The association between NfL and Cognitive Functioning in older adults diagnosed diabetes: a cross-sectional analysis from NHANES

Objective This research aimed to explore the correlation between serum Neurofilament Light Chain (NfL) levels and Cognitive Function in diabetic participants. Methods Utilizing cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) 2013 to 2014, 173 individuals aged 60 years and above with diabetes were included in the analysis. Cognitive function was measured using the Animal Fluency exercise. Weighted multivariate linear regression analysis and a restricted cubic spline model were employed to assess the association between serum NfL levels and Animal Fluency Score (CFDAST) in diabetic patients. Results Serum NfL was categorized into weighted tertiles, with participants divided into groups Q1, Q2, and Q3. Significant differences in serum NfL were observed among the groups (P < 0.01). Participants in group Q3 exhibited higher levels of hemoglobin A1c and were older compared to groups Q1 and Q2 (P < 0.01). Furthermore, when serum NfL was treated as a continuous variable, it was found to have a negative correlation with CFDAST score (P < 0.01). Group Q1 had a higher CFDAST score than group Q3, as well as group Q2 (p for trend = 0.0021). A nonlinear relationship was observed between serum NfL and CFDAST score, displaying an inverted ‘U-shaped’ curve (P-overall = 0.01, P-for-non-linear = 0.0026). Conclusions Serum NfL has the potential to serve as a clinical biomarker for early detection of cognitive impairment in diabetic individuals aged over 60 years. Highlights Study about biomarkers for diabetes-associated cognitive decline is limited. We found that there is an inverted U-shaped association between serum NfL and cognitive score. Serum NfL may be a biomarker for early detection of cognitive decline in elderly diabetics.