“An exciting nugget of information for Dexcom users was hidden among more eye-catching announcements during yesterday’s Keynote Address at Apple’s WWDC (Worldwide Developers Conference) in San Jose. Near the end of his preview of the upcoming watchOS 4 software update for Apple Watch, Kevin Lynch (VP of Technology at Apple) briefly showed a slide that included Dexcom’s CGM watchface. He stated (19:45 into the keynote address):

    “We are also now supporting native core bluetooth on the watch, which is going to enable experiences for apps that work with small devices around you. So for example, continuous glucose monitoring directly from Dexcom’s sensor… to your watch.”

    Similarly, Apple provided an information page which again specifically referenced continuous glucose monitoring as a beneficiary of the Watch’s upcoming software update (free for all Apple Watch owners, scheduled for this Fall).

    What this means: iPhone no longer required!

    As we predicted about 18 months ago when watchOS 2 was announced, the upcoming Watch OS4 software update will finally allow the Apple Watch to display CGM data without an iPhone nearby. Going for a run? You can leave your iPhone at home. Going on a flight? You can leave your iPhone in airplane mode.

    Keep in mind that owning an Apple Watch still requires owning an iPhone, so Android users can’t just go buy an Apple Watch for use with their Dexcom CGM. (Android support for Dexcom should be here any day now, though). But this new feature does allow users to be separated from their iPhone for periods of time without losing access to their CGM data.

    This also (likely) means faster CGM data on Apple Watch

    Although not explicitly stated, I predict that watchOS 4 will allow CGM data to be refreshed faster on the Apple Watch since it will be pulling data directly from the Dexcom transmitter. The way it currently works requires data to be sent from Dexcom -> iPhone -> Watch, so removing the middle man should make for faster synchronization.

    All that being said, Dexcom owners with Apple Watches can look forward to a better CGM experience with the free watchOS 4 software update scheduled for this fall.