Type 2 diabetes and cognitive decline in middle-aged men and women: the Doetinchem Cohort Study

Musical Activity Engagement, Depressive Symptoms, Physical Activity, and Cognitive Function in People With Type 2 Diabetes

BACKGROUND

Music interventions have beneficial effects on cognitive function and related risk factors, such as depressive symptoms and behavior of exercise participation. However, little research has been conducted on music's effects on people with type 2 diabetes, and evidence of the effect remains inconclusive in this population.

OBJECTIVES

Guided by the theory of music, mood, and movement (MMM), this exploratory study aimed to examine the direct and indirect effects of musical activity engagement, depressive symptoms, and physical activity on cognitive function in people with type 2 diabetes.

METHODS

The present study is a secondary data analysis using the cross-sectional data collected from the Memory, Attention, and Problem-Solving Skills for Persons With Diabetes trial conducted between 2021 and 2023. Data were collected using self-reported questionnaires and a computerized cognitive assessment tool. A total of 189 people with type 2 diabetes and subjective cognitive decline were included in the study. Path analysis was conducted using IBM SPSS AMOS to examine the pathways of the proposed conceptual framework.

RESULTS

The study results partially support the MMM model for subjective cognitive function but not objective cognitive function. The path model demonstrated the significant direct effects of musical activity engagement on physical activity, physical activity on subjective cognitive function, and depressive symptoms on physical activity as well as on subjective cognitive function. There was a significant indirect effect of musical activity engagement on subjective cognitive function through physical activity-which fully mediated this relationship. However, no significant direct effect of musical activity engagement on depressive symptoms and subjective cognitive function was found.

DISCUSSION

The findings suggest that regular assessment of the presence of depressive symptoms and physical activity participation should be done in people with type 2 diabetes to identify potential modifiable factors and develop targeted interventions for cognitive health promotion. Also, our findings provide insights into the potential use of music to facilitate physical activity and manage cognitive health in people with type 2 diabetes. This study partially supports the MMM model; however, more research with a rigorous study design and larger sample size is needed to better understand the relationships among musical activity engagement, depressive symptoms, physical activity, and cognitive function.

Effectiveness of Combined Aerobic and Resistance Exercise on Cognition, Metabolic Health, Physical Function, and Health-related Quality of Life in Middle-aged and Older Adults With Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis

OBJECTIVES

To evaluate the effectiveness of combined aerobic and resistance exercise on cognition, metabolic health, physical function, and health-related quality of life (HRQoL) in middle-aged and older adults with type 2 diabetes mellitus (T2DM).

DATA SOURCE AND STUDY SELECTION

Systematic search of CINAHL, Cochrane, EMBASE, Scopus, PubMed, ProQuest Dissertation and Thesis, PsycINFO, Web of Science databases, and gray literature from Google Scholar. Pertinent randomized controlled trials (RCTs) were selected. The Protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO CRD42023387336).

DATA EXTRACTION

The risk of bias was evaluated using the Cochrane Risk of Bias tool by 2 reviewers independently. Outcome data were extracted in a fixed-effect model if heterogeneity test were not significant and I2≤50%; otherwise, the random-effects model was used.

DATA SYNTHESIS

Sixteen studies with 2426 participants were included in this review. Combined aerobic and resistance exercise had significant positive effects on cognition (SMD=0.34, 95% CI: 0.13 to 0.55), metabolic health on HbA1c (SMD=-0.35, 95% CI: -0.48 to -0.22) and lipid profile (total cholesterol SMD=-0.20, 95% CI: -0.34 to -0.07; low-density lipoprotein SMD=-0.19, 95% CI: -0.33 to -0.05; high-density lipoprotein SMD=0.25, 95% CI: 0.12 to 0.39; and triglycerides SMD=-0.18, 95% CI: -0.31 to -0.04), physical function on aerobic oxygen uptake (SMD=0.58, 95% CI: 0.21 to 0.95) and body mass index (MD=-1.33, 95% CI: -1.84 to -0.82), and physical HRQoL (MD=4.17, 95% CI: 0.86 to 7.48). Our results showed that clinically important effects on cognition may occur in combining the low-moderate intensity of aerobic exercise and progressive intensity of resistance training, the total duration of the exercise needs to be at least 135 minutes per week, among which, resistance training should be at least 60 minutes.

CONCLUSION

Combined aerobic and resistance exercise effectively improves cognition, ameliorates metabolic health, enhances physical function, and increases physical HRQoL in middle-aged and older adults with T2DM. More RCTs and longitudinal follow-ups are required to provide future evidence of structured combined aerobic and resistance exercise on other domains of cognition.

A spontaneous hyperglycaemic cynomolgus monkey presents cognitive deficits, neurological dysfunction and cataract

Chronic hyperglycaemia is a chief feature of diabetes mellitus and complicates with many systematic anomalies. Non-human primates (NHPs) are excellent for studying hyperglycaemia or diabetes and associated comorbidities, but lack behavioural observation. In the study, behavioural, brain imaging and histological analysis were performed in a case of spontaneously hyperglycaemic (HGM) Macaca fascicularis. The results were shown that the HGM monkey had persistent body weight loss, long-term hyperglycaemia, insulin resistance, dyslipidemia, but normal concentrations of insulin, C-peptide, insulin autoantibody, islet cell antibody and glutamic acid decarboxylase antibody. Importantly, an impaired working memory in a delayed response task and neurological dysfunctions were found in the HGM monkey. The tendency for atrophy in hippocampus was observed by magnetic resonance imaging. Lenticular opacification, lens fibres disruptions and vacuole formation also occurred to the HGM monkey. The data suggested that the spontaneous HGM monkey might present diabetes-like characteristics and associated neurobehavioral anomalies in this case. This study first reported cognitive deficits in a spontaneous hyperglycaemia NHPs, which might provide evidence to use macaque as a promising model for translational research in diabetes and neurological complications.

Serum brain-derived neurotrophic factor levels in type 2 diabetes mellitus patients and its association with cognitive impairment: A meta-analysis

OBJECTIVE

To compare the serum levels of brain-derived neurotrophic factor (BDNF) in type 2 diabetes mellitus (T2DM) patients with healthy controls (HC) and evaluate the BDNF levels in T2DM patients with/without cognitive impairment.

METHODS

PubMed, EMBASE, and the Cochrane Library databases were searched for the published English literature on BDNF in T2DM patients from inception to December 2022. The BDNF data in the T2DM and HC groups were extracted, and the study quality was evaluated using the Agency for Healthcare Research and Quality. A meta-analysis of the pooled data was conducted using Review Manager 5.3 and Stata 12.0 software.

RESULTS

A total of 18 English articles fulfilled with inclusion criteria. The standard mean difference of the serum BDNF level was significantly lower in T2DM than that in the HC group (SMD: -2.04, z = 11.19, P <0.001). Besides, T2DM cognitive impairment group had a slightly lower serum BDNF level compared to the non-cognitive impairment group (SMD: -2.59, z = 1.87, P = 0.06).

CONCLUSION

BDNF might be involved in the neuropathophysiology of cerebral damage in T2DM, especially cognitive impairment in T2DM.

Higher versus lower nut consumption and changes in cognitive performance over two years in a population at risk of cognitive decline: a cohort study

BACKGROUND

Tree nuts and peanuts (henceforth, nuts) are nutrient-dense foods rich in neuroprotective components; thus, their consumption could benefit cognitive health. However, evidence to date is limited and inconsistent regarding the potential benefits of nuts for cognitive function.

OBJECTIVE

To prospectively evaluate the association between nut consumption and 2-y changes in cognitive performance in older adults at cognitive decline risk.

METHODS

A total of 6,630 participants aged 55 to 75 y (mean age 65.0±4.9 y, 48.4% women) with overweight/obesity and metabolic syndrome completed a validated semi-quantitative food frequency questionnaire and a comprehensive battery of neuropsychological tests at baseline and a 2-y follow-up. Composite cognitive scores were used to assess global, general, attention, and executive function domains. Nut consumption was categorized as <1, ≥1 to <3, ≥3 to <7, and ≥7 servings/wk (1 serving=30 g). Multivariable-adjusted linear regression models were fitted to assess associations between baseline nut consumption and 2-y cognitive changes.

RESULTS

Nut consumption was positively associated with 2-y changes in general cognitive function (P-trend <0.001). Compared with participants consuming <1 serving/wk of nuts, those categorized as consuming ≥3 to <7 and ≥7 servings/wk showed more favorable changes in general cognitive performance (β z-score [95% CI] = 0.06 [0.00,0.12] and 0.13 [0.06,0.20], respectively). No significant changes were observed in the multivariable-adjusted models for other cognitive domains assessed.

CONCLUSION

Frequent nut consumption was associated with a smaller decline in general cognitive performance over 2 y in older adults at risk of cognitive decline. Randomized clinical trials to verify our findings are warranted.

Association between P300 parameters and cognitive function in people with diabetic neuropathy

Purpose

The purpose of this study was to investigate the association between event-related potential (ERP) P300 with cognitive function in people with diabetic peripheral neuropathy (DPN).

Methods

We performed a cross-sectional analysis of 19 type 2 diabetes mellitus (T2DM) patients, aged 18 and older with DPN. The participants were assessed for neuropathy, cognitive function, & dual-task performance. DPN was examined via the administration of diabetic neuropathy symptom score (DNSS) and vibration perception threshold (VPT). Cognitive dysfunction was evaluated using Mini-mental state examination (MMSE), trail making test-B (TMT-B), and ERP P300 wave latency & amplitude. For assessing dual-task performance, the dual-task cost (DTC) was calculated using the timed-up and go (TUG) test and TUG with dual task (TUG-DT).

Results

P300 latency was linearly related to TMT-B (R = 0.31, p = 0.01) and DTC (R = 0.22, p = 0.04). A similar trend was observed in TMT-B (R = 0.13, p = 0.04) & DTC (R =0 .67, p = 0.001) with respect to P300 amplitude. MMSE did not relate with P300 latency (R = 0.14, p = 0.58) & amplitude (R = 0.63, p = .44).

Conclusion

P300 latency and amplitude are associated with cognitive function and DTC of individuals with DPN.

Research Progress on Lipocalin-2 in Diabetic Encephalopathy

Diabetic encephalopathy is a central nervous complication of diabetes mellitus which is characterized by cognitive impairment and structural and neurochemical abnormalities, which is easily neglected. Lipocalin-2 (LCN2) is a 25 kDa transporter in the lipocalin family that can transport small molecules, including fatty acids, iron, steroids, and lipopolysaccharides in the circulation. Recently, LCN2 has been found to be a significant regulator of insulin resistance and glucose homeostasis. Numerous studies have shown that LCN2 is connected to central nervous system abnormalities, including neuroinflammation and neurodegeneration, while the latest researches have found that LCN2 is closely related to the development of diabetic encephalopathy. Nevertheless, its precise role in the pathogenesis of diabetic encephalopathy remains to be determined. In this paper, we review recent evidence on the role of LCN2 in diabetic encephalopathy from multiple perspectives in order to decipher the impact of LCN2 in both the aetiology and treatment of diabetic encephalopathy.

Independent and interactive effect of type 2 diabetes and hypertension on memory functions in middle aged adults

BACKGROUND

The study distinguishes the effect of type 2 diabetes and hypertension on cognitive functions when the two diseases are alone or when they occur together, compared to healthy individuals.

METHODS

A total of 143 middle-aged adults were screened using the Wechsler Memory Scale - Revised psychometric test (verbal memory, visual memory, attention/concentration and delayed memory). Participants were divided into four groups based on their diseases: patients with type 2 diabetes (36), patients with hypertension (30), patients having both diseases (33), and healthy controls (44).

RESULTS

This study found no differences among investigated groups in verbal and visual memory, however, hypertension and both-disease group performed unfavorably compared to patients with diabetes and to healthy individuals in attention/concentration and delayed memory.

CONCLUSIONS

The findings of this study suggest that there is a relationship between hypertension and cognitive dysfunction, whereas type 2 diabetes without consequences was not proved to have an association with cognitive decline in middle-aged people.

A novel rhein-huprine hybrid ameliorates disease-modifying properties in preclinical mice model of Alzheimer's disease exacerbated with high fat diet

BACKGROUND

Alzheimer's disease (AD) is characterized by a polyetiological origin. Despite the global burden of AD and the advances made in AD drug research and development, the cure of the disease remains elusive, since any developed drug has demonstrated effectiveness to cure AD. Strikingly, an increasing number of studies indicate a linkage between AD and type 2 diabetes mellitus (T2DM), as both diseases share some common pathophysiological features. In fact, β-secretase (BACE1) and acetylcholinesterase (AChE), two enzymes involved in both conditions, have been considered promising targets for both pathologies. In this regard, due to the multifactorial origin of these diseases, current research efforts are focusing on the development of multi-target drugs as a very promising option to derive effective treatments for both conditions. In the present study, we evaluated the effect of rhein-huprine hybrid (RHE-HUP), a synthesized BACE1 and AChE inhibitor, both considered key factors not only in AD but also in metabolic pathologies. Thus, the aim of this study is to evaluate the effects of this compound in APP/PS1 female mice, a well-established familial AD mouse model, challenged by high-fat diet (HFD) consumption to concomitantly simulate a T2DM-like condition.

RESULTS

Intraperitoneal treatment with RHE-HUP in APP/PS1 mice for 4 weeks reduced the main hallmarks of AD, including Tau hyperphosphorylation, Aβ₄₂ peptide levels and plaque formation. Moreover, we found a decreased inflammatory response together with an increase in different synaptic proteins, such as drebrin 1 (DBN1) or synaptophysin, and in neurotrophic factors, especially in BDNF levels, correlated with a recovery in the number of dendritic spines, which resulted in memory improvement. Notably, the improvement observed in this model can be attributed directly to a protein regulation at central level, since no peripheral modification of those alterations induced by HFD consumption was observed.

CONCLUSIONS

Our results suggest that RHE-HUP could be a new candidate for the treatment of AD, even for individuals with high risk due to peripheral metabolic disturbances, given its multi-target profile which allows for the improvement of some of the most important hallmarks of the disease.

Brain Derived Neurotrophic Factor Interacts with White Matter Hyperintensities to Influence Processing Speed and Hippocampal Volume in Older Adults

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is a neurotrophin that plays an important role in regulating synaptic activity and plasticity.

OBJECTIVE

Given that type-2 diabetes (T2DM) increases the risk of cognitive decline, and studies have suggested lower BDNF levels may be a risk factor of diabetic neurovascular complications, we sought to investigate total white matter hyperintensities (WMH) as a moderator of the effect of BDNF on hippocampal volume and cognition.

METHODS

Older adults without dementia from the Alzheimer's Disease Neuroimaging Initiative (N = 454 including 49 with T2DM and 405 without diabetes) underwent neuropsychological evaluation, magnetic resonance imaging to quantify hippocampal and WMH volumes, and blood draw to assess BDNF.

RESULTS

Adjusting for age, sex, and APOE ɛ4 carrier status, there was a significant interaction between total WMH and BDNF on bilateral hippocampal volume in the non-T2DM group (t = 2.63, p = 0.009). Examination of main effect models with a dichotomous high/low BNDF group revealed a significant main effect for low BDNF (t = -4.98, p < 0.001), such that as WMH increased, bilateral hippocampal volume decreased. There was also a significant interaction between total WMH and BDNF on processing speed in the non-T2DM group (t = 2.91, p = 0.004). There was a significant main effect for low BDNF (t = -3.55, p < 0.001) such that as WMH increased, processing speed decreased. The interactions were not significant in the T2DM group.

CONCLUSION

These results further elucidate the protective role that BDNF plays on cognition, as well as the cognitive effects of WMH.

Treadmill exercise training alleviates diabetes-induced depressive-like behavior and cognitive impairment by improving hippocampal CA1 neurons injury in db/db mice

Patients with diabetes mellitus (DM) have an increased risk of diabetic encephalopathy symptoms such as depressive-like behaviour and cognitive impairment. Exercise is an effective strategy for preventing and treating DM and diabetic complications. The aim of this study is to investigate the effects and potential mechanisms of treadmill exercise training on diabetes-induced depressive-like behavior and cognitive impairment in db/db mice. In this study, the mice were divided into three groups (n=10 per group) as follows: healthy-sedentary (db/m), diabetes-sedentary (db/db), and diabetes-treadmill exercise training (db/db-TET). The db/db-TET mice were performed five days per week at a speed of 8m/min for 60min/day for 8 weeks, following which body weight, fasting blood glucose, insulin resistance, behavioral, synaptic ultrastructure, oxidative stress, apoptotic signaling, and inflammatory responses were evaluated. As a result, treadmill exercise training significantly decreased body weight and fasting blood glucose levels, increased insulin sensitivity, protected synaptic ultrastructure, reduced depression-like behavior, and improved learning and memory deficits in db/db mice. In addition, treadmill exercise training significantly suppressed NOX2-mediated oxidative stress, resulting in a decrease in NOX2-dependent ROS generation in the db/db mouse hippocampus CA1 region. Reduced ROS generation prevented the apoptotic signaling pathway and NLRP3 inflammasome activation, thereby ameliorating hippocampus neuronal damage. In summary, the results indicated that treadmill exercise training significantly ameliorates hippocampus injury by suppressing oxidative stress-induced apoptosis and NLRP3 inflammasome activation, consequently ameliorating diabetes-induced depressive-like behavior and cognitive impairment in db/db mice.

Alzheimer’s Disease Polygenic Risk Score Is Not Associated With Cognitive Decline Among Older Adults With Type 2 Diabetes

Objectives

Multiple risk loci for late-onset Alzheimer’s disease (LOAD) have been identified. Type 2 diabetes (T2D) is a risk factor for cognitive decline, dementia and Alzheimer’s disease (AD). We investigated the association of polygenic risk score (PRS) for LOAD with overall cognitive functioning and longitudinal decline, among older adults with T2D.

Methods

The study included 1046 Jewish participants from the Israel Diabetes and Cognitive Decline (IDCD) study, aged ≥ 65 years, diagnosed with T2D, and cognitively normal at baseline. The PRS included variants from 26 LOAD associated loci (at genome-wide significance level), and was calculated with and without APOE. Outcome measures, assessed in 18 months intervals, were global cognition and the specific domains of episodic memory, attention/working memory, executive functions, and language/semantic categorization. Random coefficient models were used for analysis, adjusting for demographic variables, T2D-related characteristics, and cardiovascular factors. Additionally, in a subsample of 202 individuals, we analyzed the association of PRS with the volumes of total gray matter, frontal lobe, hippocampus, amygdala, and white matter hyperintensities. Last, the association of PRS with amyloid beta (Aβ) burden was examined in 44 participants who underwent an 18F-flutemetamol PET scan.

Results

The PRS was not significantly associated with overall functioning or decline in global cognition or any of the specific cognitive domains. Similarly, following correction for multiple testing, there was no association with Aβ burden and other brain imaging phenotypes.

Conclusion

Our results suggest that the cumulative effect of LOAD susceptibility loci is not associated with a greater rate of cognitive decline in older adults with T2D, and other pathways may underlie this link.

Sex-dependence and comorbidities of the early-life adversity induced mental and metabolic disease risks: Where are we at?

Early-life adversity (ELA) is a major risk factor for developing later-life mental and metabolic disorders. However, if and to what extent ELA contributes to the comorbidity and sex-dependent prevalence/presentation of these disorders remains unclear. We here comprehensively review and integrate human and rodent ELA (pre- and postnatal) studies examining mental or metabolic health in both sexes and discuss the role of the placenta and maternal milk, key in transferring maternal effects to the offspring. We conclude that ELA impacts mental and metabolic health with sex-specific presentations that depend on timing of exposure, and that human and rodent studies largely converge in their findings. ELA is more often reported to impact cognitive and externalizing domains in males, internalizing behaviors in both sexes and concerning the metabolic dimension, adiposity in females and insulin sensitivity in males. Thus, ELA seems to be involved in the origin of the comorbidity and sex-specific prevalence/presentation of some of the most common disorders in our society. Therefore, ELA-induced disease states deserve specific preventive and intervention strategies.

Type 2 diabetes mellitus and cognitive decline in older adults in Germany - results from a population-based cohort

Background

A large body of evidence supports a link between type 2 diabetes mellitus (T2DM) and cognitive function, including dementia. However, longitudinal studies on the association between T2DM and decline of cognitive function are scarce and reported mixed results, and we hence set out to investigate the cross-sectional and longitudinal association between T2DM and global as well as domain-specific cognitive performance.

Methods

We used multivariable regression models to assess associations of T2DM with cognitive performance and cognitive decline in a subsample of a population-based prospective cohort study (ESTHER). This subsample (n = 732) was aged 70 years and older and had participated in telephone-based cognitive function assessment (COGTEL) measuring global and domain-specific cognitive performance during the 5- and 8-year follow-up.

Results

Total COGTEL scores of patients with prevalent T2DM were 27.4 ± 8.3 and 29.4 ± 8.7 at the 5- and 8-year measurements, respectively, and were roughly two points lower than those of T2DM-free participants after adjustment for age and sex. In cross-sectional models, after adjustment for several potential confounders, performance in verbal short-term and long-term memory tasks was statistically significantly lower in participants with T2DM, but the association was attenuated after further adjustment for vascular risk factors. The difference in total COGTEL scores reflecting global cognitive function by T2DM status after full adjustment for confounders and vascular risk factors was equivalent to a decrement in global cognitive function associated with a four-year age difference. In longitudinal models, a statistically significantly stronger cognitive decline in patients with T2DM was observed for working memory.

Conclusions

In this sample of older individuals, T2DM was associated with worse performance and stronger decline in a cognitive function test. Memory-related domains were found to be particularly sensitive to T2DM. Further large-scale prospective studies are needed to clarify potential T2DM-related predictors of cognitive decline and possible consequences on the abilities to perform patient self-management tasks in diabetes care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03151-y.

Sex Differences in the Association Between Midlife Cardiovascular Conditions or Risk Factors With Midlife Cognitive Decline

BACKGROUND AND OBJECTIVES

The prevalence of midlife cardiovascular conditions and risk factors is higher in men than women. Associations between midlife cardiovascular conditions or risk factors and midlife cognitive decline have been reported, but few studies have assessed sex differences in these associations.

METHODS

We included 1,857 participants enrolled in the population-based Mayo Clinic Study of Aging who were 50 to 69 years of age at baseline. Participants were evaluated every 15 months by a coordinator, including neurologic evaluation and neuropsychological testing. The neuropsychological testing used 9 tests to calculate global cognitive and domain-specific (memory, language, executive function, and visuospatial skills) z scores. Nurse abstractors reviewed participant medical records to determine the presence of cardiovascular conditions (coronary heart disease, arrhythmias, congestive heart failure) and risk factors (hypertension, diabetes, dyslipidemia, obesity, ever smoking). Linear mixed-effect models evaluated the association between baseline cardiovascular conditions or risk factors and global and domain-specific cognitive decline. Multivariable models adjusted for demographics, APOE genotype, depression, and other medical conditions. Interactions between sex and each cardiovascular condition or risk factor were examined, and results were stratified by sex.

RESULTS

Overall, 1,465 (78.9%) participants had at least 1 cardiovascular condition or risk factor; the proportion of men was higher than women (767 [83.4%] vs 698 [74.5%], p < 0.0001). Cross-sectionally, coronary heart disease and ever smoking were associated with a lower visuospatial z score in multivariable models. Longitudinally, several cardiovascular conditions and risk factors were associated with declines in global and domain-specific z scores but not visuospatial z scores. Most cardiovascular conditions were more strongly associated with cognition among women: coronary heart disease and other cardiovascular conditions were associated with global cognitive decline only in women (all p < 0.05). In addition, diabetes, dyslipidemia, and coronary heart disease were associated with language z score decline only in women (all p < 0.05). However, congestive heart failure was associated with language z score decline only in men (all p < 0.05).

DISCUSSION

Midlife cardiovascular conditions and risk factors are associated with midlife cognitive decline. Moreover, specific cardiovascular conditions and risk factors have stronger associations with cognitive decline in midlife for women than men despite the higher prevalence of those conditions in men.

The Association Between Plasma Fatty Acid and Cognitive Function Mediated by Inflammation in Patients with Type 2 Diabetes Mellitus

PURPOSE

To verify the mediating role of inflammatory factors in plasma fatty acid-induced changes in cognitive function in patients with type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

In this study, we evaluated the cognitive function of 372 Chinese patients (the average age was 58.00 (52.50, 63.00) years) with T2DM by using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA), with plasma fatty acids measured by gas chromatography analysis and inflammatory cytokines determined by immune turbidimetric analysis and enzyme-linked immunosorbent assay (ELISA) to investigate whether there was a correlation between the plasma fatty acids, inflammatory cytokine levels and cognitive test scores in Chinese patients with T2DM.

RESULTS

We found that the increase of waist circumference and hip circumference might lead to cognitive impairment and induce the inflammatory response. Higher saturated fatty acids (SFAs) levels in plasma were linked to cognitive decline, while higher monounsaturated fatty acids (MUFAs) intake might be a protective factor for cognitive function. In addition, higher levels of plasma n-6 polyunsaturated fatty acids (n-6 PUFAs) stood out as having association with lower cognitive function scores, while higher level of plasma C22:6 n-3 could be a predictor of better cognitive function. In our study, higher SFAs led to higher proinflammatory factor levels. Apart from that, MUFAs and stearoyl-CoA desaturase-18 (SCD-18) were positively related to hypersensitive C-reactive protein (hs-CRP). Meanwhile, higher level of plasma C20:0 could lead to better MMSE delayed recall by reduce the expression of hs-CRP.

CONCLUSION

Levels of plasma SFAs, C18:3 n-6, and C20:3 n-6 could be a predictor for worse cognitive function, while MUFAs and C22:6 n-3 could be a predictor for better cognitive function. The level of hs-CRP could be a mediator of C20:0 induced the change of cognitive function.

Approach to Obesity in the Older Population

Until recently, weight loss in older obese people was feared because of ensuing muscle loss and frailty. Facing overall increasing longevity, high rates of obesity in older individuals (age ≥ 65 years) and a growing recognition of the health and functional cost of the number of obesity years, abetted by evidence that intentional weight loss in older obese people is safe, this approach is gradually, but not unanimously, being replaced by more active principles. Lifestyle interventions that include reduced but sufficient energy intake, age-adequate protein and micronutrient intake, coupled with aerobic and resistance exercise tailored to personal limitations, can induce weight loss with improvement in frailty indices. Sustained weight loss at this age can prevent or ameliorate diabetes. More active steps are controversial. The use of weight loss medications, particularly glucagon-like peptide-1 analogs (liraglutide as the first example), provides an additional treatment tier. Its safety and cardiovascular health benefits have been convincingly shown in older obese patients with type 2 diabetes mellitus. In our opinion, this option should not be denied to obese individuals with prediabetes or other obesity-related comorbidities based on age. Finally, many reports now provide evidence that bariatric surgery can be safely performed in older people as the last treatment tier. Risk-benefit issues should be considered with extreme care and disclosed to candidates. The selection process requires good presurgical functional status, individualized consideration of the sequels of obesity, and reliance on centers that are highly experienced in the surgical procedure as well as short-term and long-term subsequent comprehensive care and support.

A systematic review and meta-analysis of association between brain-derived neurotrophic factor and type 2 diabetes and glycemic profile

Several epidemiologic studies have evaluated the relation between serum/plasma brain-derived neurotrophic factor (BDNF) levels and glycemic parameters, but the findings were conflicting. We performed a systematic review and meta-analysis to compare circulating BDNF levels in individuals with type 2 diabetes (T2D) or other glycemic disorders with healthy controls and to evaluate correlation between BDNF concentrations with glycemic profile. A systematic search up to July 2020 was conducted in reliable electronic databases (MEDLINE (Pubmed), EMBASE, Scopus) and Google scholar. Sixteen observational studies compared serum/plasma BDNF levels in diabetic patients (or individuals with glycemic disorders) vs. healthy controls or reported correlations between serum BDNF levels and glycemic parameters in adults were included in the review. Overall weighted mean difference (WMD) of circulating BDNF levels in 1306 patients with T2D (or other glycemic disorders) was 1.12 ng/mL lower than 1250 healthy subjects (WMD: − 1.12; 95%CI − 1.37, − 0.88, I² = 98.7%, P < 0.001). Subgroup analysis revealed that both diabetic patients and subjects with other glycemic disorders had lower serum/plasma BDNF levels than healthy controls (WMD: − 1.74; 95%CI − 2.15, − 1.33 and WMD: − 0.49; 95%CI − 0.82, − 0.16, respectively). No significant correlation was found between BDNF levels and glycemic parameters [fasting blood glucose (FBG) (Fisher’s Z = 0.05; 95%CI − 0.21, 0.11; n = 1400), homeostatic model assessment for insulin resistance (HOMA-IR) (Fisher’s Z = 0.12; 95%CI − 0.20, 0.44; n = 732) and glycosylated hemoglobin (HbA1c) (Fisher’s Z = 0.04; 95%CI − 0.05, 0.12; n = 2222)]. We found that diabetic patients and subjects with glycemic disorders had lower circulating BDNF levels than healthy controls. However, there was no significant correlation between BDNF concentrations and glycemic parameters including FBG, HOMA-IR and HbA1c. Further prospective investigations are required to confirm these findings.

Mitochondrial Dysfunction and Mitophagy Closely Cooperate in Neurological Deficits Associated with Alzheimer's Disease and Type 2 Diabetes

Alzheimer's disease (AD) and type 2 diabetes (T2D) are known to be correlated in terms of their epidemiology, histopathology, and molecular and biochemical characteristics. The prevalence of T2D leading to AD is approximately 50-70%. Moreover, AD is often considered type III diabetes because of the common risk factors. Uncontrolled T2D may affect the brain, leading to memory and learning deficits in patients. In addition, metabolic disorders and impaired oxidative phosphorylation in AD and T2D patients suggest that mitochondrial dysfunction is involved in both diseases. The dysregulation of pathways involved in maintaining mitochondrial dynamics, biogenesis and mitophagy are responsible for exacerbating the impact of hyperglycemia on the brain and neurodegeneration under T2D conditions. The first section of this review describes the recent views on mitochondrial dysfunction that connect these two disease conditions, as the pathways are observed to overlap. The second section of the review highlights the importance of different mitochondrial miRNAs (mitomiRs) involved in the regulation of mitochondrial dynamics and their association with the pathogenesis of T2D and AD. Therefore, targeting mitochondrial biogenesis and mitophagy pathways, along with the use of mitomiRs, could be a potent therapeutic strategy for T2D-related AD. The last section of the review highlights the known drugs targeting mitochondrial function for the treatment of both disease conditions.

Glucose disturbances, cognitive deficits and white matter abnormalities in first-episode drug-naive schizophrenia

Disturbance of glucose metabolism may be implicated in cognitive deficits of schizophrenia in its early phases. Many studies have reported the important role of widespread disruption of white matter (WM) connectivity in pathogenesis, cognitive deficit and psychopathology of schizophrenia. However, no study has investigated their inter-relationships in drug-naive first episode (DNFE) patients with schizophrenia. Glucose metabolism parameters including fasting glucose, insulin and homeostasis model of assessment-insulin resistance (HOMA-IR) index, cognitive performance on the MATRICS Consensus Cognitive Battery (MCCB) and the voxel-wised WM fractional anisotropy (FA) values were examined using DTI in 39 DNFE schizophrenia and 31 control subjects. The Positive and Negative Syndrome Scale was utilized for clinical symptoms. The patients showed significantly greater fasting plasma levels of glucose and insulin and HOMA-IR, and poorer cognitive scores, together with widespread reduced FA values in five brain areas, including left and right corpus callosum, superior longitudinal fasciculus, posterior thalamic radiation, and corona radiata (all p < 0.05). Association analysis showed that glucose level was positively associated with Digital Sequence Test and Continuous Performance Test, but negatively with FA values in posterior thalamic radiation and left corpus callosum in patients (all p < 0.05). Furthermore, multiple regression analysis revealed that the interactions of glucose × FA in left corpus callosum, longitudinal fasciculus and corona radiata were independent contributors to the Brief Visuospatial Memory Test (BVMT) of MCCB, while the interaction of glucose × FA in left corpus callosum, or in longitudinal fasciculus was associated with MCCB mazes and Trail Making A Test, respectively. Therefore, abnormal glucose metabolism, cognitive impairment and widespread disruption of WM structure occur in an early course of schizophrenia onset. An interaction between glucose metabolism abnormality and the WM dysconnectivity may lead to cognitive impairment.

Long-Term Exposure to Air Pollutants and Cognitive Function in Taiwanese Community-Dwelling Older Adults: A Four-Year Cohort Study

BACKGROUND

Previous studies have assessed limited cognitive domains with relatively short exposure to air pollutants, and studies in Asia are limited.

OBJECTIVE

This study aims to explore the association between long-term exposure to air pollutants and cognition in community-dwelling older adults.

METHODS

This four-year prospective cohort study recruited 605 older adults at baseline (2011-2013) and 360 participants remained at four-year follow-up. Global and domain-specific cognition were assessed biennially. Data on PM2.5 (particulate matter≤2.5μm diameter, 2005-2015), PM10 (1993-2015), and nitrogen dioxide (NO2, 1993-2015) were obtained from Taiwan Environmental Protection Administration (TEPA). Bayesian Maximum Entropy was utilized to estimate the spatiotemporal distribution of levels of these pollutants.

RESULTS

Exposure to high-level PM2.5 (>29.98μg/m3) was associated with an increased risk of global cognitive impairment (adjusted odds ratio = 4.56; β= -0.60). High-level PMcoarse exposure (>26.50μg/m3) was associated with poor verbal fluency (β= -0.19). High-level PM10 exposure (>51.20μg/m3) was associated with poor executive function (β= -0.24). Medium-level NO2 exposure (>28.62 ppb) was associated with better verbal fluency (β= 0.12). Co-exposure to high concentrations of PM2.5, PMcoarse or PM10 and high concentration of NO2 were associated with poor verbal fluency (PM2.5 and NO2: β= -0.17; PMcoarse and NO2: β= -0.23; PM10 and NO2: β= -0.21) and poor executive function (PM10 and NO2: β= -0.16). These associations became more evident in women, apolipoprotein ɛ4 non-carriers, and those with education > 12 years.

CONCLUSION

Long-term exposure to PM2.5 (higher than TEPA guidelines), PM10 (lower than TEPA guidelines) or co-exposure to PMx and NO2 were associated with poor global, verbal fluency, and executive function over 4 years.

The Healthy Aging Index analyzed over 15 years in the general population: The Doetinchem Cohort Study

The Healthy Aging Index (HAI), an index of physiological aging, has been demonstrated to predicts mortality, morbidity and disability. We studied the longitudinal development of the HAI to identify aging trajectories and evaluated the role of baseline sociodemographic characteristics and lifestyle factors of the trajectories. Four measurements with intervals of 5 years were included from the Doetinchem Cohort Study. The HAI reflects levels of systolic blood pressure, non-fasting plasma glucose levels, global cognitive functioning, plasma creatinine levels and lung functioning. The HAI score ranges from 0 to 10: higher scores indicate a better health profile. Latent class mixture modelling was used to model within-person change and to identify aging trajectories. Area under the curve was calculated per trajectory to estimate total healthy years. In total, 2324 women and 2013 men were included. One HAI trajectory was identified for women, and two trajectories for men, labelled 'gradual' aging (76%) and 'early' aging (24%). Men who were medium/high educated, below 36 years at baseline, complied with guidelines on physical activity and were not obese in any round were associated with increased odds to 'gradual' aging of 1.46 (CI: 1.18-1.81), 1.93 (CI: 1.42-2.62), 1.26 (1.02-1.57) and 1.76 (1.32-2.35), respectively. Between 30 and 70 years of age, men in the 'early' aging trajectory had the least healthy years (29.6 years), followed by women (30.1 years), and 'gradual' aging men (34.7 years). This study emphasizes that 'physiological aging' is not only an issue of older ages. Between 30 and 70 years of age, 'early' aging men and women had approximately five healthy years less compared to 'gradual' aging men. Lifestyle factors (e.g. nutrition and physical activity) seem to play an important role in optimal aging.

The Potential Mediation of the Effects of Physical Activity on Cognitive Function by the Gut Microbiome

The population of older adults is growing dramatically worldwide. As older adults are at greater risk of developing disorders associated with cognitive dysfunction (i.e., dementia), healthcare costs are expected to double by 2040. Evidence suggests dementia may be slowed or prevented by lifestyle interventions, including physical activity (PA). PA is associated with improved cognitive function and may reduce risk for dementia by mitigating known risk factors (i.e., cardiovascular diseases) and/or by enhancing neurochemical processes. An emerging area of research suggests the gut microbiome may have similar neuroprotective effects. Altering the gut microbiome has been found to target physiological processes associated with dementia risk, and it influences gut-brain-microbiome axis signaling, impacting cognitive functioning. The gut microbiome can be altered by several means (i.e., disease, diet, prebiotics, probiotics), including PA. As PA and the gut microbiome independently influence cognitive function and PA changes the composition of the gut microbiome, cognitive improvement due to PA may be partially mediated by the gut microbiome. The present article provides an overview of the literature regarding the complex associations among PA, cognitive function, and the gut microbiome, as well as their underlying biological mechanisms. A comprehensive, theoretical model integrating evidence for the potential mediation is proposed.

Observational Study of Brain Atrophy and Cognitive Decline Comparing a Sample of Community-Dwelling People Taking Angiotensin Converting Enzyme Inhibitors and Angiotensin Receptor Blockers Over Time

BACKGROUND

Hypertension is an established risk factor for dementia. However, it is unclear whether there are differential effects of angiotensin converting enzyme inhibitor (ACEi) or angiotensin receptor blockers (ARB) on brain health. In human observational studies, the evidence for superiority of either agent remains unclear.

OBJECTIVE

To compare brain atrophy and cognitive decline between people treated with ACEi or ARB.

METHODS

Participants aged 55-90 years without dementia had brain magnetic resonance imaging and neuropsychological assessments performed at 3 time points. The sample was enriched with people with type 2 diabetes (T2D). Multivariable mixed models were used to examine longitudinal associations of antihypertensive medication class with change in cognition and total brain volume.

RESULTS

Of 565 people with longitudinal data, there were 163 on ACEi (mean age 69.9 years, T2D:64% with) and 125 on ARB (mean age 69.6 years, T2D:62%) at baseline. The baseline characteristics of those taking either an ACEi or ARB were similar with regards to age, sex, blood pressure control, and vascular risk factors. The mean duration of follow up was 3.2 years. The baseline association of ACEi and ARB use with total brain volume was similar in both groups. However, those taking an ARB had a slower rate of brain atrophy than those taking an ACEi (p = 0.031). Neither ACEi nor ARB use was associated with baseline cognitive function or cognitive decline.

CONCLUSIONS

These results support the theory that ARB may be preferable to ACEi to reduce brain atrophy. The mechanisms underlying this differential association warrant further investigation.

Association of diabetes status with cognitive impairment in two Chinese rural communities

BACKGROUND AND PURPOSE

Diabetes may be one of the risk factors of cognitive impairment. In this study, we aimed to investigate the relationship between diabetes status and cognitive impairment among the middle-aged and elderly population (≥40 years) in Chinese rural communities.

METHODS

A sample of 3392 participants aged 40 years or older from the China National Stroke Prevention Project (CSPP) between 2015 and 2017 were enrolled in this study. Cognitive function was assessed by the Beijing edition of the Montreal cognitive assessment (MoCA) scale. Cognitive impairment was diagnosed as a MoCA score < 26. Diabetes status was divided into three groups------Normal: fasting plasma glucose (FPG) ≤ 5.5 mmol/L, Prediabetes: 5.6 ≤ FPG ≤ 6.9 mmol/L, Diabetes: FPG ≥ 7.0 mmol/L or with a history of diabetes. Multivariate logistic regression was used to analyze the association between diabetes status and cognitive impairment.

RESULTS

Out of the 3392 enrolled participants, 2023(59.6%) had cognitive impairment, 1586(46.8%) had abnormal fasting plasma glucose including 867(25.6%) prediabetes and 719(21.2%) diabetes. After adjusting for potential risk factors, we found prediabetes (OR: 1.22, 95%CI: 1.03-1.45) and diabetes (OR: 1.28, 95%CI: 1.06-1.55) are all associated with cognitive impairment, especially in the domains of language (prediabetes: OR: 1.14, 95%CI: 1.05-1.25; diabetes: OR:1.13, 95%CI: 1.03-1.24), visuospatial/executive functions (diabetes: OR: 1.50, 95%CI: 1.22-1.84) and attention (diabetes: OR: 1.15, 95%CI: 1.02-1.31).

CONCLUSIONS

In this large community-based study, we found diabetes status may be an independent risk factor for cognitive impairment, particularly in domains of language, visuospatial/executive functions, and attention.

Strawberry Leaf Extract Treatment Alleviates Cognitive Impairment by Activating Nrf2/HO-1 Signaling in Rats With Streptozotocin-Induced Diabetes

Diabetes-associated cognitive impairment (DACI) is a common complication of diabetes mellitus (DM) that affects the central nervous system. Cognitive impairment, such as learning and memory impairment, and even dementia, is the main clinical manifestation of DACI. Unfortunately, there is no effective means by which to delay the cognitive symptoms of DM. Evidence has shown that strawberry leaf extract could alleviate cognitive decline, suppress oxidative stress, and reduce inflammatory responses in rats. In the present study, we evaluated the effect of strawberry leaf extract on cognitive function in a rat model of streptozotocin (STZ)-induced diabetes. After the continuous administration of strawberry leaf extract for 4 weeks, the Morris Water Maze (MWM) test results showed that the cognitive impairment of the rats was alleviated. Moreover, strawberry leaf extract significantly reduced the level of reactive oxygen species (ROS), decreased the level of malondialdehyde (MDA), improved the activity of superoxide dismutase (SOD) and catalase (CAT), decreased the mRNA expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) and decreased the protein expression of caspase-3 and caspase-9 in the hippocampus of DM rats. Also, transcription factor nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2)/hemeoxygenase-1(HO-1) signaling was activated by the administration of strawberry leaf extract. Our findings indicate that strawberry leaf extract may be a potential drug candidate for the treatment of DACI and may be used as a basis for further research on the development of drugs for cognitive impairment in diabetes.

Cardiovascular risk factors and accelerated cognitive decline in midlife: The CARDIA Study

OBJECTIVE

Increasing evidence supports an association between midlife cardiovascular risk factors (CVRFs) and risk of dementia, but less is known about whether CVRFs influence cognition in midlife. We examined the relationship between CVRFs and midlife cognitive decline.

METHODS

In 2,675 black and white middle-aged adults (mean age 50.2 ± 3.6 years, 57% female, 45% black), we measured CVRFs at baseline: hypertension (31%), diabetes mellitus (11%), obesity (43%), high cholesterol (9%), and current cigarette smoking (15%). We administered cognitive tests of memory, executive function, and processing speed at baseline and 5 years later. Using logistic regression, we estimated the association of CVRFs with accelerated cognitive decline (race-specific decline ≥1.5 SD from the mean change) on a composite cognitive score.

RESULTS

Five percent (n = 143) of participants had accelerated cognitive decline over 5 years. Smoking, hypertension, and diabetes mellitus were associated with an increased likelihood of accelerated decline after multivariable adjustment (adjusted odds ratio [AOR] 1.65, 95% confidence interval [CI] 1.00-2.71; AOR 1.87, 95% CI 1.26-2.75; AOR 2.45, 95% CI 1.54-3.88, respectively), while obesity and high cholesterol were not associated with risk of decline. These results were similar when stratified by race. The likelihood of accelerated decline also increased with greater number of CVRFs (1-2 CVRFs: AOR 1.77, 95% CI 1.02-3.05; ≥3 CVRFs: AOR 2.94, 95% CI 1.64-5.28) and with Framingham Coronary Heart Disease Risk Score ≥10 (AOR 2.29, 95% CI 1.21-4.34).

CONCLUSIONS

Midlife CVRFs, especially hypertension, diabetes mellitus, and smoking, are common and associated with accelerated cognitive decline at midlife. These results identify potential modifiable targets to prevent midlife cognitive decline and highlight the need for a life course approach to cognitive function and aging.

Study of Neurocognitive Function in Type 2 Diabetes Mellitus Patients Using P300 Event-Related Potential

Background:

Diabetes mellitus is the most prevailing metabolic disease. It causes structural and functional alterations in several organs, including the central nervous system. Altered glucose metabolism, atherosclerosis, and inflammation of blood vessels are seen in diabetes. This may lead to neuronal degeneration and decline in cognition. Event-related potential P300 can detect cognitive decline before the emergence of obvious neurological manifestations.

Objective:

The aim of this study is to assess and compare the P300 latencies in subjects with type 2 diabetes mellitus and in nondiabetic subjects and to determine the influence of type 2 diabetes mellitus on cognitive functions.

Materials and Methods:

In this study our sample size was 248 subjects, with type 2 diabetes mellitus patients (n = 124) and healthy controls (n = 124) between the age group of 31 and 60 years. This cross-sectional comparative study was conducted at SRM Medical College Hospital and Research Centre. The subjects were evaluated by a structured interview and they were assessed with a general health questionnaire to rule out any subpsychiatric illness. Fasting and postprandial blood glucose, HbA1c level, lipid profile, and creatinine were estimated. P300 amplitude and peak latencies were recorded using the standard auditory oddball paradigm.

Results:

The latencies of P300 were significantly increased and the amplitude of P300 was significantly reduced in the diabetic group when compared to the control group (P < .001). P300 latency has a positive correlation with the HbA1c levels (r = 0.136) and the duration of diabetes (r = 0.231).

Conclusion:

Prolongation of P300 latencies and the decreased amplitude in diabetic subjects may suggest the existence of a cognitive decline in individuals with type 2 diabetes compared to healthy individuals.

Association of Brain-Derived Neurotrophic Factor With Cognitive Function: An Investigation of Sex Differences in Patients With Type 2 Diabetes

OBJECTIVE

Although a reduction in brain-derived neurotrophic factor (BDNF) has been implicated as a cause of cognitive impairment in type 2 diabetes mellitus (T2DM), the role of sex in moderating this effect has not been explored.

METHODS

We compared the difference in serum BDNF and performance on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) between 96 men and 134 women with T2DM. We compared this with the difference in serum BDNF and performance in the control group (104 men, 144 women).

RESULTS

Patients with T2DM performed worse on most RBANS indices (η = 0.372, all p < .05); within T2DM patients, men performed worse than women on the delayed memory score (74.1 (12.1) versus 79.9 (11.5), p = .002) and on the total score (71.4 (11.5) versus 76.5 (10.8), p = .025). Serum BDNF was lower in patients with T2DM versus controls (7.5 (2.7) ng/ml versus 11.5 (2.7) ng/ml, p < .001), and in men compared with women (6.9 (2.4) versus 7.9 (2.8), p = .024). Serum BDNF levels positively correlated with delayed memory score in patients with T2DM (β = 0.19, p = .007). However, this association was only observed in women, not in men (pinteraction = 0.04). Among healthy controls, no sex differences were noted in either RBANS or BDNF levels (η = 0.04, Cohen's d < 0.163, all p > .05).

CONCLUSIONS

Our results show sex differences in poorer cognitive performance, lower BDNF concentration, and their relationship in T2DM patients, suggesting that female sex may be a protective factor for cognitive decline in T2DM patients. However, the findings should be regarded as preliminary because of the cross-sectional design and chronicity of the diabetes.

Association between diabetes and cognitive function at baseline in the Brazilian Longitudinal Study of Adult Health (ELSA- Brasil)

Diabetes has been associated with cognitive changes and an increased risk of vascular dementia and Alzheimer’s disease, but it is unclear whether there are associations between diabetes and early alterations in cognitive performance. The present study consisted of a cross-section analysis of 14,444 participants aged 35–74 years and from a developing country at baseline in the Brazilian Longitudinal Study of Adult Health (ELSA–Brasil); these participants were recruited between 2008 and 2010. We investigated whether there was an association between diabetes and early changes in the cognitive performance of this Brazilian population. To assess cognitive domains, we used the word-list learning, word-list delayed recall and word recognition tests along. Phonemic verbal fluency tests included semantic phonemic test (animals) and a phonemic test (words beginning with the letter F). Executive functions associated with attention, concentration and psychomotor speed were evaluated using the Trail Making Test B. The exposure variable in the study was defined as diabetes. Multiple linear regression was used to estimate the association between diabetes and cognitive performance. The results were adjusted for age, sex, education, hypertension, coronary disease, depression, physical activity, smoking, alcohol consumption, and the cholesterol/HDL-C ratio. We found a significant association between diabetes and decreased memory, language and executive function (attention, concentration and psychomotor speed) performance in this population from a country with a distinct epidemiological profile, even after adjusting for the main intervening variables.

Dietary Patterns Are Not Associated with Brain Atrophy or Cerebral Small Vessel Disease in Older Adults with and without Type 2 Diabetes

BACKGROUND

Unhealthy dietary patterns (DPs) are associated with poorer cognition, but few studies have investigated the underlying brain structural mechanisms.

OBJECTIVE

We aimed to examine the relations between DPs, brain structure, and cognition in older people with and without type 2 diabetes.

METHODS

This cross-sectional study consisted of a sample of people with (n = 343) and without type 2 diabetes (n = 346) aged 55-90 y. The 80-item Cancer Council of Victoria FFQ was used to assess dietary intake. Two DPs (prudent and traditional) for people with type 2 diabetes and 3 DPs (prudent, traditional, and Western) for those without type 2 diabetes were derived using principal component analysis. Neuropsychological tests assessed 6 cognitive domains. Brain MRI was performed to obtain gray, white matter, and hippocampal volumes and markers of small vessel disease (microbleeds, infarcts, and white matter hyperintensities). Multivariable linear regression was used to assess the cross-sectional associations between DPs, brain MRI, and cognitive variables.

RESULTS

For those without type 2 diabetes, higher adherence to the Western DP was associated with lower gray matter volume (β = -3.03 95% CI: -5.67, -0.38; P = 0.03). The addition of a cardiovascular risk score, mood, and physical activity weakened associations such that they were no longer significant (β = -1.97 (95% CI: -4.68, 0.74) P = 0.15) for the Western DP. There were no significant associations for the other DPs in people with and without type 2 diabetes.

CONCLUSIONS

In this cross-sectional study, DPs were not independently associated with brain structure in people with or without type 2 diabetes. Future prospective studies are needed to clarify the role of vascular risk factors on associations between DPs and brain health.

Time-dependent impairments in learning and memory in Streptozotocin-induced hyperglycemic rats

The sedentary lifestyle is responsible for the high prevalence of diabetes which also impairs cognition including learning and memory. Various studies have highlighted the learning and memory impairments in rodent models but data regarding the timeline of their development and their correlation to biochemical parameters are scarce. So, the present study was designed to investigate the type of memory which is more susceptible to hyperglycemia and its correlation with biochemical parameters such as inflammatory cytokines, cAMP response element binding (CREB) and protein kinase B (Akt) activation. Hyperglycemia was induced using streptozotocin (STZ, 45 mg/kg i.p.) and confirmed by measuring fasting blood glucose levels after 1 week of STZ injection. Learning and memory deficits were evaluated using the Novel Object Recognition Test (NORT) and Morris water maze (MWM), and correlated with biochemical parameters (TNF-α, IL-1β, and dopamine) at 3, 6 and 9 weeks. STZ-injected rats after 3 weeks of injection demonstrated moderate hyperglycemia (blood glucose = 7.99 ± 0.62 mM) with intact learning and reference memory; however, their working memory was impaired in MWM. Severe hyperglycemia (blood glucose = 11.51 ± 0.69 mM) accompanied by impaired short, long, and working memory was evident after 6 weeks whereas learning was intact. After 9 weeks of STZ injection, hyperglycemia was more pronounced (13.69 ± 1.43 mM) and accompanied by a learning deficit in addition to short, long, and working memory impairments. The extent of hyperglycemia either in terms of duration or severity resulted in enhanced inflammation, down-regulation of the level of dopamine, protein expression of AKT and CREB, which possibly affected learning and memory negatively.

The effect of mid-life insulin resistance and type 2 diabetes on older-age cognitive state: the explanatory role of early-life advantage

AIMS/HYPOTHESIS

Type 2 diabetes, hyperglycaemia and insulin resistance are associated with cognitive impairment and dementia, but causal inference studies using Mendelian randomisation do not confirm this. We hypothesised that early-life cognition and social/educational advantage may confound the relationship.

METHODS

From the population-based British 1946 birth cohort, a maximum number of 1780 participants had metabolic variables (type 2 diabetes, insulin resistance [HOMA2-IR] and HbA1c) assessed at age 60-64 years, and cognitive state (Addenbrooke's Cognitive Examination III [ACE-III]) and verbal memory assessed at age 69 years. Earlier-life measures included socioeconomic position (SEP), cognition at age 8 years and educational attainment. Polygenic risk scores (PRSs) for type 2 diabetes were calculated. We first used a PRS approach with multivariable linear regression to estimate associations between PRSs and metabolic traits and later-life cognitive state. Second, using a path model approach, we estimated the interrelationships between earlier-life measures, features of mid-life type 2 diabetes and cognitive state at age 69 years. All models were adjusted for sex.

RESULTS

The externally weighted PRS for type 2 diabetes was associated with mid-life metabolic traits (e.g. HOMA2-IR β = 0.08 [95% CI 0.02, 0.16]), but not with ACE-III (β = 0.04 [-0.02, 0.90]) or other cognitive outcomes. While there was an association between HOMA2-IR and subsequent ACE-III (β = -0.09 [-0.15, -0.03]), path modelling showed no direct effect (β = -0.01 [-0.06, 0.03]) after accounting for the association between childhood SEP and education with HOMA2-IR. The same pattern was observed for later-life verbal memory.

CONCLUSIONS/INTERPRETATION

Associations between type 2 diabetes and mid-life metabolic traits with subsequent cognitive state do not appear causal, and instead they may be explained by SEP in early life, childhood cognition and educational attainment. Therefore, glucose-lowering medication may be unlikely to combat cognitive impairment in older age.

Cognitive Dysfunction Among Adults With Type 2 Diabetes Mellitus in Karnataka, India

Background: Type 2 diabetes mellitus is a chronic metabolic disease characterized by hyperglycemia that affects various body systems. Elevated blood glucose levels cause brain malfunction, sorbitol-induced blood vessel damage, and degeneration of the nerves that can lead to dementia or cognitive impairment. Cognitive impairment can result in nonadherence of patients to diabetes treatment, such as diet, medication, and exercise. Methods: We used a cross-sectional design to individually interview 194 patients with type 2 diabetes in a rural field practice area in India. A questionnaire was used to collect sociodemographic and diabetes disease characteristics; anthropometric measurements were also collected. Cognitive dysfunction was assessed with the Kannada version (local language) of the Montreal Cognitive Assessment (MoCA) tool. Blood pressure was measured for all subjects using a standardized sphygmomanometer on the right arm with the patient in a sitting position. Results: Among the 194 diabetic subjects interviewed, 98 (50.5%) were cognitively impaired. More than half of the subjects (56.2%) were ≥65 years, and female participants (53.6%) outnumbered males (46.4%). The majority of patients (62.4%) had had diabetes for <10 years. The sociodemographic characteristics age, sex, education, occupation, and socioeconomic status and the anthropometric measurement of waist-to-hip ratio were significantly associated (P<0.05) with cognitive impairment. Disease characteristics, religion, and blood pressure showed no significant association with cognitive impairment. Conclusion: One in two individuals with type 2 diabetes mellitus in our study population had mild cognitive impairment. Older individuals in the low socioeconomic strata and with low levels of education were identified to be at high risk of cognitive impairment. Hence, screening and appropriate care need to be provided.

Association between Diabetes and Cognitive Function among People over 45 Years Old in China: A Cross-Sectional Study

Objectives: The aim of this study is to identify the relationship between diabetes status including characteristics of diabetes and cognition among the middle-aged and elderly population (≥45 years) in China. Methods: A sample of 8535 people who participated in the China Health and Retirement Longitudinal Study (CHARLS) from June 2011 to March 2012 was analyzed. Two cognitive domains including episodic memory and executive function were measured through questionnaires. People were classified into four groups: no diabetes, controlled diabetes, untreated diabetes, treated but uncontrolled diabetes. Weighted multiple regression model was conducted to explore the association between diabetes and cognition in full sample as well as three different age groups (45–59, 60–74, ≥75). Adjustments were made for demographics and cardiovascular risk factors. Results: After adjusting several covariates, untreated diabetes (β = −0.192, p < 0.05) was significantly associated with episodic memory. In the age group of 45–69 years, untreated diabetes (β = −0.471, p < 0.05) and HbA1c level (β = −0.074, p < 0.05) were significantly associated with episodic memory. When adjusting for cardiovascular risk factors, all correlations were non-significant. Conclusion: The cross-sectional study suggests that untreated diabetes and HbA1c are the potential risk factor for cognitive impairment, and these associations are more significant in the age group of 45–59 years old. Cardiovascular factors are important mediating factors in the pathway between diabetes and cognitive impairment. More longitudinal studies are needed to confirm these associations.

Type 2 diabetes mellitus, brain atrophy and cognitive decline in older people: a longitudinal study

AIMS/HYPOTHESIS

The aims of the study were to examine whether type 2 diabetes mellitus is associated with greater brain atrophy and cognitive decline, and whether brain atrophy mediates associations between type 2 diabetes and cognitive decline.

METHODS

Participants without dementia aged 55-90 years from the Cognition and Diabetes in Older Tasmanians (CDOT) study underwent brain MRI (ventricular and total brain volume) and neuropsychological measures (global function and seven cognitive domains) at three time points over 4.6 years. Mixed models were used to examine longitudinal associations of type 2 diabetes with cognitive and MRI measures, adjusting for covariates. A test of mediation was used to determine whether brain atrophy explained associations between type 2 diabetes and cognitive decline.

RESULTS

A total of 705 participants (diabetes: n = 348, mean age 68.2 years [SD 7.0]; no diabetes: n = 357, mean age 72.5 years [SD 7.1]) were available at baseline. Adjusting for age, sex, education and vascular risk factors, there were significant diabetes × time interactions for verbal memory (β -0.06; 95% CI -0.09, -0.02) and verbal fluency (β -0.03; 95% CI -0.06, -0.00). Although people with diabetes had lower brain (β -14.273; 95% CI -21.197, -6.580) and greater ventricular (β 2.672; 95% CI 0.152, 5.193) volumes at baseline, there were no significant diabetes × time interactions (p > 0.05) or evidence of mediation of the diabetes-cognition relationship by brain atrophy.

CONCLUSIONS/INTERPRETATION

In older community-dwelling people, type 2 diabetes is associated with decline in verbal memory and fluency over ~5 years. The effect of diabetes on brain atrophy may begin earlier (midlife).

Diabetes Is Associated with Cognitive Decline in Middle-Aged Patients

BACKGROUND

Diabetes is a major contributor to dementia in the elderly. Identifying mild cognitive decline in younger individuals with diabetes could aid in preventing the progression of the disease. The aim of our study is to compare whether patients with diabetes experience greater cognitive decline than those without diabetes.

METHODS

We conducted a cross-sectional study using population-based recruitment to identify a cohort of individuals with diabetes and corresponding control group without diabetes of 55-65 years of age. We defined diabetes according to the American Diabetes Association and conducted a battery of standardized neuropsychological tests consisting of nine verbal and nonverbal tasks assessing three cognitive domains. We defined cognitive decline as an abnormal test in one or more of the domains. We used hierarchical regression to predict abnormal cognitive function by diabetes status, adjusting for gender, education, hypertension, and depression.

RESULTS

We included 142 patients with diabetes and 167 control group patients. Those with diabetes had a mean age of 59 ± 4 years, 54% were women, the mean education level was 11 ± 4.5 years of schooling, and their hemoglobin A1c was 8.6 ± 2.5. They had an overall lower mean of all five executive function measures, all seven attention measures, and all five memory measures (P < 0.05). In multivariate analyses, all executive function beta coefficients for diabetes were significant, whereas attention had four out of seven and memory had four out of five.

CONCLUSIONS

Diabetes is associated with cognitive decline in younger patients with diabetes. Preventive strategies should be developed for the prevention of dementia in younger populations.

Impact of glycemic status on longitudinal cognitive performance in men with and without HIV infection

OBJECTIVES

To determine the relationship between glycemic status and cognitive performance in men living with HIV (MLWH) and without HIV infection.

DESIGN

A prospective HIV/AIDS cohort study in four US cities between 1999 and 2016.

METHODS

Glycemic status was categorized as normal glucose, impaired fasting glucose, controlled diabetes mellitus and uncontrolled diabetes mellitus at each semiannual visit. Cognitive performance was evaluated using nine neuropsychological tests which measure attention, constructional ability, verbal learning, executive functioning, memory and psychomotor speed. Linear mixed models were used to assess the association between glycemic status and cognition.

RESULTS

Overall, 900 MLWH and 1149 men without HIV were included. MLWH had significantly more person-visits with impaired fasting glucose (52.1 vs. 47.9%) and controlled diabetes mellitus (58.2 vs. 41.8%) than men without HIV (P < 0.05). Compared with men with normal glucose, men with diabetes mellitus had significantly poorer performance on psychomotor speed, executive function and verbal learning (all P < 0.05). There was no difference in cognition by HIV serostatus. The largest effect was observed in individuals with uncontrolled diabetes mellitus throughout the study period, equivalent to 16.5 and 13.4 years of aging on psychomotor speed and executive function, respectively, the effect of which remained significant after adjusting for HIV-related risk factors. Lower CD4+ nadir was also associated with worse cognitive performance.

CONCLUSION

Abnormalities in glucose metabolism were more common among MLWH than men without HIV and were related to impaired cognitive performance. Metabolic status, along with advanced age and previous immunosuppression, may be important predictors of cognition in the modern antiretroviral therapy era.

The Protective Effect of Astaxanthin on Cognitive Function via Inhibition of Oxidative Stress and Inflammation in the Brains of Chronic T2DM Rats

Currently, there are no effective treatments for diabetes-related cognitive dysfunction. Astaxanthin (AST), the most powerful antioxidant in nature, exhibits diverse biological functions. In this study, we tried to explore whether AST would ameliorate cognitive dysfunction in chronic type 2 diabetes mellitus (T2DM) rats. The T2DM rat model was induced via intraperitoneal injection of streptozotocin. Forty Wistar rats were divided into a normal control group, an acute T2DM group, a chronic T2DM group, and an AST group (treated with AST at a dose of 25 mg/kg three times a week). The Morris water maze test showed that the percentage of time spent in the target quadrant of the AST group was identical to that of the chronic T2DM group, while the escape latency of the AST group was decreased in comparison to that of the chronic T2DM group. Histology of the hippocampus revealed that AST ameliorated the impairment in the neurons of diabetic rats. Western blot showed that AST could upregulate nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) expression and inhibit nuclear transcription factor kappa B (NF-κB) p65 activation in the hippocampus. We found that AST increased the level of superoxide dismutase (SOD) and decreased the level of malondialdehyde (MDA) in the hippocampus. In addition, the levels of interleukin 1 beta (IL-1β) and interleukin 6 (IL-6) were reduced in the AST group compared with those in the chronic T2DM group. The findings of this research imply that AST might inhibit oxidative stress and inflammatory responses by activating the Nrf2-ARE signaling pathway.

Associations between blood cadmium levels and cognitive function in a cross-sectional study of US adults aged 60 years or older

OBJECTIVES

The relationship between cadmium exposure and cognition has been well studied in children. However, the association between environmental cadmium exposure and cognitive function has not been researched extensively in older adults. Our goal was to evaluate the association between cognitive function and blood cadmium levels in US adults aged 60 years or older.

DESIGN

A cross-sectional study.

SETTING

The US National Health and Nutrition Examination Survey (NHANES).

PARTICIPANTS

A total of 2068 adults aged 60 years or older who completed four cognitive assessment tests and blood cadmium detection in two waves of NHANES (2011-2014).

MAIN OUTCOME MEASURES

Cognitive assessment was conducted by household interview or at a Mobile Examination Center (MEC) using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word List Learning Test, the CERAD Word List Recall Test, the Animal Fluency Test and the Digit Symbol Substitution Test (DSST). We created a composite cognitive z-score to represent global cognitive function.

RESULTS

The median blood cadmium concentration in the study participants was 0.35 µg/L, and the IQR was 0.24-0.56 µg/L. In linear regression analyses, adjusting for demographics, behaviour and medical history, blood cadmium as a continuous variable was inversely associated with the composite z-score (μg/L, β=-0.11, 95% CI -0.20 to -0.03). Similarly, there was a significant association between quartiles of blood cadmium and composite z-score, with somewhat lower scores in the upper quartile of exposure (blood cadmium ≥0.63 µg/L) compared with those in the lower quartile of exposure (blood cadmium <0.25 µg/L) (μg/L, β=-0.14, 95% CI -0.25 to -0.03), and there was a trend by quartiles of blood cadmium (P<0.0001).

CONCLUSIONS

Our findings suggest that increased blood cadmium is associated with worse cognitive function in adults aged 60 years or older in the USA.

Cognition, serum BDNF levels, and BDNF Val66Met polymorphism in type 2 diabetes patients and healthy controls

Background and aims

Type 2 diabetes (T2DM) is associated with cognitive deficits. However, their pathophysiological mechanisms are still unknown. Recent study suggests that brain-derived neurotrophic factor (BDNF) is correlated with cognitive deficits in T2DM patients. This study was to determine whether altered serum BDNF levels and cognitive deficits depended on the BDNF Val66Met polymorphism in T2DM.

Results

The BDNF Val66Met polymorphism may not contribute directly to the susceptibility to T2DM. The total and nearly all index scores (all p < 0.01) except for the attention and visuospatial/constructional indexes (both p > 0.05) of RBANS were markedly decreased in T2DM compared with healthy controls. Serum BDNF levels were significantly lower in patients than that in controls (p < 0.001), and BDNF was positively associated with delayed memory in patients (p < 0.05). The Met variant was associated with worse delayed memory performance among T2DM patients but not among normal controls. Moreover, serum BDNF was positively associated with delayed memory among Met homozygote patients (β = 0.29, t = 2.21, p = 0.033), while serum BDNF was negatively associated the RBANS total score (β = –0.92, t = –3.40, p = 0.002) and language index (β = −1.17, t = –3.54, p = 0.001) among Val homozygote T2DM patients.

Conclusions

BDNF gene Val66Met variation may be associated with cognitive deficits in T2DM, especially with delayed memory. The association between lower BDNF serum levels and cognitive impairment in T2DM is dependent on the BDNF Val66Met polymorphism.

Methods

We recruited 311 T2DM patients and 346 healthy controls and compared them on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), serum BDNF levels, and the BDNF Val66Met polymorphism.

Feasibility of a multi-modal exercise program on cognition in older adults with Type 2 diabetes - a pilot randomised controlled trial

BACKGROUND

Type 2 Diabetes (T2D) is associated with increased risk of dementia. We aimed to determine the feasibility of a randomised controlled trial (RCT) examining the efficacy of exercise on cognition and brain structure in people with T2D.

METHODS

A 6-month pilot parallel RCT of a progressive aerobic- and resistance-training program versus a gentle movement control group in people with T2D aged 50-75 years (n = 50) at the University of Tasmania, Australia. Assessors were blinded to group allocation. Brain volume (total, white matter, hippocampus), cortical thickness and white matter microstructure (fractional anisotrophy and mean diffusivity) were measured using magnetic resonance imaging, and cognition using a battery of neuropsychological tests. Study design was assessed by any changes (during the pilot or recommended) to the protocol, recruitment by numbers screened and time to enrol 50 participants; randomisation by similarity of characteristics in groups at baseline, adherence by exercise class attendance; safety by number and description of adverse events and retention by numbers withdrawn.

RESULTS

The mean age of participants was 66.2 (SD 4.9) years and 48% were women. There were no changes to the design during the study. A total of 114 people were screened for eligibility, with 50 participants with T2D enrolled over 8 months. Forty-seven participants (94%) completed the study (23 of 24 controls; 24 of 26 in the intervention group). Baseline characteristics were reasonably balanced between groups. Exercise class attendance was 79% for the intervention and 75% for the control group. There were 6 serious adverse events assessed as not or unlikely to be due to the intervention. Effect sizes for each outcome variable are provided.

CONCLUSION

This study supports the feasibility of a large scale RCT to test the benefits of multi-modal exercise to prevent cognitive decline in people with T2D. Design changes to the future trial are provided.

TRIAL REGISTRATION

ANZCTR 12614000222640 ; Registered 3/3/2014; First participant enrolled 26/6/2014, study screening commenced 1/9/2014; Australian and New Zealand Clinical Trial Registry.

IMPACT OF VITAMIN D DEFICIENCY ON COGNITIVE FUNCTIONS IN TYPE 2 DIABETIC PATIENTS

OBJECTIVE

We hypothesized that vitamin D-deficient diabetic patients might demonstrate cognitive deficits and therefore investigated this association in patients with diabetes mellitus (DM).

METHODS

This study comprised 236 patients with type 2 DM (118 with vitamin D deficiency (less than 20 ng/mL) and 118 without vitamin D deficiency as the control group). All patients were outpatients in the endocrinology clinics of Baskent University, Turkey from 1 October 2013 to 31 January 2014 and, chosen in a randomized manner according to their application time. The serum vitamin D levels were measured and cognitive functions were evaluated using the Mini Mental Status Examination (MMSE).

RESULTS

The mean age in the study and control group was 57.02±7.30 and 58.92±7.58 years, respectively (p=0.051). The male:female ratio in the study and control group was 1.00:1.46 and 1.00:2.11, respectively. The study group was further divided into three subgroups: patients with mild, moderate, and severe vitamin D deficiency. The study outcomes revealed no significant relationship between the vitamin D deficiency level and the total score or subscores of the MMSE (p<0.05).

CONCLUSIONS

These study results do not confirm the hypothesis that vitamin D deficiency unfavorably affects cognitive functions in patients with type 2 DM.

The Role of Neuroticism and Psychological Flexibility in Chronic Fatigue and Quality of Life in Patients with Type 2 Diabetes

Background and Aims: The purpose of this study was to identify the role of neuroticism and psychological flexibility (PF) in quality of life (QOL) and chronic fatigue (CF) in patients with Type 2 Diabetes Mellitus (T2DM). Materials and Methods: We considered the all of the patients with T2DM over aged 30 years and living in the province of Hamadan, Iran in 2014 that were referred to the Hamadan Diabetes Center. A sample size of 170 patients was selected by the simple random sampling method. The measuring tools were completed by the patients. To test assumptions, the Pearson correlation and structural equation modeling were used. Results: The results showed that the correlation coefficient between neuroticism, with CF (r=0.579; p<0.001) and QOL (r=-0.242; p<0.001), and also correlation between PF and CF (r=0.287; p<0.001) are significant. There is no significant relationship between QOL and PF (r= -0.098; p=0.203). Structural equation modeling showed that neuroticism has a direct positive effect in CF (p<0.001) and a negative effect on QOL (p<0.001), and the PF has a significant direct effect on CF (p=0.014) and an indirect effect on QOL. The CF affects negatively on the QOL (p<0.001). Conclusion: It could be concluded that neuroticism and PF play important roles in QOL and CF and with effective intervention can help patients with diabetes to improve them QOL.

Reduced Gray Matter Volume in Patients with Type 2 Diabetes Mellitus

Background and Purpose: Previous studies of voxel-based morphometry (VBM) have found that patients with type 2 diabetes mellitus (T2DM) exhibit gray matter alterations, but these findings are inconsistent and have not been quantitatively reviewed. Therefore, the aim of this study was to conduct a quantitative meta-analysis of VBM studies of patients with T2DM.

Materials and Methods: The seed-based d mapping method was applied to quantitatively estimate the regional gray matter abnormalities in T2DM patients. We also used meta-regression to explore the effects of some demographics and clinical characteristics.

Results: Seven studies, with 8 datasets comprising 530 participants with T2DM and 549 non-T2DM controls, were included. The pooled and subgroup meta-analyses found that T2DM patients showed robustly reduced gray matter in the bilateral superior temporal gyrus, middle temporal gyrus, medial superior frontal gyrus, insula, median cingulate cortex, precuneus cortex and the left lentiform nucleus extending into the parahippocampus. The meta-regression also found that the percentage of female patients with T2DM was negatively associated with gray matter in the right superior temporal gyrus and illness duration was negatively associated with gray matter in the right middle temporal gyrus.

Conclusion: This meta-analysis indicates that T2DM patients have significantly and robustly reduced gray matter mainly in the cortical-striatal-limbic networks, which are associated with human cognition. Thereby implicating this finding in the pathophysiology of cognitive impairment in T2DM patients.

Steps to Health in Cognitive Aging: Effects of Physical Activity on Spatial Attention and Executive Control in the Elderly

The purpose of this study was to investigate whether physical activity (PA) habits may positively impact performance of the orienting and executive control networks in community-dwelling aging individuals and diabetics, who are at risk of cognitive dysfunction. To this aim, we tested cross-sectionally whether age, ranging from late middle-age to old adulthood, and PA level independently or interactively predict different facets of the attentional performance. Hundred and thirty female and male individuals and 22 adults with type 2 diabetes aged 55–84 years were recruited and their daily PA (steps) was objectively measured by means of armband monitors. Participants performed a multifunctional attentional go/no-go reaction time (RT) task in which spatial attention was cued by means of informative direct cues of different sizes followed by compound stimuli with local and global target features. The performance efficiency of the orienting networks was estimated by computing RT differences between validly and invalidly cued trials, that of the executive control networks by computing local switch costs that are RT differences between switch and non-switch trials in mixed blocks of global and local target trials. In regression analyses performed on the data of non-diabetic elderlies, overall RTs and orienting effects resulted jointly predicted by age and steps. Age predicted overall RTs in low-active individuals, but orienting effects and response errors in high-active individuals. Switch costs were predicted by age only, with larger costs at older age. In the analysis conducted with the 22 diabetics and 22 matched non-diabetic elderlies, diabetic status and daily steps predicted longer and shorter RTs, respectively. Results suggest that high PA levels exert beneficial, but differentiated effects on processing speed and attentional networks performance in aging individuals that partially counteract the detrimental effects of advancing age and diabetic status. In conclusion, adequate levels of overall PA may positively impinge on brain efficiency and attentional control and should be therefore promoted by actions that support lifelong PA participation and impact the built environment to render it more conducive to PA.