The pancreatic β cells in human type 2 diabetes

Abstract

β-cell (beta-cell) impairment is central to the development and progression of human diabetes, as a result of the combined effects of genetic and acquired factors. Reduced islet number and/or reduced β cells amount in the pancreas of individuals with Type 2 diabetes have been consistently reported. This is mainly due to increased β cell death, not adequately compensated for by regeneration. In addition, several quantitative and/or qualitative defects of insulin secretion have been observed in Type 2 diabetes, both in vivo and ex vivo with isolated islets. All this is associated with modifications of islet cell gene and protein expression. With the identification of several susceptible Type 2 diabetes loci, the role of genotype in affecting β-cell function and survival has been addressed in a few studies and the relationships between ge notype and β-cell phenotype investigated. Among acquired factors, the importance of metabolic insults (in particular glucotoxicity and lipotoxicity) in the natural history of β-cell damage has been widely underlined. Continuous improvements in our knowledge of the β cells in human Type 2 diabetes will lead to more targeted and effective strategies for the prevention and treatment of the disease.