Targeted ultrasound could be an effective, noninvasive, drug-free way to boost insulin levels in people with type 2 diabetes.
Beta cells — which are specialized cells in the pancreas — synthesize, store, and release insulin in response to the presence of sugar in the blood. This increased production helps keep levels of glucose in the blood within the normal range.
In people with diabetes, the pancreas produces too little insulin, which can lead to too much sugar in the blood that then causes damage to tissues and organs. Early on in the progression of diabetes, beta cells can become overworked, which causes insulin to build up inside. This buildup can be terminal for the beta cell. If more insulin-producing beta cells die, diabetes is exacerbated.
Certain drugs can help the beta cells release insulin, but these can be expensive and may become less effective over time. For these reasons, researchers are keen to find other ways of promoting insulin release that do not involve drugs.
Researchers at George Washington University in the US are investigating whether ultrasound might provide a way forward. Ultrasound describes sound waves of a frequency above the level of human hearing that is often associated with scanning techniques. But ultrasound has also been used in treating kidney stones, prostate cancer, and it is even being considered as a treatment option for Parkinson’s disease
Earlier, scientists had shown that ultrasound can encourage cultured beta cells to release insulin, but it had not been tested on living animals. The researchers have now successfully used ultrasound to stimulate insulin release from beta cells in the pancreases of mice.
To investigate, they gave mice either a control treatment or a single 5-minute exposure to ultrasound at the frequency of 1 megahertz. The researchers took blood samples immediately before and after the ultrasound or control session. The scientists found that the mice they treated with ultrasound had increased insulin production compared with the control mice. Also, more importantly, they found that there was no associated reduction in glucose levels; despite a hike in insulin, glucose in the blood seemed untouched.
Scientists are continuing to refine their use of ultrasound on the pancreas, however, it remains complicated as the pancreas has a number of other roles in addition to producing insulin, such as the excretion of digestive enzymes and antagonistic hormones. It is possible that when the pancreas are stimulated they could release these biological products alongside insulin and lead to a range of other effects. Scientists are now investigating this potential problem in more detail.
Nevertheless, the researchers are optimistic as they feel that through careful selection of ultrasound parameters, it could be possible to provide a safe, controlled, and targeted stimulation of insulin release from the pancreatic beta cells. Trials in humans are still a long way off.