DPP4 and diabetes mellitus: Schwartz Schwartz SL SL Treatment of elderly patients with type 2 diabetes mellitus: a systematic review of the benefits and risks of dipeptidyl peptidase-4 inhibitors Treatment of elderly patients with type 2 diabetes mellitus: a systematic review of the benefits and risks of dipeptidyl peptidase-4 inhibitors Am J Geriatr Pharmacother Am J Geriatr Pharmacother 2010 2010 10.1016/j.amjopharm.2010.10.003 10.1016/j.amjopharm.2010.10.003 supplied-pmid 21335294?