Continuous Glucose Monitoring With Low-Carbohydrate Diet Coaching in Adults With Prediabetes: Mixed Methods Pilot Study (Preprint)

Abstract

BACKGROUND Type 2 Diabetes Mellitus (T2DM) is preventable, yet few patients with prediabetes participate in prevention programs. Use of user-friendly continuous glucose monitors (CGM) with low-carbohydrate diet coaching is a novel strategy to prevent T2DM. OBJECTIVE The objective of this study was to determine patient satisfaction and feasibility of an intervention pairing CGM use and low-carbohydrate diet coaching in patients with prediabetes to drive dietary behavior change. METHODS We conducted a mixed methods single arm pilot and feasibility study at a suburban family medicine clinic. Fifteen adults with prediabetes, defined as hemoglobin A1c (HbA1c) between 5.7 and 6.4, and BMI > 30 kg/m2 were recruited to participate. The intervention and assessments took place during three in-person study visits and two qualitative phone interviews (post-intervention and 6-months post-intervention). At Visit 1, participants were asked to wear a continuous glucose monitor (CGM) and complete a food and craving log for ten days. At Visit 2, they reviewed their food and craving log with CGM results and received low-carbohydrate diet coaching, including learning about carbohydrates and personalized feedback. A second CGM sensor, with the ability to scan and see glucose trends, was placed and participants logged food and cravings as they tried to reduce their total carbohydrate intake (<100 g/day). At Visit 3, participants reviewed their CGM and log data. Primary outcome was satisfaction with use of CGM and low carbohydrate diet. Secondary outcomes included feasibility, weight and hemoglobin A1c (HbA1c) change, and percent time in hyperglycemia. Changes in attitudes and risk perception of developing diabetes were also assessed. RESULTS There overall satisfaction rate with intervention was a 93% satisfaction. The intervention induced a reduction in weight of 1.4 lb ( p=0.02) and in HbA1c of 0.71 mmol/mol, p < .001 from enrollment. Though not significant, percent time above glucose goal and average daily glucose decreased during the study period. Qualitative interview themes indicated: 1) no major barriers to CGM use; 2) acceptance of low carbohydrate diet; 3) CGM helped to visualize the impact of carbohydrates on the body, inciting dietary changes. CONCLUSIONS Use of CGMs and low-carbohydrate diet coaching to drive dietary change in patients with prediabetes is feasible and acceptable to patients. This novel method deserves further exploration as preliminary data indicates CGM with low-carbohydrate diet coaching supported dietary change, which may ultimately prevent T2DM. CLINICALTRIAL ClinicalTrials.gov NCT03695913