Comparative Study on Self-Monitoring of Blood Glucose and Non-invasive Blood Glucose Sensor Using Short-wavelength Near-infrared Spectroscopy in Glycemic Index Determination

Postprandial hyperglycaemia control is important to prevent or treat diabetes, and also to lower the risk of complications. The glycemic index (GI) is one of the indices for controlling postprandial blood glucose levels. Both blood glucose control in diabetic patients and GI determinations require frequent blood samplings by self-monitoring of blood glucose, which is a major burden for patients and subjects. Thus, a new non-invasive method for measuring blood glucose is highly desirable. We examined the GI for five kinds of combination meals such as rice with vegetables (cabbage, komatsuna, tomato, soybean, and nagaimo) using white rice as a reference food. In addition, the non-invasive blood glucose determination using near-infrared (NIR) spectroscopy was studied as part of the GI determination. Spectra in the short-wavelength NIR region from 700 to 1 050 nm were measured on the palm of the hand. For each 2-h GI test, the blood glucose level was estimated from the spectral intensity by using simple linear regression analysis. Our results indicate that the GI for all combination meals was below 100 as determined by the reference food, and the blood glucose value was accurately estimated using the NIR technique during each GI test.