4. Discussion
fasting blood glucose, mean fasting blood glucose, taste and sensory, T2DM, glucometabolic
DISEASE, MINOR, INSULIN SENSITIVITY
In this study, we investigated the effect of an 8-week supplementation regimen with two different formulations of aronia extract, i.e., fermented and non-fermented formulations, and compared with placebo on glucometabolic parameters in subjects with T2DM. We hypothesized that both aronia extracts would improve glucose metabolism in comparison to placebo, with AUC and iAUC during OGTT being the primary endpoint. We found no significant impact on waist circumference, BMI, HbA1c, fructosamine, or fasting values of insulin, glucose, GLP-1, or glucagon. Additionally, we detected no impact on the AUC of glucose or insulin or influence on insulin sensitivity. However, we did observe a minor increase in body weight and an elevation of the fasting level of GIP in the FAE group. Notably, the increase in GIP was significantly higher after intervention with FAE compared to placebo, whereas no intergroup differences were observed in relation to body weight.Regarding incretins, it is well-established that GLP-1 analogs improve disease outcomes for individuals with T2DM [We chose to incorporate the aronia extracts in snack bars as we expected higher compliance in comparison to, e.g., pills or capsules. Indeed, we observed an excellent compliance of above 95% for those who completed the trial. Nevertheless, it is possible that the nutritional composition of the bars contributed to the observed slight increases in weight, BMI, and waist circumference after supplementation with FAE and AE. The test products were high in sugar, as raisins were used to make the aronia pulp eatable and improve taste and sensory acceptance. Since it has been demonstrated that the consumption of raisins only produces a minor increase in postprandial blood glucose [Additionally, we found no significant differences in fasting and long-term blood glucose control, glucose tolerance, or insulin concentrations following any of the interventions. This is in contrast to results from in vitro and in vivo animal models of T2DM that have reported positive effects on the aforementioned parameters [It is worth mentioning that overall, the participants in our study were rather well-regulated with fasting blood glucose of ~8.4 mol/L and HbA1c of ~54 mmol/mol. Consequently, it could be questioned whether our participants were too well controlled regarding risk markers to demonstrate any improvements after supplementation. In contrast, Simeonov et al. reported a pre-intervention mean fasting glucose of ~13.3 mmol/L and a mean HbA1c of ~79 mmol/mol, which were subsequently reduced to a level similar to our baseline values after supplementation, resulting in a mean fasting blood glucose of ~9.1 mol/L and HbA1c of ~58 mmol/mol.One notable strength of our study is the high amount of anthocyanins provided. In comparison, the studies included in our aforementioned systematic review generally employed aronia supplements that typically provided between 300 mg and a maximum of 600 mg polyphenols per day [We hypothesized that FAE would deliver an increased amount of bioavailable polyphenols, potentially resulting in improved efficacy. It should be considered that fermentation might have the opposite effect and make the polyphenols more susceptible to degradation [