Indeed, one of diabetics' greatest fears is sliding into a coma during sleep from plummeting glucose. So diabetics, and parents of diabetic children, pleaded with the FDA on Monday to quickly allow the GlucoWatch to sell. Not tested on children Skinner and her husband set alarm clocks to wake them every two hours every night, so they can prick Michael's finger while he sleeps and check his blood sugar. But to parents' distress, California-based Cygnus has not yet tested the GlucoWatch on any children, so if the FDA approves its sale, it initially will be only for adults. How it works The GlucoWatch, which would require a prescription, looks like a wristwatch.
Patients slide a thin plastic sensor onto the watch's back each time they strap it on.
Small electric currents extract a tiny portion of glucose from fluid in skin cells to measure it every 20 minutes for 12 hours. Cygnus said studies found the GlucoWatch as accurate as standard blood tests, which themselves sometimes are erroneous. But FDA officials warned that 25 percent of the time, GlucoWatch readings can differ from blood tests by about 30 percent - meaning if the GlucoWatch reads a glucose level of 150, it might really be anywhere from 135 to 165. Experts said that was mainly a concern in detecting hypoglycemia, blood sugar that drops below a measure of 70. But patients can program the GlucoWatch to sound an alarm well before glucose drops that low, giving them time to do a finger-prick blood test to verify their real level, the company said.