I mountain bike with a diabetic friend who uses a TSlim insulin pump to monitor blood/sugar levels.
He has to stop and fish this device out of his pocket in order to see how his levels are doing.

He has been able to link the TSlim to his iPhone to read the numbers but it occurs to me that he may be able to link it also to his Garmin Forerunner 45 smart watch. That would be far less disruptive to his ride.

I have no knowledge of smart watches so am asking if anyone here knows whether this sort of link up is possible?
If not achievable directly, might it be possible to get the feed second-hand through a link to his iPhone?