APOE and Alzheimer disease: Moreover, studies have found correlations between AD and factors such as levels of Hcy (homocysteine) [9], ApoE ε4 (Apolipoprotein E ε4) [10], vitamin B6/B12 [11], S100B [12], folate, glucose metabolism (blood glucose, glycated hemoglobin, and serum insulin) [13], adiponectin, and thyroid-related hormones.