October 1 (WNN) — Researchers at Boston University said Friday that drugs prescribed for type 2 diabetes may actually increase insulin resistance in the body by increasing hormone production to unhealthy levels, making the disease worse.
He said the medical field has long believed that insulin resistance, or increased insulin tolerance, causes elevated levels of the hormone in the blood.
As a result, drugs such as metformin and a class of drugs called thiazolidinediones, or TZDs, are often used to lower blood sugar in people with type 2 diabetes by increasing the release of insulin into the bloodstream.
However, elevated blood insulin levels in people with the disease may actually result from overproduction of the hormone by beta cells in the pancreas, they argued in a paper published Friday by the journal Diabetes.
This process, called hyperinsulinemia, may be caused by excess nutrients and environmental toxins, and drugs designed to boost insulin production can build up a greater tolerance to it after prolonged use, the researchers said.
“Our article describes a testable model in which chronic excess nutrient exposure results in insulin hypersecretion from beta cells that contributes to hyperinsulinemia,” co-author Barbara E. Corky said in a press release.
“Hyperinsulinemia usually precedes measurable insulin resistance and type 2 diabetes. It is seen as a normal response to insulin resistance rather than as a possible cause,” said Corkey, a professor emeritus at Boston University School of Medicine.
Insulin is a hormone produced by the pancreas that allows tissues such as muscle and fat to use sugar, or glucose, from the blood as fuel for the body’s energy needs, according to Corkey and his colleagues.
It is released from the pancreas into the bloodstream when blood sugar levels rise, perhaps after a meal, to keep them within a normal, healthy range.
According to the American Diabetes Association, people with insulin resistance or impaired insulin sensitivity have built up tolerance to the hormone.
The association says that resistance makes insulin less effective and, as a result, the body’s fat and muscle cells need more to process the sugar and the liver to store it.
This means that people with type 2 diabetes tend to store more sugar in the blood, causing the pancreas to produce even more insulin, it says.
Because of this increased production of insulin, which can lead to hyperinsulinemia, many people with type 2 diabetes have elevated insulin even when blood sugar is normal, Corki and colleagues said.
Medications that further increase insulin production only alleviate the problem by telling the body that it needs more of the hormone to process the sugar, he said.
“Increased insulin release from the pancreas makes blood insulin levels high and contributes to insulin resistance,” Corkey said.
“New therapeutic solutions that involve lowering insulin levels before type 2 diabetes develops may be needed to prevent insulin resistance from developing into type 2 diabetes,” she said.