Severe hypoglycaemia and late-life cognitive ability in older people with Type 2 diabetes: the Edinburgh Type 2 Diabetes Study

The Role of the Neural Exposome as a Novel Strategy to Identify and Mitigate Health Inequities in Alzheimer's Disease and Related Dementias

With the continuous increase of the elderly population, there is an urgency to understand and develop relevant treatments for Alzheimer's disease and related dementias (ADRD). In tandem with this, the prevalence of health inequities continues to rise as disadvantaged communities fail to be included in mainstream research. The neural exposome poses as a relevant mechanistic approach and tool for investigating ADRD onset, progression, and pathology as it accounts for several different factors: exogenous, endogenous, and behavioral. Consequently, through the neural exposome, health inequities can be addressed in ADRD research. In this paper, we address how the neural exposome relates to ADRD by contributing to the discourse through defining how the neural exposome can be developed as a tool in accordance with machine learning. Through this, machine learning can allow for developing a greater insight into the application of transferring and making sense of experimental mouse models exposed to health inequities and potentially relate it to humans. The overall goal moving beyond this paper is to define a multitude of potential factors that can increase the risk of ADRD onset and integrate them to create an interdisciplinary approach to the study of ADRD and subsequently translate the findings to clinical research.

The Effects of Type 2 Diabetes on Cognitive Performance: A Review of Reviews

BACKGROUND

Multiple systematic reviews have found that type 2 diabetes is associated with cognitive decrements. However, these reviews are heterogeneous in terms of methodology, quality and results, making it difficult for researchers and clinicians to build an informed overall picture. We therefore conducted a review of systematic reviews on the association between type 2 diabetes and cognitive decrements in relation to healthy controls.

METHODS

Following a pre-registered research protocol, we searched four major databases. Nine systematic reviews met our inclusion criteria: seven were meta-analyses and two were narrative syntheses. We assessed the risk of bias in each review and reported all effect sizes and confidence intervals obtained.

RESULTS

Type 2 diabetes was associated with cognitive decrements in all reviews, with small or negligible effect sizes obtained in the largest meta-analyses. The most studied cognitive domains were attention, executive functions, memory, processing speed and working memory. All reviews had methodological issues and were rated as having a high or an unclear risk of bias.

CONCLUSIONS

Type 2 diabetes appears to be associated with lower cognitive performance in several cognitive domains and in different age groups. However, high-quality meta-analyses on the subject are still needed. Future reviews must follow the PRISMA guidelines and take into account the risk of bias of the original studies through sensitivity analyses and the heterogeneity of the studies by conducting subgroup analyses for example according to age group and disease duration. The meta-analyses that aim to study the entire type 2 diabetes population without excluding severe comorbidities, should assess concept formation and reasoning, construction and motor performance, perception, and verbal functions and language skills in addition to the cognitive domains that have been most frequently analysed in the reviews conducted so far.

Effect of hypoglycemia on cognitive performance in older patients with diabetes: A meta-analysis

GOALS

The goal of this study was to use meta-analysis to compile information from various studies to investigate the existence and severity of cognitive impairment in elderly diabetes patients who have hypoglycemic episodes.

MATERIALS AND TECHNIQUES

For research studies on the relationship between hypoglycemia and cognitive decline or dementia in persons older than 45 years, we searched the PubMed, EMBASE, Cochrane Library, CNKI, WanFang, CBM and VIP databases for the period 1989 to 2022. We conducted random effects inverse variance on the meta-analysis and used the I2 statistic to assess heterogeneity.

RESULT

We selected 44 of the 518 studies we retrieved, 7 being appropriate for meta-analysis. Six thousand and forty-five individuals were involved in total. Both types of older diabetic patients with hypoglycemia performed considerably worse on tests of general intelligence than control participants (standardized mean difference, 0.58; 95% CI, 0.88-0.28). Also, elderly type-2 diabetes patients with hypoglycemic episodes had significantly worse memory performance (standardized mean difference, 0.19; 95% CI, 0.29-0.09). Additionally, we found that older type-2 diabetes patients with hypoglycemia had significantly poorer psychomotor function than those without hypoglycemia (standardized mean difference, 0.51; 95% CI, 0.38-0.63).

Asian Best Practices for Care of Diabetes in Elderly (ABCDE)

The elderly population with diabetes is diverse with the majority experiencing a decline in physical and mental capabilities, impacting the entire diabetes management process. Therefore, a need for geriatric-specific guidelines, especially for the Asian population, was identified and subsequently developed by an expert panel across government and private institutions from several Asian countries. The panel considered clinical evidence (landmark trials, position papers, expert opinions), recommendations from several important societies along with their decades of clinical experience and expertise, while meticulously devising thorough geriatric-specific tailored management strategies. The creation of the ABCDE best practices document underscores and explores the gaps and challenges and determines optimal methods for diabetes management of the elderly population in the Asian region.

Potential Roles of Glucagon-Like Peptide-1 and Its Analogues in Dementia Targeting Impaired Insulin Secretion and Neurodegeneration

Dementia is a chronic, irreversible condition marked by memory loss, cognitive decline, and mental instability. It is clinically related to various progressive neurological diseases, including Parkinson’s disease, Alzheimer’s disease, and Huntington’s. The primary cause of neurological disorders is insulin desensitization, demyelination, oxidative stress, and neuroinflammation accompanied by various aberrant proteins such as amyloid-β deposits, Lewy bodies accumulation, tau formation leading to neurofibrillary tangles. Impaired insulin signaling is directly associated with amyloid-β and α-synuclein deposition, as well as specific signaling cascades involved in neurodegenerative diseases. Insulin dysfunction may initiate various intracellular signaling cascades, including phosphoinositide 3-kinase (PI3K), c-Jun N-terminal kinases (JNK), and mitogen-activated protein kinase (MAPK). Neuronal death, inflammation, neuronal excitation, mitochondrial malfunction, and protein deposition are all influenced by insulin. Recent research has focused on GLP-1 receptor agonists as a potential therapeutic target. They increase glucose-dependent insulin secretion and are beneficial in neurodegenerative diseases by reducing oxidative stress and cytokine production. They reduce the deposition of abnormal proteins by crossing the blood-brain barrier. The purpose of this article is to discuss the role of insulin dysfunction in the pathogenesis of neurological diseases, specifically dementia. Additionally, we reviewed the therapeutic target (GLP-1) and its receptor activators as a possible treatment of dementia.

The Risk Factors of Severe Hypoglycemia in Older Patients with Dementia and Type 2 Diabetes Mellitus

BACKGROUND

The adequate glycemic control and risk factors for hypoglycemia in older patients with dementia and type 2 diabetes mellitus (T2DM) remain unclear. This study aimed to analyze the status of glycemic control and determine the risk of hypoglycemia among these groups.

METHODS

A hospital admission record due to hypoglycemia through an emergency room with glucose supplementation in the Chang Gung Memorial Hospital was identified as a hypoglycemic event. Patients with dementia and T2DM without hypoglycemic events throughout the study period were defined as the control group. We gathered patients aged ≥65 years with a diagnosis of Alzheimer's dementia (AD) and T2DM between 2001 and 2018 in the Chang Gung Research Database (CGRD). We extracted data included medication use, diagnoses, and biochemistry data from hospital records.

RESULTS

A total of 3877 older patients with dementia and T2DM with regular visits to the outpatient department were enrolled in this study. During the two-year follow-up period, 494 participants (12.7%) experienced hypoglycemia. Multivariable logistic multivariable regression models for hypoglycemic events showed that metformin had a protective effect (odds ratio (OR) = 0.75, p = 0.023), insulin had the highest risk (OR = 4.64, p < 0.001). Hemoglobin A1c (HbA1c) levels were not correlated with hypoglycemic events (OR = 0.95, p = 0.140). Patients with hypoglycemic episodes had a significantly higher proportion of ≥2 Charlson Comorbidity Index scores than those without hypoglycemic episodes (83.2% versus 56.4%, p < 0.001).

CONCLUSIONS

Drug regimen affects hypoglycemic episodes but not HbA1c in older patients with dementia and T2DM. In addition, patients with more comorbidities experience an increased risk of hypoglycemia.

No Effects of Acute Psychosocial Stress on Working Memory in Older People With Type 2 Diabetes

Type 2 diabetes (T2D) has been considered a public health threat due to its growing prevalence, particularly in the older population. It is important to know the effects of psychosocial stress and its potential consequences for some basic cognitive processes that are important in daily life. Currently, there is very little information about how people with T2D face acute psychosocial stressors, and even less about how their response affects working memory (WM), which is essential for their functionality and independence. Our aim was to characterize the response to an acute laboratory psychosocial stressor and its effects on WM in older people with T2D. Fifty participants with T2D from 52 to 77 years old were randomly assigned to a stress (12 men and 12 women) or control (12 men and 14 women) condition. Mood and physiological (cortisol, C, and salivary alpha-amylase, sAA) responses to tasks were measured. In addition, participants completed a WM test before and after the stress or control task. Our results showed that the TSST elicited higher negative affect and greater C and sAA responses than the control task. No significant differences in WM were observed depending on the exposure to stress or the control task. Finally, participants who showed higher C and sAA responses to the stressor had lower WM performance. Our results indicate that medically treated older adults with T2D show clear, typical mood and physiological responses to an acute psychosocial stressor. Finally, the lack of acute psychosocial stress effects on WM suggests that it could be related to aging and not to this disease, at least when T2D is adequately treated.

Incidence and prevalence of hypoglycaemia in type 1 and type 2 diabetes individuals: A systematic review and meta-analysis

BACKGROUND

Previous meta-analysis investigating the incidence and prevalence of hypoglycaemia in both types of diabetes is limited. The purpose of this review is to conduct a systematic review and meta-analysis of the existing literature which investigates the incidence and prevalence of hypoglycaemia in individuals with diabetes.

METHODS

PubMed, Embase and Cochrane library databases were searched up to October 2018. Observational studies including individuals with diabetes of all ages and reporting incidence and/or prevalence of hypoglycaemia were included. Two reviewers independently screened articles, extracted data and assessed the quality of included studies. Meta-analysis was performed using a random effects model with 95% confidence interval (CI) to estimate the pooled incidence and prevalence of hypoglycaemia in individuals with diabetes.

RESULTS

Our search strategy generated 35,007 articles, of which 72 studies matched the inclusion criteria and were included in the meta-analysis. The prevalence of hypoglycaemia ranged from 0.074% to 73.0%, comprising a total of 2,462,810 individuals with diabetes. The incidence rate of hypoglycaemia ranged from 0.072 to 42,890 episodes per 1,000 person-years: stratified by type of diabetes, it ranged from 14.5 to 42,890 episodes per 1,000 person-years and from 0.072 to 16,360 episodes per 1,000-person years in type 1 and type 2 diabetes, respectively.

CONCLUSION

Hypoglycaemia is very common among individuals with diabetes. Further studies are needed to investigate hypoglycaemia-associated risk factors.

The Association between Cognitive Impairment and Diabetic Foot Care: Role of Neuropathy and Glycated Hemoglobin

Diabetes mellitus is associated with impairment in cognitive functions which can complicate adherence to self-care behaviors. We evaluated the incidence of cognitive impairment in patients with diabetes mellitus to determine the strength of the association between diabetic foot (a complication that occurs in about 10% of diabetic patients), adherence to the clinician’s recommendations, glycemic control, and cognitive function. A prospective study was carried out in a probabilistic sample of older patients with diabetic foot living in three nursing homes. Cognitive functions were evaluated by the MMSE (Mini-Mental State Examination), the Trail Making test (TMT), and the Michigan neuropathy screening instrument (MNSI). There were no significant associations between cognitive function and neuropathy or foot alterations, although glycated hemoglobin (HB1Ac > 7%) significantly (p < 0.05) associated with MMSE and adherence to treatment in the 1 month follow-up visit. Receiver operating characteristic curve analysis showed that both HB1Ac and the MNSI score significantly (p < 0.05) discriminate subsequent adherence to treatment for foot complication, with a sensitivity of 80.0–73.3% and specificity 70.6–64.7%, respectively. Proper control of foot complications in diabetic patients involves appropriate glycemic control and less severe neuropathy, and seems to be unrelated to cognitive dysfunction, and warrants further studies in order to tailor appropriate treatments to central and peripheral nervous system disorders. Poor glycemic control (Hb1Ac level > 7%) and a neuropathy score of 5.5 in the MNSI are the best-cut off points to discriminate poor adherence to the clinician’s recommendations for self-care behaviors in people with diabetic foot complication. In this study, we observed that foot disorders were associated with impaired global cognitive function in elderly patients (aged ≥ 65). Podiatrists and physicians should consider cognitive dysfunction as an important chronic complication in the management of diabetic foot.

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.

Cognitive Dysfunction in Older Adults with Type 2 Diabetes: Links, Risks, and Clinical Implications

The prevalence of comorbid diabetes and cognitive dysfunction increases as the population ages. Diabetes increases the risk of progression of cognitive dysfunction through a spectrum of cognitive decline to mild cognitive impairment then to dementia. Cognitive dysfunction, especially impairment in the executive domain, has a negative impact on patients' self-care tasks. With further progression of dementia and the development of behavioral problems, the challenge to carers and health care professionals looking after these patients is significant. Therefore, clinical trials are needed to explore the impact of novel hypoglycemic therapy on cognitive function as an important outcome in this population.

The Interaction Between Sleep and Metabolism in Alzheimer's Disease: Cause or Consequence of Disease?

Alzheimer's disease (AD) is the most common form of dementia and affects over 45 million people worldwide. Both type-2-diabetes (T2D), a metabolic condition associated with aging, and disrupted sleep are implicated in the pathogenesis of AD, but how sleep and metabolism interact to affect AD progression remains unclear. In the healthy brain, sleep/wake cycles are a well-coordinated interaction between metabolic and neuronal activity, but when disrupted, are associated with a myriad of health-related issues, including metabolic syndrome, cardiovascular disease, T2D, and AD. Therefore, this review will explore our current understanding of the relationship between metabolism, sleep, and AD-related pathology to identify the causes and consequences of disease progression in AD. Moreover, sleep disturbances and metabolic dysfunction could serve as potential therapeutic targets to mitigate the increased risk of AD in individuals with T2D or offer a novel approach for treating AD.

A contemporary biological pathway of islet amyloid polypeptide for the management of diabetic dementia

Major challenges of dealing elder patients with diabetes mellitus (DM) are the individualization of consideration in persons with various comorbid types of conditions. In spite of the fact that microvascular and macrovascular problems associated with DM are well documented, there is only a few numbers of reports viewing different conditions, for example, cognitive dysfunction. Cognitive dysfunction is of specific significance due to its effect on self-care and quality of life. All in all, the etiology of cognitive dysfunction in the maturing populace is probably going to be the grouping of ischemic and degenerative pathology. It is likewise trusted that Hyperglycemia is engaged with the system of DM-related cognitive dysfunction. At present, it isn't certain in the case of enhancing glycemic control or utilizing therapeutic agents can enhance the risk of cognitive decay. Amylin was later characterized as an amyloidogenic peptide, confined from a beta cell tumor and called islet amyloid polypeptide (IAPP), and after that, amylin. Conversely, we investigate the beneficial role and hypothesizing the mechanism of amylin related expanding the level and activation of CGRP receptor to enhance the cognition declination amid diabetic dementia.

Cognitive Frailty in Older People with Type 2 Diabetes Mellitus: the Central Role of Hypoglycaemia and the Need for Prevention

PURPOSE OF REVIEW

To highlight the central role of hypoglycaemia in the causation of cognitive frailty and explore ways of recognition and prevention of hypoglycaemia.

RECENT FINDINGS

Cognitive frailty is an emerging new concept defined as the concomitant presence of physical frailty and cognitive impairment. In older people with diabetes, cognitive frailty is associated with an increased risk of mortality greater than from either physical frailty or cognitive impairment alone. Hypoglycaemia is directly associated with increased risk of cognitive impairment and physical frailty which are the two components of cognitive frailty. The incidence of hypoglycaemia in older people with diabetes is rising and hypoglycaemia-related hospitalisation has overtaken that of hyperglycaemia. Recognition of hypoglycaemic episodes in old age remains challenging which leads to misdiagnoses and under-reporting. Therefore, hypoglycaemia prevention strategies are needed. Research is still required to investigate whether prevention of hypoglycaemia would lead to a reduction in the incidence of cognitive frailty.

Serum high-density lipoprotein cholesterol is a protective predictor of executive function in older patients with diabetes mellitus

AIMS/INTRODUCTION

Older people with diabetes mellitus are at high risk for cognitive impairment or dementia. The clinical predictors for cognitive decline in older people with diabetes mellitus were elucidated.

MATERIALS AND METHODS

This was a secondary analysis of a vitamin B12 intervention trial in older people with diabetes mellitus. A total of 271 non-demented individuals were followed up at 9-month intervals for 27 months. We explored the association between baseline clinical features with changes in cognitive measures (Clinical Dementia Rating scale, Neuropsychological Test Battery including executive function z-scores, psychomotor speed z-scores and memory z-scores).

RESULTS

A total of 152 participants had normal cognition (Clinical Dementia Rating 0) and 119 had cognitive impairment (Clinical Dementia Rating 0.5) at baseline. After 27 months, 41 participants had cognitive decline, 36 of whom were cognitively normal at baseline. Multiple logistic regression showed no significant clinical predictor of global cognitive decline. Higher high-density lipoprotein cholesterol (HDL-C) was associated with better executive performance at month 27 (β = 0.359, P < 0.001). Multilevel modeling showed that the highest tertile of HDL-C was associated with better executive function z-scores than the lowest tertile of HDL-C at all time-points.

CONCLUSIONS

Among older people with diabetes mellitus, higher serum HDL-C was associated with better executive function.

Hypoglycemia and Incident Cognitive Dysfunction: A Post Hoc Analysis From the ORIGIN Trial

OBJECTIVE

Epidemiological studies have reported a relationship between severe hypoglycemia, cognitive dysfunction, and dementia in middle-aged and older people with type 2 diabetes. However, whether severe or nonsevere hypoglycemia precedes cognitive dysfunction is unclear. Thus, the aim of this study was to analyze the relationship between hypoglycemia and incident cognitive dysfunction in a group of carefully followed patients using prospectively collected data in the Outcome Reduction with Initial Glargine Intervention (ORIGIN) trial.

RESEARCH DESIGN AND METHODS

This prospective cohort analysis of data from a randomized controlled trial included individuals with dysglycemia who had additional cardiovascular risk factors and a Mini-Mental State Examination (MMSE) score ≥24 (N = 11,495). Severe and nonsevere hypoglycemic events were collected prospectively during a median follow-up time of 6.2 years. Incident cognitive dysfunction was defined as either reported dementia or an MMSE score of <24. The hazard of at least one episode of severe or nonsevere hypoglycemia for incident cognitive dysfunction (i.e., the dependent variable) from the time of randomization was estimated using a Cox proportional hazards model after adjusting for baseline cardiovascular disease, diabetes status, treatment allocation, and a propensity score for either form of hypoglycemia.

RESULTS

This analysis did not demonstrate an association between severe hypoglycemia and incident cognitive impairment either before (hazard ratio [HR] 1.16; 95% CI 0.89, 1.52) or after (HR 1.00; 95% CI 0.76, 1.31) adjusting for the severe hypoglycemia propensities. Conversely, nonsevere hypoglycemia was inversely related to incident cognitive impairment both before (HR 0.59; 95% CI 0.52, 0.68) and after (HR 0.58; 95% CI 0.51, 0.67) adjustment.

CONCLUSIONS

Hypoglycemia did not increase the risk of incident cognitive dysfunction in 11,495 middle-aged individuals with dysglycemia.

Are we missing hypoglycaemia? Elderly patients with insulin-treated diabetes present to primary care frequently with non-specific symptoms associated with hypoglycaemia

INTRODUCTION

We assessed if patients with known hypoglycaemia present on other occasions with non-specific symptoms associated with (but not diagnosed as) hypoglycaemia, potentially representing missed hypoglycaemia.

METHODS

335 primary care records (5/2/12-4/2/13) from patients aged >65 (79 on insulin, 85 on sulphonylureas, 121 on metformin only, 50 without diabetes) were assessed for hypoglycaemia episodes and consultations with non-specific symptoms, "hypo clues".

RESULTS

27/79(34%) insulin-treated patients had >1 documented hypoglycaemia episode, compared to 4/85(5%) sulphonylurea-treated patients, 2/121(2%) metformin-only treated patients, and none without diabetes, p<0.001. "Hypo clue" consultations were common: 1.37 consultations/patient/year in insulin-treated patients, 0.98/patient/year in sulphonylurea-treated, 0.97/patient/year in metformin only-treated, and 0.78/patient/year in non-diabetic patients, p=0.34. In insulin-treated patients with documented hypoglycaemia, 20/27(74%) attended on another occasion with a "hypo clue" symptom, compared to 21/52(40%) of those without hypoglycaemia, p=0.008. No significant difference in the other treatment groups. Nausea, falls and unsteadiness were the most discriminatory symptoms: 7/33(21%) with hypoglycaemia attended on another occasion with nausea compared to 14/302(5%) without hypoglycaemia, p=0.002; 10/33(30%) vs 36/302(12%) with falls, p=0.007; and 5/33(15%) vs 13/302(4%) with unsteadiness, p=0.023.

CONCLUSIONS

Non-specific symptoms are common in those >65 years. In insulin-treated patients at high hypoglycaemia risk, nausea, falls and unsteadiness should prompt consideration of hypoglycaemia.

Hypoglycaemia in the over 75s: Understanding the predisposing factors in type 2 diabetes (T2DM)

INTRODUCTION

Hypoglycaemia has been recognised as a problem in the treatment for type 2 diabetes. Here we describe how levels of HbA1C and treatment with a sulphonylurea or insulin relate to risk of significant hypoglycaemia.

METHODS

Incident hypoglycaemia as recorded for the previous 10 years was determined from the GP records for patients with T2DM aged 75 years or more.

RESULTS

The anonymised GP records of 5974 T2DM patients (2934 men and 3040 women) aged 75 years or more were analysed. Mean age of the men was 81.0 (95% confidence interval (CI) 80.9-81.2) years and of the women was 82.2 (95% CI 82.0-82.4) years. Hypoglycaemic events of significance were recorded in 4.9% of men and 5.1% of women. The prevalence of hypoglycaemia was higher in those with a higher concurrent HbA1C. HbA1C for those people with a recorded significant hypoglycaemic attack(s) was 57.9 (95% CI 56.4-59.4) mmol/mol compared to those with no history of hypoglycaemic episodes at 51.6 (95% CI 51.3-52.0) mmol/mol (p<0.002). Even for those on sulphonylurea and/or insulin treatment, hypoglycaemia prevalence increased with HbA1C: for patients with an HbA1C of <48mmol/mol, age and gender adjusted hypoglycaemia prevalence was 11.1%, for HbA1C of 48-57mmol/mol, prevalence 9.9%, for HbA1C 58-67mmol/mol prevalence, 13.2% and for HbA1C 68mmol/mol or more, prevalence of hypoglycaemia was 16.1%. There was a slight fall in HbA1C by age (normalised β -0.069, p<0.001) and no difference by level of social disadvantage. Treatment with a sulphonylurea or insulin very significantly increased the likelihood of a hypoglycaemic episode: odds ratio (OR) 8.94 (95% CI 6.45-12.42), p<0.001, independent of age, BMI, Townsend index and gender.

CONCLUSION

Prevalence of hypoglycaemia was greater in those individuals with higher HbA1C and in those on sulphonylurea/insulin treatment. Our findings suggest that it is variance in blood glucose rather than overall lower blood glucose levels that predisposes older people to hypoglycaemia.

The current status of treatment-related severe hypoglycemia in Japanese patients with diabetes mellitus: A report from the committee on a survey of severe hypoglycemia in the Japan Diabetes Society

Despite great strides in pharmacotherapy for diabetes, there is increasing concern over the risk of hypoglycemia in patients with diabetes receiving pharmacotherapy as they become increasingly older. This has prompted the Japan Diabetes Society (JDS) to initiate a survey on the current status of severe hypoglycemia in clinical settings. In July 2015, following approval from the JDS Scientific Survey/Research Ethics Committee, the JDS extended an invitation to executive educators, who represented a total of 631 healthcare facilities accredited by the JDS for diabetes education, to participate in the proposed survey. Of these, those who expressed their willingness to participate in the survey were sent an application form required for obtaining ethical approval at these healthcare facilities and were then asked, following approval, to enter relevant clinical data on an unlinked, anonymous basis in a web-based registry. The current survey was fully funded by the JDS Scientific Survey/Research Committee. A case registry (clinical case database) was launched after facility-specific information (healthcare facility database) was collected from all participating facilities and after informed consent was obtained from all participating patients. With severe hypoglycemia defined as the "presence of hypoglycemic symptoms requiring assistance from another person to treat and preferably venous plasma glucose levels at onset/diagnosis of disease or at presentation clearly less than 60 mg/dL (capillary whole blood glucose, less than 50 mg/dL)", the current survey was conducted between April 1, 2014 and March 31, 2015, during which facility-specific information was collected from a total of 193 facilities with a total of 798 case reports collected from 113 facilities. Of the 193 respondent facilities, 149 reported having an emergency department as well, with the median number of patients who required emergency transportation services to reach these facilities totaling 4,962 annually, of which those with severe hypoglycemia accounted for 0.34% (17). The respondent facilities accommodated a total of 2,237 patients with severe hypoglycemia annually, with the number of patients thus accommodated being 6.5 patients per site. A total of 1,171 patients were admitted for severe hypoglycemia, with the number of patients thus admitted being 4.0 per site, who accounted for 52.3% of all patients visiting annually for severe hypoglycemia. A review of the 798 case reports collected during the survey revealed that 240, 480 and 78 patients had type 1 diabetes, type 2 diabetes, and other types of diabetes, respectively; those with type 2 diabetes were shown to be significantly older (median [interquartile range], 77.0 [68.0-83.0]) than those with type 1 diabetes (54.0 [41.0-67.0]) (P < 0.001); and the BMI was shown to be significantly higher for those with type 2 diabetes (22.0 [19.5-24.8] kg/m2 ) than for those with type 1 diabetes (21.3 [18.9-24.0] kg/m2 ) (P = 0.003). It was also found that the median estimated glomerular filtration rate (eGFR) was significantly lower among those with type 2 diabetes (50.6 mL [31.8-71.1]/min/1.73 m2 ) than among those with type 1 diabetes (73.3 [53.5-91.1] mL/min/1.73 m2 ) (P < 0.001). Again, the median HbA1c value at onset of severe hypoglycemia was shown to be 7.0 (6.3-8.1)% among all patients examined, 7.5 (6.9-8.6)% among those with type 1 diabetes, and 6.8 (6.1-7.6)% among those with type 2 diabetes, with the HbA1c value at onset of hypoglycemia being significantly lower among those with type 2 diabetes (P < 0.001). Antecedent symptoms of severe hypoglycemia were shown to be present, absent and unknown in 35.5, 35.6, and 28.9% of all patients, respectively, with the incidence of symptomatic hypoglycemia being significantly lower among those with type 1 diabetes (41.0%) than among those with type 2 diabetes (56.9%). The antidiabetic agents used in those with type 2 diabetes were insulin preparations (292 patients including 29 receiving concomitant sulfonylureas [SUs]) (60.8%), SUs (159 insulin-naïve patients) (33.1%), and no insulin preparations or SUs (29 patients) (6.0%). Of the 798 patients surveyed, 296 patients (37.2%) were shown to have required emergency transportation services for severe hypoglycemia before. Thus, the survey revealed, for the first time, the current status of treatment-related severe hypoglycemia in Japan and clearly highlights the acute need for implementing preventive measures against hypoglycemia not only through education on hypoglycemia but through optimization of antidiabetic therapy for those at high risk of severe hypoglycemia or those with a history of severe hypoglycemia.

The current status of treatment-related severe hypoglycemia in Japanese patients with diabetes mellitus: a report from the committee on a survey of severe hypoglycemia in the Japan Diabetes Society

Despite great strides in pharmacotherapy for diabetes, there is increasing concern over the risk of hypoglycemia in patients with diabetes receiving pharmacotherapy as they become increasingly older. This has prompted the Japan Diabetes Society (JDS) to initiate a survey on the current status of severe hypoglycemia in clinical settings. In July 2015, following approval from the JDS Scientific Survey/Research Ethics Committee, the JDS extended an invitation to executive educators, who represented a total of 631 health-care facilities accredited by the JDS for diabetes education, to participate in the proposed survey. Of these, those who expressed their willingness to participate in the survey were sent an application form required for obtaining ethical approval at these health-care facilities and were then asked, following approval, to enter relevant clinical data on an unlinked, anonymous basis in a Web-based registry. The current survey was fully funded by the JDS Scientific Survey/Research Committee. A case registry (clinical case database) was launched after facility-specific information (healthcare facility database) was collected from all participating facilities and after informed consent was obtained from all participating patients. With severe hypoglycemia defined as the "presence of hypoglycemic symptoms requiring assistance from another person to treat and preferably venous plasma glucose levels at onset/diagnosis of disease or at presentation clearly less than 60 mg/dL (capillary whole blood glucose, less than 50 mg/dL)", the current survey was conducted between April 1, 2014 and March 31, 2015, during which facility-specific information was collected from a total of 193 facilities with a total of 798 case reports collected from 113 facilities. Of the 193 respondent facilities, 149 reported having an emergency department as well, with the median number of patients who required emergency transportation services to reach these facilities totaling 4962 annually, of which those with severe hypoglycemia accounted for 0.34% (17). The respondent facilities accommodated a total of 2237 patients with severe hypoglycemia annually, with the number of patients thus accommodated being 6.5 patients per site. A total of 1171 patients were admitted for severe hypoglycemia, with the number of patients thus admitted being 4.0 per site, who accounted for 52.3% of all patients visiting annually for severe hypoglycemia. A review of the 798 case reports collected during the survey revealed that 240, 480, and 78 patients had type 1 diabetes, type 2 diabetes, and other types of diabetes, respectively; those with type 2 diabetes were shown to be significantly older [median (interquartile range), 77.0 (68.0-83.0)] than those with type 1 diabetes [54.0 (41.0-67.0)] (P < 0.001); and the BMI was shown to be significantly higher for those with type 2 diabetes [22.0 (19.5-24.8) kg/m²] than for those with type 1 diabetes [21.3 (18.9-24.0) kg/m²] (P = 0.003). It was also found that the median estimated glomerular filtration rate (eGFR) was significantly lower among those with type 2 diabetes [50.6 mL (31.8-71.1)/min/1.73 m²] than among those with type 1 diabetes [73.3 (53.5-91.1) mL/min/1.73 m²] (P < 0.001). Again, the median HbA1c value at onset of severe hypoglycemia was shown to be 7.0 (6.3-8.1)% among all patients examined, 7.5 (6.9-8.6)% among those with type 1 diabetes, and 6.8 (6.1-7.6)% among those with type 2 diabetes, with the HbA1c value at onset of hypoglycemia being significantly lower among those with type 2 diabetes (P < 0.001). Antecedent symptoms of severe hypoglycemia were shown to be present, absent, and unknown in 35.5, 35.6, and 28.9% of all patients, respectively, with the incidence of symptomatic hypoglycemia being significantly lower among those with type 1 diabetes (41.0%) than among those with type 2 diabetes (56.9%). The antidiabetic agents used in those with type 2 diabetes were insulin preparations (292 patients including 29 receiving concomitant sulfonylureas [SUs]) (60.8%), SUs (159 insulin-naïve patients) (33.1%), and no insulin preparations or SUs (29 patients) (6.0%). Of the 798 patients surveyed, 296 patients (37.2%) were shown to have required emergency transportation services for severe hypoglycemia before. Thus, the survey revealed, for the first time, the current status of treatment-related severe hypoglycemia in Japan and clearly highlights the acute need for implementing preventive measures against hypoglycemia, not only through education on hypoglycemia but also through optimization of antidiabetic therapy for those at high risk of severe hypoglycemia or those with a history of severe hypoglycemia.

Effect of recurrent severe hypoglycemia on cognitive performance in adult patients with diabetes: A meta-analysis

The purpose of this study was to investigate the existence and extent of cognitive impairment in adult diabetes mellitus (DM) patients with episodes of recurrent severe hypoglycemia, by using meta-analysis to synthesize data across studies. PubMed, EMBASE and Cochrane library search engines were used to identify studies on cognitive performance in DM patients with recurrent severe hypoglycemia. Random-effects meta-analysis was performed on seven eligible studies using an inverse-variance method. Effect sizes, which are the standardized differences between the experimental group and the control group, were calculated. Of the 853 studies, 7 studies met the inclusion criteria. Compared with control subjects, the adult DM patients with episodes of recurrent severe hypoglycemia demonstrated a significantly lowered performance on memory in both types of DM patients, and poor performance of processing speed in type 2 DM patients. There was no significant difference between adult DM patients with and those without severe hypoglycemia in other cognitive domains such as general intelligence, executive function, processing speed and psychomotor efficiency. Our results seem to confirm the hypothesis that cognitive dysfunction is characterized by worse memory and processing speed in adult DM patients with a history of recurrent severe hypoglycemia, whereas general intelligence, executive function, and psychomotor efficiency are spared.

Association of Hypoglycemia With Subsequent Dementia in Older Patients With Type 2 Diabetes Mellitus

Background

Studies have found conflicting evidence regarding the association of hypoglycemia with dementia. We evaluated an association of hypoglycemia with subsequent dementia in patients with type 2 diabetes.

Methods

This retrospective longitudinal cohort study used the Clinical Practice Research Datalink, an electronic medical records data from the United Kingdom, from 2003 to 2012. We included patients aged >65 years diagnosed with type 2 diabetes, with no prior diagnosis of dementia. Dementia was defined using diagnosis codes from medical records. All patients were followed from the date of initial diabetes diagnosis. To account for competing risk of death, we used Fine and Gray's competing risk model to determine the association of hypoglycemia with dementia while adjusting for potential confounders. Hypoglycemia was modeled as a time-dependent covariate.

Results

Of 53,055 patients, 5.7% (n = 3,018) had at least one hypoglycemia episodes. The overall incidence rate of dementia was 12.7 per 1,000 person-years. In the fully adjusted model that controlled for all confounders, the occurrence of at least one hypoglycemia episode was associated with 27% higher odds of subsequent dementia (hazard ratio = 1.27; 95% confidence interval = 1.06-1.51). The risk increased with the number of hypoglycemia episodes: one episode (hazard ratio = 1.26; 95% confidence interval = 1.03-1.54); two or more episodes (hazard ratio = 1.50; 95% confidence interval = 1.09-2.08).

Conclusions

Hypoglycemia is associated with a higher risk of dementia and may be responsible in part for the higher risk of dementia in patients with diabetes. Alternatively, hypoglycemia may be a marker for undiagnosed cognitive impairment, and we cannot rule out the possibility of reverse causation between hypoglycemia and dementia.

Diabetes is associated with risk of postoperative cognitive dysfunction: A meta-analysis

BACKGROUND

Postoperative cognitive dysfunction (POCD) occurs frequently after surgery, particularly among older people. Diabetes, chronic hyperglycemia, and a history of hypoglycemia are related to cognitive impairment, but little is known about their roles in POCD. Here, we estimated their associations with risk of POCD on the basis of published epidemiological research.

METHODS

The PubMed and Cochrane databases were searched for longitudinal studies of adults undergoing surgery with reporting of associations of diabetes status, glycemic levels, and/or a history of hypoglycemia with risk of POCD as relative risks or odds ratios. Meta-analysis Of Observational Studies in Epidemiology (MOOSE) and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed.

RESULTS

The search identified 246 publications of which 14 met inclusion criteria, reporting on a total of 2642 patients (mean age 64 y). Follow-up periods spanned 1 day to 5 years. Overall, patients with diabetes had a 1.26-fold higher risk of POCD compared with diabetes-free patients (95% CI, 1.12-1.42). A single study assessed glycemic control in patients with diabetes and identified a higher hemoglobin A1c (HbA1c) level as associated with higher POCD risk (relative risk per percent higher HbA1c, 2.0; 95% CI, 1.4-2.6). We did not find studies on glycemic levels in the nondiabetic range or on hypoglycemia as potential predictors of POCD.

CONCLUSION

Patients with diabetes appear to have a higher risk of POCD compared with diabetes-free persons. Among patients with diabetes, POCD risk may further increase with poorer glycemic control as indexed by higher HbA1c. The roles of HbA1c levels among nondiabetic persons in POCD risk warrant further research.

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.

Lower verbal intelligence is associated with diabetic complications and slower walking speed in people with Type 2 diabetes: the Maastricht Study

AIMS

To determine the association of verbal intelligence, a core constituent of health literacy, with diabetic complications and walking speed in people with Type 2 diabetes.

METHODS

This study was performed in 228 people with Type 2 diabetes participating in the Maastricht Study, a population-based cohort study. We examined the cross-sectional associations of score on the vocabulary test of the Groningen Intelligence Test with: 1) determinants of diabetic complications (HbA_1c , blood pressure and lipid level); 2) diabetic complications: chronic kidney disease, neuropathic pain, self-reported history of cardiovascular disease and carotid intima-media thickness; and 3) walking speed. Analyses were performed using linear regression and adjusted in separate models for potential confounders and mediators. Significant age- and sex-adjusted associations were additionally adjusted for educational level in a separate model.

RESULTS

After full adjustment, lower verbal intelligence was associated with the presence of neuropathic pain [odds ratio (OR) 1.18, 95% CI 1.02;1.36], cardiovascular disease (OR 1.14, 95% CI 1.01;1.30), and slower walking speed (regression coefficient -0.011 m/s, 95% CI -0.021; -0.002 m/s). These associations were largely explained by education. Verbal intelligence was not associated with blood pressure, glycaemic control, lipid control, chronic kidney disease or carotid intima-media thickness.

CONCLUSIONS

Lower verbal intelligence was associated with the presence of some diabetic complications and with a slower walking speed, a measure of physical functioning. Educational level largely explained these associations. This implies that clinicians should be aware of the educational level of people with diabetes and should provide information at a level of complexity tailored to the patient.

Cognition in Adults and Older Adults With Type 1 Diabetes: Chicken or Egg?

IN BRIEF Cognitive impairment and cognitive decline are common in adults with type 1 diabetes. Although several diabetes-related variables have been associated with cognitive functioning in both cross-sectional and longitudinal studies, inconsistencies remain. This is particularly true in older adults. Cognitive impairment appears to be both a consequence of and a risk factor for poor diabetes self-management and associated glycemic outcomes. Interventions such as cognitive compensatory strategies, assistive technology, and simplified treatment regimens may limit the impact of cognitive impairment on self-management in adults and older adults with type 1 diabetes.

Cognitive disorders in diabetic patients

This chapter gives an overview of the literature on cognitive dysfunction in adults with type 1 or type 2 diabetes. First, methods to evaluate cognitive functioning and the pattern and severity of cognitive dysfunction in relation to diabetes will be discussed. The reader will note that diabetes is associated with worse cognitive functioning and an increased dementia risk. Next, diabetes-associated abnormalities on brain MRI, including reductions in brain volume - i.e., cerebral atrophy - and vascular lesions, will be addressed. At the group level there are clear relations between these imaging abnormalities and cognitive dysfunction, but at the level of the individual patient these relations are often less clear. Subsequently, risk factors for cognitive performance will be discussed. Evidently, these risk factors are related to diabetes type and the age of the patients involved. For type 1 diabetes, an early age at diabetes onset is the most consistent risk factor, whereas in type 2 diabetes, vascular risk factors and vascular comorbidities are consistent indicators of increased risk. The final section of the chapter addresses possible preventive and treatment measures and implications for daily care.

Pituitary Adenlylate Cyclase Activating Peptide Protects Adult Neural Stem Cells from a Hypoglycaemic milieu

Hypoglycaemia is a common side-effect of glucose-lowering therapies for type-2 diabetic patients, which may cause cognitive/neurological impairment. Although the effects of hypoglycaemia in the brain have been extensively studied in neurons, how hypoglycaemia impacts the viability of adult neural stem cells (NSCs) has been poorly investigated. In addition, the cellular and molecular mechanisms of how hypoglycaemia regulates NSCs survival have not been characterized. Recent work others and us have shown that the pituitary adenylate cyclase-activating polypeptide (PACAP) and the glucagon-like peptide-1 receptor (GLP-1R) agonist Exendin-4 stimulate NSCs survival against glucolipoapoptosis. The aim of this study was to establish an in vitro system where to study the effects of hypoglycaemia on NSC survival. Furthermore, we determine the potential role of PACAP and Exendin-4 in counteracting the effect of hypoglycaemia. A hypoglycaemic in vitro milieu was mimicked by exposing subventricular zone-derived NSC to low levels of glucose. Moreover, we studied the potential involvement of apoptosis and endoplasmic reticulum stress by quantifying protein levels of Bcl-2, cleaved caspase-3 and mRNA levels of CHOP. We show that PACAP via PAC-1 receptor and PKA activation counteracts impaired NSC viability induced by hypoglycaemia. The protective effect induced by PACAP correlated with endoplasmic reticulum stress, Exendin-4 was ineffective. The results show that hypoglycaemia decreases NSC viability and that this effect can be substantially counteracted by PACAP via PAC-1 receptor activation. The data supports a potential therapeutic role of PAC-1 receptor agonists for the treatment of neurological complications, based on neurogenesis impairment by hypoglycaemia.

Association between hypoglycemia and dementia in patients with type 2 diabetes

In addition to increased risks of macrovascular and microvascular complications, patients with type 2 diabetes mellitus (T2DM) usually also are at increased risk for cognitive impairment and dementia. Hypoglycemia, a common consequence of diabetes treatment, is considered an independent risk factor for dementia in patients with T2DM. Hypoglycemia and dementia are clinically underestimated and are related to poor outcomes; thus, they may compromise the life expectancy of patients with T2DM. Epidemiological evidence of hypoglycemia-associated cognitive decline and dementia is highly varied. Acute, severe hypoglycemic episodes induce chronic subclinical brain damage, cognitive decline, and subsequent dementia. However, the effects of recurrent moderate hypoglycemia on cognitive decline and dementia remain largely uninvestigated. Poor glycemic control (including fluctuation of hemoglobin A1C [HbA1c] and glucose values) and the viscous circle of bidirectional associations between dementia and hypoglycemia may be clinically relevant. The possible pathophysiological hypotheses include post-hypoglycemic neuronal damage, inflammatory processes, coagulation defects, endothelial abnormalities, and synaptic dysfunction of hippocampal neurons during hypoglycemia episodes. This article reviews previous findings, provides insight into the detection of groups at high risk of hypoglycemia-associated dementia, and proposes specific strategies to minimize the potential burdens associated with hypoglycemia-related neurocognitive disorders in patients with T2DM.

The effect of frailty should be considered in the management plan of older people with Type 2 diabetes

The prevalence of diabetes is increasing especially in older age due to increased life expectancy. In old age, diabetes is associated with high comorbidity burden and increased prevalence of geriatric syndromes including frailty in addition to micro- and macro-vascular complications. The emergence of frailty may change the natural history of Type 2 diabetes from a progressive to a regressive course with increased risk of hypoglycemia. This may result in normalization of blood glucose levels and lead to a state of burnt-out diabetes in frail older people with significant weight loss. Although guidelines suggest relaxed glycemic control in frail elderly with diabetes, complete withdrawal of hypoglycemic medications may be necessary in these frail populations to reduce the risk of hypoglycemia.

Lay abstract: Diabetes is a common disease especially in older people. Aging is associated with reduced appetite and reduced food intake due to lack of exercise and diminished energy consumption. In certain individuals this may be significant leading to weight loss, malnutrition and the development of frailty. As a result the doses of diabetes medications may be too strong for this frail population especially if they have organ dysfunction reducing medication clearance and increasing the risk of low blood glucose level events. Therefore, reduction or complete withdrawal of diabetes medications may be considered in this frail group.

Bi-directional interaction between hypoglycaemia and cognitive impairment in elderly patients treated with glucose-lowering agents: a systematic review and meta-analysis

AIMS

To examine the bi-directional relationship, whereby hypoglycaemia is a risk factor for dementia, and where dementia increases risk of hypoglycaemia in older patients with diabetes mellitus treated with glucose-lowering agents.

METHODS

We searched MEDLINE and EMBASE over a 10-year span from 2005 to 2015 (with automated PubMed updates to August 2015) for observational studies of the association between hypoglycaemia and cognitive impairment or dementia in participants aged >55 years. Assessment of study validity was based on ascertainment of hypoglycaemia, dementia and risk of confounding. We conducted random effects inverse variance meta-analyses, and assessed heterogeneity using the I(2) statistic.

RESULTS

We screened 1177 citations, and selected 12 studies, of which nine were suitable for meta-analysis. There were a total of 1,439,818 participants, with a mean age of 75 years. Meta-analysis of five studies showed a significantly increased risk of dementia in patients who had hypoglycaemic episodes: pooled odds ratio 1.68 [95% confidence interval (CI) 1.45, 1.95]. We also found a significantly increased risk of hypoglycaemia in patients with dementia: pooled odds ratio from five studies 1.61 (95% CI 1.25, 2.06). Limitations of the study were heterogeneity in the meta-analysis, and uncertain ascertainment of dementia and hypoglycaemic outcomes and temporal relationships. Publication bias may have favoured the reporting of more significant findings.

CONCLUSIONS

Our meta-analysis shows a bi-directional relationship between cognitive impairment and hypoglycaemia in older patients. Glucose-lowering therapy should be carefully tailored and monitored in older patients who are susceptible to cognitive decline.

High-fat diet impairs spatial memory and hippocampal intrinsic excitability and sex-dependently alters circulating insulin and hippocampal insulin sensitivity

BACKGROUND

High-fat diets promoting obesity/type-2 diabetes can impair physiology and cognitive performance, although sex-dependent comparisons of these impairments are rarely made. Transient reductions in Ca(2+)-dependent afterhyperpolarizations (AHPs) occur during memory consolidation, enhancing intrinsic excitability of hippocampal CA1 pyramidal neurons. In rats fed standard diets, insulin can enhance memory and reduce amplitude and duration of AHPs.

METHODS

Effects of chronic high-fat diet (HFD) on memory, circulating insulin, and neuronal physiology were compared between young adult male and female Long-Evans rats. Rats fed for 12 weeks (from weaning) a HFD or a control diet (CD) were then tested in vivo prior to in vitro recordings from CA1 pyramidal neurons.

RESULTS

The HFD significantly impaired spatial memory in both males and females. Significant sex differences occurred in circulating insulin and in the insulin sensitivity of hippocampal neurons. Circulating insulin significantly increased in HFD males but decreased in HFD females. While the HFD significantly reduced hippocampal intrinsic excitability in both sexes, CA1 neurons from HFD females remained insulin-sensitive but those from HFD males became insulin-insensitive.

CONCLUSIONS

Findings consistent with these have been characterized previously in HFD or senescent males, but the effects observed here in young females are unique. Loss of CA1 neuronal excitability, and sex-dependent loss of insulin sensitivity, can have significant cognitive consequences, over both the short term and the life span. These findings highlight needs for more research into sex-dependent differences, relating systemic and neural plasticity mechanisms in metabolic disorders.

Diabetes, Dementia and Hypoglycemia

We are experiencing an epidemic of both diabetes and dementia among older adults in this country. The risk for dementia appears to be increased in patients with diabetes, and patients with dementia and diabetes appear to be at greater risk for severe hypoglycemia. In addition, there may be an increased risk for developing dementia by older patients with diabetes who have had episodes of severe hypoglycemia, although this issue is controversial. In this article, we review the factors that contribute to the increased risk for dementia in older adults with diabetes and outline the complex relationships between hypoglycemia and dementia.

Drug-related risk of severe hypoglycaemia in observational studies: a systematic review and meta-analysis

BACKGROUND

Diabetes mellitus (DM) leads to multiple complications, including severe hypoglycaemia events (SHEs). SHEs can impact a patient's quality of life and compliance and may directly result in additional costs to the health care system. The aim of this review was to evaluate the risk of severe hypoglycaemia in patients with type 1 (T1) and 2 (T2) DM as observed in everyday clinical practice for various drug regimens.

METHODS

We conducted a systematic review of observational (retrospective or prospective) studies in the MEDLINE, Embase, and Cochrane Library databases that covered at least 100 children or adults with T1/T2 DM. In T1 DM, basal-bolus/pre-mix insulin (human or analogue) and insulin pump were reviewed, and in T2 DM, basal-bolus/pre-mix insulin (human or analogue), oral antidiabetic drugs supported with basal insulin (human or analogue), sulfonylureas in monotherapy, and combined oral treatment were reviewed. In order to estimate SHE rates, we extracted data on the time horizon of the study, number of patients, number of SHEs, and number of patients experiencing at least one SHE. We used a random effects model to estimate the annual SHE rate. We considered the risk for other antidiabetic medications in T2 DM to be negligible and the results of our main review yielded no observational data for premixes in T1 DM so they were assessed based on relative rates taken from additional systematic reviews. The study, being a desk research, did not involve any human subjects (including human material or human data) and no ethical committee approval was asked for. For the same reason there was no need to collect informed consent for participation in the study.

RESULTS

We identified 76 observational studies encompassing 707,722.30 patient-years. The estimated annual SHE rate varied from 0.168 (95 % CI 0.123-0.237) for insulin pump up to 1.628 for biphasic human insulin in T1 DM patients, and from 0.0035 for oral antidiabetic drugs up to 0.554 (95 % CI 0.157-7.534) for basal-bolus with human insulin in T2 DM patients.

CONCLUSIONS

Our review indicates that SHE rates differ between patients depending on treatment regimen. However, SHEs are also driven by other factors. Proper modelling techniques are needed to use various types of information in published studies.

Optimal glycaemic control in elderly people with type 2 diabetes: what does the evidence say?

The global prevalence of type 2 diabetes mellitus (T2DM) is rising in an ageing population through a combination of lifestyle changes and greater longevity. However, by excluding participants aged over 70 years, most major interventional trials on which current diabetes therapeutic guidelines are based have failed to provide specific evidence to support the prescribed management of diabetes in elderly people. While diabetes per se has a significant impact on the elderly person, the side effects of medications, particularly hypoglycaemia, prevent optimisation of diabetes treatment. Hypoglycaemia is associated with significant morbidity, to which elderly people are often more vulnerable because of factors such as the effects of ageing, progressive renal impairment, frailty, polypharmacy and cognitive decline. T2DM is associated with accelerated cognitive decline in some individuals, and recurrent severe hypoglycaemia has been implicated as a potential contributory factor. Although the evidence for selection of appropriate glycaemic targets in elderly patients is sparse, it is now acknowledged that prevention of hypoglycaemia must influence individualisation of treatment goals in this vulnerable group. This should also be reflected by the choice of anti-diabetes agents that are initiated when diet and lifestyle advice is ineffective. Recently developed international guidelines, which have specifically addressed the management of diabetes in elderly people, highlight the importance of a pragmatic management approach rather than attempting to achieve a generic glycated haemoglobin goal and are summarised in this article.

Evaluating the Association between Diabetes, Cognitive Decline and Dementia

The aim of this article is to review the association between diabetes mellitus, cognitive decline and dementia, including the effects of cognitive decline and dementia on self management of diabetes. This is a literature review of primary research articles. A number of contemporary research articles that met the inclusion criteria were selected for this review paper. These articles were selected using a number of search strategies and electronic databases, such as EBSCOhost Research and SwetsWise databases. The duration of diabetes, glycated haemoglobin levels and glycaemic fluctuations were associated with cognitive decline and dementia. Similarly, hypoglycaemia was significantly related to increased risk of developing cognitive decline and dementia. Furthermore, cognitive decline and dementia were associated with poorer diabetes management. There is evidence of the association between diabetes, cognitive decline and dementia including the shared pathogenesis between diabetes and Alzheimer’s disease. In addition, the self management of diabetes is affected by dementia and cognitive decline. It could be suggested that the association between diabetes and dementia is bidirectional with the potential to proceed to a vicious cycle. Further studies are needed in order to fully establish the relationship between diabetes, cognitive decline and dementia. Patients who have diabetes and dementia could benefit from structured education strategies, which should involve empowerment programmes and lifestyle changes. The detection of cognitive decline should highlight the need for education strategies.

Complementary glucagonostatic and insulinotropic effects of DPP-4 inhibitors in the glucose-lowering action in Japanese patients with type 2 diabetes

The dipeptidyl peptidase-4 (DPP-4) inhibitors have a low risk of causing hypoglycemia as monotherapy. However, insulin administration is frequently required, particularly in patients with type 2 diabetes and with reduced insulin secretory capacity. The effects of adding DPP-4 inhibitors were evaluated using continuous glucose monitoring (CGM) in Japanese patients with type 2 diabetes who were insufficiently controlled by basal insulin with biguanide. The effects of adding DPP-4 inhibitors on blood glucose and plasma insulin and glucagon levels were evaluated. Δ glucagon showed a significant association with post-prandial glucose increase in the group with diminished insulin secretory capacity, C-peptide index (CPI) <0.8 (p = 0.016), while Δ C-peptide reached significant association in the group with relatively intact insulin secretory capacity, CPI ≥0.8 (p = 0.017). The mean plasma glucose levels and M values were similarly improved in patients treated with the three DPP-4 inhibitors. Hypoglycemia did not occur in any of the DPP-4 inhibitor groups. In conclusion, complementary glucagonostatic and insulinotropic effects of adding DPP-4 inhibitors are involved in the glucose-lowering action of Japanese patients with type 2 diabetes according to their insulin secretory capacity. Such combination therapy may well be a superior therapeutic option for the treatment of diabetes in Japanese patients who often exhibit reduced insulin secretory capacity.

Mechanisms of hypoglycemia unawareness and implications in diabetic patients

Hypoglycemia unawareness (HU) is defined at the onset of neuroglycopenia before the appearance of autonomic warning symptoms. It is a major limitation to achieving tight diabetes and reduced quality of life. HU occurs in approximately 40% of people with type 1 diabetes mellitus (T1DM) and with less frequency in T2DM. Though the aetiology of HU is multifactorial, possible mechanisms include chronic exposure to low blood glucose, antecedent hypoglycaemia, recurrent severe hypoglycaemia and the failure of counter-regulatory hormones. Clinically it manifests as the inability to recognise impeding hypoglycaemia by symptoms, but the mechanisms and mediators remain largely unknown. Prevention and management of HU is complex, and can only be achieved by a multifactorial intervention of clinical care and structured patient education by the diabetes team. Less know regarding the impact of medications on the development or recognition of this condition in patients with diabetes. Several medications are thought to worsen or promote HU, whereas others may have an attenuating effect on the problem. This article reviews recent advances in how the brain senses and responds to hypoglycaemia, novel mechanisms by which people with insulin-treated diabetes develop HU and impaired counter-regulatory responses. The consequences that HU has on the person with diabetes and their family are also described. Finally, it examines the evidence for prevention and treatment of HU, and summarizes the effects of medications that may influence it.

The impact of diabetes on cognitive decline: potential vascular, metabolic, and psychosocial risk factors

Older people with type 2 diabetes are at increased risk of developing cognitive impairment, for which several potential risk factors have been proposed. The present article reviews evidence in people with type 2 diabetes for associations of cognitive impairment with a range of vascular, metabolic, and psychosocial risk factors, many of which have a higher prevalence in people with type 2 diabetes than in non-diabetic adults of a similar age. Definitive research studies in this field are few in number. The risk factors may be involved in causal pathways or may act as useful markers of cerebrovascular damage (or both), and for which relatively consistent evidence is available, include poor glycemic control, hypoglycemia, microvascular disease, inflammation, and depression. For macrovascular disease, the strength of the association with cognitive impairment appears to depend on which vascular system has been examined. A role for pre-morbid ability in young adulthood as influencing the risk of both diabetes and cognitive impairment has also been suggested. The importance of considering inter-relationships between risk factors when investigating their potential contribution to cognitive impairment in future investigations is discussed.

Intensive glycaemic control and cognitive decline in patients with type 2 diabetes: a meta-analysis

The aim of this meta-analysis was to compare the effect of intensive vs standard glycaemic control on cognitive decline in type 2 diabetic patients. A systematic search of PubMed and ALOIS was conducted from inception up to October 30, 2014. Randomised controlled trials (RCTs) of type 2 diabetic patients comparing the rate of change in cognitive function among participants assigned to intensive vs standard glycaemic control were included. An inverse-variance-weighted random effects model was used to calculate standardised mean differences (SMDs) and 95% CIs. A total of 24 297 patients from five RCTs were included in the meta-analysis. Follow-up ranged from 3.3 to 6.2 years. The result from the pooled analysis showed that intensive glycaemic control was not associated with a slower rate of cognitive decline in patients with type 2 diabetes, compared with standard glycaemic control (SMD=0.02; 95% CI=-0.03 to 0.08) although there was some heterogeneity across individual studies (I(2)=68%, P for heterogeneity=0.01). There are few diabetes control trials including cognitive endpoints and a small number of trials comparing intensive and standard treatment strategies. Currently, intensive glycaemic control should not be recommended for prevention of cognitive decline in patients with type 2 diabetes because there is no evidence of its effectiveness. Moreover, the use of intensive diabetes treatment results in an increase of risk of hypoglycaemia, which is linked to a greater risk of poor cognition.

Hypoglycemia in older people - a less well recognized risk factor for frailty

Recurrent hypoglycemia is common in older people with diabetes and is likely to be less recognized and under reported by patients and health care professionals. Hypoglycemia in this age group is associated with significant morbidities leading to both physical and cognitive dysfunction. Repeated hospital admissions due to frequent hypoglycemia are also associated with further deterioration in patients' general health. This negative impact of hypoglycemia is likely to eventually lead to frailty, disability and poor outcomes. It appears that the relationship between hypoglycemia and frailty is bidirectional and mediated through a series of influences including under nutrition. Therefore, attention should be paid to the management of under nutrition in the general elderly population by improving energy intake and maintaining muscle mass. Increasing physical activity and having a more conservative approach to glycemic targets in frail older people with diabetes may be worthwhile.