Progress of Diabetic Severity and Risk of Dementia

Heterogeneity in the effect of type 2 diabetes on dementia incidence in a diverse cohort of Asian American and non-Latino White older adults

Dementia incidence is lower among Asian Americans than among Whites, despite higher prevalence of type 2 diabetes, a well-known dementia risk factor. Determinants of dementia, including type 2 diabetes, have rarely been studied in Asian Americans. We followed 4846 Chinese, 4129 Filipino, 2784 Japanese, 820 South Asian, and 123 360 non-Latino White members of a California-based integrated health-care delivery system from 2002 to 2020. We estimated dementia incidence rates by race/ethnicity and type 2 diabetes status, and we fitted Cox proportional hazards and Aalen additive hazards models for the effect of type 2 diabetes (assessed 5 years before baseline) on age of dementia diagnosis, controlling for sex/gender, educational attainment, nativity, height, race/ethnicity, and a race/ethnicity × diabetes interaction. Type 2 diabetes was associated with higher dementia incidence in Whites (hazard ratio [HR] = 1.46; 95% CI, 1.40-1.52). Compared with Whites, the estimated effect of diabetes was larger in South Asians (HR = 2.26; 95% CI, 1.48-3.44), slightly smaller in Chinese (HR = 1.32; 95% CI, 1.08-1.62) and Filipino (HR = 1.31; 95% CI, 1.08-1.60) individuals, and similar in Japanese individuals (HR = 1.44; 95% CI, 1.15-1.81). Heterogeneity in this association across Asian subgroups may be related to type 2 diabetes severity. Understanding this heterogeneity may inform prevention strategies to prevent dementia for all racial and ethnic groups.

Clinical characteristics and healthcare utilisation associated with undiagnosed cognitive impairment in elderly patients with diabetes in a primary care setting: a population-based cohort study

OBJECTIVES

The objective of this study is to report the prevalence, clinical characteristics and healthcare utilisation of patients with type 2 diabetes (T2DM) and previously undiagnosed cognitive impairment who were identified as having a low Montreal Cognitive Assessment (MoCA) score.

DESIGN

A population-based cohort study comparing clinical characteristics, medications, outpatient and inpatient care of patients with a MoCA score <19 to MoCA >26 using descriptive statistics, linear regression and multivariate logistic regression.

SETTING

Electronic medical records of a large health maintenance organisation in Israel.

PARTICIPANTS

350 patients, age >65 with T2DM who participated in a cognitive function screening initiative using MoCA, and had a follow-up visit during the 12 months after screening.

RESULTS

130 (37.1%) had a MoCA score >26 and 68 (19.4%) <19. Patients with MoCA<19 had more diabetes-related complications, poorer glycaemic and lipid control, fewer visits to their main primary care physician (PCP; 3.9±3.2 vs 7.3±4.2 visits/year p=0.008), shorter duration of PCP visits (8.3±4.5 vs 4.0±3.5 min, p=0.007), fewer nutritionist and endocrinologist visits, and lower participation in diabetes or smoking cessation workshops. They were less likely to be treated with glucagon-like peptide-1 (GLP-1) agonists, dipeptidyl peptidase-4 inhibitor (DPP-4), or sodium-glucose transport protein 2 (SGLT-2) inhibitors and more likely to receive insulin or sulfonylurea. Moreover, they had more emergency room visits (ER; 15 (11.5%) vs 16 (23.5%), p=0.019), hospitalisations (8 (6.2%) vs 22 (32.4%), p=0.001), and longer hospital stays (4.3±3.2 vs 14.5±9.8, p=0.001). Using statistical models, MoCA<19 was identified as a risk factor for fewer and shorter PCP visits and more ER visits and hospitalisations.

CONCLUSIONS

This study highlights the high prevalence of undiagnosed severe cognitive impairment in elderly patients with T2DM and its association with poor outpatient care. Appropriate interventions are needed to improve outcomes and prevent hospitalisation in this high-risk population.

Diabetes: a tipping point in neurodegenerative diseases

Diabetes is associated with an increased risk and progression of Alzheimer's (AD) and Parkinson's (PD) diseases. Conversely, diabetes may confer neuroprotection against amyotrophic lateral sclerosis (ALS). It has been posited that perturbations in glucose and insulin regulation, cholesterol metabolism, and mitochondrial bioenergetics defects may underlie the molecular underpinnings of diabetes effects on the brain. Nevertheless, the precise molecular mechanisms remain elusive. Here, we discuss the evidence from molecular, epidemiological, and clinical studies investigating the impact of diabetes on neurodegeneration and highlight shared dysregulated pathways between these complex comorbidities. We also discuss promising antidiabetic drugs, molecular diagnostics currently in clinical trials, and outstanding questions and challenges for future pursuit.

Using progression in adapted diabetes complications severity index score to predict erectile dysfunction in men affected by type 2 diabetes mellitus

OBJECTIVE

This study is on the use of the adapted Diabetes Complications Severity Index (aDCSI) for erectile dysfunction (ED) risk stratification in male patients with type 2 diabetes mellitus (DM).

METHODS

This is a retrospective study with records obtained from Taiwan's National Health Insurance Research Database. Adjusted HRs (aHRs) were estimated by multivariate Cox proportional hazards models with 95% confidence intervals (CIs)..

RESULTS

A population of 84 288 eligible male patients with type 2 DM were included. Compared with change in aDCSI score of 0.0-0.5 per year, the aHRs and the corresponding 95% CIs for other changes in aDCSI scores are summarised as follows: 1.10 (0.90 to 1.34) for change in aDCSI score of 0.5-1.0 per year; 4.44 (3.47 to 5.69) for change in aDCSI score of 1.0-2.0 per year; and 10.9 (7.47 to 15.9) for change in aDCSI score of >2.0 per year..

CONCLUSIONS

Progression in aDCSI score might be used for ED risk stratification in men affected by type 2 DM.

The Correlation between Metformin Use and Incident Dementia in Patients with New-Onset Diabetes Mellitus: A Population-Based Study

The evidence of metformin's effect on dementia is conflicting. This study investigates the association between metformin use and the risk of dementia among patients with diabetes mellitus (DM). This study included patients with new-onset DM between 2002 and 2013. We divided the patients into patients who used metformin and patients who did not. Two models were used to assess metformin use: the cumulative defined daily dose (cDDD) of metformin use and the intensity of metformin use. This study with 3-year and 5-year follow-ups investigated the risk of dementia among patients with DM who used metformin. At the 3-year follow-up, patients who received cDDD < 300 had an odds ratio (OR) of developing dementia of 0.92 (95% confidence interval [CI] = 0.89-0.96); patients who used metformin at intensities <10 and 10-25 DDD/month had ORs of 0.92 (95% CI: 0.87-0.97) and 0.92 (95% CI: 0.85-1.00), respectively. Metformin use at cDDD 300-500 (OR = 0.80, 95% CI = 0.56-1.15) or >500 (OR = 1.48, 95% CI = 0.48-4.60) or at an intensity >25 DDD/month (OR = 0.84, 95% CI = 0.60-1.18) were not associated with an incident of dementia. There were similar results at the 5-year follow-up. Patients with a low intensity of metformin use had a lower risk of dementia. However, higher doses of metformin with higher intensity exhibited no protective role in dementia. Prospective clinical trials are warranted to evaluate the actual underlying mechanisms between metformin dosage and the risk of dementia.

Effect of renin-angiotensin system antihypertensive medication use on cognitive function in diabetes mellitus with obesity or overweight: An ancillary study to the Action for Health in Diabetes (Look AHEAD) trial

AIM

To determine whether antihypertensive medication (AHM) acting through the renin angiotensin system (RAS-AHM), compared with other AHM, can mitigate effects on cognitive function and risk for impairment in a population with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

This secondary analysis of the randomized controlled Action for Health in Diabetes (Look AHEAD) study included 712 community-dwelling participants who were followed over 15 years. Logistic regression was used to relate RAS-AHM use to cognitive impairment, and linear regression was used to relate RAS-AHM use to domain-specific cognitive function after adjusting for potential confounders.

RESULTS

A total of 563 individuals reported RAS-AHM use and 149 reported other-AHM use during the study. RAS-AHM users have college or higher education (53%), had higher baseline glycated haemoglobin (57 mmol/mol), and reported higher diabetes medication use (86%), while other-AHM users were more likely to be White (72%), obese (25%) and to have cardiovascular history (19%). RAS-AHM use was not associated with a reduced risk of dementia compared with other-AHM use. We did observe better executive function (Trail Making Test, part B, P < 0.04), processing speed (Digit Symbol Substitution Test, P < 0.004), verbal memory (Rey Auditory Verbal Learning Test-delayed recall, P < 0.005), and composite score (P < 0.008) among RAS-AHM users compared with other-AHM users.

CONCLUSION

In this sample of adults with T2DM, free of dementia at baseline, we observed a slower decline in processing speed, executive function, verbal memory, and composite score among RAS-AHM users.

Dose-Response Association of Metformin with Parkinson's Disease Odds in Type 2 Diabetes Mellitus

Background. Studies have demonstrated that patients with diabetes mellitus who receive metformin have a lower risk of developing Parkinson’s disease (PD). However, studies have also suggested that metformin may increase the risk of PD. In this study, we investigated whether metformin use was associated with the risk of PD in type 2 diabetes mellitus (T2DM). Methods. In this population-based cross-sectional study, patients with T2DM diagnosed between 2001 and 2018 were enrolled. We categorized these patients as metformin users or nonusers. Participants below 50 years old were excluded. Two models were employed to evaluate the associations of metformin exposure and use intensity with PD after 3 and 5 years of follow-up. Results. Patients with T2DM who received <300 cumulative defined daily doses (cDDD) of metformin and those with metformin use intensity of <10 DDD/month had respective odds ratios (ORs) for PD of 0.88 (95% confidence interval [CI] = 0.83−0.94) and 0.87 (95% CI = 0.81−0.93) in a 3-year follow-up. In a 5-year follow-up, such patients had respective ORs for PD of 0.94 (95% CI = 0.90−0.98) and 0.93 (95% CI = 0.89−0.98). Patients with T2DM who received ≥300 cDDD of metformin or used metformin with intensity of ≥10 DDD/month experienced no neuroprotective effects after 3 or 5 years. Conclusions. Metformin was associated with PD odds in T2DM in a dose−response association manner. Patients who received low dosage and intensity of metformin use were associated with lower odds of PD, while higher dosage and intensity of metformin use had no neuroprotective effect.

Potential of prevention strategies for the modifiable risk factor type 2 diabetes with relation to the future number of dementia patients in Germany- a multi-state projection through 2040

BACKGROUND

We assess the impact of prevention strategies regarding type 2 diabetes as a modifiable risk factor for dementia and its consequences for the future number of dementia patients in Germany.

METHODS

We used a random sample of health claims data (N = 250,000) of insured persons aged 50+ drawn in 2014, and data on population size and death rates in 2015 from the Human Mortality Database. Using exponential hazard models, we calculated age- and sex-specific transition probabilities and death rates between the states (no diabetes/no dementia, diabetes/no dementia, no diabetes/dementia, diabetes/dementia). In multi-state projections, we estimated the future number of dementia cases aged 75+ through 2040 depending on the development of the incidence of diabetes among persons without diabetes and without dementia, and the dementia incidence among persons with and without diabetes.

RESULTS

In 2015 there were 1.53 million people with dementia aged 75+ in Germany. A relative annual reduction in death rates of 2.5% and in dementia incidence in persons without diabetes of 1% will increase this number to 3.38 million by 2040. A relative reduction of diabetes incidence by 1% annually would decrease dementia cases by around 30,000, while a reduction of dementia incidence among people with diabetes by 1% would result in 220,000 fewer dementia cases. Both prevention strategies combined would prevent 240,000 dementia cases in 2040.

CONCLUSIONS

The increase in life expectancy is decisive for the future number of people with dementia. Strategies of better diabetes treatment have the potential to lower the increase in the number of dementia patients in the coming decades.

Diabetes duration and the risk of dementia: a cohort study based on German health claims data

Objective

Diabetes is a risk factor for dementia but little is known about the impact of diabetes duration on the risk of dementia. We investigated the effect of type 2 diabetes duration on the risk of dementia.

Design

Prospective cohort study using health claims data representative for the older German population. The data contain information about diagnoses and medical prescriptions from the in- and outpatient sector.

Methods

We performed piecewise exponential models with a linear and a quadratic term for time since first type 2 diabetes diagnosis to predict the dementia risk in a sample of 13,761 subjects (2,558 dementia cases) older than 65 years. We controlled for severity of diabetes using the Adopted Diabetes Complications Severity Index.

Results

We found a U-shaped dementia risk over time. After type 2 diabetes diagnosis the dementia risk decreased (26% after 1 year) and reached a minimum at 4.75 years, followed by an increase through the end of follow-up. The pattern was consistent over different treatment groups, with the strongest U-shape for insulin treatment and for those with diabetes complications at the time of diabetes diagnosis.

Conclusions

We identified a non-linear association of type 2 diabetes duration and the risk of dementia. Physicians should closely monitor cognitive function in diabetic patients beyond the first few years after diagnosis, because the later increase in dementia occurred in all treatment groups.

Vascular complications of diabetes: natural history and corresponding risks of dementia in a national cohort of adults with diabetes

AIMS

This study aimed to determine the trajectory of diabetic vascular diseases and to investigate the association between vascular diseases and dementia.

METHODS

We included adults aged ≥ 50 years with newly diagnosed type 2 diabetes (n = 173,118) from 2001 to 2005 who were followed-up until December 31, 2013 in the Taiwan's National Health Insurance Research Database. Multivariable Cox regression models were constructed to estimate hazard ratios (HRs) and confidence limits (CLs) for all-cause dementia in relation to the number, types, and occurrence patterns of vascular disease.

RESULTS

Within 1 year of diabetes diagnosis, 26.3% of adults developed their first vascular disease. During the 1,864,279 person-years of follow-up, 17,426 adults had all-cause dementia, corresponding to an incidence of 97.9 cases/10,000 person-years in 127,718 adults with at least one vascular disease and 67.5 cases/10,000 person-years in 45,400 adults without vascular diseases. Across all age groups, adults who subsequently developed a vascular disease in two one-year windows since diabetes diagnosis had the highest incidence of all-cause dementia. In comparison with adults without vascular diseases, HR for all-cause dementia was 1.99 (CL: 1.92-2.07) for those with one vascular disease only; 2.04 (CL: 1.98-2.13) for two or more vascular diseases; 3.56 (CL: 3.44-3.70) for stroke only; and 2.06 (CL: 1.99-2.14) for neuropathy alone. Similar associations were also observed with a smaller magnitude for adults with nephropathy, retinopathy, cardiovascular disease, or peripheral arterial disease.

CONCLUSIONS

Patients with diabetes-related complications, particularly stroke and neuropathy, and those with rapidly developed vascular diseases appeared to have a high risk of dementia.

Frailty modifies the association between opioid use and mortality in chronic kidney disease patients with diabetes: a population-based cohort study

The prevalence of chronic pain in patients with chronic kidney disease (CKD) and diabetes mellitus is high and correlates with higher frailty risk, but satisfactory pain control frequently fails, necessitating opioid initiation. We aimed to examine whether opioid use affected their outcomes and whether such a relationship was modified by frailty. From the longitudinal cohort of diabetes patients (n = 840,000), we identified opioid users with CKD (n = 26,029) and propensity score-matched them to opioid-naïve patients in a 1:1 ratio. We analyzed the associations between opioid use and long-term mortality according to baseline frailty status, defined by the modified FRAIL scale. Among all, 20.3% did not have any FRAIL items, while 57.2%, 20.6%, and 1.9% had 1, 2, and at least 3 positive FRAIL items, respectively. After 4.2 years, 16.4% died. Cox proportional hazard regression showed that opioid users exhibited an 18% higher mortality risk (HR 1.183, 95% CI 1.13-1.24) with a dose- and duration-responsive relationship, compared to opioid-naive ones. Furthermore, the mortality risk posed by opioids was observed only in CKD patients without frailty but not in those with frailty. In conclusion, opioid use increased mortality among patients with CKD, while this negative outcome influence was not observed among frail ones.

Associations of diabetes severity and risk of depression: a population-based cohort study

OBJECTIVE

Previous literature investigating effects of diabetes complications on subsequent depression have been inconsistent. We aim to investigate associations of diabetes, complication severity, and depression.

DESIGN

This study used a nationwide database to establish an 11-year cohort comprised of people with new onset Type II diabetes mellitus (DM) aged 20 and above.

METHOD

Severity of DM was measured using the adapted Diabetes Complication Severity Index (aDCSI). Status of depression was determined by having one recorded depression diagnosis from the inpatient setting or three recorded depression diagnoses from the outpatient setting. The risk of depression was analyzed by multivariate Cox proportional models.

RESULTS

In 50,590 cases with new onset DM from years 2000 to 2011, the incidence of depression increased with severity and rates of progressions in diabetes complications regardless of demographic status, comorbidities, or medication compliance. Adjusted hazard ratios (aHR) of depression were 1.21, 1.25, 1.48 (p<0.001 for trend) in patients with a total aDCSI score of 1, 2, and > 3, respectively. Risks of depression were the highest in subgroup with the most serious progression (change of aDCSI score >2 per year) (aHR ranged between 11.6~26.0). Elevated risks of depression (aHR: 1.59~4.36) were also observed in the slower progression subgroups throughout the disease course.

CONCLUSIONS

Risks of depression were associated with multiple DM-related complications and rates of progression in severity.

The diabetic brain and cognition

The prevalence of both Alzheimer's disease (AD) and vascular dementia (VaD) is increasing with the aging of the population. Studies from the last several years have shown that people with diabetes have an increased risk for dementia and cognitive impairment. Therefore, the authors of this consensus review tried to elaborate on the role of diabetes, especially diabetes type 2 (T2DM) in both AD and VaD. Based on the clinical and experimental work of scientists from 18 countries participating in the International Congress on Vascular Disorders and on literature search using PUBMED, it can be concluded that T2DM is a risk factor for both, AD and VaD, based on a pathology of glucose utilization. This pathology is the consequence of a disturbance of insulin-related mechanisms leading to brain insulin resistance. Although the underlying pathological mechanisms for AD and VaD are different in many aspects, the contribution of T2DM and insulin resistant brain state (IRBS) to cerebrovascular disturbances in both disorders cannot be neglected. Therefore, early diagnosis of metabolic parameters including those relevant for T2DM is required. Moreover, it is possible that therapeutic options utilized today for diabetes treatment may also have an effect on the risk for dementia. T2DM/IRBS contribute to pathological processes in AD and VaD.

Risk of allergic conjunctivitis in patients with type 1 diabetes mellitus: a population-based retrospective cohort study

OBJECTIVE

In accordance with the dichotomy between T helper type 1(Th1) and T helper type 2 (Th2) responses, the occurrence of allergic conjunctivitis (AC) and type 1 diabetes mellitus (T1DM) is, in theory, inversely related in the individual. However, recent studies investigating the association between the two diseases are controversial.

DESIGN

Population-based cohort study.

SETTING

We used claims data of the National Health Insurance Research Database of Taiwan.

PARTICIPANTS

We identified 4160 patients aged 1-30 years with newly diagnosed T1DM and no history of AC at baseline. For each patient with T1DM, four non-T1DM controls (n=16,640) were matched by sex. The mean follow-up time was 6 years.

PRIMARY AND SECONDARY OUTCOME MEASURES

Multivariate Cox proportional hazards regression analysis was used to evaluate the risk of AC. We additionally evaluated the association between risk of AC and T1DM progression by examining Diabetes Complications Severity Index (aDCSI) changes from the date of diagnosis until the end of follow-up.

RESULTS

The overall incidence of allergic conjunctivitis (AC) was higher in the type 1 diabetes mellitus (T1DM) cohort than in the control cohort (23.0 vs 13.5 per 1000 person-years, adjusted incidence rate ratio (aIRR): 1.59, 95% CI 1.47 to 1.71). Relative to that in patients with mildly progressive T1DM, the risk of AC increased as the adapted Diabetes Complications Severity Index (aDCSI) increased (aIRR: 1.68, 3.78 and 18.8, with yearly changes in aDCSI score: 0.51 to 1.00, 1.01 to 2.00, and >2.00 vs <0.51, respectively; for trend <0.001).

CONCLUSION

Patients with T1DM are at an elevated risk of developing AC; this risk increases with T1DM progression. The T helper type 1/T helper type 2 hypothesis is an overly simplistic explanation for this association.

Diabetes Complications Severity Index (DCSI)-Update and ICD-10 translation

AIMS

The Diabetes Complications Severity Index (DCSI) converts diagnostic codes and laboratory results into a 14-level metric quantifying the long-term effects of diabetes on seven body systems. Adoption of the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) necessitates translation from ICD-9-CM and creates refinement opportunities.

METHODS

ICD-9 codes for secondary and primary diabetes plus all five ICD-10 diabetes categories were incorporated into an updated tool. Additional modifications were made to improve the accuracy of severity assignments.

SUBJECTS

The tools were tested in a Medicare Advantage population.

RESULTS

In the type 2 subpopulation, prevalence steadily declined with increasing score according to the updated DCSI tool, whereas the original tool resulted in an aberrant local prevalence peak at DCSI = 2. In the type 1 subpopulation, score prevalence was greater in type 1 versus type 2 subpopulations (3 versus 0) according to both instruments. Both instruments predicted current-year inpatient admissions risk and near-future mortality, using either purely ICD-9 data or a mix of ICD-9 and ICD-10 data.

DISCUSSION

While the performance of the tool with purely ICD-10 data has yet to be evaluated, this updated tool makes assessment of diabetes patient severity and complications possible in the interim.

Associations between anxiety and depression symptoms and cognitive testing and neuroimaging in type 2 diabetes

AIMS

Anxiety, depression, accelerated cognitive decline, and increased risk of dementia are observed in individuals with type 2 diabetes. Anxiety and depression may contribute to lower performance on cognitive tests and differences in neuroimaging observed in individuals with type 2 diabetes.

METHODS

These relationships were assessed in 655 European Americans with type 2 diabetes from 504 Diabetes Heart Study families. Participants completed cognitive testing, brain magnetic resonance imaging, the Brief Symptom Inventory Anxiety subscale, and the Center for Epidemiologic Studies Depression-10.

RESULTS

In analyses adjusted for age, sex, educational attainment, and use of psychotropic medications, individuals with comorbid anxiety and depression symptoms had lower performance on all cognitive testing measures assessed (p≤0.005). Those with both anxiety and depression also had increased white matter lesion volume (p=0.015), decreased gray matter cerebral blood flow (p=4.43×10(-6)), decreased gray matter volume (p=0.002), increased white and gray matter mean diffusivity (p≤0.001), and decreased white matter fractional anisotropy (p=7.79×10(-4)). These associations were somewhat attenuated upon further adjustment for health status related covariates.

CONCLUSIONS

Comorbid anxiety and depression symptoms were associated with cognitive performance and brain structure in a European American cohort with type 2 diabetes.