Extended Data Fig. 1: Plasma NfL trajectory with age in humans and mice.
From: A neuronal blood marker is associated with mortality in old age
a-c, Plasma NfL concentration of the human age cohort presented in Fig. 1b. Scatter plots for (a) log NfL concentration, (b) log NfL concentration for females versus males, and (c) NfL variance in plasma with aging (n = 122). NfL variance was calculated using a 10-year sliding window. Local polynomial regression fitting using LOESS was done. Thick lines represent LOESS fitted values and shaded areas representing the standard errors around the model estimates. Although the cohort appears too small for a reliable description of the age-related changes, the data are consistent with previous work of a slow and more linear increase until approximately 70 years of age, followed by a much more rapid increase (Khalil, M., et al. Serum neurofilament light levels in normal aging and their association with morphologic brain changes. Nat Commun 11, 812, 2020). Interestingly, the present data may suggest that this rapid increase reaches a plateau in nonagenarians and centenarians. It is possible that at these ages individuals with very high NfL levels die out and thus reduce the further increase on a population level (Christensen, K., McGue, M., Petersen, I., Jeune, B. & Vaupel, J.W. Exceptional longevity does not result in excessive levels of disability. Proc Natl Acad Sci U S A 105, 13274, 2008). d-f, Plasma NfL concentration of the aging C57BL/6 J mouse cohort presented in Figure 3a-c. Scatter plots for (d) log NfL concentration; (e) log NfL concentration for females versus males; and (f) NfL variance in plasma with aging (n = 114). NfL variance was calculated using a 5-month sliding window. Local polynomial regression fitting using LOESS was done. Thick lines represent LOESS fitted values and shaded areas represent the standard errors around the model estimates. Similar to the human data, a slow and more linear increase until approximately 15–18 months of age is followed by a much more rapid increase with an increased variance towards the end of the lifespan.
