6656 Frequently sampled HbA1c Shows Low-Sodium, High-Carbohydrate Rice Diet To Be Effective in Type 2 Diabetes

Abstract Disclosure: F.A. Neelon: None. S. Sanoff: None. P. Lin: None. Hemoglobin and glucose react to form HbA1c, which persists until red blood cells (RBCs) are removed from circulation. Since RBCs survive approximately 122 days, HbA1c is usually measured at intervals of months to years, but more frequent measurement can illuminate changes in blood glucose (BG). We used Beach’s equation for the kinetics of HbA1c formation, to construct graphical depictions of how HbA1c should decline over the 122 days after a drop from constantly high to constantly normal BG levels. As part of routine patient care (not an experimental protocol), we measured HbA1c at 2-4-week intervals in a convenience sample of 10 patients (one of whom was evaluated on 2 occasions) with Type 2 diabetes, obesity, and elevated HbA1c who attended the now defunct Rice Diet Program (RDP) in Durham, NC. All were fed 3 meals/day, comprising 800-1000 kcal of rice, fruits, grains, and vegetables (70-90% carbohydrates) and 300 mg of sodium. Two patients were initially taking insulin; 1, glipizide; and 1, sitagliptin, exenatide, metformin; all hypoglycemic agents were eventually discontinued, and none added. Mean initial HbA1c of 9.7% (range, 8.3-11.7) fell to a mean of 6.2% (range 5.3-8.4) after a mean of 82 days (range, 41-139). Variability in final HbA1c values reflects, at least in part, variable duration of voluntary residence at the RDP. In 9 patients, HbA1c declined in close accordance with the course predicted for complete normalization of blood glucose from the very start of the diet; in 1 patient, HbA1c declined slowly for 25 days, after which the rate increased to near that for complete normalization of BG. Plots of Hb1c values extrapolate back through the point of origin, implying normalization of BG occurs within days of starting the RDP, and is maintained thereafter. Data from frequent measurement of HbA1c show: 1) Normalization of BG occurs almost immediately upon dietary restriction, implying that hyperglycemia in Type 2 diabetes is driven by daily calorie excess, not by accumulated calorie excess (ie, obesity). 2) Contrary to some misperceptions, a high-carbohydrate, sodium- and calorie-restricted diet is not deleterious to ― and may actually benefit ― glucose control in Type 2 diabetes. Presentation: 6/3/2024