Useful meal tolerance test (MTT) for carbohydrate amount and post-prandial blood glucose

Background: Low carbohydrate diet (LCD) has been effective for type 2 diabetes mellitus (T2DM), because of less post-prandial increase of blood glucose. Case presentation: The case is 62-year-old male with T2DM, who had experience of LCD a few years ago. He developed diabetic exacerbation as HbA1c 10.7% in autumn 2021. Results: He began super-LCD with 12% of carbohydrate in calorie ratio, and recorded the pictures of detail food intake every day and 45-minunte post-prandial blood glucose for long. His HbA1c decreased to 7.1% for 9 weeks. For breakfast, carbohydrate amount varies from 19.7 g to 51.1g, and 45-min post-prandial blood glucose distribute 121mg/dL to 226mg/dL. The relationship between carbohydrate amount in breakfast and 45-min post-prandial blood glucose was investigated. As a result, significant correlation was observed between them (R2=0.46, p<0.05). Regression curve revealed y=2.5897x+73.226, in which the slope of the straight line is 2.6. Discussion and Conclusion: Obtained data may suggest that carbohydrate 1g can increase post-prandial glucose 2.6mg/dL. As to the standard fact of carbohydrate metabolism in the textbook, 3.0mg/dL glucose increase per carbohydrate 1g has been observed. Restricted carbohydrate intake would be beneficial for improving glucose variability in T2DM

Improved Insulin Resistance and Glucose Variability by Super-Low Carbohydrate Diet

Background Diabetes mellitus (DM) has been more prevalent. American Diabetes Association (ADA) proposed the Standards of Medical Care in Diabetes-2022. For nutritional therapy, low carbohydrate diet (LCD) has been recognized for its benefits. Authors have continued diabetic research concerning LCD and meal tolerance test (MTT). Case Presentation The case is 61-year-old male with type 2 diabetes mellitus (T2DM) for years. His hemoglobin A1c (HbA1c) increased to 7.8% in autumn 2021, and further evaluation and treatment was conducted including LCD, daily check of meal and carbohydrate amount, 75 g OGTT, glucagon stimulation test (GST) and others. Results He was on super-LCD method including 12% of carbohydrate. His carbohydrate intake amount and 45-minutes post-prandial blood glucose showed significant correlation. The results of 75 g OGTT twice in May 2020 and December 2021 showed that similar pattern of glucose and insulin responses and insulinogenic index (IGI). In contrast, they showed decreased fasting immuno-reactive insulin (IRI) and Homeostasis model assessment insulin resistance (HOMA-R). For GST, C-peptide showed normal response. Discussion and Conclusion Judging from the results of MTT, OGTT, GST and IGI, he seems to show rather decreased insulin resistance by LCD associated with preserved insulin secretion ability to some degree. Further investigation would be required from pathophysiological point of view