Effects of Longitudinal Glucose Exposure on Cognitive and Physical Function: Results from the Action for Health in Diabetes Movement and Memory Study

Multimorbidity and Functional Disability among Older Adults: The Role of Inflammation and Glycemic Status - An Observational Longitudinal Study

INTRODUCTION

Specific multimorbidity combinations, in particular those including arthritis, stroke, and cognitive impairment, have been associated with high burden of activities of daily living (ADL)-instrumental activities of daily living (IADL) disability in older adults. The biologic underpinnings of these associations are still unclear.

METHODS

Observational longitudinal study using data from the Health and Retirement Study (N = 8,618, mean age = 74 years, 58% female, 25% non-white) and negative binomial regression models stratified by sex to evaluate the role of inflammatory and glycemic biomarkers (high-sensitivity C-reactive protein (hs-CRP) and HbA1c) in the association between specific multimorbidity combinations (grouped around one of eight index diseases: arthritis, cancer, cognitive impairment, diabetes, heart disease, hypertension, lung disease, and stroke; assessed between 2006 and 2014) and prospective ADL-IADL disability (2 years later, 2008-2016). Results were adjusted for sociodemographic characteristics, body mass index, number of coexisting diseases, and baseline ADL-IADL score.

RESULTS

Multimorbidity combinations indexed by arthritis (IRR = 1.1, 95% CI = 1.01-1.20), diabetes (IRR = 1.19, 95% CI = 1.09-1.30), and cognitive impairment (IRR = 1.11, 95% CI = 1.01-1.23) among men and diabetes-indexed multimorbidity combinations (IRR = 1.07, 95% CI = 1.01-1.14) among women were associated with higher ADL-IADL scores at increasing levels of HbA1c. Across higher levels of hs-CRP, multimorbidity combinations indexed by arthritis (IRR = 1.06, 95% CI = 1.02-1.11), hypertension (IRR = 1.06, 95% CI = 1.02-1.11), heart disease (IRR = 1.06, 95% CI = 1.01-1.12), and lung disease (IRR = 1.14, 95% CI = 1.07-1.23) were associated with higher ADL-IADL scores among women, while there were no significant associations among men.

CONCLUSION

The findings suggest potential for anti-inflammatory management among older women and optimal glycemic control among older men with these particular multimorbidity combinations as focus for therapeutic/preventive options for maintaining functional health.

Cognitive function and cardiorespiratory fitness affect gait speed in type-2 diabetic patients without neuropathy

AIM

To identify physical, cognitive, and metabolic factors affecting gait speed in patients with type-2 diabetes mellitus (T2DM) without neuropathy.

METHODS

This cross-sectional study enrolled 71 diabetic patients without neuropathy (mean age 55.87±7.74 years, 85.9% women). Neuropathy status was assessed with Douleur Neuropathique 4. We used a cut-off point for gait speed of 1 m/s to classify the participants into two groups: slow walkers (SW) and average and brisk walkers (ABW). The groups were compared in terms of age, sex, body mass index (BMI), hemoglobin A1c (HbA1c), fasting glucose, systolic blood pressure, maximal aerobic capacity (VO2 max), percentage of muscle mass, percentage of lower extremity muscle mass, Mini-Mental State Examination (MMSE) score, and years of education.

RESULTS

Compared with the ABW group, the SW group had significantly lower VO2 max (14.49±2.95 vs 16.25±2.94 mL/kg/min) and MMSE score (25.01±3.21 vs 27.35±1.97), fewer years of education, and these patients were more frequently women (P<0.05). In the multivariate regression models, the combination of VO2 max, sex, and MMSE score explained only 23.5% of gait speed (P<0.001). MMSE score and VO2max independently determined gait speed after adjustment for age, BMI, HbA1c, fasting glucose, systolic blood pressure, percent of muscle mass, percent of lower extremity muscle mass, and years of education.

CONCLUSION

In diabetic patients without neuropathy, physical impairment and disability could be prevented by an improvement in aerobic capacity and cognitive function.

Cognitive function and cardiorespiratory fitness affect gait speed in type-2 diabetic patients without neuropathy

AIM

To identify physical, cognitive, and metabolic factors affecting gait speed in patients with type-2 diabetes mellitus (T2DM) without neuropathy.

METHODS

This cross-sectional study enrolled 71 diabetic patients without neuropathy (mean age 55.87±7.74 years, 85.9% women). Neuropathy status was assessed with Douleur Neuropathique 4. We used a cut-off point for gait speed of 1 m/s to classify the participants into two groups: slow walkers (SW) and average and brisk walkers (ABW). The groups were compared in terms of age, sex, body mass index (BMI), hemoglobin A1c (HbA1c), fasting glucose, systolic blood pressure, maximal aerobic capacity (VO2 max), percentage of muscle mass, percentage of lower extremity muscle mass, Mini-Mental State Examination (MMSE) score, and years of education.

RESULTS

Compared with the ABW group, the SW group had significantly lower VO2 max (14.49±2.95 vs 16.25±2.94 mL/kg/min) and MMSE score (25.01±3.21 vs 27.35±1.97), fewer years of education, and these patients were more frequently women (P<0.05). In the multivariate regression models, the combination of VO2 max, sex, and MMSE score explained only 23.5% of gait speed (P<0.001). MMSE score and VO2max independently determined gait speed after adjustment for age, BMI, HbA1c, fasting glucose, systolic blood pressure, percent of muscle mass, percent of lower extremity muscle mass, and years of education.

CONCLUSION

In diabetic patients without neuropathy, physical impairment and disability could be prevented by an improvement in aerobic capacity and cognitive function.

Baseline associations between biomarkers, cognitive function, and self-regulation indices in the Cognitive and Self-regulatory Mechanisms of Obesity Study

OBJECTIVE

Understanding how biological, cognitive, and self-regulatory factors are related to obesity, and weight regulation is clearly needed to optimize obesity prevention and treatment. The objective of this investigation was to understand how baseline biological, cognitive, and self-regulatory factors are related to adiposity at the initiation of a behavioral weight loss intervention among treatment-seeking adults with overweight/obesity.

METHODS

Participants (N = 107) in the Cognitive and Self-regulatory Mechanisms of Obesity Study (Identifier-NCT02786238) completed a baseline assessment with anthropometric, cardiometabolic, inflammatory, cognitive function, and self-regulation measures as part of a larger on-going trial. Data were analyzed with linear regression.

RESULTS

At baseline, body mass index, body fat percentage, and waist circumference (WC) were positively associated with fasting insulin and insulin resistance. Higher WC was related to higher fasting glucose and hemoglobin A1c (HbA1c). Higher glucose and insulin resistance levels were related to lower list sorting working memory. Higher glucose and HbA1c levels were negatively associated with reading scores. Cognitive function and self-regulation indices were unrelated.

CONCLUSIONS

In adults with overweight/obesity entering a weight loss treatment study: (1) elevated WC and associated glycemic impairment were negatively associated with cognition, (2) poorer executive function and reading abilities were associated with poorer glycemic control, and (3) objectively measured cognitive functions were unrelated to self-reported/behavioral measures of self-regulation. Such findings increase understanding of the relationships between adiposity, biomarkers, cognition, and self-regulation at treatment initiation and may ultimately inform barriers to successful obesity treatment response.

Legacy of a 10-Year Multidomain Lifestyle Intervention on the Cognitive Trajectories of Individuals with Overweight/Obesity and Type 2 Diabetes Mellitus

INTRODUCTION

Weight loss and increased physical activity interventions are commonly recommended for individuals with type 2 diabetes (T2D) and overweight or obesity. We examined the impact of randomization to an intensive lifestyle intervention (ILI) on trajectories of cognitive function over 10 years in a cohort of participants in a randomized clinical trial who had T2D and overweight/obesity at baseline.

METHODS

Participants aged 45-76 years were enrolled in 2001-2004 and were randomized to the ILI or a diabetes support and education (DSE) condition. Cognitive function was assessed in 3,938 participants at up to 4 time points 8-18 years after randomization. General linear mixed effects models examined cognitive trajectories over time. Subgroup analyses focused on sex, individuals with baseline body mass index >30, those carrying the APOE ε4 allele, and those with a baseline history of cardiovascular disease (CVD).

RESULTS

Overall, there were no differences in the rate of cognitive decline by intervention arm. Subgroup analyses showed that participants who had a baseline history of CVD and were randomized to the ILI arm of the study performed significantly worse on the Stroop Color Word Test than those in the DSE arm.

DISCUSSION/CONCLUSIONS

The ILI did not result in preserved cognitive function or slower rates of cognitive decline in this cohort of individuals who had T2D and were overweight or obese at baseline.

Sex-Specific Association of Endogenous PCSK9 With Memory Function in Elderly Subjects at High Cardiovascular Risk

Background: Growing evidence indicates that cognitive decline and cardiovascular diseases (CVDs) share common vascular risk factors. Protease proprotein convertase subtilisin/kexin type 9 (PCSK9) is associated with CV disease risk and has been also involved in neuronal differentiation.

Aim: Evaluate whether in patients at high CV risk cognitive function is related to PCSK9 levels.

Methods. One hundred sixty-six patients (67 female) were enrolled. A detailed neuropsychological (NP) assessment was performed. PCSK9 levels were measured with ELISA.

Results: Men had significantly higher short-term memory, executive function, and praxic and mental representation skills, as reflected by Forward Digit Span (FDS) (p = 0.005), Trail Making Test-A (TMT-A) (p = 0.047), Clock Drawing Test (CDT) (0.016). Endogenous PCSK9 levels were higher in female (p = 0.005). On linear regression analysis PCSK9 predicts short term memory only in females (Beta = 0.408, p = 0.001), with an interaction between PCSK9 and gender (p = 0.004 for interaction PCSK9 by sex). The association of PCSK9 with FDS in female was partially mediated by waist circumference (mediation effect 8.5%).

Conclusions: In patients at high CV risk short term memory was directly related to PCSK9 levels only in women, revealing the relevance of sex in this relationship. The association of PCSK9 with memory function may be mediated, at least in part, by waist circumference.

Prognostic Value of Glycated Hemoglobin in Frail Older Diabetic Patients With Hip Fracture

BACKGROUND

Previous studies have shown increased risk of fracture in older patients with poor or strict glycemic control (glycated hemoglobin, HbA1c, ≥ 8% or < 6-7% respectively); however, these reports did not investigate the oldest-old population. Comprehensive geriatric assessment (CGA) and a patient-centered approach have been proven to improve the quality of care in the management of Type 2 Diabetes Mellitus (T2DM) in the older patients, but data regarding T2DM in patients with fragility fractures are still lacking.

AIM

To investigate the prognostic role of HbA1c and frailty level in older diabetic patients admitted for hip fracture.

METHODS

Prospective observational cohort study conducted on diabetic geriatric patients consecutively hospitalized for hip fracture in the orthogeriatric unit of a tertiary care hospital. Preoperative comprehensive geriatric assessment (CGA) was performed. Using the Clinical Frailty Scale (CFS), diabetic patients were categorized in robust (CFS < 5) and frail (CFS ≥ 5), and further stratified according to HbA1c values [Tertile 1 (T1) HbA1c < 48 mmol/mol, Tertile 2 (T2) 48-58 mmol/mol and Tertile 3 (T3) > 58 mmol/mol). Comparisons between continuous variables were performed with analysis of non-parametric test for independent samples, while relationships between categorical variables were assessed by chi-square test. Using logistic multivariate regression, we evaluated the determinants of 1-year all-cause mortality in diabetic older patients with hip fracture.

RESULTS

Among the 1319 older patients (mean age 82.8 ± 7.5 years, 75.9% females) hospitalized for hip fracture, 204 (15.5%) had a previous diagnosis of T2DM. T2DM patients showed an increased proportion of multiple concurrent fractures occurred during the accidental fall or syncope (12.7% vs 11.2%, p=0.02). One-year mortality after hip fracture surgery was significantly higher in T2DM as compared to not diabetic patients (21.2% vs 12.5%, p<0.001). No significant difference in mortality was found across HbA1c tertiles; however, frail diabetic patients in the second and third HbA1c tertiles showed higher mortality risk compared to the robust counterparts (26.9% vs 5%, p=0.001 for T2 and 43.5% vs 13.3%, p=<0.05 for T3), while no difference was observed among those in T1.

CONCLUSIONS

Frail patients with HbA1c ≥ 48 mmol/L showed an increased mortality risk as compared to robust counterparts. CFS represents an important tool to select diabetic subjects with higher likelihood of adverse outcome.

The Relation of Diabetes to Memory Function

PURPOSE OF REVIEW

Research has consistently shown that type 2 diabetes (T2D) is associated with increased risk of all-cause dementia. Because one of the most common clinical presentations of early stage dementia is memory impairment, we examined the relationship of T2D with memory function, using the recently published scientific literature.

RECENT FINDINGS

We conducted a structured review to identify studies of "T2D and memory" published since 2015. After review of the 129 articles retrieved, we identified 14 studies meeting the inclusion and exclusion criteria. Among the eight studies with a single assessment of memory function in time (mostly cross-sectional), six found an association of T2D with lower memory function, but mostly in select subgroups of persons. Separately, six studies included repeated measures of memory (longitudinal design). Four out of six longitudinal studies found that T2D was related with a faster decline in memory, while two did not. Among the four studies showing a relation with memory decline, two had sample sizes of 9000-10,000 persons. Further, three longitudinal studies controlled for hypertension and stroke as covariates, and results suggested that common vascular risk factors and diseases do not account for the relation. While mechanistic studies clearly support a role for cerebrovascular disease in the relation of T2D with cognition, emerging data suggest that insulin resistance in the brain itself may also play a role. Most, but not all, recently published studies suggest that T2D is associated with a lower level and faster decline in memory function. This association does not appear to be fully accounted for by common vascular processes. More research will clarify the mechanisms linking T2D to memory and dementia.

Risk of mini-mental state examination (MMSE) decline in the elderly with type 2 diabetes: a Chinese community-based cohort study

BACKGROUND

We aimed to investigate the correlation of factors involved in the change of Mini-Mental State Examination (MMSE) and type 2 diabetes in the elderly.

METHODS

This study was a secondary analysis of a prospective cohort study. Type 2 diabetes patients aged > 55 years were recruited and assigned into three groups based on their glycated hemoglobin (HbA1c) levels: HbA1c < 7, 7% ≤ HbA1c < 8% and HbA1c ≥8%. MMSE decline was considered the endpoint. Factors related to MMSE decline were identified by univariate and multivariate regression analyses.

RESULTS

Altogether, 1519 subjects were included, 883 in the Low group, 333 in the Median group, and 303 in the High group. Age ≥ 75 years, education below elementary school level, not participating in seminars or consultation on healthcare, physical activity less than 30 min/day, cerebrovascular disease history, MMSE score at baseline, and HBA1c ≥8% were associated with cognitive decline by univariate and multivariate analysis. When the other factors were adjusted for, HBA1c ≥8% was independently associated with the severity of cognitive decline (β = 0.58, 95%CI:0.06-1.11, P = 0.029) and the occurrence of cognitive decline (odds ratio (OR) = 1.55, 95%CI:1.13-2.12, P = 0.007).

CONCLUSIONS

In elderly patients with type 2 diabetes, HbA1c ≥8% is an independent factor for cognitive decline and is also associated with the severity of the cognitive decline.

A Different View to Older Diabetics: Management of Treatment According to Cognitive Functions

Background and aims. Diabetes Mellitus is a chronic systemic disease which has multiple complications and the presence of these complications affects the management of disease. It is also important to consider cognitive functions when managing the treatment of older diabetics. In this study, we aimed to make proposals for the appropriate drug choice to preserve cognitive functions in elderly diabetics.

Matherial and methods. A total of 270 older diabetic patients were reviewed. Possible risk factors of cognitive impairment were investigated. Correlation analysis was performed between MMSE and GDS, age, HbA1c, duration of diabetes.

Results. Sulfonylurea (adj. OR: 2.33, %95 CI: 1.11-4.90) and insulin treatment (adj. OR: 3.79, %95 CI: 1.56-9.21) were found associated with increased risk of cognitive impairment. In addition, there was a negative correlation between MMSE and GDS (r: -.129, p<0.05).

Conclusion. We suggest that insulin and sulfonylureas should be used with caution in those with cognitive impairment.

Prospective association between added sugars and frailty in older adults

Background

Sugar-sweetened beverages and added sugars (monosaccharides and disaccharides) in the diet are associated with obesity, diabetes, and cardiovascular disease, which are all risk factors for decline in physical function among older adults.

Objective

The aim of this study was to examine the association between added sugars in the diet and incidence of frailty in older people.

Design

Data were taken from 1973 Spanish adults ≥60 y old from the Seniors-ENRICA cohort. In 2008-2010 (baseline), consumption of added sugars (including those in fruit juices) was obtained using a validated diet history. Study participants were followed up until 2012-2013 to assess frailty based on Fried's criteria. Statistical analyses were performed with logistic regression adjusted for age, sex, education, smoking status, body mass index, energy intake, self-reported comorbidities, Mediterranean Diet Adherence Score (excluding sweetened drinks and pastries), TV watching time, and leisure-time physical activity.

Results

Compared with participants consuming <15 g/d added sugars (lowest tertile), those consuming ≥36 g/d (highest tertile) were more likely to develop frailty (OR: 2.27; 95% CI: 1.34, 3.90; P-trend = 0.003). The frailty components "low physical activity" and "unintentional weight loss" increased dose dependently with added sugars. Association with frailty was strongest for sugars added during food production. Intake of sugars naturally appearing in foods was not associated with frailty.

Conclusions

The consumption of added sugars in the diet of older people was associated with frailty, mainly when present in processed foods. The frailty components that were most closely associated with added sugars were low level of physical activity and unintentional weight loss. Future research should determine whether there is a causal relation between added sugars and frailty.

Neurocognitive Deficits in a Cohort With Class 2 and Class 3 Obesity: Contributions of Type 2 Diabetes and Other Comorbidities

OBJECTIVE

This study examined the relationship between specific metabolic and vascular risk factors and cognition in adults with severe obesity.

METHODS

A total of 129 adults (with BMI ≥ 35 kg/m² ) underwent a baseline clinical evaluation and neuropsychological assessment. Regression analyses examined the relationship between cognition and medical factors (BMI, hemoglobin A1c, diabetes, hypertension, continuous positive airway pressure use, obstructive sleep apnea [OSA], and osteoarthritis).

RESULTS

Diabetes was associated with deficits in overall cognitive performance and with deficits in the executive processing speed and verbal fluency domains. Hemoglobin A1c was inversely related to overall cognitive performance and deficits in the attention domain. Participants using continuous positive airway pressure to treat OSA had stronger learning and memory performance, whereas OSA was associated with reduced total learning. Elevated BMI together with diabetes diagnosis was associated with reduced verbal fluency and greater variability in sustained attention.

CONCLUSIONS

Obesity-associated comorbidities most notably appeared to have a greater relative influence on cognitive performance than BMI itself in adults with severe obesity. This likely reflects the fact that a very elevated BMI was ubiquitous and thereby probably exerted a similar influence among all adults in the cohort. Accordingly, in the context of severe obesity, diabetes and other comorbidities may have greater sensitivity to cognitive deficits than BMI alone.

Carbohydrates and cognitive function

PURPOSE OF REVIEW

Recent evidence documents the negative impact of obesity, diabetes mellitus, and other metabolic dysregulation on neurocognitive function. This review highlights a key dietary factor in these relationships: refined carbohydrates.

RECENT FINDINGS

Chronic consumption of refined carbohydrates has been linked to relative neurocognitive deficits across the lifespan. Hippocampal function is especially impacted, but prefrontal and mesolimbic reward pathways may also be altered. Early life exposure to refined carbohydrates, (i.e., prenatal, juvenile, and adolescence periods) may be particularly toxic to cognitive functioning. The impact of acute carbohydrate administration is mixed, with some findings showing benefits while others are neutral or negative. Potential mechanisms of the carbohydrate-cognition relationship include dysregulation in metabolic, inflammatory, and vascular factors, whereas moderators include age, genetic factors, physiological (e.g., glucoregulatory) function and the timing and type of carbohydrate exposure. Critically, the negative neurocognitive impacts of diets high in refined carbohydrates have been shown to be independent of total body weight.

SUMMARY

Neurocognitive deficits induced by a diet high in refined carbohydrates may manifest before overt obesity or metabolic disease onset, suggesting that researchers and providers may need to target subclinical metabolic, inflammatory, and vascular dysregulation factors in efforts to preserve cognitive function across the lifespan.

Cognitive and gait decrements among non-demented older adults with Type 2 diabetes or hypertension: a systematic review

OBJECTIVE

Older adults with Type 2 diabetes (DM2) and hypertension (HTN) often experience cognitive weaknesses. Growing evidence suggests that such weaknesses place patients at risk for gait disturbance and falls. The current systematic review evaluated (a) the impact of DM2 and HTN on cognition and gait and (b) the association between cognition and gait in the context of DM2 and HTN.

METHODS

PubMed was searched to identify studies published in English before 15 April 2017 that evaluated both cognition and gait among non-demented older adults either as a function of DM2 or HTN status or as a function of continuous variables that indicate disease severity and/or management (e.g. blood pressure, HbA1C). Risk of bias was assessed by examining the method of verifying HTN/DM2 and excluding dementia as well as included covariates.

RESULTS

In the majority of studies reviewed (n = 17), both DM2 and HTN status were associated with poorer cognitive and/or gait functioning (8 out of 10 studies). In addition, in 10 out of 11 studies cognition was reliably associated with gait. For continuous variables, higher systolic blood pressure (measured with ambulatory methods) was consistently related to poorer cognition and slower gait, but other continuous variables (e.g. HbA1C) were studied inconsistently with inconclusive results.

CONCLUSIONS

Cognitive and gait decrements are not only common in the context of HTN and DM2, but also are related to each other. This suggests that clinical neuropsychologists should address cognitive contributions to gait disturbance and falls in their clinical work and research with these patient populations.