Why Insulin Was Never a 'Cure' for Diabetes
When it was first isolated in 1921 by Canadian researchers Fred Banting and Charles Best, and injected soon after into diabetic children, insulin was rightly celebrated as a 20th-century miracle drug, but wrongly deemed a “cure” for the disease.
Banting and Best did not foresee the extraordinary trouble caused by taking the hormone from an external source rather than having it secreted as needed by the pancreas. It’s nearly impossible to set a daily dose.
Back when I was diagnosed with Type 1 diabetes in 1975, little had changed in over half a century. Insulin had been purified compared with the mucky stuff that Banting and Best first isolated, and an additive was found to make a longer-acting version that could last up to 12 hours.
The hospital nurse who taught me how to inject myself told me with great enthusiasm that I was lucky because disposable plastic syringes had just come on the market, so I wouldn’t need to boil and sterilize a glass syringe three times a day. Yippee!
So much for “progress.” Every morning, I had to inject a set dose of long-acting insulin and a small dose of short-acting insulin, both of them derived from a pig or cow pancreas. At dinner, I was supposed to take a second injection of short-acting insulin, and at bedtime, I was to take a third injection, again of long-acting.
And because there was no way, outside of a laboratory, to check one’s blood-glucose level, I was supposed to match my food intake to the insulin schedule by eating the exact amount of food at exactly the same time every breakfast, lunch and dinner, with regular snacks between meals.
In practice it was all madness. I was an 18-year-old English major with much more interest in girls, graffiti and guitars than in becoming a dietary robot.
As a result, three times in the first five years after my diagnosis, I found myself waking up in the back of an ambulance, where medics had just given me an injection of glucagon, the hormone that prods the liver to instantly release its stored-up glycogen, a dense form of glucose.
And, lest you think me a special kind of idiot, I can assure you that similar events pockmark the lives of nearly everyone with Type 1, unless they’re really, truly obsessives who follow a fantastically strict diet-and-exercise routine (and are just plain lucky).
The first big breakthrough since the discovery of insulin came with the advent of home blood-glucose testing in the early 1980s, allowing diabetics to check their sugar level in a minute or two with a drop of blood on a reagent strip. Now I could quickly see if I was running high, in which case I injected a bit of insulin, or low, in which I’d grab a sip of juice or anything else sweet.
A decade later, insulin pumps became widespread. They released the hormone via a thin catheter injected under the skin and changed every three days. Instead of having to whip out a needle every time insulin was needed, diabetics could just press a button on the pump.
The next big step came in 2005, with the advent of the continuous glucose monitor (CGM). Like the pump, a CGM includes a slender filament injected under the skin and kept there for a period of days, but in this case it’s a minuscule electrode that senses changes in conductivity due to glucose levels. Instead of having to prick your finger for a drop of blood to place on a strip inserted into your blood-glucose meter, you could just glance at your CGM monitor to see if you’re high or low, rising or falling.
Taking appropriate corrective action with a press of your insulin pump or a handful of gummy bears couldn’t be easier, right?
Wrong. The overriding problem with all this technology is that it sucks up that most precious of resources: mindshare. Like sheep in a meadow, the pump and CGM require the good diabetic shepherd to pay ceaseless attention. What’s my current reading? How many carbs are in this sandwich? How much insulin should I pump?
Calculating these things is not easy (especially, of course, when you’re asleep, not to mention working, watching a baseball game, out on a date, going for a run or otherwise engaged in life).
And the job is made inhumanly difficult because even the fastest-acting insulin currently on the market takes over an hour to reach peak effectiveness, while a meal begins raising glucose levels within minutes. It’s as if you have to swing your baseball bat nearly an hour before the pitcher throws the ball.
But wait a minute. What was that word I mentioned earlier? Calculating. What could possibly do a better job of calculating than a human does? Hmmm. Wait a minute, it’s on the tip of my tongue . . .