APOE and diabetes mellitus: Due to the strong associations that have been drawn between AD and DM, it is imperative to examine the drugs used to treat these diseases. The focus is toward those drugs used to treat DM, as it is the primary condition these patients face and treated. For instance, rosiglitazone, a drug used to treat DM, has been shown to increase insulin sensitivity and, in turn, increase the memory and attention of those with AD but without the APOE e4 allele [33].