שנת סיום: 2023
כותרת עבודת הדוקטורט: The Link between Diet and Glycemic Control in Various Stages
of Diabetes Mellitus
מנחים: פרופ' שירה זלבר-שגיא ופרופ' ערן סגל
ABSTRACT
Background and aims: Dietary changes are crucial for preventing and managing type-2 diabetes (T2DM) and its complications. However, individuals at risk or newly diagnosed with T2DM often struggle to establish preventive behaviors and meet glycemic control goals. This study explores how personalized nutrition and lifestyle changes affect glycemic control in two high-risk groups: women with a history of gestational diabetes (GDM), who are at increased risk for T2DM and individuals newly diagnosed with T2DM.
Methods: We applied two complementary study designs. A randomized cross-over clinical trial including a dietary intervention in individuals with newly diagnosed T2DM (N=23) to evaluate the effects of Personalized-Postprandial-Targeting (PPT) diet, relies on a machine learning algorithm that integrates clinical and microbiome features to predict personal postprandial glucose responses (PPGR), on glycemic control and metabolic health. At first, we sought to compare the PPT diet to the commonly recommended Mediterranean style (MED) diet. For that end participants were randomly assigned to a crossover trial of two 2-week-long dietary interventions: either PPT-MED or MED-PPT diets. We further evaluated the long-term effects of PPT diet by an additional 6-month PPT intervention (n = 16). The second study was a cross-sectional design aimed to examine the associations of GDM in the past on current glycemic behavior, we assessed dietary intake and clinical parameters in 549 non-pregnant women who participated in two other cohorts: the personalized nutrition project (PNP observational) and the prediabetes dietary intervention (PNP-intervention). We mainly focused on women who were currently with prediabetes and GDM in the past (n=101) or without (n=275). Participants were comprehensively profiled including glycemic status assessed by both blood parameters and continuous-glucose-monitoring (CGM) measures, gut microbiome composition, blood tests and dietary intake (food diary) which was reported on a dedicated mobile app. We further assessed their adherence to the Mediterranean diet based on iMED score adjusted for the Israeli population.
Results: In the RCT a total of 23 individuals with newly diagnosed T2DM (aged 53.5 ± 8.9 years, 48% males, BMI 30.8±7.4 kg/m2) participated in the dietary intervention. In the crossover intervention, PPT diet led to significant lower levels of CGM-based measures as compared to the MED diet, such as average PPGR (mean difference between diets, −19.8 ± 16.3 mg/dl × h, p < 0.001) and blood fructosamine (−16.4 ± 37 μmol/dl, p < 0.0001). Furthermore, at the end of 6 months, the PPT intervention led to significant improvements in multiple metabolic health parameters, including: HbA1c (mean ± SD, −0.39 ± 0.48%, p < 0.001), fasting glucose (−16.4 ± 24.2 mg/dl, p = 0.02) and triglycerides (−49 ± 46 mg/dl, p < 0.001). Importantly, 61% of the participants exhibited diabetes remission. In the cross-sectional study we assessed a total of 549 non pregnant women (aged 49.8 ± 10 years, BMI 28.3±6.1 kg/m2, 50.1% with prediabetes, 18.4% with previous GDM). In the prediabetes population subgroup, in an adjusted multivariable regression, previous GDM was associated with worse glycemic control expressed by higher variability in glycemic responses as measured by CGM during the connection (for example, j-Index, representing glycemic variability, OR=3.19, 95%CI 1.53-6.64, p=0.002). Furthermore, across the subgroup of all women with previous GDM, adherence to Mediterranean diet was further associated with lower risk of prediabetes (OR=0.156, 95% CI 0.038-0.647, p=0.01). Conclusion: Our findings suggest that dietary intake plays a crucial role in both preventing and managing early diabetes, as demonstrated through two distinct study designs. The implementation of a PPT diet in the intervention study and the utilization of the iMED adjusted score in the cross-sectional study were both linked to enhanced glycemic control and improved metabolic health parameters, providing evidence for the clinical effectiveness of dietary interventions in the prevention and management of diabetes. These findings emphasize the fundamental importance of incorporating nutritional care in all healthcare systems.