A systematic review of the effect of prior hypoglycaemia on cognitive function in type 1 diabetes

Nocturnal hypoglycemia in the era of continuous glucose monitoring

Nocturnal hypoglycemia is a common acute complication of people with diabetes on insulin therapy. In particular, the inability to control glucose levels during sleep, the impact of external factors such as exercise, or alcohol and the influence of hormones are the main causes. Nocturnal hypoglycemia has several negative somatic, psychological, and social effects for people with diabetes, which are summarized in this article. With the advent of continuous glucose monitoring (CGM), it has been shown that the number of nocturnal hypoglycemic events was significantly underestimated when traditional blood glucose monitoring was used. The CGM can reduce the number of nocturnal hypoglycemia episodes with the help of alarms, trend arrows, and evaluation routines. In combination with CGM with an insulin pump and an algorithm, automatic glucose adjustment (AID) systems have their particular strength in nocturnal glucose regulation and the prevention of nocturnal hypoglycemia. Nevertheless, the problem of nocturnal hypoglycemia has not yet been solved completely with the technologies currently available. The CGM systems that use predictive models to warn of hypoglycemia, improved AID systems that recognize hypoglycemia patterns even better, and the increasing integration of artificial intelligence methods are promising approaches in the future to significantly minimize the risk of a side effect of insulin therapy that is burdensome for people with diabetes.

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.

Metaphoric perceptions of individuals with diabetes in Turkey: A content analysis

Background

The diagnosis of diabetes mellitus adversely impacts the quality of life due to treatment, changes in daily life, functional disability, and emerging complications. Using metaphors to convey perceptions of diseases and life experiences is crucial for understanding healthcare behaviors.

Objective

This study aimed to explore the metaphorical perceptions of "diabetes" and "being a person with diabetes" within a sample group of individuals with diabetes in Turkey.

Methods

A qualitative design was employed to investigate the metaphoric perceptions of 72 people with diabetes. Data were collected face-to-face between 15 May and June 2023 using a semi-structured questionnaire. Data were analyzed using content analysis.

Results

From the statements of the individuals with diabetes in the sample, seven metaphoric themes related to diabetes - "pain and distress, helplessness and hopelessness, instability, attention and sensitivity, captivity, positive outlook and acceptance, deprivation" - and six metaphoric themes concerning being a person with diabetes - "suffocation and distress, helplessness, powerlessness and disappointment, captivity, attention and sensitivity, guilt, and being worn out" - were identified. Commonly recurring sub-themes with negative connotations included "darkness, well, convict, prison, captivity, microbe, infectious disease, a hot flush, guilt, clouding life, and being ruined." Some positively framed statements included "friend, traffic sign, and driving a car."

Conclusion

The majority of patients in the study used negative metaphors, with fewer expressing positive sentiments regarding the necessity of accepting and paying attention to the disease. Defining individuals' metaphorical perceptions of their disease may enable the provision of better quality and holistic care. Nurses, in particular, play a crucial role in facilitating behavioral changes for patients with diabetes to achieve self-management.

Nocturnal hypoglycemia is associated with next day cognitive performance in adults with type 1 diabetes: Pilot data from the GluCog study

OBJECTIVE

 Individuals with type 1 diabetes (T1D) have increased risk for cognitive dysfunction and high rates of sleep disturbance. Despite associations between glycemia and cognitive performance using cross-sectional and experimental methods few studies have evaluated this relationship in a naturalistic setting, or the impact of nocturnal versus daytime hypoglycemia. Ecological Momentary Assessment (EMA) may provide insight into the dynamic associations between cognition, affective, and physiological states. The current study couples EMA data with continuous glucose monitoring (CGM) to examine the within-person impact of nocturnal glycemia on next day cognitive performance in adults with T1D. Due to high rates of sleep disturbance and emotional distress in people with T1D, the potential impacts of sleep characteristics and negative affect were also evaluated.

METHODS

 This pilot study utilized EMA in 18 adults with T1D to examine the impact of glycemic excursions, measured using CGM, on cognitive performance, measured via mobile cognitive assessment using the TestMyBrain platform. Multilevel modeling was used to test the within-person effects of nocturnal hypoglycemia and hyperglycemia on next day cognition.

RESULTS

 Results indicated that increases in nocturnal hypoglycemia were associated with slower next day processing speed. This association was not significantly attenuated by negative affect, sleepiness, or sleep quality.

CONCLUSIONS

 These results, while preliminary due to small sample size, showcase the power of intensive longitudinal designs using ambulatory cognitive assessment to uncover novel determinants of cognitive fluctuation in real world settings, an approach that may be utilized in other populations. Findings suggest reducing nocturnal hypoglycemia may improve cognition in adults with T1D.

Diabetes, antidiabetic medications and risk of dementia: A systematic umbrella review and meta-analysis

AIMS

The objective of this umbrella review and meta-analysis was to evaluate the effect of diabetes on risk of dementia, as well as the mitigating effect of antidiabetic treatments.

MATERIALS AND METHODS

We conducted a systematic umbrella review on diabetes and its treatment, and a meta-analysis focusing on treatment. We searched MEDLINE/PubMed, Embase, PsycINFO, CINAHL and the Cochrane Library for systematic reviews and meta-analyses assessing the risk of cognitive decline/dementia in individuals with diabetes until 2 July 2023. We conducted random-effects meta-analyses to obtain risk ratios and 95% confidence intervals estimating the association of metformin, thiazolidinediones, pioglitazone, dipeptidyl peptidase-4 inhibitors, α-glucosidase inhibitors, meglitinides, insulin, sulphonylureas, glucagon-like peptide-1 receptor agonists (GLP1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2is) with risk of dementia from cohort/case-control studies. The subgroups analysed included country and world region. Risk of bias was assessed with the AMSTAR tool and Newcastle-Ottawa Scale.

RESULTS

We included 100 reviews and 27 cohort/case-control studies (N = 3 046 661). Metformin, thiazolidinediones, pioglitazone, GLP1RAs and SGLT2is were associated with significant reduction in risk of dementia. When studies examining metformin were divided by country, the only significant effect was for the United States. Moreover, the effect of metformin was significant in Western but not Eastern populations. No significant effect was observed for dipeptidyl peptidase-4 inhibitors, α-glucosidase inhibitors, or insulin, while meglitinides and sulphonylureas were associated with increased risk.

CONCLUSIONS

Metformin, thiazolidinediones, pioglitazone, GLP1RAs and SGLT2is were associated with reduced risk of dementia. More longitudinal studies aimed at determining their relative benefit in different populations should be conducted.

Is fear of hypoglycemia a major barrier to an active lifestyle in children and adolescents with type 1 diabetes? The Diactive-1 Study

Studies on fear of hypoglycemia as a barrier to physical activity among youth with type 1 diabetes (T1D) have been limited and controversial, most of which used self-reported assessment. The aim of the study was to evaluate the relationship between fear of hypoglycemia and physical activity and glycemic metrics in children and adolescents with T1D. Seventy-four participants (6-18 years of age; 44.6% females) with T1D were included in the study. Physical activity was assessed through accelerometry on nine consecutive days, and blood glucose metrics were simultaneously tracked using continuous glucose monitoring (time-in-range and hypoglycemic events). A closed question was used to evaluate the avoidance of physical activity due to fear of hypoglycemia. Fifteen participants (20%) reported avoiding physical activity due to fear of hypoglycemia. The group reporting no fear of hypoglycemia showed lower total physical activity (-35.33 min/day, 95% confidence interval [CI] (-77.57 to -1.47)) and light physical activity (-29.81 min/day, 95% CI -64.01 to -2.75) and higher sedentary time (77.95 min/day, 95% CI 26.46-136.87) per day compared with those with fear of hypoglycemia. No difference was found between those patients with fear of hypoglycemia in terms of meeting the recommendations of glycated hemoglobin, glucose coefficient of variation, and time-in-range when compared to those with no fear of hypoglycemia. In conclusion, children and adolescents with fear of hypoglycemia were more active, less sedentary, and had similar glycemic metrics to those without fear. Our results therefore suggest that fear of hypoglycemia may be less of a barrier to an active lifestyle than previously believed.

Diabetes complications and cognitive function in young adults with youth-onset type 1 or type 2 diabetes: the SEARCH for Diabetes in Youth Study

Aims/hypotheses

People with type 1 (T1D) or type 2 diabetes (T2D) who also have diabetes complications can have pronounced cognitive deficits. It remains unknown, however, whether and how multiple diabetes complications co-occur with cognitive dysfunction, particularly in youth-onset diabetes.

Methods

Using data from the SEARCH for Diabetes in Youth study cohort, a prospective longitudinal cohort, we examined clustering of complications and their underlying clinical factors with performance on cognitive tests in young adults with youth-onset T1D or T2D. Cognition was assessed via the NIH Toolbox Cognition Battery. The main cognitive variables were age-corrected scores for composite fluid cognition and associated cognitive subdomains. Diabetes complications included retinopathy, microalbuminuria, and peripheral neuropathy (PN). Lipids, systolic blood pressure (SBP), hemoglobin A1c, and other clinical factors were included in the analyses. Clustering was applied separately to each group (T1D=646; T2D=165). A three-cluster(C) solution was identified for each diabetes type. Mean values and frequencies of all factors were compared between resulting clusters.

Results

The average age-corrected score for composite fluid cognition differed significantly across clusters for each group (p<0.001). People with T1D and the lowest average fluid cognition scores had the highest frequency of self-reporting at least one episode of hypoglycemia in the year preceding cognitive testing and the highest prevalence of PN. Persons with T2D and the lowest average fluid cognition scores had the highest SBP, the highest central systolic and diastolic blood pressures, and highest prevalence of PN.

Conclusions/interpretations

These findings highlight shared (PN) and unique factors (hypoglycemia in T1D; SBP in T2D) that could be targeted to potentially mitigate cognitive issues in young people with youth-onset diabetes.

Evaluación del desempeño cognitivo en escolares y adolescentes con diabetes mellitus tipo 1

The study aimedto evaluate the cognitive functioning of children and adolescents with type 1 diabetes mellitus (T1DM) recruited from the IAHULA Endocrinology Outpatient Unit and to compare it to that of non-diabetics as to investigate the influence on cognition of factors re-lated to the disease. An analytical, cross-sectional observational study was carried out on a group of 30 patients with T1DM between 8 and 16 years of age and on a control group of 30 individuals matched by age, gender, education, and socioeconomic status. Interrogation and review of medi-cal records to obtain data on the clinical characteristics and treatment of T1DM were conducted. The WISC IV test was then applied to evaluate cognition and intellectual coefficient (IQ). The average age of the diabetic patients was 13.27±2.31 years, and half of them were male. Lower scores were found in the different domains of the WISC IV in the group with T1DM (p<0.01). The IQ was found to be lower in children with T1DM than in con-trols (75.47±13.87 vs. 88.57±11.06; p=0.0001). Likewise, a higher fre-quency of IQ scores below the 10th percentile was observed in the diabetic children (63.3% vs. 33.3%; p=0.02; Odds ratio: 3.45; 95%CI: 1.19-9.99). It was concluded that T1DM negatively impacts the cognitive performance of children and adolescents. Cognitive evaluation of these patients is recom-mended, as it could affect their daily life.

Cognitive screening among older adults with diabetes across diverse clinic settings

AIMS

Diabetes increases risk of cognitive dysfunction and dementia, which can make it harder to manage diabetes. We aimed to examine cognitive screening for older adults with diabetes in 1) endocrine (Endo), 2) geriatric (Geri) and 3) multidisciplinary endocrine-geriatric (Geri-Endo), to study differences between these settings and to elucidate risk factors of cognitive dysfunction.

METHODS

We performed cognitive screening for subsets of patients ≥ age 65 with diabetes in one large healthcare system. We compared results and differences from the three clinic types and used adjusted multivariate logistic regression models to predict risk of cognitive dysfunction.

RESULTS

Among 198 patients screened, those in Geri-Endo (N = 86) and Geri (N = 32) were more likely to have lower Mini-Cog scores, higher prevalence of hypertension and cardiovascular (CV) events. Endo and Geri-Endo patients had longer durations of diabetes, higher incidence of hypoglycemia, and were more likely to use insulin. Age > 75 years (p = 0.0105), previous CV events (p = 0.0006) and body mass index < 30 (p = 0.0115) were significantly associated with lower Mini-Cog scores.

CONCLUSIONS

Our study shows that cognitive screening can help identify at risk older adults with diabetes. Thus, yearly screening should be part of routine diabetes care.

Evaluation of motor vehicle crashes between scooter riders and car drivers after diagnosis of type 2 diabetes in Taiwan

BACKGROUND

Despite the plausibility that diabetes may increase the risk of motor vehicle crashes (MVCs) due to various diabetes related complications and co-morbidity, findings from epidemiological studies on the relationship between diabetes and MVCs remained inclusive mainly due to heterogeneity in the study design and failure to complete consideration of potential confounders. This study re-visited this putative association with an improved study design.

METHOD

This study employed a controlled before-after study design and included 1,264,280 people aged 18-75 years with T2D newly diagnosed from 2009-2014 and an equal number of age-, sex-, and time-matched controls. The rate ratios (RRs) of vehicle type-specific incidence rates of MVCs in the 1 and 2 years before and after diabetes diagnosis (or the matched dates) were compared between the individuals with type 2 diabetes (T2D) and their matched controls.

RESULTS

The rate of MVCs increased slightly among people with T2D over 1 and 2 years following diabetes diagnosis, with RRs of 1.04 (95% confidence interval [CI]=1.02-1.07) and 1.11 (95% CI=1.09-1.13), respectively. These RRs were comparable to those obtained for controls (1.06 and 1.12, respectively). By contrast, the RRs of scooter crashes were significantly higher in the T2D group than in the control group during the 1 year (1.28 vs. 1.08, p < 0.001) and 2 years (1.32 vs. 1.08, p < 0.001) following diabetes diagnosis.

CONCLUSION

T2D diagnosis was associated with a moderate but significant increase in the risk of MVCs among scooter drivers, but not among car drivers.

Hypoglycemia, Vascular Disease and Cognitive Dysfunction in Diabetes: Insights from Text Mining-Based Reconstruction and Bioinformatics Analysis of the Gene Networks

Hypoglycemia has been recognized as a risk factor for diabetic vascular complications and cognitive decline, but the molecular mechanisms of the effect of hypoglycemia on target organs are not fully understood. In this work, gene networks of hypoglycemia and cardiovascular disease, diabetic retinopathy, diabetic nephropathy, diabetic neuropathy, cognitive decline, and Alzheimer's disease were reconstructed using ANDSystem, a text-mining-based tool. The gene network of hypoglycemia included 141 genes and 2467 interactions. Enrichment analysis of Gene Ontology (GO) biological processes showed that the regulation of insulin secretion, glucose homeostasis, apoptosis, nitric oxide biosynthesis, and cell signaling are significantly enriched for hypoglycemia. Among the network hubs, INS, IL6, LEP, TNF, IL1B, EGFR, and FOS had the highest betweenness centrality, while GPR142, MBOAT4, SLC5A4, IGFBP6, PPY, G6PC1, SLC2A2, GYS2, GCGR, and AQP7 demonstrated the highest cross-talk specificity. Hypoglycemia-related genes were overrepresented in the gene networks of diabetic complications and comorbidity; moreover, 14 genes were mutual for all studied disorders. Eleven GO biological processes (glucose homeostasis, nitric oxide biosynthesis, smooth muscle cell proliferation, ERK1 and ERK2 cascade, etc.) were overrepresented in all reconstructed networks. The obtained results expand our understanding of the molecular mechanisms underlying the deteriorating effects of hypoglycemia in diabetes-associated vascular disease and cognitive dysfunction.