Midlife metabolic syndrome and neurocognitive function in a mixed Asian sample

Metabolic syndrome and cognitive deficits in the Greek cohort of Epirus Health Study

BACKGROUND

Metabolic syndrome is considered an important risk factor for cognitive decline and dementia. However, the evidence in middle-aged individuals is still conflicting. The aim of the study was to explore the association between metabolic syndrome and its individual components with cognitive function and to investigate possible interaction between sex, age and genetic predisposition for metabolic syndrome and Alzheimer's disease in a middle-aged Greek cohort.

METHODS

A total of 2,077 healthy adults (mean age: 46.7 years) were included in the primary cross-sectional analysis and 305 of them in secondary prospective analyses. Metabolic syndrome was defined by the revised National Cholesterol Education-Adult Treatment Panel III and the International Diabetes Federation criteria. Cognitive function was measured primarily with the Trail Making, Verbal fluency and Logical Memory test, and in secondary prospective analyses with online versions of Posner cueing task, an emotional recognition task, Corsi block-tapping task and Stroop task.

RESULTS

Multivariable linear regressions showed an association of metabolic syndrome with lower performance in attention (β=1.62 seconds, 95% CI=0.20, 3.04) and memory (β=-0.62 words, 95% CI=-1.19, -0.05) that could be driven by associations with elevated fasting glucose and abdominal obesity. Similar associations were observed in the secondary prospective analyses.

CONCLUSION

In summary, metabolic syndrome was associated with cognitive deficits in domains related with the cognitive profile of vascular cognitive impairment.

Association Between Metabolic Syndrome and Decline in Cognitive Function: A Cross-Sectional Study

AIM

We investigated whether metabolic syndrome (MetS) is associated with a decline in cognitive function in a cohort of middle-aged and elderly individuals without known cognitive dysfunction diseases in Qatar.

METHODS

We conducted a cross-sectional study on randomly selected participants aged 40-80 years from the Qatar Biobank, with data on cognitive tests and MetS components. Participants with a history of dementia, stroke, or mental disorders were excluded. MetS was diagnosed using the NCEP-ATP III criteria and cognitive performance was assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB). Two cognitive function domains were assessed. These are speed of reaction, measured using the Reaction Time (RT), and short-term visual memory, measured using the Paired Associate Learning (PAL) test. Multivariable logistic regression models were used to determine associations between MetS and poor speed of reaction and poor memory performance.

RESULTS

The mean age of the participants included was 49.8 years (SD 6.7). Of these, 51.9% were females and 88.0% were of Qatari nationality. Most of the 1000 participants had MetS (n=302) or 1-2 MetS components (n=523), whereas only 170 had no MetS components. There was a strong association between MetS and poor memory performance (OR 1.76, 95% CI 1.04-2.96, P=0.034), but a weaker association with poor speed of reaction (OR 1.5, 95% CI 0.89-2.50, P=0.125).

CONCLUSION

In middle-aged and elderly individuals, MetS was strongly associated with diminished short-term visual memory, psychomotor coordination and motor speed.

Frailty and Quality of Life in Older Adults with Metabolic Syndrome - Findings from the Healthy Older People Everyday (HOPE) Study

OBJECTIVES

Metabolic syndrome (MetS) and frailty are both associated with increased morbidity and mortality. Frailty is associated with reduced quality of life (QoL) but association of QoL with MetS have produced mixed results suggesting that other factors such as disease burden, obesity and depression may have a more significant influence. We aim to investigate the demographics of frail participants with MetS, and relationship between frailty and QoL in MetS.

METHODS

Cross-sectional population study involving 292 older adults ≥ 65 years with MetS. MetS was defined using the Modified ATP III for Asians which requires the presence of 3 or more of the following 5 components 1) waist circumference ≥ 90cm for males or ≥ 80cm for females, 2) TG ≥ 150mg/dL, 3) HDLc < 40mg/dL in males or < 50mg/dL in females, 4) blood pressure ≥ 130/85mmHg or use of anti-hypertensive medication, and 5) fasting plasma glucose ≥ 100mg/dL or use of pharmacological treatment for diabetes mellitus. Data were collected on demographics, frailty (FRAIL), QoL (Euroqol-5D), perceived health, functional status, cognition, Timed-Up-and-Go (TUG), and hand-grip strength (HGS).

RESULTS

40.4% of the participants were pre-frail (MetSprefrail) and 7.2% were frail (MetSfrail). MetSfrail were significantly older, had lower education level, higher polypharmacy burden and higher prevalence of diabetes. The prevalence of at least 1 activity of daily living impairment was 4 times higher, and depression 9 times higher than their robust counterparts. MetSfrail also had longer TUG, higher prevalence of poor grip strength and poor perceived health. After adjusting for age, gender and education, MetSfrail was significantly associated with much higher odds of EQ-5D moderate to extreme problems with mobility (Odds Ratio (OR) =10.99, CI 2.62-46.14), usual activities (OR=37.82, CI 3.77-379.04) and pain (OR=10.79, CI 3.18-36.62). EQ-5D Index Value and Perceived Health improved by 0.1 (Mean Difference (MD) =0.07, CI 0.04-0.10) and 6.0 (MD=6.01, CI 3.29-8.73) respectively as frailty status improved.

CONCLUSION

Frailty in MetS is associated with depression, polypharmacy, greater functional impairment, poorer QoL and perceived health. Frailty screening and personalized management is crucial in MetS as frailty may be a mediator for negative outcomes in MetS, and frailty may be reversible.

Functional magnetic resonance imaging response as an early biomarker of cognitive decline in elderly patients with metabolic syndrome

OBJECTIVES

We assessed whether potential changes in brain activation patterns of elderly individuals with metabolic syndrome (MetS) who were cognitively healthy (without mild cognitive impairment or dementia) were associated with cognitive decline in executive function in the short-term.

METHOD

We analyzed 43 individuals (23 MetS, 20 controls) using a global geriatric evaluation, a neuropsychological battery, and task-related (attention) fMRI exam. Correlation analysis between the fMRI signal at baseline and cognitive impairment after 1year was based on the voxel-based Pearson coefficient, corrected for multiple comparisons.

RESULTS

At baseline, MetS patients showed reduced brain response in frontal and parietal regions compared to controls. After one year, the MetS group also showed a decline in verbal fluency performance. fMRI response in the right dorsolateral prefrontal cortex and bilateral parietal lobes was negatively correlated with verbal fluency decline in the MetS group.

DISCUSSION

Our results provide an early biomarker of the possible development of cognitive impairment, particularly in the executive function, of elderly individuals suffering from MetS. These findings also point to an up or down regulation which could be interpreted as compensatory mechanism for possible brain tissue burden caused by MetS.

Linking Resting-State Networks in the Prefrontal Cortex to Executive Function: A Functional Near Infrared Spectroscopy Study

Executive function (EF) plays vital roles in our everyday adaptation to the ever-changing environment. However, limited existing studies have linked EF to the resting-state brain activity. The functional connectivity in the resting state between the sub-regions of the brain can reveal the intrinsic neural mechanisms involved in cognitive processing of EF without disturbance from external stimuli. The present study investigated the relations between the behavioral executive function (EF) scores and the resting-state functional network topological properties in the Prefrontal Cortex (PFC). We constructed complex brain functional networks in the PFC from 90 healthy young adults using functional near infrared spectroscopy (fNIRS). We calculated the correlations between the typical network topological properties (regional topological properties and global topological properties) and the scores of both the Total EF and components of EF measured by computer-based Cambridge Neuropsychological Test Automated Battery (CANTAB). We found that the Total EF scores were positively correlated with regional properties in the right dorsal superior frontal gyrus (SFG), whereas the opposite pattern was found in the right triangular inferior frontal gyrus (IFG). Different EF components were related to different regional properties in various PFC areas, such as planning in the right middle frontal gyrus (MFG), working memory mainly in the right MFG and triangular IFG, short-term memory in the left dorsal SFG, and task switch in the right MFG. In contrast, there were no significant findings for global topological properties. Our findings suggested that the PFC plays an important role in individuals' behavioral performance in the executive function tasks. Further, the resting-state functional network can reveal the intrinsic neural mechanisms involved in behavioral EF abilities.