Francisco Javier Basterra-Gortari

Background/Objectives: While many studies have explored the association between circulating branched-chain amino acids (BCAAs) and type 2 diabetes mellitus (T2DM), evidence on the prospective relationship between dietary BCAA intake and T2DM risk remains limited. We aimed to explore this relationship—both total and by dietary source—in a Mediterranean cohort. Methods: We used data from the SUN Project, a prospective and dynamic cohort of Spanish university graduates initiated in 1999. Dietary intake was assessed with a validated 136-item food frequency questionnaire at baseline and at 10 years. BCAA intake (valine, leucine, isoleucine) was estimated using the USDA amino acid database and adjusted for energy intake by the residual method. Participants were followed biennially through questionnaires to identify incident T2DM cases, confirmed by a supplementary questionnaire and medical report, following the ADA diagnostic criteria. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for potential confounders across four multivariable models. BCAA intake was modeled both categorically (tertiles) and continuously (per 0.5% energy or 5 g/day increase). Analyses were stratified by age and recruitment period. Results: After exclusions, 20,154 participants were included (mean follow-up: 14.67 ± 5.8 years), with 220 incident T2DM cases identified. For each 0.5% energy increment intake from BCAA, there was no association with T2DM (adjusted HR: 1.01; 95% CI: 0.69–1.20). Among men, the adjusted HR was 0.91, 95% CI: 0.69–1.20. Among women, it was 1.40, 95% CI: 0.94–2.09. In the overall cohort, higher BCAA intake showed a non-significant inverse association with the T2DM risk when comparing extreme tertiles (HR = 0.81; 95% CI: 0.48–1.37), which strengthened when repeated dietary measures were considered (HR = 0.70; 95% CI: 0.46–1.06, p-trend = 0.06). Analyses by BCAA sources (animal vs. plant) and stratified by sex, weight status, and age did not reveal consistent patterns, though exploratory findings suggested potential effect modification by sex and adiposity. Sensitivity analyses confirmed the lack of robust associations, with some subgroup-specific signals being limited by low event numbers and wide CIs. Conclusions: Given the power limitations and the modest, non-significant associations observed, these findings should be considered preliminary evidence that may help guide future research on the role of dietary BCAAs in glucose metabolism and diabetes risk.

Background and Objectives: Gestational diabetes mellitus (GDM) is one of the most common medical conditions in pregnancy, with adverse effects on maternal and neonatal outcomes. Evidence suggests a beneficial effect of plant-based dietary patterns, rich in foods derived from plant sources and low in animal foods, on type 2 diabetes; however, their effects on GDM remain unclear. We aimed to investigate the association between pre-pregnancy provegetarian food patterns and the incidence of GDM in a Spanish cohort. Materials and Methods: This subsample of the Seguimiento Universidad de Navarra (SUN) cohort analyzed 3589 Spanish university graduate pregnant women with a mean (standard deviation) age of 28 (±4.3) who were initially free of pre-existing diabetes at baseline. Dietary food consumption was evaluated through a validated, 136-item semi-quantitative food frequency questionnaire. The pre-pregnancy provegetarian food pattern was obtained by assigning positive scores to plant-based food groups and reverse scores to animal food groups. Energy-adjusted quintiles were applied to allocate points to construct the provegetarian food pattern, ranging from 12 to 60 points. Logistic regression models were performed to estimate the odds ratios (OR) of GDM across quintiles of a pre-pregnancy provegetarian food pattern, using the lowest quintile as the reference category. Results: We identified 178 incidence cases of GDM. Women in the highest quintile (Q5) of provegetarian food pattern before pregnancy exhibited a 42% relative reduction in the odds of GDM [adjusted OR (95% CI) Q5 vs. Q1: 0.58 (0.35, 0.97); p-trend = 0.109]. Higher consumption of meat and dairy before pregnancy was associated with a significantly increased risk of GDM [adjusted OR (95% CI) Q5 vs. Q1: 1.94 (1.19, 3.16); p-trend = 0.005] and [adjusted OR (95% CI) Q5 vs. Q1: 1.77 (1.07, 2.94); p-trend = 0.082], respectively. Conclusions: Higher pre-pregnancy consumption of a provegetarian food pattern was associated with a lower risk of developing GDM in Spanish women. Further studies are needed to confirm these findings.

Previous studies suggested that dietary polyphenols could reduce the incidence and complications of type-2 diabetes (T2D); although the evidence is still limited and inconsistent. This work analyzes whether changing to a diet with a higher polyphenolic content is associated with an improved glucose profile. At baseline, and at 1 year of follow-up visits, 5921 participants (mean age 65.0 ± 4.9, 48.2% women) who had overweight/obesity and metabolic syndrome filled out a validated 143-item semi-quantitative food frequency questionnaire (FFQ), from which polyphenol intakes were calculated. Energy-adjusted total polyphenols and subclasses were categorized in tertiles of changes. Linear mixed-effect models with random intercepts (the recruitment centers) were used to assess associations between changes in polyphenol subclasses intake and 1-year plasma glucose or glycosylated hemoglobin (HbA1c) levels. Increments in total polyphenol intake and some classes were inversely associated with better glucose levels and HbA1c after one year of follow-up. These associations were modified when the analyses were run considering diabetes status separately. To our knowledge, this is the first study to assess the relationship between changes in the intake of all polyphenolic groups and T2D-related parameters in a senior population with T2D or at high-risk of developing T2D.