Diabetics, who typically also suffer weight problems, now can lower their blood sugar levels to normal and lose weight in a slow, steady manner thanks to an injectable drug recently approved by the U.S. Food and Drug Administration, say Spokane doctors who have been researching the drug.


Those benefits alone can help lower a diabetic patients blood pressure and cholesterol, and eliminate the need for some other medications, says Dr. Carol Wysham, an endocrinologist at Rockwood Clinic PS, of Spokane. Wysham was Rockwoods principal investigator in a three-year study to determine the effects of high- and low-level doses of the new drug, called Byetta, on 20 Spokane-area diabetics. Extension trials of that study will continue until December.


Dr. Kennedy Cathcart, of Northside Internal Medicine Associates PS, of Spokane, also studied Byettas use in another 10 diabetics, a small portion of the 1,500 patients in the nationwide Phase 3 study.


This is the biggest breakthrough in patient control of diabetes in the past 10 years, says Wysham.


Patients are trained to inject themselves twice daily with the synthetic drug, using a tiny needle that Wysham asserts is almost painless to use. Currently, they do the injections once before breakfast and once before supper, but on the horizon is another FDA investigation about half-way through the licensing process that could lead to the release of a derivative of Byetta that would only have to be injected once a week, Wysham says.


In diabetes, the pancreas is unable to produce enough insulin to allow glucose, the source of the bodys energy, to enter cells freely, says Wysham. A hormone called glucagon-like popypeptide (GLP-1), which is produced in the intestines, stimulates insulin secretion in healthy people, but is lacking in diabetics. Once Byetta is released in the bloodstream, it goes to the pancreas and stimulates insulin secretion just like GLP-1


Normally, other drugs are given to diabetics in the early stages of the disease to increase insulin secretion or to improve the bodys sensitivity to the insulin it already makes, Wysham says. Insulin injections are then prescribed when thats the only way a patient can get enough to meet the bodys needs, she says. Byetta differs from other medications in that it quits causing additional insulin to be produced when the level of sugar in the blood reaches a normal range, she says.


We dont know why diabetics have less GLP-1, says Wysham, but the average diabetic has 30 percent to 40 percent less of it than the average non-diabetic.


Byetta is structurally similar to GLP-1 and can do all the things the hormone does, Wysham says. She says both slow how fast that food leaves the stomach and both promote decreased appetite.


Researchers have known about GLP-1 for 15 years, but a common enzyme makes it ineffective quickly after its introduced into the body, and that has prevented its injection into the body to cure diabetes. In healthy bodies, a relatively steady flow of GLP-1 keeps the pancreas active.


About five years ago, a New York hormone researcher named Dr. John Eng discovered that the chemical composition of the saliva of a Gila monster, a poisonous lizard indigenous to the deserts of the southwestern U.S. and Mexico, is almost identical to that of GLP-1.


Amylin Pharmaceuticals, of San Diego, capitalized on Engs research and created the synthesized version of the Gila monsters saliva that became the subject of the FDA trials, and finally introduced what became the federally-approved drug Byetta.


Wysham says that to protect the integrity of the study, she was not informed of patient glucose levels for many months after testing began, but adds she did see patients consistently losing weight while taking the drug. The average patient lost 15 pounds during the study, she says, while five patients have lost more than 20 pounds and two have lost more than 40 pounds.


The 20 Rockwood patients included in the study were selected because they were already on diabetes medication, yet their standard blood sugars werent being controlled, Wysham says.


About two-thirds of the patients in the study here were given different injectable doses of Byetta to take home and add to their medication plan, and about one-third were given injectable placebos to take home and take in addition to their medications.


Trained to inject themselves at the clinic, the patients would do so at the prescribed times twice daily for a month before coming in for a physical exam. An assistant would give the exams, but Wysham closely monitored exam and laboratory results to study the liver, kidney, blood counts, and other functions of each person in the study.


Wysham hopes that Byetta will slow, or even stop, the progression of diabetes before it gets to the point at which a patient must have insulin therapy.


Insulin can allow a diabetic to live almost a normal life, even to run marathons, but untreated diabetes can lead to such vascular problems as heart attacks, strokes, kidney failures, and eye disease, Wysham says.


The practical results of injecting insulin and injecting Byetta are almost the same, with the exception that Byetta enables disbetics to lose weight, says Wysham. In a recently completed six-month study comparing patients who took one insulin shot daily to patients who took two Byetta shots daily, the average insulin patient gained four pounds, and the average Byetta patient lost five pounds, Wysham says.


She says that 102-week extension trials indicate the weight loss continues at a similar rate for diabetics who use Byetta. In contrast, insulin users normally continue to gain weight at that pace for the first two years after beginning insulin therapy, then see their rate of weight gain taper off, Wysham says.


She says that almost every oral diabetic medication causes weight gain, low blood sugar, or both, causing complications in the effort to bring a patients glucose level under control. She notes that Byetta doesnt work in all cases, but describes an 82-week Byetta study in which 62 percent of all participants who had previously been unable to meet clinically-established glucose measurement standards did so after the trial.


Wysham says 90 percent of all diabetics are overweight, and the availability of Byetta in the marketplace as recently as this past June is already having an impact on those who suffer from the disease.


The cost of Byetta, though certainly not inexpensive, is comparable to other commonly used diabetic drugs and is covered under most health-insurance plans, Wysham says. She estimates the wholesale cost of the drug at about $150 a month.