Pinprick No More? Glowing Beads Could Monitor Blood Sugar for Diabetes

Oct. 5, 2010— -- Peter Kasenenko has lived with diabetes for more than 30 years. In this time, he has learned to keep his blood sugar tightly controlled -- but it hasn't always been a simple proposition.

Nor has it been a painless one. Most of the more than 200 million people with diabetes worldwide prick their fingers several times a day to monitor blood sugar. For these people, the pancreas cannot perform the delicate balancing act needed to maintain normal blood sugar and thus prevent complications in the heart, kidney, retinal and nervous system.

After some quick calculations, Kasenenko estimates that he has pricked his finger 38,690 times in the past 20 years.

Since April, Kasenenko has used a device known as a continuous glucose monitor -- CGM for short -- which records his blood sugar levels day and night.

"CGMs are the best invention ever," says Kasenenko, a 45-year-old legal secretary. "Management is a full-time job. It's like you're trying to pretend you're a pancreas when you're not."

Current CGMs, which are inserted under the skin in the abdomen, are not meant to replace the standard finger pricks and shots -- though they can analyze trends in a patient's blood sugar levels by measuring rising and falling blood sugar levels.

But a new animal study suggests that there may be a day when all the information diabetic patients need about their blood sugar levels could come from glowing beads in their wrists.

In a study published Monday in the Proceedings of the National Academy of Sciences, researchers from the University of Tokyo report they created small beads coated in fluorescent dye, and injected and implanted them under the skin of diabetic mice. The beads -- about the size of the inner diameter of a doctor's needle -- are meant to monitor glucose levels continuously in the mice.

When blood sugar goes up, the fluorescent dye shines brighter under the skin. When it goes down, the fluorescence is reduced.

"We know that the device works for one month in mice," says Shoji Takeuchi, lead author of the paper. "We expect it could work for three. We are optimistic that this device could help diabetes patients in the future."

Takeuchi believes he will be able to treat humans with the device in five to ten years.

Glowing Beads for Blood Sugar Monitoring Seem Safe -- in Mice

According to the research, the fluorescent microbeads provided reliable measures of glucose levels without visibly affecting the health of the mice during the 30-day monitoring period. The study authors wanted to develop highly-sensitive, stable, long-lasting, and injectable fluorescent microbeads to solve the issue of inaccuracy.

Endocrinologists not directly involved with the research said improvements in current glucose monitoring devices are needed.

"I think that an accurate, reliable, and cost-effective continuous glucose monitor would be the holy grail of diabetes management," says Dr. Alan Shuldiner, professor of medicine and head of the division of Endocrinology and Nutrition at the University of Maryland in Baltimore. "There has been a lot of promise [with continuous glucose monitoring], but no major breakthroughs. The current sensors are a small step forward, but far from panacea."

Whether the beads are the answer to this problem remains to be seen. Kasenenko, for one, remains skeptical, asking, "How do I quantify what the change in luminescence means?"

The beads would have to show blood sugar levels within 15 percent accuracy so that patients know what action to take, says Kasenenko.

Lorraine Sisto, whose seven-year-old son Caleb was diagnosed three years ago with diabetes, says the theory of a CGM is wonderful. With continuous information, the device helps to manage diabetes better. But sometimes, the CGM isn't totally accurate.

"When things go wrong, it can make living diabetes even more intense and stressful," says Sisto. "I am all for any kind of advancement that will improves the lives of diabetics."