+Metformin: Metformin in combination; GKAs: Glucokinase Activator drugs;
Y/N: YES/NO; mg·d-1: mg·day-1; QD:
once a day; BID: twice a day. The included references: Meininger et al.
2011; Wilding et al.2013; Zhang et al.2013; Amin et al.2015; Zhi et
al.2016; Zhu et al.2018; Vella et al.2019.