How Blue Jays prospect Aaron Parker manages diabetes

DUNEDIN, Fla. — The brown leather fanny pack dangles from Aaron Parker’s waist everywhere he goes at the Toronto Blue Jays player development complex. Bullpens, meeting rooms, dugouts. You could call it his emergency pancreas.

Parker, a catcher drafted by the Blue Jays in the sixth round of the 2024 draft, is a Type 1 diabetic. His biological pancreas doesn’t produce enough insulin, the hormone that allows cells to uptake glucose from the blood stream for energy. Elevated blood glucose levels trigger a host of unpleasant downstream health impacts and, if left untreated, lead to organ failure.

Parker doesn’t want that. The 23-year-old UC Santa Barbara product aims to continue working his way up the minor-league ladder after reaching high-A Vancouver in 2025. So, when he leaves the house every morning, the fanny pack comes with him.

“It’s my rainy-day pack,” Parker says, thumbing through a blood glucose testing kit, syringes, insulin vials, a pack of Skittles and glucagon medication, which he can use to stimulate the release of stored blood sugar from his liver if he ever takes too much insulin. “And it looks good, too. People like it.”

This all started when Parker was 13. As a multi-sport athlete, he’d manipulate his body weight depending on the season — 145 pounds for baseball, 140 pounds for football and 135 pounds for wrestling. At the end of that cycle, he’d regain the 10 pounds and start over again.

But this time, following wrestling season, he lost nearly 20 pounds in less than three weeks despite eating more than he normally does, dropping to 118. He was lethargic, intensely thirsty and urinating constantly. He’d get fatigued standing up from the couch and walking to the washroom.

Something wasn’t right. A doctor’s appointment was made. All of Parker’s symptoms and a simple blood sugar test pointed directly to one culprit. The first thing a shocked Parker and his parents did when they got home was search the internet for professional athletes with Type 1 diabetes. Turned out there were many. 

“Once I saw that, I was determined that I was going to do everything I want to do,” Parker says. “You don’t have much choice. It’s not going away.”

The job Parker’s pancreas stopped doing in his teens is now handled by a closed-loop insulin delivery system that regulates his blood sugar throughout the day. He wears a continuous glucose monitor which constantly communicates with an insulin pump, instructing it to increase or decrease the amount of basal insulin it releases. 

Parker can manage the system through his phone. In recent years, closed-loop technology has advanced to the point that a personalized algorithm can predict how much glucose will be in his blood stream 30 to 60 minutes into the future.

Parker’s system has different settings for when he’s actively in a game as opposed to living his day-to-day life. Catching nine innings is an endurance sport. As his muscles burn through their stored glycogen throughout the game, they progressively tap into blood glucose for energy.

That lessens Parker’s need for insulin, which is why his pump is programmed to release less during games. The average adult walking around living their daily life would want a blood sugar concentration somewhere south of 100 milligrams per decilitre when fasted and a bit north of it following meals. But Parker’s found his ideal range is 150-250 mg/dL in-game, although he knows other diabetics who have had success at 120 mg/dL or even lower. 

“I’ll typically back off and be a little less aggressive with my insulin to make sure that if I go hit a triple, I’m not going to crash after a big sprint or something,” he says. “Sometimes when you’re in a stressful situation, your heart rate gets up and it can feel a little hypoglycemic at times. Which is why I tend to run it a little higher so I don’t have to worry about it actually being hypoglycemia.”

That would be bad. Hypoglycemia occurs when blood sugar levels drop below 70 mg/dL, triggering a series of physiological responses ranging from subtle (shakiness, heavy sweating, increased heart rate) to troublesome (blurred vision, light-headedness, loss of balance), to severe (seizure, loss of consciousness). 

Of course, Parker’s gotten pretty good at tracking his diet and managing his levels. He hasn’t had a close call since he was 13, shortly after his diagnosis, when he hit a triple, didn’t feel well, and discovered his blood glucose bordering 70 mg/dL upon testing. Either he hadn’t eaten enough carbohydrates prior to his game or he’d introduced too much insulin to his blood stream.

That was during the trial-and-error phase. Now, he knows to get some good fruit in at breakfast as a slow-digesting carbohydrate source and not to eat too late at night so his body has enough time to move any sugar he consumes into the blood stream before he goes to bed. If he falls asleep while his glucose is still rising or before his insulin has peaked, he could wake up either hypoglycemic or hyperglycemic, which occurs when blood glucose climbs too high.

Nowadays, Parker always has some candy in the back pocket of his baseball pants in case he needs a quick-digesting sugar hit. Gummies, Skittles, sour candies. In a perfect world, he’d eat a banana. But catching nine innings isn’t a perfect world. Hence the brown leather pancreas he keeps wrapped around his waist in case of a rainy day.

“Just having that security on the field is what’s important for me,” he says. “I’ve got plenty of other things to worry about behind the plate.”