes mellitus (T1DM) are increasingly common comorbidities and the treatment is quite challenging. In that sense, evidence indicates that the anticonvulsant pregabalin is highly effective in treating severe cases of anxiety, as well as PTSD and diabetic neuropathic pain which is also very prevalent in T1DM. Herein, the short- and long-term effects of a single injection of pregabalin on the acquisition of a fear extinction memory and parameters of anxiety in induced-T1DM animals were investigated. For that, we used the contextual fear conditioning (CFC) and elevated plus maze paradigms, respectively. A putative antioxidant activity was also evaluated. Our findings demonstrated that induced-T1DM animals presented greater expression of fear memory, difficulty in extinguishing this fear memory, associated with a more pronounced anxiety-like response. Pregabalin was able to induce a short and long-lasting effect by facilitating the acquisition of the fear extinction memory and inducing a later anxiolytic-like effect. Also, the increased lipid peroxidation levels in the hippocampus and prefrontal cortex of induced-T1DM rats were reduced after pregabalin injection, while the decreased levels of reduced glutathione were increased in the hippocampus. Despite the need for more studies to understand the mechanism of action of pregabalin under these conditions, our data demonstrate for the first time that a single injection of pregabalin in a specific time window was able to improve behavioral parameters in addition to inducing neuroprotective effect. Thus, pregabalin has potential worth exploring for the treatment of PTSD and/or Anxiety associated with T1DM.

Diabetic retinopathy and cognitive dysfunction: a systematic review and meta-analysis

BACKGROUND

This study aims to determine the relationship between diabetic retinopathy (DR) and cognitive dysfunction as well as explores the effects of DR on different cognitive domains.

METHODS

A systematic search of PubMed, Embase, Web of Science, Wanfang data, CBM, CNKI, and VIP databases from their inception to October 2021. The pooled odds ratio (ORs), hazard ratio (HRs), and 95% confidence interval (CIs) were calculated.

RESULTS

Twenty-two studies met the inclusion criteria and meta-analysis included 15 studies. The presence of DR reflects a higher risk of cognitive dysfunction (OR = 2.45; 95% CI: 1.76-3.41; HR = 1.34 95% CI: 1.10-1.62). Cohort study combined risk was 2.62 (95% CI: 1.93-3.56), in cross-sectional study was 2.07 (95% CI: 1.11-3.88). The pooled OR was 2.38 (95% CI: 1.83-3.10) and 3.11 (95% CI: 1.15-8.40) in Asia and Oceania. No such association was found in North America (OR = 2.22; 95% CI: 0.77-6.38). The pooled risk was 2.47 (95% CI: 1.76-3.48) in patients with T2DM, while did not identify an association between these two conditions in T1DM. The combined unadjusted and adjusted ORs were 2.72 (95% CI: 1.99-3.73) and 2.06 (95% CI: 1.49-2.85). DR severity and the risk of cognitive impairment showed a positive correlation and mainly impaired the speeds of psychomotor and information processing.

CONCLUSIONS

DR can help to identify people at high risk of cognitive dysfunction. Further studies are indispensable for exploring the relationship between DR and cognitive impairment in the patients for different age, gender and race, as well as to assess the risk of cognitive impairment in different populations.

The Impact of Hypo- and Hyperglycemia on Cognition and Brain Development in Young Children with Type 1 Diabetes

Human and experimental animal data suggest both hyperglycemia and hypoglycemia can lead to altered brain structure and neurocognitive function in type 1 diabetes (T1D). Young children with T1D are prone to extreme fluctuations in glucose levels. The overlap of these potential dysglycemic insults to the brain during the time of most active brain and cognitive development may cause cellular and structural injuries that appear to persist into adult life. Brain structure and cognition in persons with T1D are influenced by age of onset, exposure to glycemic extremes such as severe hypoglycemic episodes, history of diabetic ketoacidosis, persistent hyperglycemia, and glucose variability. Studies using brain imaging techniques have shown brain changes that appear to be influenced by metabolic abnormalities characteristic of diabetes, changes apparent at diagnosis and persistent throughout adulthood. Some evidence suggests that brain injury might also directly contribute to psychological and mental health outcomes. Neurocognitive deficits manifest across multiple cognitive domains. Moreover, impaired executive function and mental health can affect patients' adherence to treatment. This review summarizes the current data on the impact of glycemic extremes on brain structure and cognitive function in youth with T1D and the use of new diabetes technologies that may reduce these complications.

Albuminuria as a risk factor for mild cognitive impairment and dementia-what is the evidence?

Kidney dysfunction can profoundly influence many organ systems, and recent evidence suggests a potential role for increased albuminuria in the development of mild cognitive impairment (MCI) or dementia. Epidemiological studies conducted in different populations have demonstrated that the presence of increased albuminuria is associated with a higher relative risk of MCI or dementia both in cross-sectional analyses and in studies with long-term follow-up. The underlying pathophysiological mechanisms of albuminuria's effect are as yet insufficiently studied, with several important knowledge gaps still present in a complex relationship with other MCI and dementia risk factors. Both the kidney and the brain have microvascular similarities that make them sensitive to endothelial dysfunction involving different mechanisms, including oxidative stress and inflammation. The exact substrate of MCI and dementia is still under investigation, however available experimental data indicate that elevated albuminuria and low glomerular filtration rate are associated with significant neuroanatomical declines in hippocampal function and grey matter volume. Thus, albuminuria may be critical in the development of cognitive impairment and its progression to dementia. In this review, we summarize the available evidence on albuminuria's link to MCI and dementia, point to existing gaps in our knowledge and suggest actions to overcome them. The major question of whether interventions that target increased albuminuria could prevent cognitive decline remains unanswered. Our recommendations for future research are aimed at helping to plan clinical trials and to solve the complex conundrum outlined in this review, with the ultimate goal of improving the lives of patients with chronic kidney disease.

Cognitive Deficits in Type-1 Diabetes: Aspects of Glucose, Cerebrovascular and Amyloid Involvement

The evidence shows that individuals with type-1 diabetes mellitus (T1DM) are at greater risk of accelerated cognitive impairment and dementia. Although, to date the mechanisms are largely unknown. An emerging body of literature indicates that dysfunction of cerebral neurovascular network and plasma dyshomeostasis of soluble amyloid-β in association with impaired lipid metabolism are central to the onset and progression of cognitive deficits and dementia. However, the latter has not been extensively considered in T1DM. Therefore, in this review, we summarised the literature concerning altered lipid metabolism and cerebrovascular function in T1DM as an implication for potential pathways leading to cognitive decline and dementia.

The JUBILE cohort: Quality of life after more than 40 years with type 1 diabetes

AIM

The incidence of type 1 diabetes is increasing, and more people are going to live many years with the disease. Quality of life might become the most challenging long-term complication. The JUBILE study describes the quality of life of people living with type 1 diabetes for more than 40 years.

METHODS

Patients were recruited from 35 French regional or university hospitals: patients and physicians completed questionnaires, validated by the Delphi method. From 1200 questionnaires circulated, 808 patients and their physicians returned questionnaires.

RESULTS

The duration of type 1 diabetes was 49 ± 6 years (mean±SD), age at diagnosis 15 ± 10 years, HbA1c 7.4 ± 0.9% [58 ± 10 mmol/mol] and 52% were men. Macrovascular disease was present in 32%, 46% had no or only mild non proliferative retinopathy. Insulin pumps were used by 25% and insulin pen/syringe users injected 3.9 ± 2.1 times per day. Blood glucose was self monitored at least five times per day by 67% of patients. Men had 1.8 ± 1.2 children, women 1.4 ± 1.0. More than half (55%) of this population was working, 38% had a university degree. Patients still had a busy life, going out (59%), eating out (82%), playing sports (38%) and travelling (66%). No differences appeared based on age, duration of diabetes, demography or social features.

CONCLUSIONS

Living a long and pleasant life is possible with type 1 diabetes. Diabetes does not prevent people from having children, working at highly qualified jobs, travelling abroad: a message of hope that is comforting for patients, their family, relatives and the medical teams.

Relationship between Diabetic Retinopathy and Systemic Neurodegenerative Diseases: A Systematic Review and Meta-analysis

TOPIC

To examine the potential role of systemic neurodegeneration, this study aimed to provide an overview of the available evidence on the relationship between diabetic retinopathy (DR) and systemic neurodegeneration.

CLINICAL RELEVANCE

The association between DR and systemic neurodegeneration is inconsistent in the literature. A summary estimate on the measures of association is important to establish whether DR may be used as a risk marker of systemic neurodegeneration.

METHODS

We searched the literature databases PubMed/MEDLINE, EMBASE, and Cochrane Library on October 3, 2020, for all observational studies on humans evaluating the association between DR and systemic neurodegenerative diseases. Two authors conducted the literature search, study selection, and data extraction in an independent fashion. Studies were reviewed qualitatively in text and quantitatively in meta-analyses. Heterogeneity was evaluated with Cochran's Q and I², and Funnel plot was used to investigate for skewed results and possible publication bias.

RESULTS

We identified 27 eligible studies with a total of 1 398 041 patients with diabetes. Diagnosis of DR was made using fundus photography or examination (n = 20), health registries (n = 4), was self-reported (n = 1), or was not disclosed in the remaining studies. Neurodegenerative conditions studied were cognitive impairment (n = 23), Alzheimer's disease (n = 3), and Parkinson's disease (n = 1). In cross-sectional and longitudinal studies, respectively, presence of any DR was associated with present (odds ratio [OR], 1.57; 95% confidence interval [CI], 1.02-2.43, P = 0.043) and incident (OR, 2.36; 95% CI, 1.50-3.71, P = 0.00021) systemic neurodegeneration, but severity of DR was not associated with differences in systemic neurodegeneration (OR, 0.98; 95% CI, 0.45-2.15, P = 0.96).

CONCLUSIONS

In this systematic review, DR appears to be a marker of systemic neurodegeneration. Further studies are warranted to better elucidate the clinical practical implications of this relationship.

Cognitive performance declines in older adults with type 1 diabetes: results from 32 years of follow-up in the DCCT and EDIC Study

BACKGROUND

With improved treatment, individuals with type 1 diabetes are living longer but there is limited information on the effects of type 1 diabetes on cognitive ability as they become older adults. We followed up individuals with type 1 diabetes to identify independent risk factors for cognitive decline as people age.

METHODS

1051 participants with type 1 diabetes enrolled in the Diabetes Control and Complications Trial (DCCT) and its follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) study. Participants completed cognitive assessments at baseline (median age 27 years) and 2, 5, 18, and 32 years later (median age 59). HbA_1c levels, frequency of severe hypoglycaemia, non-glycemic risk factors such as elevated blood pressure, and microvascular and macrovascular complications were assessed repeatedly. We examined the effects of these on measures of memory and psychomotor and mental efficiency. These studies are registered with clinicaltrials.gov, NCT00360815 (DCCT) and NCT00360893 (EDIC).

FINDINGS

Over 32 years of follow-up, we found substantive declines in memory and psychomotor and mental efficiency. Between 18 and 32 years of follow-up, the decline in psychomotor and mental efficiency was five times larger than the change from baseline to year 18. Independent of the other risk factors and comorbidities, exposure to higher HbA_1c levels, more episodes of severe hypoglycaemia, and elevated systolic blood pressure were associated with greater decrements in psychomotor and mental efficiency that was most notable by year 32 (p<0·0001). The combined effect of the presence of these three risk factors is the equivalent to an additional 9·4 years of age.

INTERPRETATION

Cognitive function declines with ageing in type 1 diabetes. The association of glycaemia and blood pressure levels with cognitive decline suggests that better management might preserve cognitive function.

FUNDING

United States National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Disease.

Discoveries from the study of longstanding type 1 diabetes

Award programmes that acknowledge the remarkable accomplishments of long-term survivors with type 1 diabetes have naturally evolved into research programmes to determine the factors associated with survivorship and resistance to chronic complications. In this review, we present an overview of the methodological sources of selection bias inherent in survivorship research (selection of those with early-onset diabetes, incidence-prevalence bias and bias from losses to follow-up in cohort studies) and the breadth and depth of literature focusing on this special study population. We focus on the learnings from the study of longstanding type 1 diabetes on discoveries about the natural history of insulin production loss and microvascular complications, and mechanisms associated with them that may in future offer therapeutic targets. We detail descriptive findings about the prevalence of preserved insulin production and resistance to complications, and the putative mechanisms associated with such resistance. To date, findings imply that the following mechanisms exist: strategies to maintain or recover beta cells and their function; activation of specific glycolytic enzymes such as pyruvate kinase M2; modification of AGE production and processing; novel mechanisms for modification of renin-angiotensin-aldosterone system activation, in particular those that may normalise afferent rather than efferent renal arteriolar resistance; and activation and modification of processes such as retinol binding and DNA damage checkpoint proteins. Among the many clinical and public health insights, research into this special study population has identified putative mechanisms that may in future serve as therapeutic targets, knowledge that likely could not have been gained without studying long-term survivors.

Altered resting cerebral blood flow specific to patients with diabetic retinopathy revealed by arterial spin labeling perfusion magnetic resonance imaging

BACKGROUND

Previous neuroimaging studies have shown that patients with diabetic retinopathy (DR) were accompanied by abnormalities in cerebral functional and structural architecture, whereas the resting cerebral blood flow (CBF) alterations in patients with DR are not well understood.

PURPOSE

To explore CBF alterations in patients with DR using pseudo-continuous arterial spin labeling (pCASL) imaging.

MATERIAL AND METHODS

Thirty-one individuals with DR (15 men, 16 women; mean age = 53.38 ± 9.12 years) and 33 healthy controls (HC) (12 men, 21 women; mean age = 51.61 ± 9.84 years) closely matched for age, sex, and education, underwent pCASL imaging scans. Two-sample T test was conducted to compare different CBF values between two groups.

RESULTS

Patients with DR exhibited significantly increased CBF values in the left middle temporal gyrus (Brodmann's area, BA 22) and the bilateral supplementary motor area (BA3) and decreased CBF values in the bilateral calcarine (BA17,18) and bilateral caudate relative to HC group (two-tailed, voxel level at P < 0.01, Gaussian random field (GRF), cluster level at P < 0.05). Moreover, the HbA1c (%) level showed a positive correlation with CBF values in the bilateral caudate (r = 0.473, P = 0.007) in patients with DR.

CONCLUSION

Our results highlighted that patients with DR had abnormal CBF values in the visual cortices, caudate, middle temporal gyrus, and supplementary motor area, which might reflect vision and sensorimotor and cognition dysfunction in patients with DR. These findings might help us to understanding the neural mechanism of patients with DR.

On the physiology of cognitive decline in type 1 diabetes

OBJECTIVES

Type 1 diabetes mellitus (T1DM) may be associated with cognitive impairment and notably a decline in psychomotor speed, information processing speed and attention. The mechanism for this decline is uncertain. Previous studies by our group and others have demonstrated a decline in EEG-power and event-related potential amplitude in T1DM. The objectives of the present study were to explore whether 1) the association between event-related potential (N100) amplitude and psychomotor speed is different between T1DM and healthy subjects, and 2) the decline in N100 amplitude depends on duration of diabetes.

METHODS

Patients with T1DM (N = 204) and healthy control subjects (N = 358) were included in a cross-sectional study. Event-related brain potentials were recorded with auditory reaction tasks. Psychomotor speed was evaluated with the Grooved Pegboard test in a subset of the patients (N = 70) and the healthy control subjects (N = 89).

RESULTS

Patients with T1DM had a decrease in the N100 amplitude that correlated with a decline in psychomotor speed, longer duration of diabetes and increasing age. In healthy controls, the N100 amplitude did not decrease with age and the association between psychomotor speed and N100 amplitude was absent.

CONCLUSION

The association between psychomotor speed and N100 amplitude is likely to be a specific trait for T1DM since it was not found in healthy controls and was dependent on diabetes duration. Our findings indicate that the pathogenesis of cognitive decline in T1DM may involve a disease-related factor with a long-term influence on the N100 amplitude.

Acute and chronic neuroinflammation is triggered by diabetic ketoacidosis in a rat model

INTRODUCTION

Cognitive decline is common in patients with type 1 diabetes and has been attributed to the effects of chronic hyperglycemia and severe hypoglycemia. Diabetic ketoacidosis (DKA) has only recently been suspected to be involved in causing cognitive decline. We hypothesized that DKA triggers both acute and chronic neuroinflammation, contributing to brain injury.

RESEARCH METHODS AND DESIGN

We measured concentrations of cytokines, chemokines and matrix metalloproteinases (MMP) in serum and brain tissue lysates in juvenile rats during and after DKA (during acute DKA, 24 hours and 7 days after DKA), and compared these to healthy controls and hyperglycemic controls. We also measured cytokine, chemokine and MMP concentrations in serum and brain tissue of adult rats (70 days) that had experienced DKA as juveniles and compared these measurements to those of adult diabetic rats without exposure to DKA.

RESULTS

During acute DKA in the juvenile rats, serum concentrations of CCL3, tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and MMP-9 were significantly increased. Serum concentrations of IL-2 and IL-17A increased 7 days after DKA recovery. In brain tissue lysates, concentrations of CCL3, CCL5, interferon (IFN)-γ and MMP-9 were significantly elevated during acute DKA. In adult rats that had DKA as juveniles (28 days previously), serum concentrations of IL-1ß and brain concentrations of IL-10 and IL-12p70 were elevated in comparison to diabetic rats without prior DKA. Composite scores for highly correlated cytokines and chemokines (mean z-scores for IL-10, IL-1ß, TNF-α, IL-17A, IFN-γ, CXCL-1 and CCL5) were also significantly elevated in adult rats with prior DKA.

CONCLUSIONS

These data confirm that DKA causes acute systemic inflammation and neuroinflammation in a rat model. Importantly, the neuroinflammatory response triggered by DKA is long-lasting, suggesting the possibility that DKA-induced chronic neuroinflammation could contribute to long-term cognitive decline in individuals with diabetes.

Hypoglycaemia and its management in primary care setting

Hypoglycaemia is common in patients with type 1 diabetes and type 2 diabetes and constitutes a major limiting factor in achieving glycaemic control among people with diabetes. While hypoglycaemia is defined as a blood glucose level under 70 mg/dL (3.9 mmol/L), symptoms may occur at higher blood glucose levels in individuals with poor glycaemic control. Severe hypoglycaemia is defined as an episode requiring the assistance of another person to actively administer carbohydrate, glucagon, or take other corrective actions to assure neurologic recovery. Hypoglycaemia is the most important safety outcome in clinical studies of glucose lowering agents. The American Diabetes Association Standards of Medical Care recommends that a management protocol for hypoglycaemia should be designed and implemented by every hospital, along with a clear prevention and treatment plan. A tailored approach, using clinical and pathophysiologic disease stratification, can help individualize glycaemic goals and promote new therapies to improve quality of life of patients. Data from recent large clinical trials reported low risk of hypoglycaemic events with the use of newer anti-diabetic drugs. Increased hypoglycaemia risk is observed with the use of insulin and/or sulphonylureas. Vulnerable patients with T2D at dual risk of severe hypoglycaemia and cardiovascular outcomes show features of "frailty." Many of such patients may be better treated by the use of GLP-1 receptor agonists or SGLT2 inhibitors rather than insulin. Continuous glucose monitoring (CGM) should be considered for all individuals with increased risk for hypoglycaemia, impaired hypoglycaemia awareness, frequent nocturnal hypoglycaemia and with history of severe hypoglycaemia. Patients with impaired awareness of hypoglycaemia benefit from real-time CGM. The diabetes educator is an invaluable resource and can devote the time needed to thoroughly educate the individual to reduce the risk of hypoglycaemia and integrate the information within the entire construct of diabetes self-management. Conversations about hypoglycaemia facilitated by a healthcare professional may reduce the burden and fear of hypoglycaemia among patients with diabetes and their family members. Optimizing insulin doses and carbohydrate intake, in addition to a short warm up before or after the physical activity sessions may help avoiding hypoglycaemia. Several therapeutic considerations are important to reduce hypoglycaemia risk during pregnancy including administration of rapid-acting insulin analogues rather than human insulin, pre-conception initiation of insulin analogues, and immediate postpartum insulin dose reduction.

Social participation is an important health behaviour for health and quality of life among chronically ill older Chinese people

BACKGROUND

Health behaviours (physical activity, maintenance of a healthy diet and not smoking) are known to be beneficial to the health and well-being of chronically ill people. With China's ageing population and increased prevalence of people with chronic diseases, the improvement of unhealthy behaviours in this population has become crucial. Although recent studies have highlighted the importance of social participation for health and quality of life (QoL) among older people, no study to date has included social participation along with more traditional health behaviours. Therefore, this study aimed to identify associations of multiple health behaviours (social participation, physical activity, maintenance of a healthy diet and not smoking) with health and QoL outcomes (including cognitive and physical function) among chronically ill older adults in China.

METHODS

For this nationally representative cross-sectional study, wave 1 data from the World Health Organization's Study on global AGEing and adult health (China) were examined. In total, 6629 community-dwelling older adults (mean age, 64.9 years) with at least one chronic disease were included. Multivariate linear regression analyses were used to evaluate associations of health behaviours with health and QoL outcomes while controlling for background characteristics.

RESULTS

Greater social participation was associated with better QoL [β = 0.127, standard error (SE) = 0.002, p < 0.001], cognitive function (β = 0.154, SE = 0.033, p < 0.001) and physical function (β = - 0.102, SE = 0.008, p < 0.001). Physical activity was associated with better QoL (β = 0.091, SE = 0.015, p < 0.001) and physical function (β = - 0.155, SE = 0.062, p < 0.001). Sufficient fruit and vegetable consumption was associated with better QoL (β = 0.087, SE = 0.015, p < 0.001).

CONCLUSIONS

Our findings suggest that social participation is an important health behaviour for quality of life and cognitive function among chronically ill older people in China. Health promotion programmes should expand their focus to include social participation as a health behaviour, in addition to physical activity, maintenance of a healthy diet and not smoking.

Sleep, self-management, neurocognitive function, and glycemia in emerging adults with Type 1 diabetes mellitus: A research protocol

Type 1 Diabetes (T1D) affects 1.6 million Americans, and only 14% of emerging adults ages 18-25 years achieve targets for glycemic control (A1C < 7.0%). Sleep deficiency, including habitual short sleep duration (<6.5 hr total sleep time and high within-person variability in total sleep time), is associated with poorer glycemic control. Emerging adults with T1D have a more pronounced sleep extension on weekends compared with matched controls, consistent with sleep deficiency; however, associations among sleep variability and glycemic control have not been explored in this population. Sleep deficiency may affect the complex higher-order neurocognitive functioning needed for successful diabetes self-management (DSM). We report the protocol for an ongoing study designed to characterize sleep and the associations among sleep deficiency, neurocognitive function, DSM, diabetes quality of life, and glycemia among a sample of 40 emerging adults with T1D. We monitor sleep via wrist-worn actigraphy and glucose via continuous glucose monitoring concurrently over 14 days. We are collecting data on self-report and objective sleep, a 10-min psychomotor vigilance test on a PVT-192 device, a 3-min Trail Making Test on paper, and questionnaires, including twice-daily Pittsburgh sleep diaries using Research Electronic Data Capture (REDCap)^TM . Results from this study will be used to support the development and testing of the efficacy of a tailored sleep self-management intervention that may improve total sleep time, sleep variability, neurocognitive function, DSM, glycemic control, and glucose variability among emerging adults with T1D.

The cognitive and psychological effects of living with type 1 diabetes: a narrative review

Across the lifespan, type 1 diabetes mellitus has a profound (neuro)psychological impact. In young people, type 1 diabetes can interfere with psychosocial development and hamper school performance. In adulthood, it can interfere with work life, relationships and parenting. A substantial minority of adults with type 1 diabetes experience coping difficulties and high diabetes-related distress. In youth and adulthood, type 1 diabetes is related to mild cognitive decrements as well as affective disorders, such as depression and anxiety. There is limited literature available that explores the interaction between cognitive and psychological comorbidity and underlying mechanisms. The aims of the present narrative review were to summarize the current state of the literature regarding both cognitive and psychological comorbidities in type 1 diabetes across the lifespan, and to explore potential links between the two domains of interest to make suggestions for future research and clinical practice.

The Relationship of Coronary Artery Calcium and Clinical Coronary Artery Disease with Cognitive Function: A Systematic Review and Meta-Analysis

AIM

Coronary artery disease (CAD) and cognitive impairment are common in the elderly, with evidence for shared risk factors and pathophysiological processes. The coronary artery calcium (CAC) score is a marker of subclinical CAD, which may allow early detection of individuals prone to cognitive decline. Prior studies on associations of CAC and clinical CAD with cognitive impairment had discrepant results. This systematic review aims to evaluate the association of (sub)clinical CAD with cognitive function, cognitive decline, and diagnosis of mild cognitive impairment (MCI) or dementia.

METHODS

A systematic search was conducted in MEDLINE, Embase, and Web of Science until February 2019, supplemented with citations tracking. Two reviewers independently screened studies and extracted information including odds ratios (ORs) and hazard ratios (HRs).

RESULTS

Forty-six studies, 10 on CAC and 36 on clinical CAD, comprising 1,248,908 participants were included in the systematic review. Studies about associations of (sub)clinical CAD with cognitive function and cognitive decline had heterogeneous methodology and inconsistent findings. Two population-based studies investigated the association between CAC and risk of dementia over 6-12.2 years using different CAC scoring methods. Both found a tendency toward higher risk of dementia as CAC severity increased. Meta-analysis in 15 studies (663,250 individuals) showed an association between CAD and MCI/dementia (pooled OR 1.32, 95%CI 1.17-1.48) with substantial heterogeneity (I²=87.0%, p＜0.001). Pooled HR of CAD for incident MCI/dementia over 3.2-25.5 years in six longitudinal studies (70,060 individuals) was 1.51 (95%CI 1.24-1.85), with low heterogeneity (I²=14.1%, p=0.32). Sensitivity analysis did not detect any study that was of particular influence on the pooled OR or HR.

CONCLUSIONS

Limited evidence suggests the CAC score is associated with risk of dementia. In clinical CAD, risk of MCI and dementia is increased by 50%, as supported by stronger evidence.

Activation of mineralocorticoid receptors facilitate the acquisition of fear memory extinction and impair the generalization of fear memory in diabetic animals

RATIONALE

Studies point out a higher prevalence of posttraumatic stress disorder (PTSD) in individuals with diabetes mellitus. It is known that glucocorticoid (GR) and mineralocorticoid (MR) receptors are implicated in fear memory processes and PTSD. However, there is no preclinical studies addressing the involvement of these receptors on abnormal fear memories related to diabetic condition.

OBJECTIVES

By inducing a contextual conditioned fear memory, we generate a suitable condition to investigate the extinction and the generalization of the fear memory in streptozotocin-induced diabetic (DBT) rats alongside the expression of the cytosolic and nuclear GR and MR in the hippocampus (HIP) and prefrontal cortex (PFC). Moreover, we investigated the involvement of the MR or GR on the acquisition of fear memory extinction and on the generalization of this fear memory. When appropriate, anxiety-related behavior was evaluated.

METHODS

Male Wistar rats received one injection of steptozotocin (i.p.) to induce diabetes. After 4 weeks, the animals (DBTs and non-DBTs) were subjected to a conditioned contextual fear protocol.

RESULTS

The expression of MR and GR in the HIP and PFC was similar among all the groups. The single injection of MR agonist was able to facilitate the acquisition of the impaired fear memory extinction in DBTs animals together with the impairment of its generalization. However, the GR antagonism impaired only the generalization of this fear memory which was blocked by the previous injection of the MR antagonist. All treatments were able to exert anxiolytic-like effects.

CONCLUSIONS

The results indicate that MR activation in DBT animals disrupts the overconsolidation of aversive memory, without discarding the involvement of emotional behavior in these processes.

The relationship between cognitive function and having diabetes in patients treated with hemodialysis

PURPOSE

Patients undergoing maintenance hemodialysis (MHD) have a higher prevalence of cognitive impairment and inferior cognitive performance than the general population, and those with cognitive impairment are at higher risk of death than those without cognitive impairment. Having diabetes has been associated with an increased risk of cognitive decline in end-stage kidney disease patients treated with peritoneal dialysis or kidney transplant. However, these findings may not extend to the hemodialysis population. Thus, we aim to investigate the relationship between having diabetes and cognitive function in MHD patients.

METHODS

This was a cross-sectional study. A total of 203 patients treated with MHD from two blood purification centers were enrolled as subjects. The Chinese version of the Montreal Cognitive Assessment (MoCA) was utilized to assess cognitive function.

RESULTS

MHD patients with diabetes had a significantly higher prevalence of global cognitive impairment and inferior performance in global cognition, visuospatial/executive function, naming, language, abstraction and orientation tasks compared with those without diabetes. According to the multiple linear analyses, having diabetes was significantly associated with lower global cognitive function, naming, and language scores, with β coefficients and 95% CIs of -1.30 [ -2.59, -0.01], -0.25 [-0.47, -0.02], and -0.32 [-0.58, -0.07], respectively (all P < 0.05). Having diabetes could not independently predict an increased risk of global cognitive impairment.

CONCLUSIONS

In MHD patients, having diabetes is significantly associated with lower cognitive function scores. Medical staff should evaluate early and focus on the decline of cognitive function in MHD patients with diabetes, in order to achieve early diagnosis and early intervention.

Locus of Control and Cognition in Older Adults With Type 1 Diabetes: Evidence For Sex Differences From the Study of Longevity in Diabetes (SOLID)

OBJECTIVE

Life expectancy for individuals with type 1 diabetes mellitus (T1DM) has increased recently; however, it is unknown how diabetes care attitudes affect late-life brain health.

RESEARCH DESIGN AND METHODS

The Study of Longevity in Diabetes (SOLID) consists of 734 older adults with T1DM, reporting diabetes locus of control (dLOC), age of diabetes diagnosis and other demographics, history of hypoglycemic episodes, and depressive symptoms. Global and domain-specific (language, executive function, episodic memory, simple attention) cognitive functioning was assessed at in-person interviews. Cross-sectional associations between dLOC and cognition were estimated using covariate-adjusted linear regression models in pooled and sex-stratified models.

RESULTS

In pooled analyses, a 1-point increase in dLOC (more internal) was positively associated with global cognition [β=0.05, 95% confidence interval (CI): 0.02, 0.07], language (β=0.04, 95% CI: 0.01, 0.07), and executive function (β=0.04, 95% CI: 0.01, 0.07), but not episodic memory or simple attention. However, in sex-stratified analyses, this effect was seen only in males and not females.

CONCLUSIONS

In elderly individuals with T1DM, we found associations between dLOC and cognition overall and in men but not women. Underlying sex differences should be considered in future research or interventions on psychosocial characteristics for cognition.

Altered Gray Matter Volume in Patients With Type 1 Diabetes Mellitus

Background and Purpose: Many imaging studies have reported structure alterations in patients with type 1 diabetes mellitus (T1DM) by using voxel-based morphometry (VBM). Nevertheless, the results reported were inconsistent and had not been reviewed quantitatively. Accordingly, the quantitative meta-analysis which including VBM studies of patients with T1DM was conducted. Materials and Methods: The gray matter volume alterations in patients with T1DM was estimated by using the software seed-based d mapping. Meantime, the meta-regression was applied to detect the effects of some demographics and clinical characteristics. Results: Six studies were finally included, which with 6 datasets comprising 414 T1DM patients and 216 healthy controls. The pooled meta-analyses detected that patients with T1DM showed robustly increased gray matter volume in the left dorsolateral superior frontal gyrus and middle frontal gyrus and a decreased gray matter volume in the right lingual gyrus, cerebellum, precuneus, the left inferior temporal gyrus, and middle temporal gyrus. The meta-regression showed that the mean age, the female patient's ratio, duration of illness and HbAlc% for T1DM patients were not linearly related with gray matter alterations. Conclusion: This meta-analysis demonstrates that gray matter volume decreases in T1DM patients were mainly locates in the cortical regions and cerebellum.

Cognitive dysfunctions in individuals with diabetes mellitus

Some patients with type 1 and type 2 diabetes mellitus (DM) present with cognitive dysfunctions. The pathophysiology underlying this complication is not well understood. Type 1 DM has been associated with a decrease in the speed of information processing, psychomotor efficiency, attention, mental flexibility, and visual perception. Longitudinal epidemiological studies of type 1 DM have indicated that chronic hyperglycemia and microvascular disease, rather than repeated severe hypoglycemia, are associated with the pathogenesis of DM-related cognitive dysfunction. However, severe hypoglycemic episodes may contribute to cognitive dysfunction in high-risk patients with DM. Type 2 DM has been associated with memory deficits, decreased psychomotor speed, and reduced frontal lobe/executive function. In type 2 DM, chronic hyperglycemia, long duration of DM, presence of vascular risk factors (e.g., hypertension and obesity), and microvascular and macrovascular complications are associated with the increased risk of developing cognitive dysfunction. The pathophysiology of cognitive dysfunction in individuals with DM include the following: (1) role of hyperglycemia, (2) role of vascular disease, (3) role of hypoglycemia, and (4) role of insulin resistance and amyloid. Recently, some investigators have proposed that type 3 DM is correlated to sporadic Alzheimer's disease. The molecular and biochemical consequences of insulin and insulin-like growth factor resistance in the brain compromise neuronal survival, energy production, gene expression, plasticity, and white matter integrity. If patients claim that their performance is worsening or if they ask about the effects of DM on functioning, screening and assessment are recommended.

Elevated brain glutamate levels in type 1 diabetes: correlations with glycaemic control and age of disease onset but not with hypoglycaemia awareness status

AIMS/HYPOTHESIS

Chronic hyperglycaemia in type 1 diabetes affects the structure and functioning of the brain, but the impact of recurrent hypoglycaemia is unclear. Changes in the neurochemical profile have been linked to loss of neuronal function. We therefore aimed to investigate the impact of type 1 diabetes and burden of hypoglycaemia on brain metabolite levels, in which we assumed the burden to be high in individuals with impaired awareness of hypoglycaemia (IAH) and low in those with normal awareness of hypoglycaemia (NAH).

METHODS

We investigated 13 non-diabetic control participants, 18 individuals with type 1 diabetes and NAH and 13 individuals with type 1 diabetes and IAH. Brain metabolite levels were determined by analysing previously obtained ¹H magnetic resonance spectroscopy data, measured under hyperinsulinaemic-euglycaemic conditions.

RESULTS

Brain glutamate levels were higher in participants with diabetes, both with NAH (+15%, p = 0.013) and with IAH (+19%, p = 0.003), compared with control participants. Cerebral glutamate levels correlated with HbA_1c levels (r = 0.40; p = 0.03) and correlated inversely (r = -0.36; p = 0.04) with the age at diagnosis of diabetes. Other metabolite levels did not differ between groups, apart from an increase in aspartate in IAH.

CONCLUSIONS/INTERPRETATION

In conclusion, brain glutamate levels are elevated in people with type 1 diabetes and correlate with glycaemic control and age of disease diagnosis, but not with burden of hypoglycaemia as reflected by IAH. This suggests a potential role for glutamate as an early marker of hyperglycaemia-induced cerebral complications of type 1 diabetes. ClinicalTrials.gov NCT03286816; NCT02146404; NCT02308293.

Cognitive Dysfunction in Type 1 Diabetes Mellitus

CONTEXT

We have summarized key studies assessing the epidemiology, mechanisms, and consequences of cognitive dysfunction (CD) in type 1 diabetes.

EVIDENCE SYNTHESIS

In a number of studies, the severity of CD in type 1 diabetes was affected by the age of onset and duration, and the presence of proliferative retinopathy and autonomic neuropathy. Diabetes-related CD has been observed, not only in adults, but also in children and adolescents. Most neuroimaging studies of patients with type 1 diabetes did not show any differences in whole brain volumes; however, they did reveal selective deficits in gray matter volume or density within the frontal, posterior, and temporal cortex and subcortical gray matter. Studies of middle-age adults with long-standing type 1 diabetes using diffusion tensor imaging have demonstrated partial lesions in the white matter and decreased fractional anisotropy in posterior brain regions. The mechanisms underlying diabetes-related CD are very complex and include factors related to diabetes per se and to diabetes-related cardiovascular disease and microvascular dysfunction, including chronic hyperglycemia, hypoglycemia, macro- and microvascular disease, and increased inflammatory cytokine expression. These mechanisms might contribute to the development and progression of both vascular dementia and Alzheimer disease.

CONCLUSIONS

Higher rates of CD and faster progression in type 1 diabetes can be explained by both the direct effects of altered glucose metabolism on the brain and diabetes-related cardiovascular disease. Because the presence and progression of CD significantly worsens the quality of life of patients with diabetes, further multidisciplinary studies incorporating the recent progress in both neuroimaging and type 1 diabetes management are warranted to investigate this problem.

The presence of cerebral white matter lesions and lower skin microvascular perfusion predicts lower cognitive performance in type 1 diabetes patients with retinopathy but not in healthy controls-A longitudinal study

OBJECTIVE

Cognitive impairments in type 1 diabetes may result from hyperglycemia-associated cerebral microangiopathy. We aimed to identify cerebral microangiopathy and skin microvascular dysfunction-as a surrogate marker for generalized microvascular function-as predictors of cognitive performance over time.

METHODS

In this prospective cohort study, 25 type 1 diabetes patients with proliferative retinopathy and 25 matched healthy controls underwent neurocognitive testing at baseline and after follow-up (3.8 ± 0.8 years). At baseline, 1.5-T cerebral magnetic resonance imaging was used to detect WML and cerebral microbleeds. Skin capillary perfusion was assessed by means of capillary microscopy.

RESULTS

In type 1 diabetes patients, but not in healthy controls, the presence of WML (ß = -0.419; P = 0.037) as well as lower skin capillary perfusion (baseline: ß = 0.753; P < 0.001; peak hyperemia: ß = 0.743; P = 0.001; venous occlusion: ß = 0.675; P = 0.003; capillary recruitment: ß = 0.549; P = 0.022) at baseline was associated with lower cognitive performance over time, independent of age, sex, HbA1c, and severe hypoglycemia. The relationship between WML and lower cognitive performance was significantly reduced after adjusting for capillary perfusion.

CONCLUSIONS

These data fit the hypothesis that cerebral microangiopathy is a manifestation of generalized microvascular dysfunction, leading to lower cognitive performance.

Clinically significant cognitive impairment in older adults with type 1 diabetes

AIMS

Little is known about cognition in older adults with type 1 diabetes. The aim of this study was to identify correlates of clinically significant cognitive impairment.

METHODS

Neuropsychological, diabetes-related and glycemic (HbA1c, Continuous Glucose Monitoring; CGM) data were collected from 201 older adults (≥60 years) with longstanding type 1 diabetes.

RESULTS

Clinically significant cognitive impairment (≥2 cognitive tests ≥1.5 SD below normative data) occurred in 48% of the sample. After controlling for age, gender, education and diabetes duration, we found that hypoglycemia unawareness, recent severe hypoglycemic events, any microvascular complication, higher HbA1c and CGM average nocturnal glucose were all associated with increased odds of clinically significant cognitive impairment (ORs = 1.01-2.61), while CGM nocturnal % time below 60 mg/dL was associated with a decreased odds of cognitive impairment (OR = 0.94). Diabetes duration, diagnosis age, daytime CGM, and lifetime severe hypoglycemic events were not related to cognitive impairment status.

CONCLUSIONS

Clinically significant cognitive impairment was common in older adults with type 1 diabetes. Diabetes-related correlates of cognitive impairment were identified, including hypoglycemia unawareness, recent severe hypoglycemic events, and CGM variables. Longitudinal research is needed to determine if these variables predict cognitive decline and if their modification alters outcomes.

Mild Cognitive Impairment in Young Type 1 Diabetes Mellitus Patients and Correlation with Diabetes Control, Lipid Profile, and High-sensitivity C-reactive Protein

BACKGROUND

It has been an established fact that diabetes mellitus (DM) is associated with lower levels of cognitive function and may be a risk factor for the development of mild cognitive impairment (MCI) and dementia. Most of these studies involved elderly diabetes patients and aging itself may contribute to cognitive impairment. Since a majority of the individuals with DM are between the ages of 40 and 59 years, it is crucial to determine the factors that contribute to cognitive impairment in these patients. So this study was done to correlate the various physical and metabolic parameters with MCI in young individuals with type 1 DM.

MATERIALS AND METHODS

In this cross-sectional study, 126 patients with type 1 DM underwent cognitive assessment by the Montreal Cognitive Assessment test and their cognitive levels were correlated with their HbA1c, lipid profile, and high-sensitivity C-reactive protein (hs-CRP).

RESULTS

The prevalence of MCI was 71.42%. MCI was significantly correlated with HbA1c, serum triglycerides, low-density lipoprotein, very low-density lipoprotein, and hs-CRP levels. The factors that were statistically insignificant were the duration of diabetes, body mass index, and high-density lipoprotein levels.

CONCLUSION

Cognitive impairment is seen even in type 1 DM patients. It should be considered along with the other complications of DM.

Long-term Glycemic Control and Dementia Risk in Type 1 Diabetes

OBJECTIVE

Individuals with type 1 diabetes have experienced an increase in life expectancy, yet it is unknown what level of glycemic control is ideal for maintaining late-life brain health. We investigated the association of long-term glycemic control with dementia in older individuals with type 1 diabetes.

RESEARCH DESIGN AND METHODS

We followed 3,433 members of a health care system with type 1 diabetes, aged ≥50 years, from 1996 to 2015. Repeated measurements of hemoglobin A_1c (HbA_1c), dementia diagnoses, and comorbidities were ascertained from health records. Cox proportional hazards models were fit to evaluate the association of time-varying glycemic exposure with dementia, with adjustment for age, sex, race/ethnicity, baseline health conditions, and frequency of HbA_1c measurement.

RESULTS

Over a mean follow-up of 6.3 years, 155 individuals (4.5%) were diagnosed with dementia. Patients with ≥50% of HbA_1c measurements at 8-8.9% (64-74 mmol/mol) and ≥9% (≥75 mmol/mol) had 65% and 79% higher risk of dementia, respectively, compared with those with <50% of measurements exposed (HbA_1c 8-8.9% adjusted hazard ratio [aHR] 1.65 [95% CI 1.06, 2.57] and HbA_1c ≥9% aHR 1.79 [95% CI 1.11, 2.90]). By contrast, patients with ≥50% of HbA_1c measurements at 6-6.9% (42-52 mmol/mol) and 7-7.9% (53-63 mmol/mol) had a 45% lower risk of dementia (HbA_1c 6-6.9% aHR 0.55 [95% CI 0.34, 0.88] and HbA_1c 7-7.9% aHR 0.55 [95% CI 0.37, 0.82]).

CONCLUSIONS

Among older patients with type 1 diabetes, those with majority exposure to HbA_1c 8-8.9% and ≥9% had increased dementia risk, while those with majority exposure to HbA_1c 6-6.9% and 7-7.9% had reduced risk. Currently recommended glycemic targets for older patients with type 1 diabetes are consistent with healthy brain aging.

Accelerated executive functions decline and gray matter structural changes in middle-aged type 1 diabetes mellitus patients with proliferative retinopathy

BACKGROUND

The aim of the present study was to determine trajectories of cognitive and cortical changes over time in middle-aged patients with type 1 diabetes mellitus (T1DM) and proliferative retinopathy.

METHODS

Twenty-five patients and 25 controls underwent neuropsychological assessment and neuroimaging twice in a mean (±SD) of 3.56 ± 0.65 and 3.94 ± 0.91 years, respectively (P = 0.098). Cognitive assessment included the domains of general cognitive ability, memory, information processing speed, executive functions, attention, and motor and psychomotor speed. Symmetrized percentage change in local cortical thickness, surface area, and volume was determined using the FreeSurfer 6 vertex-wise general linear model method. Analyses were performed uncorrected and corrected for baseline systolic blood pressure and depressive symptoms.

RESULTS

In patients versus controls, accelerated executive function decline was accompanied by, but not related to, lower left frontal and temporal surface area, left parietal and right frontal thickness, and bilateral frontal and right posterior cingulate volume (family-wise error [FWE]-corrected P < 0.05 for all). In patients, lower executive performance was related to loss of right precuneus surface area (P_FWE  = 0.005). Higher HbA1c during follow-up was related to executive function decline (r = -0.509, P = 0.016) and loss of left hemisphere surface area (r_{corrected analysis}  = -0.555, P = 0.007).

CONCLUSIONS

After 3.5 years of follow-up, middle-aged T1DM patients with proliferative retinopathy, mild focal changes in executive functions, and cortical structure were found, which may indicate accelerated aging.

Close relationships and diabetes management across the lifespan: The good, the bad, and autonomy

Relationships are linked with positive and negative self-management and illness outcomes for individuals with type 1 diabetes. Explanations for these mixed associations have remained separated in psychosocial research in type 1 diabetes by relationship type (e.g. parent vs spouse) and individual's age (e.g. adolescence vs older adulthood). In this conceptual review, we present a novel perspective that close relationships across the lifespan may be beneficial for illness self-management when they support individuals' sense of autonomy, defined from a Basic Psychological Needs perspective. Processes of autonomy support are crucial for promoting illness management across all ages and relationship types.

Adiponectin Mediates Running-Restored Hippocampal Neurogenesis in Streptozotocin-Induced Type 1 Diabetes in Mice

Streptozotocin (STZ)-induced diabetes impairs learning and memory performance and reduces adult hippocampal neurogenesis. Physical exercise brings beneficial effects. We have previously shown that adiponectin, an adipocyte-secreted hormone critically involved in the pathology of diabetes, is a key mediator for exercise-enhanced adult hippocampal neurogenesis. Here, we tested whether adiponectin is required for exercise to restore adult hippocampal neurogenesis in an animal model of diabetes. The findings showed that a single injection of 195 mg/kg STZ-induced diabetes significantly increased serum levels of corticosterone and reduced hippocampal adiponectin levels in adult mice. STZ injection also significantly reduced the number of Ki67 and doublecortin (DCX) positive cells and the ratio of co-labeling of DCX and bromodeoxyuridine (BrdU) in the hippocampal dentate region, indicating a decrease in adult hippocampal neurogenesis. Two-week voluntary wheel running significantly restored hippocampal neurogenesis in the diabetic wild-type mice, but not adiponectin knockout mice, indicating that adiponectin is critical for physical exercise to restore hippocampal adult neurogenesis in mice with diabetes. The results suggest that increasing adiponectin levels could be a therapeutic approach to restore hippocampal neurogenesis impairment in individuals with diabetes.

Luteolin Ameliorates Cognitive Impairments by Suppressing the Expression of Inflammatory Cytokines and Enhancing Synapse-Associated Proteins GAP-43 and SYN Levels in Streptozotocin-Induced Diabetic Rats

Luteolin, a flavonoid isolated from Cirsium japonicum, has antioxidant, anti-inflammatory and neuroprotective activities. Our previous studies brought a prospect that luteolin benefited diabetic rats with cognitive impairments. In this study, we examined whether luteolin could suppress the inflammatory cytokines, thus increasing synapse-associated proteins in streptozotocin (STZ)-induced diabetes in rat models. The model rats underwent luteolin treatment for 8 consecutive weeks, followed by assessment of cognitive performances with MWM test. Nissl staining was employed to assess the neuropathological changes in the hippocampus and the effects of luteolin on diabetic rats. With animals sacrificed, expressions of inflammatory cytokines including interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) and synapse-associated proteins including growth-associated protein-43 (GAP-43) and synaptophysin (SYN) were determined. The results affirmed improvement of behavioral performances in the MWM test, downexpression of glycation end products (AGEs) in the plasma and the receptor for advanced glycation end products in the hippocampus, inhibition of IL-1β and TNF-α in both the hippocampus and plasma in diabetic rats. Furthermore, luteolin treatment upregulated the expressions of GAP-43 and SYN in the hippocampus. Thus, luteolin could ameliorate the cognitive dysfunctions in STZ-induced diabetic rat model.

Neural dysfunction and retinopathy in persons with type 1 diabetes

OBJECTIVE

To determine associations of microvascular and neuropathic complications of diabetes cross-sectionally and longitudinally in persons with long-term type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

Persons receiving care for T1D in South Central Wisconsin were identified in 1979-1980 and examined approximately every 5 years. Associations between neuropathic and microvascular complications were examined at most prior visits, when information on several neuropathic complications was collected. Temporal relationships were examined by modeling incidence between examinations across the visits.

RESULTS

Adjusting for duration of diabetes, glycated hemoglobin, and systolic blood pressure, the following were cross-sectionally associated with prevalent PDR (proliferative diabetic retinopathy): the presence of sensory neuropathy (SN) as reported at each Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) examination (odds ratio (OR) = 2.76, confidence interval (CI) = 1.71, 4.48) and the heartrate variability measures RMSD (square root of the mean of squared differences of successive RR intervals) (OR = 0.24, CI = 0.16, 0.37) and SDNN (standard deviation of successive RR intervals) (OR = 0.26, CI = 0.17, 0.39). Findings were similar for prevalent ME (macular edema) as assessed from spectral-domain optical coherence tomography (SD-OCT). The presence of PDR (OR = 2.13, CI = 1.63, 2.78) and ME (OR = 2.36, CI = 1.66, 3.34) were both significantly associated with incident WESDR SN. WESDR SN was associated with incident PDR (OR = 1.53, CI = 1.09, 2.15) but not incident ME (OR = 1.31, CI = 0.92, 1.87).

CONCLUSIONS

Sensory neuropathy and heartrate variability were significantly associated with prevalent PDR and ME in people with long-term T1D. PDR and ME were significantly associated with incident sensory neuropathy, and sensory neuropathy was significantly associated with incident PDR. Studies using earliest detectable markers of microvascular and neurologic abnormalities are needed to determine which of the two systems 'fails' first. Such information might suggest a temporal sequence of diabetes complications.

Long-term changes in retinal vascular diameter and cognitive impairment in type 1 diabetes

OBJECTIVE

To assess associations between cognitive impairment and longitudinal changes in retinal microvasculature, over 18 years, in adults with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Participants of the Pittsburgh Epidemiology of Diabetes Complications Study received ≥3 fundus photographs between baseline (1986-1988) and time of cognitive assessment (2010-2015: N = 119; 52% male; mean age and type 1 diabetes duration 43 and 34 years, respectively). Central retinal arteriolar equivalent and central retinal venular equivalent were estimated via computer-based methods; overall magnitude and speed of narrowing were quantified as cumulative average and slope, respectively. Median regression models estimated associations of central retinal arteriolar equivalent and central retinal venular equivalent measures with cognitive impairment status, adjusted for type 1 diabetes duration. Interactions with HbA1c, proliferative retinopathy and white matter hyperintensities were assessed.

RESULTS

Compared with participants without cognitive impairment, those with clinically relevant cognitive impairment experienced 1.8% greater and 31.1% faster central retinal arteriolar equivalent narrowing during prior years (t = -2.93, p = 0.004 and t = -3.97, p < 0.0001, respectively). Interactions with HbA1c, proliferative retinopathy and white matter hyperintensities were not significant. No associations were found between central retinal arteriolar equivalent at baseline, at time of cognitive testing, or any central retinal venular equivalent measures, and cognitive impairment.

CONCLUSION

Long-term arterial retinal changes could indicate type 1 diabetes-related cognitive impairment. Studies examining longitudinal central retinal arteriolar equivalent changes as early biomarkers of cognitive impairment risk are warranted.

Diabetic Retinopathy and Dementia in Type 1 Diabetes

OBJECTIVE

Retinopathy impacts over one-third of those with diabetes mellitus and is associated with impaired cognitive performance and cerebrovascular lesions in middle-aged adults with type 1 diabetes. However, the association between diabetic retinopathy (DR) and risk of dementia in type 1 diabetes is unknown. We investigated the association between DR and incident dementia in a large, elderly population with type 1 diabetes.

METHODS

A cohort of 3742 patients with type 1 diabetes aged 50 years and above was followed from January 1, 1996 to September 30, 2015 for incident dementia. DR diagnoses were identified from electronic medical records. Age as timescale Cox proportional hazard models evaluated associations between time-updated DR and dementia risk. Models were adjusted for demographics, severe glycemic events, glycosylated hemoglobin, and vascular comorbidities.

RESULTS

Among 3742 patients with type 1 diabetes (47% female, 21% nonwhite), 182 (5%) were diagnosed with dementia during a mean follow-up of 6.2 years. No significant association was found between DR and incident dementia in the main analyses [adjusted Hazard Ratio=1.12; 95% confidence interval, 0.82-1.54), nor among subgroup restricted to those aged 60 years and above or 70 years and above.

CONCLUSIONS

DR was not associated with risk of dementia, suggesting that pathophysiological processes underlying dementia may be different in type 1 versus type 2 diabetes.

Type 1 Diabetes Mellitus and Cognitive Impairments: A Systematic Review

Type 1 diabetes mellitus (T1DM) is a major subtype of diabetes and is usually diagnosed at a young age with insulin deficiency. The life expectancy of T1DM patients has increased substantially in comparison with that three decades ago due to the availability of exogenous insulin, though it is still shorter than that of healthy people. However, the relation remains unclear between T1DM and dementia as an aging-related disease. We conducted a systematic review of existing literature on T1DM and cognition impairments by carrying out searches in electronic databases Medline, EMBASE, and Google Scholar. We restricted our review to studies involving only human subjects and excluded studies on type 2 diabetes mellitus or non-classified diabetes. A meta-analysis was first performed on the relationship between T1DM and cognitive changes in youths and adults respectively. Then the review focused on the cognitive complications of T1DM and their relation with the characteristics of T1DM, glycemic control, diabetic complications, comorbidities, and others. First, age at onset, disease duration, and glycemic dysregulation were delineated for their association with cognitive changes. Then diabetic ketoacidosis, angiopathy, and neuropathy were examined as diabetic complications for their involvement in cognitive impairments. Lastly, body mass index and blood pressure were discussed for their relations with the cognitive changes. Future studies are needed to elucidate the pathogenesis of T1DM-related cognitive impairments or dementia.

Altered eigenvector centrality is related to local resting-state network functional connectivity in patients with longstanding type 1 diabetes mellitus

INTRODUCTION

Longstanding type 1 diabetes (T1DM) is associated with microangiopathy and poorer cognition. In the brain, T1DM is related to increased functional resting-state network (RSN) connectivity in patients without, which was decreased in patients with clinically evident microangiopathy. Subcortical structure seems affected in both patient groups. How these localized alterations affect the hierarchy of the functional network in T1DM is unknown. Eigenvector centrality mapping (ECM) and degree centrality are graph theoretical methods that allow determining the relative importance (ECM) and connectedness (degree centrality) of regions within the whole-brain network hierarchy.

METHODS

Therefore, ECM and degree centrality of resting-state functional MRI-scans were compared between 51 patients with, 53 patients without proliferative retinopathy, and 49 controls, and associated with RSN connectivity, subcortical gray matter volume, and cognition.

RESULTS

In all patients versus controls, ECM and degree centrality were lower in the bilateral thalamus and the dorsal striatum, with lowest values in patients without proliferative retinopathy (P_FWE  < 0.05). Increased ECM in this group versus patients with proliferative retinopathy was seen in the bilateral lateral occipital cortex, and in the right cuneus and occipital fusiform gyrus versus controls (P_FWE  < 0.05). In all patients, ECM and degree centrality were related to altered visual, sensorimotor, and auditory and language RSN connectivity (P_FWE  < 0.05), but not to subcortical gray matter volume or cognition (P_FDR  > 0.05).

CONCLUSION

The findings suggested reorganization of the hierarchy of the cortical connectivity network in patients without proliferative retinopathy, which is lost with disease progression. Centrality seems sensitive to capture early T1DM-related functional connectivity alterations, but not disease progression. Hum Brain Mapp 38:3623-3636, 2017. © 2017 Wiley Periodicals, Inc.

Cognitive Dysfunction in Older Adults With Diabetes: What a Clinician Needs to Know

One of the challenges of managing older adults with diabetes is the individualization of care in people with multiple comorbid conditions. Although macrovascular and microvascular complications of diabetes are well recognized, there is a lack of awareness regarding other conditions such as cognitive dysfunction, depression, and physical disabilities. Cognitive dysfunction is of particular importance because of its impact on self-care and quality of life. In this Perspective, I discuss common and practical questions faced by clinicians managing diabetes in older adults who also have cognitive dysfunction.