Beta Cell Dysfunction
Beta cells reside in the pancreas, where they do the important job of producing insulin for the body. Beta cells produce insulin, and also secrete insulin when they are signaled to do so by an increase in glucose levels in the blood. Without adequate insulin, blood glucose levels rise too high, a defining characteristic of any type of diabetes.
In type 2 diabetes, beta cells churn out a lot of insulin early in the disease process; type 2 is characterized by both high glucose levels, and high insulin levels in the blood. The main problem is that the body's tissues are resistant to insulin, and can't use it properly. As type 2 diabetes progresses over time, however, the beta cells seem to wear out, and eventually produce less insulin. Some people with type 2 diabetes end up having to take insulin because their beta cells are not producing enough of it.
In type 1 diabetes, the beta cells do not produce enough insulin. This is generally due to the death of the beta cells. By the time someone is diagnosed with type 1 diabetes, they may have lost 70-80% of their beta cells (it is thought, although more recent studies are testing this number). Beta cell loss occurs gradually over time, beginning before diagnosis, and continuing afterwards, until most beta cells are lost (Cnop et al. 2005). However, new research is also finding that some people with type 1 continue to produce insulin for many years (Davis et al. 2014; Oram et al. 2014), as well as proinsulin (a precursor to insulin) (Steenkamp et al. 2017), and that beta cell dysfunction (not just death) may also be a significant c Continue reading