The association between diabetes and biomarkers of cognitive impairment was significantly mediated by IL-6 (5 % for Aß40 ([1.5 %, 10 %], p-value<2 × 10−16), 4 % for Aß42 ([0.7 %, 11 %], p-value = 0.014), 8 % for pathological TMT-B ([0.2 %, 35 %], p-value = 0.046), 11 % for total Tau ([2.5 %, 40 %], p-value = 0.010), 5 % for NfL ([1.6 %, 8 %], p-value<2 × 10−16), and 12 % for Hippocampus atrophy ([3 %, 49 %], p-value = 0.004)). Here, NEFL is linked to diabetes mellitus.