HUMANA PICKING UP UNIVERSITY OF UTAH INSULIN "BUTTON" STUDY

HUMANA PICKING UP UNIVERSITY OF UTAH INSULIN "BUTTON" STUDY, with a clinical implant scheduled for Feb. 6. Developed by researchers at the University of Utah, the subcutaneous peritoneal access device, or "button," currently is implanted in 15 patients at the university's health science center. A total of 29 insulin-dependent patients have been implanted with the device, 18 of whom have accumulated an implant experience of six months or longer, according to Humana. The University of Utah has been studying the device since January 1981, under an investigational device exemption from FDA. Humana's Lexington, Kentucky hospital will try to duplicate Utah's "favorable" findings in a 30-year-old patient with Type 1 diabetes mellitus, the hospital chain operator said. Implanted an eighth of an inch below the naval, the button funnels insulin directly into the peritoneal cavity, Humana explained. Part of the dose then travels to the liver, mimicking the normal path of insulin in a healthy system. The concept is the same as that used in peritoneal dialysis catheters, a spokesman said. Patients must inject insulin into the cavity about four times a day. Two inches in diameter and three inches thick, the button is made of silicon rubber. It takes about 45 minutes to implant, Humana said. The button potentially offers several advantages over implantable insulin pumps, which are targeted to the same uncontrolled insulin-dependent segment of the diabetic population, Humana maintained. For example, the peritoneum tends to grow fibrous tissue around a pump more often than a button, with more severity, and less reversibility, the spokesman said. The button, unlike the pump, is not an electromechanical device and thus carries no risk of spontaneously pumping larger amounts of insulin than desired. Also, since the patient refills the button continuously, there is no problem with aggregate insulin stimulating an immune reaction, a possibility with the infusion pump, he said. Disadvantages of the button include a higher risk of peritonitis, as well as the inability of a doctor to make adjustments without puncturing the skin. The Humana spokesman emphasized that the button still is the experimental stage and would be appropriate only for a very small percentage of patients with Type 1 diabetes. Patients with Type 1 diabetes constitute 10% to 25% of the diabetic population. The spokesman added that this research is a "signpost for the future" for treatment of diabetes. The other possibility for control of Type 1 diabetes may lie in the transplantation of insulin-secreting islet cells from the pancreas, a concept still in the early phases of research, he said.