β cell dysfunction versus insulin resistance in the pathogenesis of type 2 diabetes in East Asians

Abstract

Type 2 diabetes (T2DM) is one of the most serious global health problems and is mainly a result of the drastic increase in East Asia, which includes over a fourth of the global diabetes population. Lifestyle factors and ethnicity are two determinants in the etiology of T2DM, and lifestyle changes such as higher fat intake and less physical activity link readily to T2DM in East Asians. It is widely recognized that T2DM in East Asians is characterized primarily by β cell dysfunction, which is evident immediately after ingestion of glucose or meal, and less adiposity compared to the disease in Caucasians. These pathophysiological differences have an important impact on therapeutic approaches. Here, we revisit the pathogenesis of T2DM in light of β cell dysfunction versus insulin resistance in East Asians and discuss ethnic differences in the contributions of insulin secretion and insulin resistance, together with incretin secretin and action, to glucose intolerance.

Fig. 1

Insulin secretion and insulin resistance in Caucasian and Japanese. a Comparison of insulin response to a 75-g glucose tolerance test in Caucasian and Japanese with normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and type 2 diabetes (DM). b Comparison of insulinogenic index in Caucasian and Japanese with NGT, IGT, and DM. c Comparison of homeostatic assessment insulin resistance (HOMA-IR) in Caucasian and Japanese with NGT, IGT, and DM (reproduced with permission from [10])