The effect of carbohydrate intake and type during breakfast on post-meal blood glucose in individuals with type 1 diabetes

Carbohydrates are the most important essential nutrient that affects postprandial glycemic response. In this study, which was conducted with the participation of 19-24 aged 14 individuals with type 1 diabetes who received multiple-dose insulin therapy, the effect of dietary carbohydrates intake and type during breakfast was investigated on the glycemic response for 240 minutes after the meal. This study was designed as a mono-center, randomized and single-blind study in order to adjust the insülin dose of the participants. All participants came to the hospital on 4 different days and took normal carbohydrate (NCH)/low glycemic index (LGI) as standard breakfast, and normal carbohydrate (NCH)/high glycemic index (HGI), low carbohydrate (LCH)/low glycemic index (LGI) and low carbohydrate (LCH)/high glycemic index (HGI) as test meals. For each participant, insulin was adjusted according to the Carbohydrate Counting method. Interstitial glucose measurements (at t=0, 30, 60, 90, 120, 150, 180, 210, 240 min) and capillary blood glucose measurements (at t=0, 15, 30, 45, 60, 90, 120, 180, 240 min) were conducted to evaluate the effect of different breakfast types after the meal on the glycemic response. By using these measurements, glucose levels were compared and the area under the incremental curve (iAUC) was calculated. In addition, the relative glycemic indexes of the test meals were calculated by accepting the value of the standard meal as 100. Interstitial glucose measurements (at t=30, 60, 90, 120, 150, 180, 210, 240 minutes) in the test meal containing NCH/HGI were higher than the values of the same measurements in the test meal containing LCH/LGI (p<0,05). Glucose values of all individuals after (at postprandial 120 minutes) a LCH/LGI meal were in the range of 80-180 mg/dL. By considering the total iAUC level and according to interstitial fluid and capillary glucose measurements, the glycemic response of a LCH/LGI meal (1496,4, 1455,4) was significantly lower than the glycemic response of a NCH/HGI meal (3146,7, 3378,4) (p<0,05). The glycemic responses of meals containing NCH/LGI and LCH/HGI were similar (p>0,05). When the relative glycemic indexes of the meals were evaluated according to the interstitial and capillary glucose measurements, the relative glycemic index of the meal containing NCH/HGI (%107,7, %109,5) was statistically significantly higher than the relative glycemic index of the meal containing LCH/LGI (%77,8, %82,9) (p<0,05). The relative glycemic index values of meals containing NCH/LGI and LCH/HGI were similar. Carbohydrate type should be taken into account along with the carbohydrates intake for a balanced meal.