When Apple launched the HealthKit back in 2014 they said that it has a "built-in support to heart rate monitor, glucose sensor, blood pressure monitor and health thermometer. Once paired, HealthKit automatically controls the accessory."
In October 2014 they told in their support forum that they took the "glucose tracking field out of commision" until the problems (which they encountered) were sorted out.
Today on https://developer.apple.com/reference/healthkit?changes=latest_minor Apple only says: "HealthKit ... also works directly with some health and fitness devices. In iOS 8.0, the system can automatically save data from compatible Bluetooth LE heart rate monitors. The system can also automatically import activity data from the M7 motion coprocessor, if available. Other devices and data sources must have a companion app that can access the data and save it to HealthKit for them."
Is this still the case in iOS 10? So if one would like to connect a blood glucose sensor, it still is not possible with HealthKit directly but only via a companion app?
Thanks