Glucose intake is influencing the concentration of AD‐related plasma biomarkers in healthy adults.

Background: Blood biomarker analyses are seen as a great aid to early diagnose and confirm underlying Alzheimer's disease (AD) pathology. Developing evidence suggests that certain confounders need to be considered which may affect the reliability of biomarker results, e.g., chronic kidney disease. However, little is known with respect to potential confounding effects of energy/nutrient intake on these biomarkers. Thus, we aim to study the short‐term effects of oral glucose intake in healthy, obese adults. Method: 111 participants (60±7y, BMI 31±4kg/m2, 47 males) ingested 300ml of a glucose syrup (75g glucose, Accu‐Chek, Roche). Neurofilament light, glial fibrillary acidic protein [GFAP], amyloid‐β 42/40 ratio, phosphorylated tau ([p‐tau] 181 and p‐tau 231) were measured in fasting (0 minutes) and postprandial blood samples collected 15, 30, 45, 60, 120 and 180 minutes after ingestion of the glucose syrup using ultra‐sensitive Single molecule array assays. Additionally, a fasting (control) group (n = 26) was followed over the same time period. Statistical analysis was done using polynomial spline of degree 3 to test for differences in parameter progression over time within and between groups. Result: In both groups, all biomarkers changed significantly over time (glucose group: all p<0.0001, fasting group all p<0.05) compared to baseline (0 minutes). The changes to baseline in GFAP were significantly different after glucose ingestion compared to the fasting state (p<0.0001). The GFAP level decreased in the early postprandial phase (until 60 minutes) and subsequently increased in the late postprandial phase. Conclusion: Our results suggest that plasma biomarkers for AD‐related pathologies are influenced by the individual nutritional status (prolonged fasting, postprandial situation). This should be considered when using AD‐related biomarkers for screening and diagnostic purposes. [ABSTRACT FROM AUTHOR]