Molecular and Genetic Medicine

Obesity, Type 2 Diabetes and Beta Cell Failure: An Asian Perspective

Abstract

Yoshifumi Saisho

Type 2 diabetes (T2DM) is characterized by insulin resistance and beta cell dysfunction. Although both factors are hallmarks of T2DM, evidence from recent studies has emerged showing that impaired beta cell function is always present in humans with T2DM, suggesting that beta cell dysfunction is a core factor in the pathogenesis of T2DM. Deficit of beta cell mass in humans with T2DM has also been reported, probably through an increase in beta cell apoptosis. Whether deficit of function or mass of beta cells is more important in beta cell dysfunction in T2DM remains unclear; however, collectively, functional beta cell mass is decreased in humans with T2DM. Beta cell dysfunction is not only present in T2DM but also progressively worsens with duration of the disease. Recent studies have also revealed that the functional beta cell mass is already impaired before the onset of T2DM, implying that beta cell dysfunction is essential in the development of T2DM. Finally, ethnic difference in beta cell function has also been proposed. Recent studies suggest that Asians have less beta cell functional capacity compared with Caucasians. Therefore, preservation or recovery of functional beta cell mass is an important therapeutic strategy to prevent, treat and even cure T2DM, and this seems to be further emphasized for Asians.