4. Discussion
T2D, hyperlipidemia, T1D, hypoglycemia, LCDs, hypoglycemic, diabetes
LIPEMIA, KIDNEY DISEASE, HYPERLIPIDEMIA, CVD, HYPOGLYCEMIA, EVENTS, DIABETES
In this randomized crossover study in people with T1D, overall postprandial glucose excursions were lower after the low-carbohydrate HP meal compared to the isocaloric high-carbohydrate meals with or without extra fiber. The HF meal increased postprandial triglyceride levels significantly more compared to the HP meal but not compared to the HC or HC-fiber meals. Glucagon excursions were higher 180 min after the HP meal compared to the HC and HF meals. In comparison with the control group, the T1D group had significantly higher peak glucose excursions after all meals.In contrast to previous studies, neither the HP nor the HF meal resulted in higher postprandial glycemia in the later postprandial phase (120–240 min) compared to the high-carbohydrate meals, which can be attributed to our isocaloric study design. In particular, previous studies in subjects with T1D have mainly compared meals and test drinks that had the same carbohydrate amount but differed in energy, fat, and/or protein content [There was no significant difference in postprandial glucose excursions between the HP and HF meal in this study, neither in the earlier nor in the later postprandial phase. However, other studies have shown that glucose levels increased significantly in the later postprandial phase after HP meals compared to isocaloric HF meals of equal carbohydrate content in T1D [Unexpectedly, the HC-fiber meal did not result in lower postprandial glycemia compared to the standard HC meal in this study, neither in the T1D group nor in the healthy controls, as seen previously in other studies [Glucagon concentrations remained significantly higher after the HP meal compared to the HC and HF meals at 180 min, in agreement with previous studies [Postprandial hyperlipidemia is an independent risk factor for CVD and is influenced by many dietary components; however, studies investigating the effect of different meals on postprandial lipemia in people with T1D are scarce. In our study, there was no difference in postprandial lipids between the isocaloric HC meals and the HF meal. The HC meals included higher amounts of simple sugars, while the HF meal had a higher amount of total fat, which are the dietary factors that have been found to increase postprandial triglycerides the most [The acute postprandial glycemic and metabolic responses after isocaloric meals could be linked to some of the long-term health effects of different diets and dietary patterns. In our study, we found more favorable glycemic effects after the HP and HF meals, which reflect the macronutrient composition of low carbohydrate diets (LCDs). LCDs have been found to reduce HbA1c in people with T2D [Regarding protein intake, evidence suggests that some people with diabetes and eGFR > 60 mL/mil per 1.73 mThis study had several strengths. It was crossover and allowed comparisons both within and between subjects. It investigated four different meals and had an isocaloric design. The meals studied were proper restaurant-cooked dishes commonly eaten in Sweden instead of test drinks/meals and the study simulated a real-life dining environment. Furthermore, the control group of healthy subjects that was used for comparisons with the T1D group was well-matched and did not differ in most baseline characteristics; HbA1c was expectedly lower, and the lower HDL-cholesterol levels could be explained by the higher number of men in the control group. Adjustments for multiple comparisons between the T1D and control group over test meals were also included.There were, however, some limitations. First, some subjects experienced hypoglycemia before the test meals and needed to compensate with extra dextrose or food. Nevertheless, we tried to correct for this by adding covariables in the linear mixed effects models. Secondly, the 4 h duration of the postprandial testing period in this study may be short, as late postprandial glycemia has been investigated between 3 and 5–6 h in previous studies [In conclusion, comparisons of real-life isocaloric meals showed that a high-protein meal with lower carbohydrate content (43 g, 33% EI) had more favorable glycemic effects than isocaloric high-carbohydrate meals (75–79 g, 53–54% EI) during a 4 h postprandial period in people with T1D. The high-protein meal also resulted in fewer hypoglycemic events and lower postprandial triglyceride excursions compared to the isocaloric high-fat meal, and, therefore, its macronutrient composition may be recommended for improving postprandial glycemic and metabolic control in people with T1D, without pre-existing kidney disease. Further studies with isocaloric meals containing all three macronutrients are needed to better understand the respective contributions of fat and protein to postprandial glycemia and lipemia in T1D.