J.KHOO1, S.LOW1, S.C.LIM1
Khoo Teck Puat Hospital1
Recording meals has always been challenging due to human factors involved in the process. With the increase in popularity of continuous glucose monitoring systems, accurate meal times have become even more important to accurately analyze the impact of diet on intraday glucose levels. As part of a study consisting of 99 normoglycaemic participants, a methodology was developed to help identify significant glucose excursions and automatically adjust manually recorded meal timings to improve accuracy of analysis.
Participants wore a Libre Sensor and kept a food diary for two weeks. Data from the fourth to tenth day was used to maximize Libre accuracy. Base Microsoft Excel was used to maximize accessibility and transferability of methodology. Meals within two hours of each other were removed to avoid cross impact. Using the raw intraday glucose readings, excursions were identified using Excel formulas based on the following criteria: an overall increase of at least 1mmol/L in blood glucose after the next 30 minutes, and two consecutive 15 minute periods of increases of more than 0.1mmol/L. Excursions were then matched to meals falling within an hour and adjusted accordingly.
1142 meals out of 3300 (34.6%) were identified automatically. 76.3% of them required some amount of time adjustment, with 23.3% requiring 30min or more. Overall, the average magnitude of adjustments made was 15±13.4min.
While only a third of meals were identified, the ease-of-use of the methodology and magnitude of adjustments made highlight both its potential usefulness and need for more accurate forms of meal capture.