Severe diabetic retinal disease and dementia risk in type 2 diabetes

Retinal biomarkers provide "insight" into cortical pharmacology and disease

The retina is an easily accessible out-pouching of the central nervous system (CNS) and thus lends itself to being a biomarker of the brain. More specifically, the presence of neuronal, vascular and blood-neural barrier parallels in the eye and brain coupled with fast and inexpensive methods to quantify retinal changes make ocular biomarkers an attractive option. This includes its utility as a biomarker for a number of cerebrovascular diseases as well as a drug pharmacology and safety biomarker for the CNS. It is a rapidly emerging field, with some areas well established, such as stroke risk and multiple sclerosis, whereas others are still in development (Alzheimer's, Parkinson's, psychological disease and cortical diabetic dysfunction). The current applications and future potential of retinal biomarkers, including potential ways to improve their sensitivity and specificity are discussed. This review summarises the existing literature and provides a perspective on the strength of current retinal biomarkers and their future potential.

Effects of Chimonanthus nitens Oliv. Leaf Extract on Glycolipid Metabolism and Antioxidant Capacity in Diabetic Model Mice

The paper investigated the antihyperglycemic and antihyperlipidemic efficacy and antioxidant capacity of Chimonanthus nitens Oliv. leaf extract (COE) in combination of high-glucose-fat diet-fed and streptozotocin-induced diabetic model mice. Various physiological indexes in diabetic model mice were well improved especially by oral administration of high dose of COE; the results were listed as follows. Fast blood glucose (FBG) level and serum triglyceride (TC), total cholesterol (TG), low-density lipoprotein cholesterol (LDLC), and malondialdehyde (MDA) as well as MDA in liver were significantly reduced; fasting serum insulin (FINS) and insulin sensitivity index (ISI) were both increased; high-density lipoprotein cholesterol (HDLC) in serum was significantly increased; total antioxidant capacity (T-AOC), activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in serum and liver were apparently enhanced; liver coefficient (LC), liver transaminase, and alkaline phosphatase (ALP) were decreased. Furthermore, pancreas islets and liver in diabetic model mice showed some extend of improvement in morphology and function after 4 weeks of COE treatment. In consequence, COE was advantageous to regulate glycolipid metabolism and elevate antioxidant capacity in diabetic model mice. Thus, the present study will provide a scientific evidence for the use of COE in the management of diabetes and its related complications.

Cognitive Function May be a Predictor of Retinopathy Progression in Patients with Type 2 Diabetes

Purpose

Microvascular and macrovascular complications of diabetes, such as retinopathy and nephropathy, progress over time and may be associated with cognitive decline. In this article, we aim to gain further insight into the association between cognitive function and retinopathy in type 2 diabetes.

Methods and Results

In this observational 8-year prospective study of 498 outpatients, demographic and clinical variables were monitored, along with retinopathy, depression, anxiety, and cognitive function. Baseline fundus photographs were available in 477 patients, 240 with no retinopathy, 110 with mild retinopathy, and 127 with moderate/more severe retinopathy. Of the first 2 groups, 279 patients were reevaluated after 8 years, of whom 181 still had no/mild retinopathy and 98 had progressed to more severe stages. On multivariate analysis, retinopathy progression was associated with being insulin-treated (p = 0.036), and worse cognitive function (p = 0.025) at baseline.

Conclusions

Cognitive function may be an independent predictor of retinopathy progression.

High rate of hypoglycemia in 6770 type 2 diabetes patients with comorbid dementia: A multicenter cohort study on 215,932 patients from the German/Austrian diabetes registry

AIMS

Dementia and type 2 diabetes (T2D) are two major phenomena in older people. To compare anti-hyperglycemic therapy and diabetes-related comorbidities between elderly T2D patients with or without comorbid dementia.

METHODS

215,932 type 2 diabetes patients aged ≥ 40 years (median [Q1;Q3]: 70.4 [61.2;77.7] years) from the standardized, multicenter German/Austrian diabetes patient registry, DPV, were studied. To identify patients with comorbid dementia, the registry was searched by ICD-10 codes, DSM-IV/-5 codes, respective search terms and/or disease-specific medication. For group comparisons, multiple hierarchic regression modeling with adjustments for age, sex, and duration of diabetes was applied.

RESULTS

3.1% (n=6770; 57% females) of the eligible T2D patients had clinically recognized comorbid dementia. After adjustment for demographics, severe hypoglycemia (insulin group: 14.8 ± 0.6 vs. 10.4 ± 0.2 events per 100 patient-years, p<0.001), hypoglycemia with coma (insulin group: 7.6 ± 0.4 vs. 3.9 ± 0.1 events per 100 patient-years, p<0.001), depression (9.9 vs. 4.7%, p<0.001), hypertension (74.7 vs. 72.2%, p<0.001), stroke (25.3 vs. 6.5%, p<0.001), diabetic foot syndrome (6.0 vs. 5.2%, p=0.004), and microalbuminuria (34.7 vs. 32.2%, p<0.001) were more common in dementia patients compared to T2D without dementia. Moreover, patients with dementia received insulin therapy more frequently (59.3 vs. 54.7%, p<0.001), but metabolic control (7.7 ± 0.1 vs. 7.7 ± 0.1%) was comparable to T2D without dementia.

CONCLUSIONS

In T2D with dementia, higher rates of hypoglycemia and other diabetes-related comorbidities were observed. Hence, the risks of a glucocentric and intense diabetes management with insulin and a focus on tight glycemic control without considering other factors may outweigh the benefits in elderly T2D patients with comorbid dementia.

Progress of Diabetic Severity and Risk of Dementia

CONTEXT

Diabetes is a risk factor for dementia, but the effects of diabetic severity on dementia are unclear.

OBJECTIVE

The purpose of this study was to investigate the association between the severity and progress of diabetes and the risk of dementia.

DESIGN AND SETTING

We conducted a 12-year population-based cohort study of new-onset diabetic patients from the Taiwan National Health Insurance Research Database. The diabetic severity was evaluated by the adapted Diabetes Complications Severity Index (aDCSI) from the prediabetic period to the end of follow-up. Cox proportional hazard regressions were used to calculate the hazard ratios (HRs) of the scores and change in the aDCSI.

PARTICIPANTS

Participants were 431,178 new-onset diabetic patients who were older than 50 years and had to receive antidiabetic medications.

MAIN OUTCOME

Dementia cases were identified by International Classification of Diseases, ninth revision, code (International Classification of Diseases, ninth revision, codes 290.0, 290.1, 290.2, 290.3, 290.4, 294.1, 331.0), and the date of the initial dementia diagnosis was used as the index date.

RESULTS

The scores and change in the aDCSI were associated with the risk of dementia when adjusting for patient factors, comorbidity, antidiabetic drugs, and drug adherence. At the end of the follow-up, the risks for dementia were 1.04, 1.40, 1.54, and 1.70 (P < .001 for trend) in patients with an aDCSI score of 1, 2, 3, and greater than 3, respectively. Compared with the mildly progressive patients, the adjusted HRs increased as the aDCSI increased (2 y HRs: 1.30, 1.53, and 1.97; final HRs: 2.38, 6.95, and 24.0 with the change in the aDCSI score per year: 0.51-1.00, 1.01-2.00, and > 2.00 vs < 0.50 with P < .001 for trend).

CONCLUSIONS

The diabetic severity and progression reflected the risk of dementia, and the early change in the aDCSI could predict the risk of dementia in new-onset diabetic patients.

Cognitive function in patients with diabetes mellitus: guidance for daily care

Diabetes mellitus is associated with an increase in the risk of dementia and the proportion of patients who convert from mild cognitive impairment (MCI) to dementia. In addition to MCI and dementia, the stages of diabetes-associated cognitive dysfunction include subtle cognitive changes that are unlikely to affect activities of daily life or diabetes self-management. These diabetes-associated cognitive decrements have structural brain correlates detectable with brain MRI, but usually show little progression over time. Although cognitive decrements do not generally represent a pre-dementia stage in patients below the age of 60-65 years, in older individuals these subtle cognitive changes might represent the earliest stages of a dementia process. Acknowledgment of diabetes-associated cognitive decrements can help to improve understanding of patients' symptoms and guide management. Future challenges are to establish the importance of screening for cognitive impairment in people with diabetes, to identify those at increased risk of accelerated cognitive decline at an early stage, and to develop effective treatments.

Diabetes and cognition

Dementia is a major cause of disability and death among older adults. Those with type 2 diabetes (T2D) are 50-100% more likely to develop dementia than those without T2D, but it is unknown whether this association reflects a causal relationship. Proposed mechanisms through which T2D could cause dementia include the effects of insulin dysregulation and chronic hyperglycemia on features of Alzheimer's disease and macrovascular and microvascular disorders in the brain. More research is needed to elucidate the link between T2D and dementia and identify strategies to maintain cognitive function among people with T2D.