Abstract
In East Asians, type 2 diabetes mellitus (T2DM) is primarily characterized by significant defects in insulin secretion and comparatively low insulin resistance. Recently, the prevalence of T2DM has rapidly increased in East Asian countries, including Korea, occurring concurrently with rising obesity rates. This trend has led to an increase in the average body mass index among East Asian T2DM patients, highlighting the influence of insulin resistance in the development of T2DM within this group. Currently, the incidence of T2DM in Korea is declining, which may indicate potential adaptive changes in insulin secretory capacity. This review focuses on the changing epidemiology of T2DM in East Asia, with a particular emphasis on the characteristics of peak functional β-cell mass.