Diabetes mellitus type 2 and primarily a lack of insulin secretion. Other potentially important mechanisms associated with type 2 diabetes and insulin resistance include: increased breakdown of lipids within fat cells, resistance to and lack of incretin, high glucagon levels in the blood, increased retention of salt and water by the kidneys, and inappropriate regulation of metabolism by the central nervous system. However, not all people with insulin resistance develop diabetes, since an impairment of insulin secretion by pancreatic beta cells is also required. The World Health Organization definition of diabetes (both type 1 and type 2) is for a single raised glucose reading
Epigenetics of diabetes Type 2 small methylation differences at isolated CpG sites have large differences in gene-expression levels On a genome wide scale studies have proven that hypomethylation in genes known to be associated with type 2 diabetes has been associated with an increase in susceptibility for the disease. CpG sites in particular display a small but significant case of hypomethylation consistently.The odds of belonging to the Type 2 Diabetes group increased by 6.1% for every 1% decrease in methylation based on microarray-based assay. These observed methylation differences are capable of producing or indicating real expression differences, which lead to the observed enhanced disease risk.