San Francisco Bay Area resident Patrick Totty writes about his experiences living with type 2 diabetesSee all posts »
The Barsoom Map of Type 2
My wife and I have two globes of Mars that we pass by each time we go from the living room into the kitchen.
The first one, 6 inches in diameter, was made 40 years ago just after the Mariner probes began sending back the first really detailed photos of Mars ever taken. The second, much larger globe, is the latest, most accurate version available, and incorporates everything we’ve learned about the red planet in the four decades since.
Linda calls the smaller, older globe “Barsoom,” the name that pulp fiction writer Edgar Rice Burroughs gave Mars in his epic juvenile sci-fi series, John Carter on Mars.
Barsoom was a fantastical desert planet, dotted with soaring cities and populated with several intelligent warlike species. All of them were awed by the swashbuckling presence of an earthman, an accidental traveler to Barsoom, who could leap through the Martian air like a bird.
Our Barsoom globe is a fanciful thing, festooned with Latin names and alternating splotches of light and dark—some of them with tendrils snaking north or south—and one gigantic volcanic crater that looks like a continent-sized ringworm.
But it’s wildly inaccurate. When I compare it to my newer globe, it’s like observing the difference between a 16th-century and 19th-century map of earth.
My two Marses have gotten me to think about what we know about type 2 diabetes. The Barsoom version, which began emerging about 2,000 years ago, was based on very little actual data. Like Burroughs’ imaginary planet, we were pretty much free to think about type 2 almost anyway we wanted:
Barsoom Type 2: Diabetes was thought to be a kidney and bladder disease. Early scientists thought that the sweet taste of diabetics’ urine (the “mellitus” in diabetes mellitus means “sweet flow”) indicated a bladder or kidney problem.
Mars 2012 Type 2: By the early 20th century, we knew that a disorder in the pancreas was the cause of diabetes. Once we learned about beta cells and insulin, the Barsoom concept of the disease was gone forever.
Barsoom Type 2: After the discovery of insulin, scientists were perplexed by the appearance of people who had diabetes but did not respond to insulin therapy. How could this be?
Mars 2012 Type 2: By the 1950s, when researchers finally developed accurate ways of measuring insulin levels, they discovered that the people who weren’t responding to insulin were actually still producing their own insulin—a contradiction to the then established definition of a diabetic.
It turns out that they were suffering from insulin resistance, a condition where even though their bodies still produced the hormone, they were resisting its effects.
Barsoom Type 2: Researchers had also long noted that the onset of diabetes seemed to have a strange tempo. Some people developed it in youth—“juvenile diabetes”—and others in adulthood—“adult onset diabetes.” Scientists couldn’t quite figure out what caused the difference.
Mars 2012 Type 2: Scientists realized that the condition of increasing resistance to insulin was one that could take years to develop. That’s when the concept of type 1 “juvenile” diabetes and type 2 “adult-onset” diabetes. (There’s now even a type 1.5 diabetes, which has characteristics of both type 1 and type 2.)
I’ll occasionally revisit Barsoom just to check our progress.