Abstract
Peripheral Arterial Disease (PAD) is a chronic and progressive disease that affects blood circulation. Poor glycemic control, especially in people with diabetes, might accelerate this illness. Photo-plethysmography (PPG) signals assess vascular health non-invasively. Acceleration Photo-plethysmograph (APG) ratios correlate with aging and vascular health. Very few studies have reported the relationship of APG ratios against age and diabetes. Various APG ratios were measured for 60 subjects (30 healthy and 30 with diabetes). Among healthy subjects, the levels of the APG ratios notably varied with age (p-value is 0.001 for b/a and p-value is 0.008 for b-c-d-e/a). The b/a ratio varied linearly with age (y = 0.001x - 1.1, R2 = 0.36), as did the b-c-d-e ratio (y = 0.008x - 1.2, R2 = 0.13). The b/a and b-c-d-e/a ratios significantly correlated with ABI (p-value 0.001). Subjects with normal ABI exhibited a negative b/a ratio. The b/a ratio increased with the severity of PAD (as per ABI) in both groups. A linear regression model of the b/a ratio effectively differentiates subjects with abnormal ABI from those with normal ABI. The b/a and (b-c-d-e)/a ratios can be used for easy and faster monitoring of peripheral arterial disease in people with diabetes.
