Apple is reported to have hired a team of biomedical engineers from other companies who are working on the project in Palo Alto.
The target is to develop a non-invasive test that does not involve taking a blood sample.
There are reports that Apple’s approach is to use optical sensors that shine light into the skin to measure glucose in the blood.
Two years ago, Leeds University reported development of a laser sensor that monitors blood glucose using low-powered lasers to measure blood glucose levels non-invasively and processing the results with portable glucometers.
Google has a similar project which uses contact lenses to measure blood sugar levels.