NEFL and diabetes mellitus: The association between long-lasting diabetes and biomarkers of cognitive impairment in cases without previously diagnosed cognitive impairment was significantly mediated by IL-6 (3 % for Aß40 ([0.8 %, 8 %], p-value = 0.008), 3 % for Aß42 ([0.6 %, 8 %], p-value = 0.014), 8 % for total Tau ([1.6 %, 41 %], p-value = 0.016), 3 % for NfL ([0.7 %, 6 %], p-value = 0.008), and 9 % for Hippocampus atrophy ([1.5 %, 37 %], p-value = 0.024)).