A Case Study of Inositol and Soluble Fiber Supplementation on Glycemic Control in an Overweight Subject

Background Soluble fiber has been shown to improve glycemic control by slowing the absorptions of glucose. And inositol has been shown to improve glycemic control in type 2 diabetes (T2D) and gestational diabetes via recruiting glucose transporter type 4 (GLUT4) to cell surface. However, neither inositol supplementation nor combination of inositol and soluble fiber supplementation has been studied in overweight. Objective To investigate if supplementation of inositol improves biological markers of glycemic control overweight and obesity, and that supplementation of inositol in combination with soluble fiber have synergistic effects to further improve these markers. Design A single cohort, uncontrolled, test-retest design was planned to be implemented over 5-weeks in which the participants supplemented 2 grams of myo-inositol twice daily for 4-weeks and then 2 grams of myo-inositol plus 2 grams of soluble fiber each twice daily for 1-week in overweight and obese subjects. Only one overweight subject was able to complete both phases of supplementation due to coronavirus disease-2019 (COVID-19), therefore the study is reported as a case study. Results Supplementation of 4 grams of myo-inositol daily for 4-weeks resulted in improved glucose parameters and lipid parameters including fasting blood glucose, post-prandial blood glucose, total blood cholesterol level, blood high-density lipoprotein (HDL) cholesterol level, and blood triglyceride level. The combination of inositol and soluble fiber supplementation further improved the total blood cholesterol level. Conclusion These results indicate there is potential benefit of inositol supplementation for sub-clinical hyperglycemic, overweight subjects on glycemic control.