Evaluation of Photoplethysmogram Responses to Occlusion and Local Thermal Tests in Diabetes Patients with Micro- and Macrovascular Dysfunction
Alexey A. Glazkov1, Denis G. Lapitan1, Xiaoman Xing2,3, Ksenya A. Krasulina1, Yulia A. Kovaleva1, Roman N. Larkov1, Sergey S. Zagarov1, Dmitry A. Rogatkin1
1Moscow Regional Research and Clinical Institute (“MONIKI”), Moscow, Russia;
2School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China, Suzhou, China;
3Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China
Abstract
This study was aimed to assess pulse waveform alterations in patients with type 2 diabetes mellitus (DM) in response to occlusion and local thermal tests.
The study analyzed three groups: healthy individuals (n=15), patients with type 2 DM and diabetic retinopathy (n=14), and those with type 2 DM and diabetic foot syndrome or peripheral arterial disease (n=16). For local thermal test, measurements were performed at the big toe by increasing skin temperature from 32°C to 42°C. The occlusion test was performed on the shoulder by increasing the pressure in the tonometer cuff to suprasystolic values for 2 minutes; the photoplethysmogram (PPG) was recorded on the index finger. Morphological as well as temporal features of PPG were extracted for quantitative analysis.
Statistically significant changes in PPG waveform shape were observed across three groups — healthy controls, DM with retinopathy, and DM with peripheral arterial disease/diabetic foot. Notably, the dicrotic notch became more pronounced during heating, indicating reduced vascular resistance. ROC analysis showed improved diagnostic informativeness of most indices after tests, supporting the value of functional PPG testing for microvascular assessment in diabetes.
Our findings support the use of functional PPG testing — especially during thermal provocation — as a sensitive, noninvasive approach to the assessment of diabetes-related vascular abnormalities. Morphological pulse waveform analysis provides additional insight into the pathophysiology of vascular dysfunction in diabetes and may help improve risk stratification and monitoring in clinical practice.
Speaker
Glazkov Alexey
Moscow Regional Research and Clinical Institute
Russia
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