In 2013, Tom Hanks admitted to David Letterman — and the world — that his doctor told him that the moderately elevated glucose levels, or prediabetes, he'd had for the past 19 years "had graduated" to full-blown Type 2 diabetes.

For 19 years he and his doctor had the opportunity to work together to prevent Type 2 diabetes, but they never did.

And now we know that's an astoundingly frequent occurrence. A new study out of the University of Florida-Gainesville says more than three quarters of the 86 million North Americans who have prediabetes get no relevant drugs or advice from their docs.

Why does this matter? Because prediabetes increases your overall cancer risk by 15 percent, your risk of cardiovascular problems by as much as 20 percent, and doubles your risk of kidney dysfunction and nerve problems.

Plus, eventually 70 percent of prediabetics develop Type 2 diabetes.

But just a little intervention can protect or restore your health.

The key is to prevent and/or reverse insulin resistance. Get regular exercise that increases aerobic endurance and builds muscle. Eat a balanced diet.

One study found that walking 30 minutes five days a week and dropping 15 pounds in a year can slash your risk of developing full-blown diabetes by 58 percent (by 71 percent for people over 60).

So get your glucose levels tested. If it’s elevated, work with your doctor to break insulin resistance.

We recommend a daily regimen of 10,000 steps, five to nine servings of veggies, and medication if necessary.