Imagine sticking yourself with a pin on the pad of your finger up to seven times a day. It's an unpleasant thought, but that is exactly what many diabetics should be doing. Several large clinical studies have shown that tight control of blood sugar slows the progression and development of long-term complications of diabetes, such as blindness and kidney failure. So sufferers must collect multiple blood samples to provide feedback for insulin dosing and other treatment.

Apart from the pain, though, tight control also introduces a risk of severe hypoglycemia—blood sugar so low that it can lead to coma or seizure.

The risk exists because tight control seeks to reduce the patient's mean glucose levels to a more normal state, but from that lower point there is a greater probability that glucose levels could accidentally become dangerously low. To counter that threat, new glucose-metering technologies that should provide relatively painless and much safer blood sugar control are entering the market.

New glucose monitors, like the model from Cygnus, derive more measurements from fewer pinpricks.

Rushing to pull down the barriers to tight glucose control, several firms have developed devices that all but eliminate the need for blood samples. In June 1999, an implantable sensor providing continuous readings, made by Medtronic MiniMed Inc. (Northridge, Calif.), became the first alternative glucose monitor to gain approval by the U.S. Food and Drug Administration. And Cygnus Inc. (Redwood City, Calif.) followed in March 2001 with its own device, which monitors glucose continuously through the skin.

While a great many innovative technologies have been proposed, only a fraction are in advanced stages of development. They fall into three categories: implantable monitors, transdermal (through the skin) meters, and meters depending on spectroscopic methods. Each is a far cry from the painful methods used over the last several decades.

By offering greater convenience and less pain, the devices encourage people to test more frequently, the extra testing providing previously unobtainable information on trends in glucose levels in response to insulin dosage and other treatments. Also, monitors that provide frequent, automatic readings can be equipped with preset alarms to warn the user of high or low glucose levels. Parents of children with diabetes, for example, can be warned of overnight low glucose, rather than having to wake up each night to check their child's blood sugar. These advances will lead to better decisions about treatment and ultimately reduce the long-term medical complications of diabetes.