Sleep Quality Is Associated with Changes in Blood Glucose and Arterial Stiffness Following Postprandial Hyperglycemia

Background/Objectives: Postprandial hyperglycemia and sleep quality can influence arterial stiffness; however, the interaction between sleep quality and postprandial hyperglycemia-induced changes in arterial stiffness remains poorly elucidated. Therefore, the purpose of this study was to investigate whether sleep quality modifies postprandial changes in blood glucose levels and arterial stiffness following a 75 g oral glucose tolerance test in healthy middle-aged and older adults. Methods: In this study on 104 healthy middle-aged and older adults (50–83 years old), arterial stiffness was assessed using carotid–femoral pulse wave velocity (cfPWV) and brachial–ankle pulse wave velocity (baPWV) before and 60 min after a 75 g oral glucose tolerance test (OGTT). Poor sleep quality was defined as a Pittsburgh Sleep Quality Index score > 5.5. Results: In the 51 participants with poor sleep quality, baPWV increased significantly from baseline to 60 min after the 75 g OGTT (p < 0.01), whereas no such change was observed in the 53 subjects with good sleep quality. baPWV was significantly higher in the poor-sleep-quality group than in the good-sleep-quality group 60 min after the 75 g OGTT (p < 0.01). Moreover, baPWV and blood glucose levels 60 min after the 75 g OGTT had a positive correlation (p < 0.01, r = 0.64). Conclusions: These findings suggest that a poor sleep quality may enhance postprandial hyperglycemia-induced arterial stiffness, whereas a good sleep quality may help protect vascular function.