Bruce Arians: Diabetes caused Patrick Peterson's weight gain, struggles

GLENDALE, Ariz. -- In a series of tweets Monday night, Cardinals cornerback Patrick Peterson clarified that he has Type 2 diabetes, not Type 1 as he had said earlier in the day.

The difference between Type 1 and Type 2 diabetes is that people with Type 1 don't produce insulin, whereas those with Type 2 produce insulin but their bodies don't use it properly, according to the American Diabetes Association. Type 1 used to be called juvenile diabetes, and it still is usually diagnosed in children and young adults. Type 2 is the more common form of the disease, according to the ADA's website.

Peterson said he now closely watches what he eats, but the disease caused him to gain weight early last season, which coach Bruce Arians said was the primary cause for Peterson's struggles early in the season.

"He was heavier than he'd been, and it was hard to control his weight," Arians said. "I think that had a lot to do with it early on."

Peterson previously said that "no question it made a big difference" but that he had gotten the condition under control. He was voted to his fourth straight Pro Bowl last season.

Peterson currently is listed by the team at 219 pounds. He said Monday he has lost weight but wouldn't say how much. Teammate and longtime friend Tyrann Mathieu estimated that Peterson weighs between 205 and 210.

"He looks pretty slim to me," Mathieu said Tuesday. "But he still has his speed. He's a physical cornerback, and I think the biggest thing for him is playing consistent each and every day.

"I don't really like the skinny Patrick. I like the 220 Patrick that runs a 4.3. I don't like the 210 Patrick that can run a 4.3."

Peterson was "pretty open" about his diabetes, said Mathieu, who saw Peterson's confidence suffer last season. Peterson and Mathieu were teammates at Louisiana State University in 2010 and were reunited three years later when Mathieu was drafted in the third round by the Cardinals.

"All I could do was be a friend for him, support him, encourage him, just try to keep him in positive spirits," Mathieu said.

Arians could sense Peterson was disappointed by the early-season criticism he received but added it was deserved, after Peterson gave up four touchdowns in his first five games, according to Pro Football Focus. During the last few games of 2014, Arians thought Peterson "played as good as anybody in the league, but he's always motivated to be the best. That's what you love about him."

After the season, Peterson and Mathieu sat down and discussed the expectations heading into 2015, which have been raised for Peterson since his diabetes is under control.

"We're two playmakers in our secondary, and we have to perform at a high level and kind of raise the level of play of our entire defense," Mathieu said. "So we really want to put that pressure on our shoulders and really perform how we're supposed to."