Intrusion errors moderate the relationship between blood glucose and regional cerebral blood flow in cognitively unimpaired older adults

Greater subjective cognitive decline severity is associated with worse memory performance and lower entorhinal cerebral blood flow in healthy older adults

OBJECTIVE

Subjective cognitive decline (SCD) is a potential early risk marker for Alzheimer's disease (AD), but its utility may vary across individuals. We investigated the relationship of SCD severity with memory function and cerebral blood flow (CBF) in areas of the middle temporal lobe (MTL) in a cognitively normal and overall healthy sample of older adults. Exploratory analyses examined if the association of SCD severity with memory and MTL CBF was different in those with lower and higher cardiovascular disease (CVD) risk status.

METHODS

Fifty-two community-dwelling older adults underwent magnetic resonance imaging, neuropsychological testing, and were administered the Everyday Cognition Scale (ECog) to measure SCD. Regression models investigated whether ECog scores were associated with memory performance and MTL CBF, followed by similar exploratory regressions stratified by CVD risk status (i.e., lower vs higher stroke risk).

RESULTS

Higher ECog scores were associated with lower objective memory performance and lower entorhinal cortex CBF after adjusting for demographics and mood. In exploratory stratified analyses, these associations remained significant in the higher stroke risk group only.

CONCLUSIONS

Our preliminary findings suggest that SCD severity is associated with cognition and brain markers of preclinical AD in otherwise healthy older adults with overall low CVD burden and that this relationship may be stronger for individuals with higher stroke risk, although larger studies with more diverse samples are needed to confirm these findings. Our results shed light on individual characteristics that may increase the utility of SCD as an early risk marker of cognitive decline.

Clinical and demographic factors modify the association between plasma phosphorylated tau-181 and cognition

INTRODUCTION

Plasma phosphorylated tau181 (p-tau181) associations with global cognition and memory are clear, but the link between p-tau181 with other cognitive domains and subjective cognitive decline (SCD) across the clinical spectrum of Alzheimer's disease (AD) and how this association changes based on genetic and demographic factors is poorly understood.

METHODS

Participants were drawn from the Alzheimer's Disease Neuroimaging Initiative and included 1185 adults aged >55 years with plasma p-tau181 and neuropsychological test data. Linear regression models related plasma p-tau181 to neuropsychological composite and SCD scores with follow-up models examining plasma p-tau181 interactions with cognitive diagnosis, APOE ε4 carrier status, age, and sex on cognitive outcomes.

RESULTS

Higher plasma p-tau181 was associated with worse memory, executive functioning, and language abilities, and greater informant-reported SCD. Visuospatial abilities and self-report SCD were not associated with plasma p-tau181. Associations were generally stronger in MCI or dementia, APOE ε4 carriers, women, and younger participants.

DISCUSSION

Higher levels of plasma p-tau181 are associated with worse neuropsychological test performance across multiple cognitive domains; however, these associations vary based on disease stage, genetic risk status, age, and sex.

Effect of admission serum glucose on the clinical prognosis of patients with acute ischemic stroke receiving alteplase intravenous thrombolysis

Objective: To investigate the effect of admission serum glucose on the clinical prognosis of patients with acute ischemic stroke receiving intravenous alteplase thrombolysis. Methods: Patients with acute ischemic stroke who received intravenous alteplase thrombolysis between January 2016 and December 2017 were enrolled. The clinical prognosis was assessed using the modified Rankin Scale (mRs) at 90 days after onset. Univariate and multivariate logistic regression analyses were conducted to investigate whether admission serum glucose was an independent factor in the 90-day prognosis. The predictive value of admission serum glucose for a 90-day poor prognosis was evaluated using receiver operating characteristic (ROC) curves. All patients were divided into two groups based on admission serum glucose levels: high admission serum glucose (above the cut-off value) and low admission serum glucose (below the cut-off value). The 90-day prognosis of patients with different admission serum glucose was analyzed. Results: A total of 138 patients were enrolled, including 79 males (57.24%), with a mean age of (68 ± 12) years and a median baseline National Institutes of Health Stroke Scale (NIHSS) score of 9 (6 to 13.75). There were 74 cases (53.62%) in the good prognosis group and 64 cases (46.37%) in the poor prognosis group. The results of the univariate analysis indicated that admission serum glucose in the good prognosis group was significantly lower than that in the poor prognosis group [(7.45 ± 2.31) versus (8.80 ± 3.65), p < .05]. Logistic regression analysis revealed that the admission serum glucose level was an independent risk factor for clinical prognosis at 90 days after onset (OR = 1.24, 95% CI:1.01-1.52). ROC curve analysis showed that the cutoff value of admission serum glucose for predicting poor prognosis 90 days after intravenous thrombolytic therapy with alteplase was 6.77 mmol/l AUC (area under curve) 0.623, 95%CI: 0.53-0.72, sensitivity 68.80%, specificity 52.70%. When compared with the admission serum glucose ≥6.77 mmol/l group (83 cases), the 90-day mRS scores in the admission serum glucose <6.77 mmol/l group (55 cases) were lower [3 (1 to 5) scores versus 1 (0 to 3) scores, Z = 2.89, p < .05]. Conclusions: In patients with acute ischemic stroke receiving intravenous alteplase thrombolytic therapy, a higher admission serum glucose level is an independent predictor of adverse neurological outcomes at 90 days postoperatively.