Sleep test identifies patients’ risk of cardiovascular disease

Swedish researchers believe a customised pulse oximeter can be used to detect changes in heart and vessel function during sleep and identify patients at risk of cardiovascular disease.

A pilot study of 148 people showed that more than 80 per cent of high-risk patients were picked up by this measurement technique. The results were published recently in the journal Chest.

In the study, researchers at the University of Gothenburg used a modified version of the pulse oximeter currently used to detect various sleep disorders during the night, such as apnoea.

The method is based on the measurement of five components of the signal from the finger: pulse-wave attenuation, pulse-rate acceleration, pulse propagation time, respiration-related pulse oscillation and oxygen desaturation.

‘We then weigh up these components in a model to assess how great a risk the patient runs of cardiovascular disease,’ said Ludger Grote, associate professor at the Centre for Sleep and Vigilance Disorders at the Sahlgrenska Academy and senior consultant at Sahlgrenska University Hospital. ‘We believe that the patient’s values reflect the risk at least as well as the individual’s risk factors “on paper”.’

The method may result in quicker and easier identification of patients at high risk of cardiovascular disease. It is hoped that it can also be used to assess the effects of treatment for cardiovascular disease, such as how weight loss and exercise can help prevent problems.

The team is now developing prototypes for a future portable device that can be used clinically. Before it can be taken into use, larger research studies are needed to confirm the results. Grote said that the team has begun this process already.