Relationships between daily acute glucose fluctuations and cognitive performance among aged type 2 diabetic patients

Assessment of fatigue severity and neurocognitive functions in the real setting of Ramadan in patients with type 2 diabetes mellitus

OBJECTIVES

Type 2 diabetes mellitus (T2DM) is linked with a risk of dementia and decline in neurocognitive function. The current observational case-control study was conducted to evaluate the effect of fasting during Ramadan on cognitive functions and fatigue severity in T2DM patients using the Cambridge Neuropsychological Test Automated Battery (CANTAB).

METHODS

This research was conducted at King Saud University Medical city, on 82 subjects including 43 control and 39 T2DM patients of both genders. The standardized Fatigue Severity Scale (FSS) and tests from CANTAB, including the Motor Screening Task (MOT), Spatial Span (SSP) and Intra-Extra Dimensional Set Shift (IED) were recorded during 3rd week and 2-3 weeks after Ramadan under controlled environmental conditions. Neurocognitive functions were recorded through CANTAB.

RESULTS

IED errors (24.43 vs 50.73, p = 0.007), MOT mean and median latency (1466.32 vs 1120.27, p = 0.002) were significantly higher in T2DM than controls. IED stages completed (7.43 vs 8.69, p = 0.003) and SSP Span length were significantly lower in T2DM than controls (4.13 vs 4.82, p = 0.059). The significant differences between T2DM patients and controls persisted in the post. T2DM patients made more errors and completed less IED stages than did the controls, indicating that a worsened flexibility of attention relative to controls. Moreover, T2DM patients exhibited longer latencies in MOT, indicating poor motor performance. A comparison of performances by T2DM patients on FSS and CANTAB during and after Ramadan showed that fasting substantially increased fatigue scales, motor performance, and working-memory capacity.

CONCLUSIONS

Patients with T2DM have impaired cognitive functions including poor motor performance, low flexibility of attention, and poor working memory capacity compared to healthy control subjects during and also in post Ramadan period. However, there is no clear statistical evidence that the cognitive functions (except for SSP SL scores) and fatigue severity of T2DM subjects differ between Ramadan and after Ramadan in both T2DM and controls.

Mechanisms and Characteristics of Sulfonylureas and Glinides

BACKGROUND

Type 2 diabetes mellitus is a complex progressive endocrine disease characterized by hyperglycemia and life-threatening complications. It is the most common disorder of pancreatic cell function that causes insulin deficiency. Sulfonylurea is a class of oral hypoglycemic drugs. Over the past half century, these drugs, together with the subsequent non-sulfonylureas (glinides), have been the main oral drugs for insulin secretion.

OBJECTIVE

Through in-depth study, the medical profession considers it as an important drug for improving blood sugar control.

METHODS

The mechanism, characteristics, efficacy and side effects of sulfonylureas and glinides were reviewed in detail.

RESULTS

Sulfonylureas and glinides not only stimulated the release of insulin from pancreatic cells, but also had many extrapanular hypoglycemic effect, such as reducing the clearance rate of insulin in liver, reducing the secretion of glucagon, and enhancing the sensitivity of peripheral tissues to insulin in type 2 diabetes mellitus.

CONCLUSION

Sulfonylureas and glinides are effective first-line drugs for the treatment of diabetes mellitus. Although they have the risk of hypoglycemia, weight gain and cardiovascular disease, their clinical practicability and safety can be guaranteed as long as they are reasonably used.

Effect of DPP-4 inhibitor on elderly patients with T2DM combined with MCI

The aim of this study was to investigate the effect of dipeptidyl peptidase-4 (DPP-4) inhibitor on blood sugar level and cognitive ability in elderly patients with type 2 diabetes mellitus (T2DM) combined with post-stroke mild cognitive impairment (MCI). Thirty patients received DPP-4 inhibitor (study group), while another thirty received sulfonylurea (control group). Six months after treatment, markers regarding blood sugar were improved in both groups (all P<0.05) without intergroup differences (all P>0.05); scores regarding cognitive ability improved in the study group (both P<0.05) and were higher versus the control group (both P<0.01); the study group had higher Aβ1-42/Aβ1-40 value versus the pretreatment value (P<0.001), which differed from the control group (P<0.05); tumor necrosis factor-α and interleukin-6 concentrations decreased in both groups, while the study group had greater reductions; C-reactive protein value decreased after treatment in the study group (all P<0.05). Using DPP-4 inhibitor in elderly patients with T2DM combined with post-stroke MCI can lower blood sugar and improve cognitive ability. The mechanism may be associated with the improvement of Aβ gathering and reduction in inflammatory response.

Association between visit-to-visit variability of HbA1c and cognitive decline: a pooled analysis of two prospective population-based cohorts

AIMS/HYPOTHESIS

The aim of this study was to investigate the association between visit-to-visit variability in HbA_1c and cognitive function decline in the elderly population.

METHODS

We performed a pooled analysis of two prospective population-based cohorts (the Health Retirement Study [HRS] and the English Longitudinal Study of Ageing [ELSA]). Cognitive function, including memory and executive function, were assessed at baseline and every 2 years, while HbA_1c levels were assessed at baseline and every 4 years. Visit-to-visit variability (VVV) in HbA_1c was calculated using the CV, SD and variation independent of the mean (VIM) during the follow-up period. Linear mixed models were used to evaluate the association between HbA_1c variability and cognitive function decline with adjustment for demographics, mean HbA_1c, education, smoking, alcohol consumption, BMI, baseline hypertension, baseline diabetes status and HDL-cholesterol.

RESULTS

The study enrolled 6237 participants (58.23% women, mean age 63.38 ± 8.62 years) with at least three measurements of HbA_1c. The median follow-up duration was 10.56 ± 1.86 years. In the overall sample, compared with the lowest quartile of HbA_1c variability, participants in the highest quartile of HbA_1c variability had a significantly worse memory decline rate (-0.094 SD/year, 95% CI -0.185, -0.003) and executive function decline rate (-0.083 SD/year, 95% CI -0.125, -0.041), irrespective of mean HbA_1c values over time. Among individuals without diabetes, each 1-SD increment in HbA_1c CV was associated with a significantly higher rate of memory z score decline (-0.029, 95% CI -0.052, -0.005) and executive function z score decline (-0.049, 95% CI -0.079, -0.018) in the fully adjusted model.

CONCLUSIONS/INTERPRETATION

We observed a significant association between long-term HbA_1c variability and cognitive decline among the non-diabetic population in this study. The effect of maintaining steady glucose control on the rate of cognitive decline merits further investigation.

Antidiabetic Drugs for the Risk of Alzheimer Disease in Patients With Type 2 DM Using FAERS

Alzheimer disease (AD) may develop after the onset of type 2 diabetes mellitus (T2DM), and the risk of AD may depend on the antidiabetic drug administered. We compared the risk of AD among 66 085 patients (≥ 65 years) with T2DM (1250 having concomitant AD) who had been administered antidiabetic drug monotherapy for T2DM who had voluntarily reported themselves in the Food and Drug Administration Adverse Event Reporting System. The risk of AD from the use of different antidiabetic drug monotherapies compared to that of metformin monotherapy was assessed by logistic regression. Rosiglitazone (adjusted reporting odds ratio [aROR] = 0.11; 95% confidence interval [CI]: 0.07-0.17; P < .001), exenatide (aROR = 0.22; 95% CI: 0.11-0.37; P < .001), liraglutide (aROR = 0.36; 95% CI: 0.19-0.62; P < .001), dulaglutide (aROR = 0.39; 95% CI: 0.17-0.77; P = .014), and sitagliptin (aROR = 0.75; 95% CI: 0.60-0.93; P = .011) were found to have a significantly lower associated risk of AD than that of metformin. Therefore, the administration of glucagon-like peptide 1 receptor agonists and rosiglitazone may reduce the risk of AD in patients with T2DM.

Apple Preload Halved the Postprandial Glycaemic Response of Rice Meal on in Healthy Subjects

This study aimed to investigate the possible glycemic effect of apple preload on acute postprandial glycemic responses (GRs) of a following rice meal, comparing with its co-ingestion counterpart and an apple sugar solution preload, based on equal carbohydrates intake. In a randomized crossover trial, 18 healthy female subjects consumed (1) rice, (2) co-ingestion of apple and rice (A+R), (3) apple preload and rice (PA+R), and (4) rice with sugar solution preload (same sugar profile as in apple) (PSS+R). Acute postprandial GR tests and subjective satiety tests were carried out for each test food. Compared with rice reference, the PA+R achieved a 50% reduction of the iAUC_0-120, a 51.4% reduction of the average peak value, and a 52.6% reduction of glycemic excursion in 240 min, while the PSS+R showed 29.7% and 31.6% reduction of peak value and glycemic excursion, respectively. No significant differences were found between R and PA+R in any of the satiety characteristics. Compared with rice control, apple preload of 15 g available carbohydrates remarkably lowered the acute postprandial GR without negative effect on satiety. The sugar component may partly contribute to the glycemic suppressing effect of the apple preload.

Diabetes mellitus and risks of cognitive impairment and dementia: A systematic review and meta-analysis of 144 prospective studies

BACKGROUND

Uncertainties persist about the associations of diabetes with risk of cognitive impairment and dementia. We aimed to illuminate these associations from various aspects.

METHODS

We identified relevant prospective studies by searching PubMed up to Jun 2019. Summary relative risks (RR) were estimated using random-effects models. Credibility of each meta-analysis was assessed. Meta-regression and subgroup analyses were conducted.

RESULTS

Of 28,082 identified literatures, 144 were eligible for inclusion in the systematic review, among which 122 were included in the meta-analysis. Diabetes conferred a 1.25- to 1.91-fold excess risk for cognitive disorders (cognitive impairment and dementia). Subjects with prediabetes also had higher risk for dementia. As for diabetes-related biochemical indicators, fasting plasma glucose (FPG) was non-linearly related to cognitive disorders; the elevated levels of 2 -h postload glucose (2h-PG), glycosylated hemoglobin (HbA1c), low and high levels of fasting plasma insulin (FPI) were associated with an increased risk of dementia. Encouragingly, the use of pioglitazone exhibited a 47% reduced risk of dementia in diabetic population.

CONCLUSIONS

Diabetes, even prediabetes and changes of diabetes-related biochemical indicators, predicted increased incidence of cognitive impairment and dementia. The protective effects of pioglitazone warrant further investigation in randomized trials.

Design and in silico modeling of Indoloquinoxaline incorporated keratin nanoparticles for modulation of glucose metabolism in 3T3-L1 adipocytes

The following study was done to assess the glucose utilizing efficiency of Indoloquinoxaline derivative incorporated keratin nanoparticles (NPs) in 3T3-L1 adipocytes. Indoloquinoxaline derivative had wide range of biological activities including antidiabetic activity. In this view, Indoloquinoxaline moiety containing N, N-dimethyl (3-fluoro-6H-indolo [3,2-b] quinoxalin-6-yl) methanamine compound was designed and synthesized, and further it is incorporated into keratin nanoparticles. The formulated NPs, drug entrapment efficiency, releasing capacity, stability, and physicochemical properties were characterized by various spectral analyzer and obtained results of characterizations were confirmed the properties of NPs. The analysis of mechanism underlying the glucose utilization of NPs was examined through molecular docking with identified target, and observed in silico study reports shown strong interaction of NPs in the binding pockets of AMPK and PTP1B. Based on the in silico screening, the formulated NPs was performed for in vitro cellular viability and glucose uptake studies on 3T3-L1 adipocytes. Interestingly, 40 μg of NPs displayed 78.2 ± 2.76% cellular viability, and no cell death was observed at lower concentrations. Further, the concentration dependent glucose utilization was observed at different concentrations of NPs in 3T3-L1 adipocytes. The results of NPs (40 μg) on glucose utilization have revealed eminent result 58.56 ± 4.54% compared to that of Metformin (10 μM) and Insulin (10 μM). The identified results clearly indicated that Indoloquinoxaline derivative incorporated keratin NPs significantly increased glucose utilization efficiency and protect the cells against the insulin resistance.

Optimizing Postprandial Glucose Management in Adults With Insulin-Requiring Diabetes: Report and Recommendations

Faster-acting insulins, new noninsulin drug classes, more flexible insulin-delivery systems, and improved continuous glucose monitoring devices offer unprecedented opportunities to improve postprandial glucose (PPG) management and overall care for adults with insulin-treated diabetes. These developments led the Endocrine Society to convene a working panel of diabetes experts in December 2018 to assess the current state of PPG management, identify innovative ways to improve self-management and quality of life, and align best practices to current and emerging treatment and monitoring options. Drawing on current research and collective clinical experience, we considered the following issues for the ∼200 million adults worldwide with type 1 and insulin-requiring type 2 diabetes: (i) the role of PPG management in reducing the risk of diabetes complications; (ii) barriers preventing effective PPG management; (iii) strategies to reduce PPG excursions and improve patient quality of life; and (iv) education and clinical tools to support endocrinologists in improving PPG management. We concluded that managing PPG to minimize or prevent diabetes-related complications will require elucidating fundamental questions about optimal ways to quantify and clinically assess the metabolic dysregulation and consequences of the abnormal postprandial state in diabetes and recommend research strategies to address these questions. We also identified practical strategies and tools that are already available to reduce barriers to effective PPG management, optimize use of new and emerging clinical tools, and improve patient self-management and quality of life.

Diabetes drugs in the fight against Alzheimer's disease

Alzheimer's disease (AD) is the most prevalent form of dementia, particularly in old age subjects. Hyperinsulinemia and insulin resistance, which are known as pathophysiological features of Type 2 Diabetes Mellitus (T2DM), have also been demonstrated to have a significant impact on cognitive impairment. Studies have shown that an altered insulin pathway may interact with amyloid-β protein deposition and tau protein phosphorylation, both leading factors for AD development. Drugs used for T2DM treatment from insulin and metformin through dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists may represent a promising approach to fight AD. With this review from animal to human studies, we aim at responding to the reasons why drugs for diabetes may represent potential treatments for AD.

How often patients on insulin therapy measure postprandial glycemia and modify insulin doses accordingly? From an on-line survey in insulin-treated diabetes patients in Spain

INTRODUCTION

Controlling postprandial glycemia (PPG) is important to achieve optimal glycemic control, but few studies have evaluated how often is measured and evaluated.

OBJECTIVES

To evaluate how often patients on insulin therapy measure PPG and modify insulin doses accordantly. As secondary objectives, we evaluated the factors conditioning elevated PPG and associated issues.

MATERIAL AND METHODS

Cross-sectional observational study based on a web-based survey from an unselected sample of adult insulin-treated patients. A p-value of < 0.05 was significant.

RESULTS

1251 patients (68% women, 38.9 ± 13 years [mean ± SD], body mass index (BMI) 24.2 ± 4.2 kg/m², diabetes duration 17.4 ± 12.8 years, insulin dose 38 ± 18 IU) participated, 1104 with autoinmmune disease (AD) and 147 with non-autoinmmune diabetes (NAD). 59% of patients had HbA1c ≤ 7%, 92.7% of patients with AD and 55.8% with NAD were attended by specialists (p < 0.001). People with AD did more often blood glucose monitoring (BGM) (p < 0.0001) and used continuous glucose monitoring systems (CGMS) (p < 0.0001). 90.1% with AD and 68.0% with NAD received instructions on measuring PPG (p < 0.001), and more with AD received specific training to change the treatment (87% vs. 61.2%, p < 0.0001) and were more proactive. However, more with NAD discussed their postprandial glucose levels with their healthcare team during clinical visits (92.5% vs. 74.1%, p < 0.0001). Regarding bolus administration, 88.6% with AD and 68.7% with NAD injected the insulin bolus before meals (p < 0.001).

CONCLUSIONS

Patients with AD determine PPG more frequently. Diabetes type, follow-up setting, number of injections and CGMS use were the most important predictive factors for PPG measurement. Diabetes education programs should address how to best monitor PPG and appropriate corrective actions.

Effects of vildagliptin, a DPP-4 inhibitor, in elderly diabetic patients with mild cognitive impairment

INTRODUCTION

There is an unclear association between type 2 diabetes and mild cognitive impairment in the elderly. Both diseases are more prevalent in the older adults compared to the younger counterpart. Some anti-diabetic drugs seem to influence positively the evolution of mild cognitive impairment. This retrospective study investigated the effect of vildagliptin, an inhibitor of the enzyme dipeptidyl peptidase-4 (DPP-4), on the cognitive functioning of elderly diabetic patients with mild cognitive impairment (MCI) documented at mini mental state examination (MMSE).

METHODS

We included 60 diabetic elderly people which were divided in 2 groups: Group A, 30 patients with HbA₁c (glycated hemoglobin) ≤7.5% and treated with metformin, and Group B, 30 patients with HbA₁c >7.5%, and treated with metformin plus vildagliptin. We collected data on MMSE, fasting plasma glucose (FPG) and HbA₁c at baseline and after 180 ± 10 days from the beginning of treatment.

RESULTS

The two groups exhibited significantly different values in FPG (P < 0.05) and HbA₁c (P < 0.01) at baseline, and in MMSE score (P < 0.001) after treatment. The intragroup comparison showed a significant (P < 0.05) reduction in MMSE score in group A, and in HbA1c (P = 0.01) in group B.

CONCLUSION

Vildagliptin in addition to metformin resulted in the maintenance of MMSE score, showing a protecting role on cognitive functioning compared to the metformin only group.

Cognitive Dysfunction in Type 1 Diabetes Mellitus

CONTEXT

We have summarized key studies assessing the epidemiology, mechanisms, and consequences of cognitive dysfunction (CD) in type 1 diabetes.

EVIDENCE SYNTHESIS

In a number of studies, the severity of CD in type 1 diabetes was affected by the age of onset and duration, and the presence of proliferative retinopathy and autonomic neuropathy. Diabetes-related CD has been observed, not only in adults, but also in children and adolescents. Most neuroimaging studies of patients with type 1 diabetes did not show any differences in whole brain volumes; however, they did reveal selective deficits in gray matter volume or density within the frontal, posterior, and temporal cortex and subcortical gray matter. Studies of middle-age adults with long-standing type 1 diabetes using diffusion tensor imaging have demonstrated partial lesions in the white matter and decreased fractional anisotropy in posterior brain regions. The mechanisms underlying diabetes-related CD are very complex and include factors related to diabetes per se and to diabetes-related cardiovascular disease and microvascular dysfunction, including chronic hyperglycemia, hypoglycemia, macro- and microvascular disease, and increased inflammatory cytokine expression. These mechanisms might contribute to the development and progression of both vascular dementia and Alzheimer disease.

CONCLUSIONS

Higher rates of CD and faster progression in type 1 diabetes can be explained by both the direct effects of altered glucose metabolism on the brain and diabetes-related cardiovascular disease. Because the presence and progression of CD significantly worsens the quality of life of patients with diabetes, further multidisciplinary studies incorporating the recent progress in both neuroimaging and type 1 diabetes management are warranted to investigate this problem.

Reduction in glucose fluctuations in elderly patients with type 2 diabetes using repaglinide: A randomized controlled trial of repaglinide vs sulfonylurea

AIMS/INTRODUCTION

Glinides are antidiabetic drugs that enhance the early phase of insulin secretion, but have been considered to be less effective at lowering blood glucose than sulfonylureas. However, glinides show a lower risk of hypoglycemia and a greater effect on postprandial hyperglycemia, and are particularly recommended for use in elderly patients with type 2 diabetes. We investigated the efficacy and safety of repaglinide compared with sulfonylurea for the treatment of elderly patients.

MATERIALS AND METHODS

In the present multicenter, prospective, randomized, open-label, controlled trial, 57 elderly lean patients with type 2 diabetes who were being treated with sulfonylureas were studied. They were either switched to repaglinide (Repa group) or continued a sulfonylurea (SU group) for 12 weeks. The primary outcome comprised the change in glycemic control, and among the secondary outcomes was the presence of hypoglycemia and drug compliance.

RESULTS

Although glycated hemoglobin (HbA1c) was not significantly different between the two groups (SU +0.02% vs Repa -0.07%), greater improvements in the glycated albumin (GA) and GA to HbA1c ratio (GA/HbA1c) were observed in the Repa group (ΔGA, SU +0.12% vs Repa -1.15%; ΔGA/HbA1c, SU +0.01 vs Repa -0.13; each P < 0.01) without increasing hypoglycemia. When the Repa group was subdivided according to whether GA improved, the SU dose before switching to repaglinide was significantly smaller and the homeostatic model assessment of β-cell function was significantly higher in the GA improvement subgroup.

CONCLUSIONS

Switching from SU to Repa improved GA and GA/HbA1c, and had favorable effects on glucose fluctuation in elderly patients with type 2 diabetes.

Acute glucose fluctuation impacts microglial activity, leading to inflammatory activation or self-degradation

Diabetes mellitus is associated with an increased risk of Alzheimer’s dementia and cognitive decline. The cause of neurodegeneration in chronic diabetic patients remains unclear. Changes in brain microglial activity due to glycemic fluctuations may be an etiological factor. Here, we examined the impact of acute ambient glucose fluctuations on BV-2 microglial activity. Biochemical parameters were assayed and showed that the shift from normal glucose (NG; 5.5 mM) to high glucose (HG; 25 mM) promoted cell growth and induced oxidative/inflammatory stress and microglial activation, as evidenced by increased MTT reduction, elevated pro-inflammatory factor secretion (i.e., TNF-α and oxygen free radicals), and upregulated expression of stress/inflammatory proteins (i.e., HSP70, HO-1, iNOS, and COX-2). Also, LPS-induced inflammation was enlarged by an NG-to-HG shift. In contrast, the HG-to-NG shift trapped microglia in a state of metabolic stress, which led to apoptosis and autophagy, as evidenced by decreased Bcl-2 and increased cleaved caspase-3, TUNEL staining, and LC3B-II expression. These stress episodes were primarily mediated through MAPKs, PI3K/Akt, and NF-κB cascades. Our study demonstrates that acute glucose fluctuation forms the stress that alters microglial activity (e.g., inflammatory activation or self-degradation), representing a novel pathogenic mechanism for the continued deterioration of neurological function in diabetic patients.

Ambulatory glucose profile in diabetes-related dementia

AIM

Diabetes-related dementia (DrD), a dementia subgroup associated with specific diabetes mellitus (DM)-related metabolic abnormalities rather than Alzheimer's disease (AD) pathology or cerebrovascular disease, is characterized by less well-controlled glycemia. We investigated the glucose level, variability and stability, and risk of hypoglycemia in DrD to determine characteristic ambulatory glucose profiles (AGP).

METHODS

We obtained AGP for 14 days of 40 patients with AD associated with DM and 19 patients with DrD using a novel sensor-based flash glucose monitoring system (FreeStyle Libre Pro).

RESULTS

Despite similar mean glucose and estimated A_1c values, the DrD group showed significantly greater glucose variability and higher percentage of time spent in hypoglycemia than the AD associated with DM group. Glucose level and variability correlated significantly and negatively with Mini-Mental State Examination in DrD, but not in AD associated with DM The estimated A_1c levels calculated from the 14 days of AGP data significantly correlated with the HbA_1c levels measured within 2 months of the insertion of the sensor.

CONCLUSIONS

DrD has a distinctively different AGP from that of AD associated with DM. Glucose variability and hypoglycemia are more involved in the pathophysiology of DrD than in that of AD associated with DM. The AGP analysis using the flash glucose monitoring system might provide useful information undetected by HbA_1c values. Geriatr Gerontol Int 2019; 19: 282-286.

Association of the Glycemic Fluctuation as well as Glycemic Control with the Pancreatic β-cell Function in Japanese Subjects with Type 2 Diabetes Mellitus

Objective It is important to preserve the pancreatic β-cell function in order to maintain good glycemic control for a long period. The aim of this study was to examine which factors are associated with the β-cell function in subjects with type 2 diabetes mellitus. Methods A total of 372 subjects with type 2 diabetes who had been hospitalized for the amelioration of their glycemic control and/or education about diabetes in Kawasaki Medical School Hospital were included in this study. We evaluated the remnant β-cell function as the HOMA-%β using the computer software program HOMA2 and estimated the glycemic fluctuation with the glycoalbumin (GA)/hemoglobin A1c (HbA1c) ratio. In addition, we divided the subjects into a relatively young group (<65 years old) (n=210) and an elderly group (≥65 years old) (n=162) and performed several analyses in each group. Results The GA/HbA1c ratio, GA and HbA1c were independent determinant factors for the HOMA-%β regardless of age. We obtained almost the same results even after excluding those subjects using insulin secretagogues. These data suggest that the glycemic fluctuation and glycemic control are associated with the remnant β-cell function in Japanese subjects with type 2 diabetes. Conclusion It is very important to reduce glycemic fluctuation as well as to maintain good glycemic control in order to preserve β-cell function in subjects with type 2 diabetes.

Diabetic ketoacidosis further increases risk of Alzheimer's disease in patients with type 2 diabetes

AIM

Diabetes mellitus (DM) is a known risk factor for dementia. It is unclear whether diabetic ketoacidosis (DKA) further increases the risk of dementia in patients with type 2 DM.

METHODS

This retrospective nationwide population-based cohort study was conducted using Taiwan's National Health Insurance database. We extracted claims data for 4451 patients with type 2 diabetes and DKA and 8902 diabetic controls matched for age, gender, diabetes complication severity index, frequency of clinic visits and baseline comorbidities between 2000 and 2002. Patients with type 1 diabetes or prior hypoglycemia before index date were excluded. All patients were tracked until new dementia diagnosis, death, or end of 2011.

RESULTS

Of the 4451 DKA patients, 211 (4.7%) and 305 (3.4%) of the 8902 diabetic controls were diagnosed as having dementia during the follow-up period. The incidence rate ratio (IRR) for dementia was 1.62 (95% CI 1.35-1.93; P < 0.0001) for patients with DKA versus diabetic patients without DKA. After adjusting for age, baseline comorbidities, geographic area, and income, patients with DKA were found to have 1.86 times the risk of developing dementia, compared to controls (95% CI 1.56-2.22, P < 0.0001). They were found to have a higher risk of Alzheimer's dementia (HR:1.86; 95% CI 1.52-2.28, P < 0.0001) but not non-Alzheimer's dementia.

CONCLUSION

Type 2 diabetes patients with DKA are at increased risk of Alzheimer's dementia but not non-Alzheimer dementia.

Fasting Glucose Variability in Young Adulthood and Cognitive Function in Middle Age: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

OBJECTIVE

To determine whether intraindividual variability in fasting glucose (FG) below the threshold of diabetes is associated with cognitive function in middle adulthood beyond increasing FG.

RESEARCH DESIGN AND METHODS

We studied 3,307 CARDIA (Coronary Artery Risk Development in Young Adults) Study participants (age range 18-30 years and enrolled in 1985-1986) at baseline and calculated two measures of long-term glucose variability: the coefficient of variation about the mean FG (CV-FG) and the absolute difference between successive FG measurements (average real variability [ARV-FG]) before the onset of diabetes over 25 and 30 years of follow-up. Cognitive function was assessed at years 25 (2010-2011) and 30 (2015-2016) with the Digit Symbol Substitution Test (DSST), Rey-Auditory Verbal Learning Test (RAVLT), Stroop Test, Montreal Cognitive Assessment, and category and letter fluency tests. We estimated the association between glucose variability and cognitive function test score with adjustment for clinical and behavioral risk factors, mean FG level, change in FG level, and diabetes development, medication use, and duration.

RESULTS

After multivariable adjustment, 1-SD increment of CV-FG was associated with worse cognitive scores at year 25: DSST, standardized regression coefficient -0.95 (95% CI -1.54, -0.36); RAVLT, -0.14 (95% CI -0.27, -0.02); and Stroop Test, 0.49 (95% CI 0.04, 0.94). Findings were similar between CV-FG with each cognitive test score at year 30 and when we used an alternative measure of variability (ARV-FG) that captures variability in successive FG values.

CONCLUSIONS

Higher intraindividual FG variability during young adulthood below the threshold of diabetes was associated with worse processing speed, memory, and language fluency in midlife independent of FG levels.

Reduced Glucose Variability With Glucose-Dependent Versus Glucose-Independent Therapies Despite Similar Glucose Control and Hypoglycemia Rates in a Randomized, Controlled Study of Older Patients With Type 2 Diabetes Mellitus

BACKGROUND

Few studies have evaluated continuous glucose monitoring (CGM) in older patients with type 2 diabetes mellitus (T2DM) not using injectable therapy. CGM is useful for investigating hypoglycemia and glycemic variability, which is associated with complications in T2DM.

METHODS

A CGM substudy of Individualized treatMent aPproach for oldER patIents in a randomized trial in type 2 diabetes Mellitus (IMPERIUM)) was conducted. Patients were vulnerable (moderately ill and/or frail) older (≥65 years) individuals with suboptimally controlled T2DM. Strategy A comprised glucose-dependent therapies (n = 26) with a nonsulfonylurea oral antihyperglycemic medication (OAM) and a glucagon-like peptide-1 receptor agonist as the first injectable. Strategy B comprised non-glucose-dependent therapies (n = 21) with sulfonylurea as the preferred OAM and insulin glargine as the first injectable. Primary endpoints were duration and percentage of time spent with blood glucose (BG) ≤70 mg/dL over 24 hours at week 24.

RESULTS

Duration and percentage of time spent with hypoglycemia at ≤70 mg/dL were similar for Strategy A and Strategy B; glycemic control improved similarly in both arms (LSM change in HbA1c at week 24; A = -1.2%, B = -1.4%). Duration and percentage time spent with euglycemia and hyperglycemia were also similar in both arms. However, Strategy A was associated with lower within-day (21.1 ± 1.2 vs 25.1 ± 1.4, P = .046) and between-day (5.4 ± 1.0 vs 9.1 ± 1.3, P = .038) BG variability (coefficient of variance [LSM ± SE]) at week 24.

CONCLUSIONS

This CGM substudy in older patients with T2DM showed lower within- and between-day BG variability with glucose-dependent therapies but similar HbA1c reductions and hypoglycemia duration with glucose-independent strategies.

Glucose excursions and hypoglycemia in patients with type 2 diabetes treated with mitiglinide/voglibose versus glimepiride: A randomized cross-over trial

BACKGROUND

Glucose excursions and hypoglycemia are associated with cardiovascular complications. However, no studies have evaluated glucose excursions and the frequency of hypoglycemia in patients treated with mitiglinide/voglibose versus glimepiride as add-on to dipeptidyl peptidase-4 inhibitor therapy.

METHODS

This cross-over trial included 20 patients with type 2 diabetes. After initiating vildagliptin 100 mg, patients were randomly assigned to receive mitiglinide 10 mg/voglibose 0.2 mg three times daily for 3 days followed by glimepiride 1 mg once daily for the subsequent 3 days as add-on therapy, or vice versa. Glucose excursions and hypoglycemia frequency were measured using 24-h continuous glucose monitoring. Metabolic profile changes were evaluated using a meal tolerance test.

RESULTS

The mean glucose levels in the mitiglinide/voglibose and glimepiride phases were identical (8.01 vs 8.24 mmol/L, respectively). However, during the mitiglinide/voglibose phase compared with the glimepiride phase, the standard deviation of glucose (1.30 vs 2.10 mmol/L; P < 0.001), mean amplitude of glycemic excursions (3.47 vs 5.28 mmol/L; P < 0.001), M-value (24.6 vs 70.0; P < 0.001), continuous overlapping net glycemic action for a 1-h time interval (22.6 vs 31.0; P < 0.001), and area under the curve >10 mmol/L (0.18 vs 0.52 mmol/L per h; P < 0.001) were significantly lower. Hypoglycemia (glucose <3.8 mmol/L) was not observed during the mitiglinide/voglibose phase, but occurred 0.35 times/day in those taking glimepiride. Moreover, the mitiglinide/voglibose phase had higher premeal and lower post-meal glucose levels than the glimepiride phase.

CONCLUSIONS

Adding mitiglinide/voglibose to vildagliptin therapy results in more efficient postprandial glucose control and less hypoglycemia than adding glimepiride.

Consuming snacks mid-afternoon compared with just after lunch improves mean amplitude of glycaemic excursions in patients with type 2 diabetes: A randomized crossover clinical trial

AIMS

Our aim was to explore the acute effects of consuming snacks at different times on glucose excursions in patients with type 2 diabetes (T2D).

METHODS

Seventeen patients with T2D [means±SD: age 67.4±9.4-years; BMI 23.5±3.1kg/m²; HbA_1c 55±6mmol/mol (7.2±1.0%)] were randomly assigned in this crossover study. Each participant wore a continuous glucose monitoring device for 4 days and consumed identical test meals on the second and third days, comprising breakfast at 0700h, lunch at 1200h and dinner at 1900h. Half the participants consumed 75kcal biscuits at 1230h (just after lunch) on the second day and at 1530h (mid-afternoon) on the third day, while the other half consumed snacks at the same times, but vice versa. Each patient's glucose parameters were compared against baseline for the 2days of snacking at different times of day.

RESULTS

Consuming snacks in the mid-afternoon led to significantly lower mean amplitudes of glycaemic excursions (mean±SEM: 5.19±0.48 vs. 6.90±0.69mmol/L, P<0.01; standard deviation: 1.75±0.17 vs. 2.16±0.21mmol/L, P<0.01) and incremental areas under the curve for glucose after dinner (479±76 vs. 663±104mmol/L per min, P<0.01) compared with snacking just after lunch, whereas mean glucose levels did not differ over the 2days.

CONCLUSION

These results suggest that consuming snacks well separated from lunch may be an effective way to suppress postprandial glucose levels and glycaemic excursions.

Effects of glycemic variability and hyperglycemia in acute ischemic stroke on post-stroke cognitive impairments

AIMS

We aimed to investigate the effect of glycemic variability in the acute stage of stroke on the development of post-stroke cognitive impairment (PSCI).

METHODS

Patients who underwent blood glucose tests at least five times within 7 days after acute ischemic stroke were included. Factors related to glycemic variability (standard deviation (SD), coefficient of variance (CV), and mean absolute glucose (MAG)) were calculated; neuropsychological assessments were administered 3 months after stroke. PSCI was defined as a score of less than -2 SDs for age-, sex-, and education-adjusted means in at least one cognitive domain.

RESULTS

A total of 354 patients were enrolled. PSCI was identified in 74 (20.9%) subjects. In the diabetic group (n = 87), MAG was a significant predictor for PSCI (adjusted OR, 1.94; 95% CI, 1.11-3.42); however, it was not significant in the non-diabetic group, although PSCI exhibited an increasing tendency within higher SD and MAG tertiles. Moreover, hyperglycemia demonstrated a detrimental effect on PSCI, regardless of diabetes status; this effect did not appear in poorly-controlled diabetic patients with HbA1c ≥ 8.0%.

CONCLUSIONS

Glycemic variability and hyperglycemia during acute ischemic stroke were identified as novel predictors for PSCI. Although this result is not evidence of a causal relationship, our study suggests that monitoring glycemic index and controlling its variability during the acute phase of ischemic stroke may help to prevent poor cognitive outcomes.

Suppression of Postprandial Blood Glucose Fluctuations by a Low-Carbohydrate, High-Protein, and High-Omega-3 Diet via Inhibition of Gluconeogenesis

Hyperglycemia significantly contributes to the development and progression of metabolic diseases. Managing postprandial blood glucose fluctuations is of particular importance for patients with hyperglycemia, but safe and effective means of reducing blood glucose levels are still lacking. Five diets with varying macronutrient ratios and omega-3 fatty acid amounts were tested for their blood glucose-lowering effects in male C57BL/6J mice. The diets with potent blood glucose-lowering effects were further investigated for their underlying mechanisms and their beneficial effects on hyperglycemia models. Mice given the low-carbohydrate, high-protein, and high-omega-3 (LCHP+3) diet exhibited a rapid reduction of the blood glucose levels that remained consistently low, regardless of feeding. These effects were associated with reduced amino acid gluconeogenesis, due to the inhibition of hepatic alanine transaminase (ALT). Furthermore, the LCHP+3 intervention was effective in reducing the blood glucose levels in several disease conditions, including type 1 diabetes mellitus, hormone-induced hyperglycemia, and diet-induced metabolic syndrome. Our findings identify the LCHP+3 diet as a potent blood glucose-lowering diet that suppresses postprandial blood glucose fluctuations through the inhibition of gluconeogenesis and may have great clinical utility for the management of metabolic diseases with hyperglycemia.

Postprandial Glycaemic Responses of Dried Fruit-Containing Meals in Healthy Adults: Results from a Randomised Trial

The aim of this study was to explore the glycaemic response (GR) patterns of four dried fruits (DF) and the mixed meals containing dried fruits, rice and almonds. Dried apples (DApp), dried jujubes (DJ), raisins (Ra) and dried apricots (DApr) were tested in eleven healthy subjects in random order. Test meals included the following 3 groups: (1) dried fruits containing 50 g available carbohydrates; (2) mixed meals consisting of DF and rice (DF + R), each contributing 25 g available carbohydrates; (3) Group (2) supplemented with 30 g almonds (DF + R + A). The postprandial GR and other characteristics in 240 min were investigated. The GI values of 4 DFs were 43 for DApp, 55 for DJ, 56 for both Ra and DApr. The DApp displayed the smallest amplitude of glycaemic excursion within 240 min (MAGE0⁻240). Compared with rice, the DApp + R meal elicited a significantly reduced GR and a smaller MAGE0⁻240 (GI 81 vs. 65). With the addition of almonds, the GIs and MAGE0⁻240 decreased significantly in all DF + A + R combinations except DApp + R + A. The ratio of total fructose/glucose contents of test meals were negatively correlated to GIs. Dried fruits and nuts may have the potential to mitigate the postprandial GR when jointly introduced into glycaemic management diets.

Relationship of a Special Acidified Milk Protein Drink with Cognitive Performance: A Randomized, Double-Blind, Placebo-Controlled, Crossover Study in Healthy Young Adults

A previous in vivo study with rats suggested that a special milk protein drink manufactured using an acidification procedure to suppress the aggregation of milk proteins was absorbed quickly after feeding. We performed a randomized, double-blind, placebo-controlled, repeated-measure crossover study to investigate the short-term effects on cognitive performance in 29 healthy young adult men after they consumed this drink in the morning. After an overnight fast, subjects were tested for performance in the Uchida⁻Kraepelin serial arithmetic test and the Stroop test as well as for subjective feeling, body temperature, and heart rate variability before and after consumption of either the acidified milk protein drink or an isoenergetic placebo drink. Subjects showed a significant improvement in performance in the Uchida⁻Kraepelin test, the primary outcome measured, when they consumed the acidified milk protein drink compared with the placebo control condition. In addition, consumption of the acidified milk protein drink, compared with the placebo control, was associated with increases in vagally-mediated heart rate variability indices which, from recent theoretical perspectives, may reflect a higher ability to modulate cognitive and behavioral processes. There was no significant difference in subjective feelings and body temperature between the test drink conditions. These data suggest that consumption of the acidified milk protein drink may improve cognitive performance, with possible involvement of physiological systems that regulate cognition and behavior.

Low education and lack of spousal relationship are associated with dementia in older adults with diabetes mellitus in Nigeria

BACKGROUND

The relationship between dementia and type 2 diabetes mellitus (T2DM) in older adults is well established in the literature. However, there have been few studies on this relationship in older adults living in low- and middle-income countries, and most demographic projections predict that older adult population will increase substantially in these regions by 2050.

METHODS

In this study, older adults with T2DM attending a tertiary health facility were examined and compared with community-dwelling older adults without T2DM. The participants were assessed using the Consortium to Establish Registry for Alzheimer's Disease, the Stick Design Test, the 30-item Geriatric Depression Scale, and the Instrumental Activities of Daily Living Scale. Additionally, all the participants had a physical examination, including assessment of glycated haemoglobin, fasting blood glucose, lipid profile, and HIV status. A consensus diagnosis of dementia was made based on the criteria for dementia in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, and the International Classification for Diseases, 10th edition. The data were analyzed using SPSS version 20 for Windows.

RESULTS

This study included 224 diabetic patients and 116 controls. A total of 27 diabetic patients (12.1%) had dementia, 19 of whom were women. Of the 27 diabetic patients with dementia, 25 patients (92.6%) had Alzheimer's disease and 2 patients (7.4%) had mixed dementia (vascular dementia and Alzheimer's disease). Only one person among the controls had Alzheimer's type dementia. Dementia in the diabetic patients was significantly associated with advancing age, female gender, education level, duration of diabetes, and absence of a spouse.

CONCLUSION

Dementia is common in older adults with T2DM in this low-resource setting, and the risk factors for dementia were similar to those reported in earlier studies in Western societies.

Altered Odor-Induced Brain Activity as an Early Manifestation of Cognitive Decline in Patients With Type 2 Diabetes

Type 2 diabetes is reported to be associated with olfactory dysfunction and cognitive decline. However, whether and how olfactory neural circuit abnormalities involve cognitive impairment in diabetes remains uncovered. This study thus aimed to investigate olfactory network alterations and the associations of odor-induced brain activity with cognitive and metabolic parameters in type 2 diabetes. Participants with normal cognition, including 51 patients with type 2 diabetes and 41 control subjects without diabetes, underwent detailed cognitive assessment, olfactory behavior tests, and odor-induced functional MRI measurements. Olfactory brain regions showing significantly different activation between the two groups were selected for functional connectivity analysis. Compared with the control subjects, patients with diabetes demonstrated significantly lower olfactory threshold score, decreased brain activation, and disrupted functional connectivity in the olfactory network. Positive associations of the disrupted functional connectivity with decreased neuropsychology test scores and reduced pancreatic function were observed in patients with diabetes. Notably, the association between pancreatic function and executive function was mediated by olfactory behavior and olfactory functional connectivity. Our results suggested the alteration of olfactory network is present before clinically measurable cognitive decrements in type 2 diabetes, bridging the gap between the central olfactory system and cognitive decline in diabetes.

Timing of Exercise Affects Glycemic Control in Type 2 Diabetes Patients Treated with Metformin

OBJECTIVE

The purpose of the study was to examine the acute effects of the timing of exercise on the glycemic control during and after exercise in T2D.

METHODS

This study included 26 T2D patients (14 women and 12 men) who were treated with metformin. All patients were tested on four occasions: metformin administration alone (Metf), high-intensity interval training (HIIT) performed at 30 minutes (EX30), 60 minutes (EX60), and 90 minutes (EX90) postbreakfast, respectively. Glucose, insulin, and superoxide dismutase (SOD) activity were examined.

RESULTS

Glucose decreased significantly after the exercise in EX30, EX60, and EX90. Compared with Metf, the decline in glucose immediately after the exercise was larger in EX30 (-2.58 mmol/L; 95% CI, -3.36 to -1.79 mmol/L; p < 0.001), EX60 (-2.13 mmol/L; 95% CI, -2.91 to -1.34 mmol/L; p < 0.001), and EX90 (-1.87 mmol/L; 95% CI, -2.65 to -1.08 mmol/L; p < 0.001), respectively. Compared with Metf, the decrease in insulin was larger in EX30 and EX60 (both p < 0.001).

CONCLUSIONS

Timing of exercise is a factor to consider when prescribing exercise for T2D patients treated with metformin. This trial is registered with ChiCTR-IOR-16008469 on 13 May 2016.

Glycemic Variability Percentage: A Novel Method for Assessing Glycemic Variability from Continuous Glucose Monitor Data

BACKGROUND

High levels of glycemic variability are still observed in most patients with diabetes with severe insulin deficiency. Glycemic variability may be an important risk factor for acute and chronic complications. Despite its clinical importance, there is no consensus on the optimum method for characterizing glycemic variability.

METHOD

We developed a simple new metric, the glycemic variability percentage (GVP), to assess glycemic variability by analyzing the length of the continuous glucose monitoring (CGM) temporal trace normalized to the duration under evaluation. The GVP is similar to other recently proposed glycemic variability metrics, the distance traveled, and the mean absolute glucose (MAG) change. We compared results from distance traveled, MAG, GVP, standard deviation (SD), and coefficient of variation (CV) applied to simulated CGM traces accentuating the difference between amplitude and frequency of oscillations. The GVP metric was also applied to data from clinical studies for the Dexcom G4 Platinum CGM in subjects without diabetes, with type 2 diabetes, and with type 1 diabetes (adults, adolescents, and children).

RESULTS

In contrast to other metrics, such as CV and SD, the distance traveled, MAG, and GVP all captured both the amplitude and frequency of glucose oscillations. The GVP metric was also able to differentiate between diabetic and nondiabetic subjects and between subjects with diabetes with low, moderate, and high glycemic variability based on interquartile analysis.

CONCLUSION

A new metric for the assessment of glycemic variability has been shown to capture glycemic variability due to fluctuations in both the amplitude and frequency of glucose given by CGM data.

Mild cognitive impairment in type 2 diabetes mellitus and related risk factors: a review

Type 2 diabetes mellitus (T2DM) is a global epidemic disease and has become a significant health problem. Many studies have raised concern about the mild cognitive impairment (MCI) with T2DM and even the Alzheimer’s disease patients with T2DM. The incidence of MCI is higher in individuals with T2DM than those without diabetes. Cognitive changes might affect everyday activities depending on the work and situation. Although the exact pathophysiology of MCI in T2DM is unclear, many studies suggest that the alterations in pathoglycemia, diabetic complications, related end products, and physical/psychological status are significant risk factors. In this article, we systematically overview the studies to illustrate the related risk factors of cognitive impairment in patients with T2DM. Further high quality studies and treatment need to be initiated and it will become incumbent on clinicians to identify and cure the earliest signs of clinical impairment.

Hyperglycemia induces attention and gait deficits in diabetic mellitus patients

AIMS

Patients with diabetes mellitus experience a large number of falls and bone fractures that are not related solely to complications of the disease. The purpose of our study was to determine whether transient hyperglycemia affects attentional functions and gait.

METHODS

This was a case-control study. We asked 17 patients with type 1 or type 2 diabetes mellitus to perform three visual tests and one visual and auditory attention test (Phasic Alert A1-4 and A2-3, Go/No Go, Intermodal Comparison). Mean response time (ms) and total number of errors were assessed. Ten of the patients also performed a tandem gait test consisting of three steps. The total distance travelled (TDT, in mm) by the center of pressure was measured with a pressure-sensitive calibrated platform. Transient hyperglycemia was defined as blood glucose level greater than 13, 8 mmol/L at the time of the test. These same patients were retested 1-3 days later at a blood glucose level at least 5, 5 mmol/L lower than the initial values (T24-72h). Nineteen patients with diabetes mellitus were matched with the original participants and performed the same test under normoglycemic conditions.

RESULTS

During transient hyperglycemia, the mean response time (ms) and the TDT were significantly longer. The mean response time for the four tests increased by 53, 5 ms (P < 0.001). There was no increase in the number of errors. The TDT of the center of pressure increased significantly by 102 mm (P < 0.001).

CONCLUSIONS

Transient hyperglycemia alters attention and gait in patients with diabetes mellitus.

Effect of exercise timing on elevated postprandial glucose levels

There is no consensus regarding optimal exercise timing for reducing postprandial glucose (PPG). The purpose of the present study was to determine the most effective exercise timing. Eleven participants completed four different exercise patterns 1) no exercise; 2) preprandial exercise (jogging); 3) postprandial exercise; and 4) brief periodic exercise intervention (three sets of 1-min jogging + 30 s of rest, every 30 min, 20 times total) in a random order separated by a minimum of 5 days. Preprandial and postprandial exercise consisted of 20 sets of intermittent exercise (1 min of jogging + 30 s rest per set) repeated 3 times per day. Total daily exercise volume was identical for all three exercise patterns. Exercise intensities were 62.4 ± 12.9% V̇o2peak. Blood glucose concentrations were measured continuously throughout each trial for 24 h. After breakfast, peak blood glucose concentrations were lower with brief periodic exercise (99 ± 6 mg/dl) than those with preprandial and postprandial exercise (109 ± 10 and 115 ± 14 mg/dl, respectively, P < 0.05, effect size = 0.517). After lunch, peak glucose concentrations were lower with brief periodic exercise than those with postprandial exercise (97 ± 5 and 108 ± 8 mg/dl, P < 0.05, effect size = 0.484). After dinner, peak glucose concentrations did not significantly differ among exercise patterns. Areas under the curve over 24 h and 2 h postprandially did not differ among exercise patterns. These findings suggest that brief periodic exercise may be more effective than preprandial and postprandial exercise at attenuating PPG in young active individuals.

NEW & NOTEWORTHY This was the first study to investigate the effect of different exercise timing (brief periodic vs. preprandial vs. postprandial exercise) on postprandial glucose (PPG) attenuation in active healthy men. We demonstrated that brief periodic exercise attenuated peak PPG levels more than preprandial and postprandial exercise, particularly in the morning. Additionally, PPG rebounded soon after discontinuing postprandial exercise. Thus, brief periodic exercise may be better than preprandial and postprandial exercise at attenuating PPG levels.

Alternative Measures of Hyperglycemia and Risk of Alzheimer's Disease in the Community: The Hisayama Study

CONTEXT AND OBJECTIVE

We investigated the associations of hemoglobin A1c (HbA1c), glycated albumin (GA), GA/HbA1c ratio, and 1,5-anhydroglucitol (1,5-AG) with the development of Alzheimer's disease (AD).

DESIGN AND PARTICIPANTS

A total of 1187 community-dwelling Japanese subjects aged ≥65 years without dementia were followed up for an average of 4.8 years.

RESULTS

The age- and sex-adjusted incidence of AD increased significantly with higher quartiles of GA/HbA1c ratio, and a similar tendency was seen for GA, whereas no such association was observed for HbA1c and 1,5-AG. After adjusting for potential confounding factors, positive association of GA/HbA1c ratio with the risk of AD remained significant: the multivariable-adjusted hazard ratio (HR) was significantly higher in the third [HR = 2.11, 95% confidence interval (CI) = 1.16 to 3.82] and fourth (HR = 2.01, 95% CI = 1.09 to 3.68) quartile than in the first quartile. Among subjects with normal glucose tolerance, those with high GA/HbA1c ratio had a higher risk of AD than those with low GA/HbA1c ratio (HR = 1.82, 95% CI = 1.05 to 3.16), and a similar tendency was found in those with glucose intolerance (HR = 1.73, 95% CI = 0.96 to 3.13). No such associations were observed for HbA1c, GA, and 1,5-AG, regardless of glucose tolerance status.

CONCLUSIONS

Our findings suggest that elevated GA/HbA1c ratio-but not HbA1c, GA, or 1,5-AG level-is significantly associated with the risk of AD in subjects both with and without glucose intolerance. GA/HbA1c ratio may be a useful biomarker for predicting incident AD.

Glucose Peaks and the Risk of Dementia and 20-Year Cognitive Decline

OBJECTIVE

Hemoglobin A_1c (HbA_1c), a measure of average blood glucose level, is associated with the risk of dementia and cognitive impairment. However, the role of glycemic variability or glucose excursions in this association is unclear. We examined the association of glucose peaks in midlife, as determined by the measurement of 1,5-anhydroglucitol (1,5-AG) level, with the risk of dementia and 20-year cognitive decline.

RESEARCH DESIGN AND METHODS

Nearly 13,000 participants from the Atherosclerosis Risk in Communities (ARIC) study were examined. Dementia was ascertained from surveillance, neuropsychological testing, telephone calls with participants or their proxies, or death certificate dementia codes. Cognitive function was assessed using three neuropsychological tests at three visits over 20 years and was summarized as z scores. We used Cox and linear mixed-effects models. 1,5-AG level was dichotomized at 10 μg/mL and examined within clinical categories of HbA_1c.

RESULTS

Over a median time of 21 years, dementia developed in 1,105 participants. Among persons with diabetes, each 5 μg/mL decrease in 1,5-AG increased the estimated risk of dementia by 16% (hazard ratio 1.16, P = 0.032). For cognitive decline among participants with diabetes and HbA_1c <7% (53 mmol/mol), those with glucose peaks had a 0.19 greater z score decline over 20 years (P = 0.162) compared with those without peaks. Among participants with diabetes and HbA_1c ≥7% (53 mmol/mol), those with glucose peaks had a 0.38 greater z score decline compared with persons without glucose peaks (P < 0.001). We found no significant associations in persons without diabetes.

CONCLUSIONS

Among participants with diabetes, glucose peaks are a risk factor for cognitive decline and dementia. Targeting glucose peaks, in addition to average glycemia, may be an important avenue for prevention.

Insights Into the Current Management of Older Adults With Type 2 Diabetes in the Ontario Primary Care Setting

OBJECTIVE

The Goal Oriented controL of Diabetes in the Elderly populatioN (GOLDEN) Program assessed the management of older persons with type 2 diabetes in Canadian primary care.

METHODS

Data were extracted from the records of 833 consecutively identified persons 65 years of age or older who had type 2 diabetes and were taking 1 antihyperglycemic agent or more; they were managed by 64 physicians from 36 Ontario clinics.

RESULTS

More than half (53%) had glycated hemoglobin (A1C) levels of 7.0% or lower, 41% had blood pressure levels below 130/80 mm Hg, and 73% had low-density lipoprotein levels of 2.0 mmol/L or lower; 19% met all 3 criteria. Over the past year, 11% had been assessed for frailty, 16% for cognitive dysfunction and 19% for depression; 88% were referred for eye checkups, and 83% had undergone foot examinations. One-tenth were taking 4 or more antihyperglycemic agents, 87% statins and 52% an angiotensin-converting enzyme inhibitor. More than half of those with high clinical complexity had A1C levels of 7.0% or lower; of these, one-third were taking a sulfonylurea, and one-fifth were taking insulin. In the patients with A1C levels of 7.0% or above and low clinical complexity, there was often no up-titration or initiation of additional antihyperglycemic agents.

CONCLUSIONS

Older persons with type 2 diabetes often have multiple comorbidities. Unlike eye and foot examinations, there was less emphasis on evaluating for frailty, cognitive dysfunction and depression. The GOLDEN patients had generally well-controlled glycemic, blood pressure and cholesterol profiles, but whether these would be reflected in a "sicker" population is not known. Personalized strategies are necessary to avoid undertreatment of "healthy" older patients and overtreatment of the frail elderly.

Twenty-four-hour variations in blood glucose level in Japanese type 2 diabetes patients based on continuous glucose monitoring

Aims/Introduction

High fluctuations in blood glucose are associated with various complications. The correlation between glycated hemoglobin (HbA1c) level and fluctuations in blood glucose level has not been studied in Japanese patients with type 2 diabetes. In the present study, blood glucose profile stratified by HbA1c level was evaluated by continuous glucose monitoring (CGM) in Japanese type 2 diabetes patients.

Materials and Methods

Our retrospective study included 294 patients with type 2 diabetes who were divided by HbA1c level into five groups (≥6.0 to <7.0%, ≥7.0 to <8.0%, ≥8.0 to <9.0%, ≥9.0 to <10.0% and ≥10%). The correlation between HbA1c level and CGM data was analyzed. The primary end‐point was the difference in blood glucose fluctuations among the HbA1c groups.

Results

The mean blood glucose level increased significantly with increasing HbA1c (P_trend < 0.01). The standard deviation increased with increases in HbA1c (P_trend < 0.01). The mean amplitude of glycemic excursions did not vary significantly with HbA1c. The levels of maximum blood glucose, minimum blood glucose, each preprandial blood glucose, each postprandial maximum blood glucose, range of increase in postprandial glucose from pre‐meal to after breakfast, the area under the blood concentration–time curve >180 mg/dL and percentage of the area under the blood concentration–time curve >180 mg/dL were higher with higher HbA1c. Mean glucose level and pre‐breakfast blood glucose level were significant and independent determinants of HbA1c.

Conclusions

In Japanese patients treated for type 2 diabetes, the mean amplitude of glycemic excursions did not correlate with HbA1c, making it difficult to assess blood glucose fluctuations using HbA1c. Parameters other than HbA1c are required to evaluate fluctuations in blood glucose level in patients receiving treatment for type 2 diabetes.

Sedentary behavior as a risk factor for cognitive decline? A focus on the influence of glycemic control in brain health

Cognitive decline leading to dementia represents a global health burden. In the absence of targeted pharmacotherapy, lifestyle approaches remain the best option for slowing the onset of dementia. However, older adults spend very little time doing moderate to vigorous exercise and spend a majority of time in sedentary behavior. Sedentary behavior has been linked to poor glycemic control and increased risk of all-cause mortality. Here, we explore a potential link between sedentary behavior and brain health. We highlight the role of glycemic control in maintaining brain function and suggest that reducing and replacing sedentary behavior with intermittent light-intensity physical activity may protect against cognitive decline by reducing glycemic variability. Given that older adults find it difficult to achieve current exercise recommendations, this may be an additional practical strategy. However, more research is needed to understand the impact of poor glycemic control on brain function and whether practical interventions aimed at reducing and replacing sedentary behavior with intermittent light intensity physical activity can help slow cognitive decline.

Cognitive impairment and dementia: a new emerging complication of type 2 diabetes-The diabetologist's perspective

Type 2 diabetes mellitus (T2D) and Alzheimer's disease (AD) are two of the most common diseases of aging around the world. Given the frequency with which T2D and AD occur, the notion that people with T2D may be at increased risk for AD has large societal consequences, and understanding the mechanistic links between these diseases is imperative for the development of effective AD prevention and treatment strategies. Apart from being an accelerator of AD, T2D is associated with a progressive cognitive decline. Impaired insulin signaling, inflammation, the accumulation of advanced glycation end-products and oxidative stress all play an essential role in the pathogenesis of both AD and diabetic complications. Therefore, it is reasonable to postulate that these pathways are involved in the increased risk of dementia that occurs in the T2D population. The early diagnosis of cognitive impairment and the identification of the subset of patients at a higher risk of developing AD is a challenge for healthcare providers, and meeting it will permit us to implement a personalized medicine, which is an essential issue in diabetes care with significant therapeutic implications. The main gaps that should be filled to achieve this objective are examined.

Diabetic retinopathy is a neurodegenerative disorder

Since 1875, controversy has ensued over whether ocular diabetic complications are primarily vasculopathic or neuropathic in nature. Here, we discuss the historical context by which diabetic retinopathy (DR) came to be considered a primary vasculopathy, in contrast to more recent data suggesting the importance of diabetic retinal neurodegeneration (DRN) as the primary manifestation of ocular diabetic damage. Unsurprisingly, DRN parallels other diabetic complications related to neuropathy. In general, there are three possible relationships between microvascular DR and DRN: i) microvasculopathy causes neurodegeneration; ii) neurodegeneration causes microvasculopathy or iii) they are mutually independent. The authors' group has recently produced experimental data showing that DRN precedes even the earliest manifestations of DR microvasculopathy. In combination with earlier studies showing that focal implicit time delays predicted future development of DR microvasculopathy in the same location, relationships i) and iii) are unlikely. As such, ii) is the most likely relationship: DRN is a cause of DR. Granted, additional studies are needed to confirm this hypothesis and elucidate the mechanism of diabetes-induced neurodegeneration. We conclude this review by proposing experimental approaches to test the hypothesis that DRN causes DR. If confirmed, this new paradigm may lead to earlier detection of ocular diabetic damage and earlier treatment of early DR, thereby preventing visual loss in people with diabetes.

Reducing Barriers to Patient-Reported Outcome Measures for People With Cognitive Impairments

The field of rehabilitation has increasingly called for the use of patient-reported outcome measures (PROMs) in research and practice. Given that many rehabilitation patients present with conditions associated with cognitive impairments, it is imperative to reduce barriers to PROM use for this population. The purpose of this article is to develop a comprehensive understanding of cognitive accessibility that can prospectively inform the design of PROMs. We put forth the following definition of cognitive accessibility for PROMs: cognitive accessibility is present when assessment design anticipates respondent variability in cognitive abilities and, to the greatest extent possible, reduces cognitive demands and/or supports cognitive processes to enable respondents with a range of cognitive abilities to interpret and respond to assessment items as intended. Our operationalization of cognitive accessibility in measurement in the field of rehabilitation is informed by 2 assumptions: (1) cognitive accessibility results from an interaction between the individual's capacities and the demands of the assessment and assessment context, and (2) individuals with cognitive impairments have the right to be involved in decisions about their lives, including health care decisions. This article proposes 3 design features that can be optimized for cognitive accessibility: content, layout, and administration procedures. We end with a discussion of next steps that the field of rehabilitation measurement can undertake to advance our understanding of cognitive accessibility.

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.

Efficacy and Safety of Vildagliptin as an Add-On Therapy in Inadequately Controlled Type 2 Diabetes Patients Treated With Basal Insulin

Background

The aim of this study was to investigate the efficacy and safety of vildagliptin as an add-on therapy for patients with type 2 diabetes mellitus inadequately controlled with basal insulin.

Methods

Twenty-four patients treated with basal insulin and oral anti-diabetes drugs were randomly allocated into two groups: the control group (did not receive any add-on drugs) and vildagliptin group (received vildagliptin 100 mg/day for 6 months). The primary outcome was changes in hemoglobin A1c (HbA1c) from baseline to end of study.

Results

Treatment with vildagliptin significantly reduced HbA1c from 8.1±0.7% at baseline to 7.1±0.7% (P < 0.01), while there was no significant change of HbA1c in the control group. Vildagliptin group showed significant reduction of HbA1c compared with control group (-1.0±0.3% vs. 0.2±0.8%, P < 0.01). In addition, vildagliptin group showed a significant increase in 1,5-anhydroglucitol compared with the control group (4.5 ± 3.4 vs. 0.5 ± 4.1 μg/mL, P < 0.05). Mild hypoglycemia was reported in one patient of the vildagliptin group and two patients of the control group.

Conclusion

Vildagliptin improved glycemic control without increasing hypoglycemia in Japanese type 2 diabetes inadequately controlled with basal insulin treatment and other oral anti-diabetes drugs. This study was registered with UMIN (University Hospital Medical Information Network ID#000010849).

Hypoglycemia is associated with dementia in elderly patients with type 2 diabetes mellitus: An analysis based on the Korea National Diabetes Program Cohort

AIM

Although hypoglycemia is associated with cognitive dysfunction, including dementia, in patients with type 2 diabetes mellitus (DM), the data are equivocal. The purpose of this study was to investigate the association between hypoglycemia, dementia, and other cognitive dysfunctions.

METHODS

This was a prospective observational study based upon the Korea National Diabetes Program (KNDP). Among the 4540 participants in the KNDP cohort, individuals aged ⩾60years without any history of hypoglycemia or cognitive dysfunction (n=1957) were included. Nationally representative data from the Health Insurance Review and Assessment Service of Korea claim database were used to obtain a more precise determination of patient outcome.

RESULTS

During a mean follow-up period of 3.4±0.9years, 118 subjects experienced hypoglycemia-related events. The incidence of dementia and cognitive dysfunction was 7.5 cases per 1000 person-years (PY) and 0.61 cases per 1000 PY, respectively. In the subjects who experienced hypoglycemic events (relative to those who did not), the incidence of dementia was significantly higher (P=0.0139), but the incidence of cognitive dysfunction was not (P=0.1106). Hypoglycemic events were associated with dementia (HR, 2.689; 95% CI, 1.080-6.694, P=0.0335) following multiple adjustments. There was also a significant linear trend toward an increased dementia risk commensurate with an increasing number of hypoglycemic events (P=0.0286).

CONCLUSIONS

Hypoglycemia is significantly associated with the risk of dementia in Korean type 2 DM patients aged ⩾60years.

Cognitive impairment in elderly patients with type 2 diabetes mellitus: prevalence and related clinical factors

Aim

Diabetes mellitus is reported to be a risk factor for dementia. We evaluated the cognitive function in elderly diabetic patients and estimated the prevalence of patients with cognitive impairment and looked for any related clinical factors.

Subjects and methods

Using 281 elderly (65 years of age or older) Japanese patients with type 2 diabetes mellitus who were free of clinically evident cognitive impairment, we evaluated their cognitive function with the Mini Mental State Examination (MMSE).

Results

The MMSE score of all the participants was 27.3 ± 2.4 with 31.3% of them being in the abnormal range (tentatively defined normal range as having an MMSE score of 27-30). Multiple regression analysis disclosed that fasting serum non-esterified fatty acid (NEFA), estimated glomerular filtration ratio (eGFR) and insulin treatment were significantly related factors for the MMSE score, in addition to age and schooling history, which are extremely strong factors.

Conclusions

We revealed that approximately one-third of elderly type 2 diabetic patients who were free of clinically evident cognitive impairment had impaired cognitive function, demonstrating that the MMSE score was significantly correlated with fasting NEFA level, renal function, insulin treatment, age and schooling history.