DPP4 and diabetes mellitus: Interestingly, a previous study by Che-Wuan Yu et al. provided evidence that sulfonylureas may be a suboptimal choice when compared to dipeptidyl peptidase-4 (DPP-4) inhibitors, not assessed herein, for cognitive longevity, leveraging the question as to whether expanding beyond the mainstay DM treatments alone to evaluate possible benefits of combination therapy both on metrics of diabetes control and also neurodegeneration prevention would prove useful in maximizing the utility of existing medications [21].