Emerging roles of kisspeptin/galanin in age-related metabolic disease

•Kisspeptin and galanin have a common ancestral genetic origin.•The diverse functions of kisspeptin/galanin in type 2 diabetes.•Kisspeptin and galanin contribute to sex differences in pathophysiology of T2DM.•Activation of kisspeptin/kiss1r increases insulin sensitivity and energy metabolism.•Activation of galanin/GALR2 increases insulin sensitivity and energy metabolism.