Diabetes Mellitus is Associated With Higher Serum Neurofilament Light Chain Levels in the General US Population

Abstract

Context: Serum neurofilament light chain (sNfL) levels are biomarkers of neuroaxonal injury in multiple neurological diseases. Objective: Given the paucity of data on the distribution of sNfL levels in the general population, in the present study we identified predictors of sNfL levels in a community setting and investigated the association between diabetes and sNfL. Methods: sNfL levels were measured in 2070 people aged 20 to 75 years from the general US population (275 with and 1795 without diabetes) that participated in the 2013-2014 cycle of the National Health and Nutrition Examination Survey. We evaluated the association between diabetes and sNfL levels after adjustment for age, sex, race-ethnicity, alcohol use, and kidney function using a multivariable linear regression model. Cognitive function was evaluated in a subset of participants aged 60 to 75 years using the Consortium to Establish a Registry for Alzheimer's Disease-Word Learning test, the Animal Fluency test, and the Digit Symbol Substitution test. Results: The weighted prevalence of diabetes was 10.4% (95% CI, 9.0-11.9). In each age stratum, patients with diabetes exhibited higher sNfL levels compared with nondiabetic participants. Age, proportion of males, prevalence of diabetes, and homeostatic model of insulin resistance increased progressively across quartiles of sNfL levels in the overall population, whereas estimated glomerular filtration rate (eGFR) showed an opposite trend. In the multivariable model, age, sex, eGFR, alcohol use and diabetes were significantly associated with sNfL levels. Moreover, higher sNfL levels were associated with worse performance in all 3 cognitive function tests. Conclusion: Diabetes is associated with higher sNfL. Further large-scale and prospective studies are needed to replicate our results and evaluate the ability of sNfL to predict the incidence of neuropathy and dementia in this patient population.