Study of the Correlation between Tear Glucose Concentrations and Blood Glucose Concentrations

To achieve intensive glucose control for avoiding diabetic complications, it is necessary for diabetic patients to measure their blood glucose levels frequently. However, all currently available methods for blood glucose monitoring, including the finger prick method, are invasive. One of the possible noninvasive glucose monitoring approaches is tear glucose monitoring. Previous studies have showed the correlations between blood and tear glucose concentrations. But these correlations were not accurate sufficiently because the methods for tear sample collection were not standardized. For clinical development of tear glucose monitoring as a tool for predicting the blood glucose concentrations, we recruited 10 nondiabetic subjects and 20 diabetic subjects, observed the daily blood and tear glucose dynamics using samples collected under the standardized method, and determined the correlation between the blood and tear glucose concentrations. Preprandial blood glucose levels of diabetic subjects were significantly higher than those of nondiabetic subjects (p < 0.001), and preprandial tear glucose levels of diabetic subjects had a higher tendency than those of nondiabetic subjects (p = 0.051). Two hours postprandial blood and tear glucose levels of diabetic subjects were significantly higher than those of nondiabetic subjects (p < 0.001, p < 0.05, respectively). The blood and tear glucose dynamics showed that the behavior of the tear glucose concentrations paralleled that of the blood glucose concentrations. A linear mixed model for diabetic subjects revealed the existence of a significant association between the blood glucose concentrations and tear glucose concentrations (p < 0.001), and the association consisted even after adjusting for HbA1c levels and conditions of meals. In conclusion, tear glucose monitoring would be a tool for predicting the blood glucose levels noninvasively for various diabetic patients. Disclosure M. Aihara: None. N. Kubota: None. T. Kadowaki: Consultant; Self; Novo Nordisk A/S, AstraZeneca, Merck Sharp & Dohme Corp.. Research Support; Self; Kissei Pharmaceutical Co., Ltd., Taisho Pharmaceutical Co., Ltd., Sanofi, Kyowa Hakko Kirin Co., Ltd., Novo Nordisk A/S, Astellas Pharma, Daiichi Sankyo Company, Limited, Takeda, Mitsubishi Tanabe Pharma Corporation, Ono Pharmaceutical Co., Ltd., Merck Sharp & Dohme Corp., Nippon Boehringer Ingelheim Co. Ltd.. Speaker's Bureau; Self; Astellas Pharma, AstraZeneca, Merck Sharp & Dohme Corp., Ono Pharmaceutical Co., Ltd., Takeda, Eli Lilly and Company, Nippon Boehringer Ingelheim Co. Ltd., Novo Nordisk A/S.