Grabbing the golden ring pg. 3
Initially, all insulin was isolated from either beef or pork pancreas tissue. Before long, demand for insulin was outgrowing the supply of slaughterhouse pancreases. It was a great relief when, in 1979, recombinant DNA techniques made high-volume production of human insulin possible. The U.S. Food and Drug Administration approved the use of the new insulin — called Humulin — in 1982.
Meanwhile, the years between 1950 and 1970 saw leaps in our understanding of glucose metabolism and insulin’s role in it. Vanderbilt was one of the foremost places in the world for metabolism research, due in large part to the efforts of Charles “Rollo” Park, a physician scientist who helped define how insulin “carries” glucose into cells. Assuming the helm of a physiology department of only two scientists, he set out to build a program centered on metabolism of sugars.
Park’s work and reputation attracted an impressive array of talent to Vanderbilt, including Nobel laureate Earl Sutherland, Jr., and diabetes clinician Oscar B. Crofford.
In the 1970s and 1980s, research discoveries and therapeutic innovations came fast and furious. For diabetic patients, the horizon glimmered with hints of an improved ability to monitor and control glucose levels. The means for measuring hemoglobin A1c, a way of monitoring longer term glucose control, was developed in 1977, and the first insulin pump was introduced in 1979. In that same year, trials for the use of laser photocoagulation in the treatment of diabetic retinopathy began. In the early ‘80s, other methods of insulin delivery were being explored — including microencapsulated islet cells and nasal insulin — and new, more powerful blood sugar lowering drugs entered the market.
By this time, a series of publications from a number of laboratories had suggested that tight control of blood-glucose levels could prevent or retard the onset of diabetic complications. As a result of these reports, in 1983 the government launched the Diabetes Control and Complications Trial. Widely considered the best-run clinical trial every carried out, the DCCT showed unequivocally that rigorous control of blood sugar reduces the risk and severity of long-term complications.
Improvements in insulin delivery and glucose monitoring were essential to conducting the DCCT, and by the time the results from the study became public in the early 1990s, diabetic patients had gained the ability to measure blood sugar levels at home, rather than having to go to a doctor. This newfound self-sufficiency allowed the tighter control that the DCCT touted, but patients soon found that freedom came at a price: a greater risk of hypoglycemic episodes. Innovations such as non-invasive glucose meters and implantable insulin pumps are helping to overcome the risk, however, making insulin-dependence an easier condition to bear.
And so the efforts continue. Yet with all that that’s been discovered about diabetes, much remains to be learned. To achieve a world without diabetes, whether through prevention or by cure, is the ultimate goal of these many efforts. At this rate, perhaps a second miracle is not too much to hope for.