Relationship between acute glucose variability and cognitive decline in type 2 diabetes: A systematic review and meta-analysis

5. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes-2025

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.

The clinical importance of measuring glycaemic variability: Utilising new metrics to optimise glycaemic control

With the widespread use of continuous glucose monitoring (CGM), glycaemic variability (GV) is a glucose metric that has been gaining increasing attention. However, unlike other glucose metrics that are easily defined and have clear targets, GV has a large number of different measures given the complexity involved in assessment. While variabilities in HbA1c, fasting and postprandial glucose have been incorporated under the GV banner, short-term variability in glucose, within day and between days, is more in keeping with the correct definition of GV. This review is focused on short-term GV, as assessed by CGM data, although studies calculating GV from capillary glucose testing are also mentioned as appropriate. The different measures of GV are addressed, and their potential role in microvascular and macrovascular complications, as well as patient-related outcomes, discussed. It should be noted that the independent role of GV in vascular pathology is not always clear, given the inconsistent findings in different populations and the close association between GV and hypoglycaemia, itself an established risk factor for adverse outcomes. Therefore, this review attempts, where possible, to disentangle the contribution of GV to diabetes complications from other glycaemic parameters, particularly hypoglycaemia. Evidence to date strongly suggests an independent role for GV in vascular pathology but future large-scale outcome studies are required to fully understand the exact contribution of this metric to vascular complications. This can be followed by setting appropriate GV measures and targets in different diabetes subgroups, in order to optimise glycaemic management and limit the risk of complications.

Increased Risk of Alzheimer's Disease With Glycemic Variability: A Systematic Review and Meta-Analysis

There is increasing evidence that establishes a connection between fluctuations in glucose metabolism and the onset of Alzheimer's disease (AD). Current research supports the notion that this metabolic imbalance significantly affects cognitive health. However, the specific mechanisms through which these fluctuations influence neurodegeneration, eventually leading to AD, require further exploration. This study aims to determine the risk of AD among individuals with fluctuations in blood glucose levels, with or without type 2 diabetes mellitus (T2DM), further providing the most recent and thorough overview of the evidence in this area. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, a thorough search was carried out utilizing particular phrases in the PubMed, Elsevier, Research Gate, and Cochrane databases: ("glucose variability" or "glycemic variability" or "glucose fluctuation" or "glucose instability" or "glycemic fluctuation") and ("Alzheimer's disease" or "Alzheimer disease" or "Alzheimer dementia" or "Alzheimer"). Studies published between January 2014 to January 2024, written in English, and examining the relationship between glucose variability and AD, were included. The outcomes measured were risk of cognitive impairment and AD, cognitive performance, and risk of AD. The results of the literature search produced 142 records, with six studies meeting the eligibility criteria. Parameters for glycemic variability included fasting plasma glucose (FPG) variability, glycated hemoglobin (HbA1c) variability, FPG variability independent of the mean (VIM), FPG coefficient of variation (CV), and FPG standard deviation (SD). The studies revealed a positive correlation between glycemic variability and the risk of AD over time, and the findings indicated that maintaining stable glycemic levels may reduce the risk of cognitive decline among individuals with or without T2DM. Due to the small number of studies that are currently available, despite a calculated relative risk of 2.65 indicating a higher risk of AD among subjects with glycemic variability, the inclusion of the null value in the confidence interval (0.61-11.45) renders these findings not statistically significant. This comprehensive review demonstrated that, in people with or without diabetes, glycemic variability influences cognitive decline and the risk of AD. The studies demonstrated a correlation between higher fluctuations in glucose levels and an increased risk of AD, highlighting the importance of managing blood sugar levels to mitigate dementia risks. Despite these strong associations, the actual incidence rates of AD in the studied populations remained relatively low. Overall, the results were not statistically significant. Further research is recommended to explore the risk of AD among individuals with fluctuations in blood glucose levels.

Ageing well with diabetes: the role of technology

Over the past two decades there has been a substantial rise in the adoption of diabetes therapeutic technology among children, adolescents and younger adults with type 1 diabetes, and its use is now also advocated for older individuals. Older people with diabetes are more prone to experience hypoglycaemia because of numerous predisposing factors and are at higher risk of hypoglycaemic events requiring third-party assistance as well as other adverse sequelae. Hypoglycaemia may also have long-term consequences, including cognitive impairment, frailty and disability. Diabetes in older people is often characterised by marked glucose variability related to age-associated changes such as variable appetite and levels of physical activity, comorbidities and polypharmacotherapy. Preventing hypoglycaemia and mitigating glucose excursions may have considerable positive impacts on physical and cognitive function and general well-being and may even prevent or improve frailty. Technology for older people includes continuous glucose monitoring systems, insulin pumps, automated insulin delivery systems and smart insulin pens. Clinical trials and real-world studies have shown that older people with diabetes benefit from technology in terms of glucose management, reductions in hypoglycaemic events, emergency department attendance and hospital admissions, and improvement in quality of life. However, ageing may bring physical impairments and other challenges that hinder the use of technology. Healthcare professionals should identify older adults with diabetes who may benefit from therapeutic technology and then adopt an individualised approach to education and follow-up for individuals and their caregivers. Future research should explore the impact of diabetes technology on outcomes relevant to older people with diabetes.

The usefulness of the retina for identifying people with type 2 diabetes with prodromal stages of dementia

Type 2 diabetes (T2D) is associated with cognitive impairment and dementia. The detection of cognitive impairment is important because this population is at higher risk of experiencing difficulties in the self-management of diabetes. Mild cognitive impairment (MCI) often remains undiagnosed due to lack of simple tools for screening at large scale. This represents an important gap in the patients' management because subjects with diabetes and MCI are at high risk of progressing to dementia. Due to its developmental origin as a brain-derived tissue, the retina has been proposed as a potential means of non-invasive and readily accessible exploration of brain pathology. Recent evidence showed that retinal imaging and/or functional tests are correlated with the cognitive function and brain changes in T2D. Simple retinal functional tests (i.e. retinal microperimetry) have proven to be useful as reliable tool for the cognitive evaluation and monitoring in patients with T2D>65 years. This review gives an overall update on the usefulness of retinal imaging in identifying patients with T2D at risk of developing dementia.

The "Hit and Run" Hypothesis for Alzheimer's Disease Pathogenesis

Alzheimer's disease (AD) is a devastating neurodegenerative disorder affecting millions worldwide. Emerging research has challenged the conventional notion of a direct correlation between amyloid deposition and neurodegeneration in AD. Recent studies have suggested that amyloid and Tau deposition act as a central nervous system (CNS) innate immune driver event, inducing chronic microglial activation that increases the susceptibility of the AD brain to the neurotoxicity of infectious insults. Although modifiable risk factors account for up to 50% of AD risk, the mechanisms by which they interact with the core process of misfolded protein deposition and neuroinflammation in AD are unclear and require further investigation. This update introduces a novel perspective, suggesting that modifiable risk factors act as external insults that, akin to infectious agents, cause neurodegeneration by inducing recurrent acute neurotoxic microglial activation. This pathological damage occurs in AD pathology-primed regions, creating a "hit and run" mechanism that leaves no discernible pathological trace of the external insult. This model, highlighting microglia as a pivotal player in risk factor-mediated neurodegeneration, offers a new point of view on the complex associations of modifiable risk factors and proteinopathy in AD pathogenesis, which may act in parallel to the thoroughly studied amyloid-driven Tau pathology, and strengthens the therapeutic rationale of combining immune modulation with tight control of risk factor-driven insults.