Smart health monitors such as Fitbits can detect when a person is ill before they start experiencing symptoms, a study has found.
Sensors in wearable health trackers could be used to spot infections, inflammation and even insulin resistance, researchers at Stanford School of Medicine in California said.
The devices, which cost from £25 to more than £650, can monitor sleep, activity and calorie intake among a variety of measurements.
As part of the study, published in the journal PLOS Biology, researchers used bespoke software on smart watches to collect data on changes in heart rate and skin temperature. They used this data to predict when someone would fall ill. Michael Snyder, the lead author, said: “We want to tell when people are healthy and also catch illnesses at their earliest stages.”
The study followed 60 people and found the biosensors flagged up colds and complex conditions such as lyme disease which is spread by ticks.
The devices could also help to distinguish participants with insulin resistance, a precursor for type 2 diabetes, the study found. Personal biosensors could potentially be developed into a simple test for those at risk of type 2 diabetes by detecting variations in heart rate patterns, which tend to differ from those not at risk.
The team designed and tested an algorithm combining participants’ daily steps, daytime heart rate and the difference between daytime and nighttime heart rate. They were then able to predict which individuals in the study were likely to be insulin-resistant.
Professor Snyder predicted that people would wear devices containing as many sensors as a car. The technology could collect data on blood pressure and body temperature daily, providing a more accurate record than yearly check-ups by a doctor.