Association Between Remote Dielectric Sensing and Body Mass Index

Remote dielectric sensing (ReDS) is a non-invasive, electromagnetic energy-based technology to quantify pulmonary congestion. However, the accuracy of ReDS values in patients with a variety of physiques has not been fully validated. Prospective successive measurements of ReDS values and body mass index (BMI) were performed on admission in consecutive hospitalized patients with cardiovascular diseases. Patients were stratified into 4 groups according to the WHO classification: underweight (BMI < 18.5), normal weight (18.5 ≤BMI < 24.9), pre-obese (25.0 ≤BMI < 29.9), and obese (30.0 ≤BMI). The indexed ReDS value was defined as a ReDS value divided by the modified congestion score index (the severity of pulmonary congestion on chest X-ray). The indexed ReDS values were compared among the 4 stratified groups. A total of 436 patients (76 [69, 82] years old and 254 men) were included. The median indexed ReDS values were 21.3 (19.1, 23.8), 25.7 (21.0, 29.5), 25.7 (20.3, 31.0), and 28.0 (21.1, 34.0) in underweight, normal weight, pre-obese, and obese patients, respectively, highlighting the underweight group had the lowest values (P < 0.001). ReDS values may be underestimated and specific caution should be paid in its interpretation in underweight patients.