Jonathan S. Geller, BGR:

According to our source, Apple’s sights are now set on the epidemic of diabetes, and the company plans to introduce a game-changing glucose monitoring feature in an upcoming Apple Watch. An estimated 30 million people suffer from diabetes in the US alone, according to the American Diabetes Association, so Apple’s efforts could lead to a historic achievement in the world of health and fitness.

And:

Apple also plans to introduce interchangeable “smart watch bands” that add various functionality to the Apple Watch without added complexity, and without increasing the price of the watch itself. This could also mean that the glucose monitoring feature will be implemented as part of a smart band, rather than being built into the watch hardware.

A smart band is a natural evolution of, extension to the Apple Watch. Each Apple Watch includes a diagnostic six pin port, so there’s already a path for data flow between your existing Apple Watch and a new band.