MiRNAs profile as biomarkers of nutritional therapy for the prevention of type 2 diabetes mellitus: From the CORDIOPREV study.

BACKGROUND AND AIM: The incidence of type 2 diabetes mellitus (T2DM) has increased worldwide. One of the first actions to reduce the risk of this disease is to implement healthy dietary models; however, no universal dietary strategies have so far been established. In addition, MicroRNAs (miRNAs) are emerging as new biomarkers to predict disease. We aimed to study whether miRNAs could be used to select the nutritional therapy to prevent T2DM development in patients with cardiovascular disease. METHODS: All patients from the CORDIOPREV study without T2DM at baseline according to the American Diabetes Association (ADA) diagnostic criteria (n = 462) were included in the present study. Of them, after a median dietary intervention period of 60 months with two diets (Low fat or Mediterranean diets), 107 developed T2DM and 355 subjects did not develop the disease. The plasma levels of 24 miRNAs were measured at baseline by qRT-PCR. The risk of T2DM was evaluated by Cox regression analysis based on the plasma levels of the miRNAs at baseline and according to the dietary intervention. Finally, pathways analyses were carried out to identify target genes regulated by the miRNAs studied and cellular processes which could be associated with T2DM development. RESULTS: Cox regression analyses showed that patients with low plasma levels of miR-145 at baseline showed a higher risk of developing T2DM after consumption of an LFHCC diet. In addition, patients with low levels of miR-29a, miR-28-3p and miR-126 and high plasma levels of miR-150 at baseline showed a higher risk of developing T2DM after consumption of the Med diet. Finally, pathways analysis showed an interaction of miR-126 and miR-29a in the modulation of FoxO, TNF-α, PI3K-AKT, p53 and mTOR signaling, associated with T2DM development. CONCLUSION: Our results suggest that circulating miRNAs could be used in clinical practice as a new tool for selecting the most suitable diet to prevent type 2 diabetes mellitus development in patients with cardiovascular disease. CLINICAL TRIALS NUMBER: NCT00924937.

Prediabetes diagnosis criteria, type 2 diabetes risk and dietary modulation: The CORDIOPREV study.

AIM: Our objective was to investigate the role of two healthy diets in modulating the risk of type 2 diabetes (T2DM) development associated with each prediabetes diagnosis criteria in coronary heart disease patients. Additionally, we explored the pathophysiological characteristics and the risk of developing T2DM in patients with different prediabetes criteria. METHODS: We included 462 patients from the CORDIOPREV study without T2DM at baseline: 213 had prediabetes defined by impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) (PreDM-IFG/IGT); 180 had prediabetes by isolated hemoglobin glycated plasma levels (PreDM-isolated-HbA1c), and 69 were not prediabetics (non-PreDM), according to the American Diabetes Association criteria. Patients were randomized to consume either a Mediterranean or a low-fat diet. We performed a COX proportional hazards regression analysis to determine the T2DM risk according to diet and the prediabetes criteria after a median follow-up of 60 months. RESULTS: We found higher T2DM risk (HR: 2.98; 95% CI 1.27-6.98) in PreDM-IFG/IGT than in PreDM-isolated-HbA1c (HR: 2.31; 95% CI 0.97-5.49) compared with non-PreDM. Long-term consumption of a low-fat diet was associated with a lower risk of T2DM when compared to the Mediterranean diet in the PreDM-IFG/IGT group (HR: 3.20; 95% CI 0.75-13.69 versus HR: 4.70; 95% CI 1.12-19.67, respectively). Moreover, we found the highest risk of T2DM development associated with patients who had both IFG and IGT (HR: 2.15; 95% CI 1.11-4.16). Patients who had both IFG and IGT and consumed a low-fat diet had a lower T2DM risk than those who consumed a Mediterranean diet (HR: 1.53; 95% CI 0.53-4.39 versus HR: 3.33; 95% CI 1.34-8.30, respectively). CONCLUSION: Our results suggest that the type of diet consumed may modulate the risk of T2DM development according to the prediabetes diagnosis criteria. Specifically, our study showed that the consumption of a low-fat diet was more beneficial than a Mediterranean diet in patients with IFG and IGT. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrials.govNCT00924937.

Postprandial endotoxemia may influence the development of type 2 diabetes mellitus: From the CORDIOPREV study.

BACKGROUND & AIMS: Insulin resistance (IR) and impaired beta-cell function are key determinants of type 2 diabetes mellitus (T2DM). Intestinal absorption of bacterial components activates the toll-like receptors inducing inflammation, and this in turn IR. We evaluated the role of endotoxemia in promoting inflammation-induced insulin resistance (IR) in the development of T2DM, and its usefulness as predictive biomarker. METHODS: We included in this study 462 patients from the CORDIOPREV study without T2DM at baseline. Of these, 107 patients developed T2DM according to the American Diabetes Association (ADA) diagnosis criteria after a median follow-up of 60 months (Incident-DIAB group), whereas 355 patients did not developed it during this period of time (Non-DIAB group). RESULTS: We observed a postprandial increase in lipopolysaccharides (LPS) levels in the Incident-DIAB at baseline (P < 0.001), whereas LPS levels were not modified in the Non-DIAB. Disease-free survival curves based on the LPS postprandial fold change improved T2DM Risk Assessment as compared with the previously described FINDRISC score (hazard ratio of 2.076, 95% CI 1.149-3.750 vs. 1.384, 95% CI 0.740-2.589). Moreover, disease-free survival curves combining the LPS postprandial fold change and FINDRISC score together showed a hazard ratio of 3.835 (95% CI 1.323-11.114), linked to high values of both parameters. CONCLUSION: Our results suggest that a high postprandial endotoxemia precedes the development of T2DM. Our results also showed the potential use of LPS plasma levels as a biomarker predictor of T2DM development. CLINICAL TRIALS.GOV. IDENTIFIER: NCT00924937.

Low Intake of Vitamin E Accelerates Cellular Aging in Patients With Established Cardiovascular Disease: The CORDIOPREV Study.

Leukocyte telomere length (LTL) shortening is a biomarker of cellular aging that can be decelerated by diet. We aimed to investigate the effect of dietary intake of vitamin E on biomarkers of cellular senescence in patients with established cardiovascular disease. To this end, DNA from 1,002 participants of the CORDIOPREV study (NCT00924937) was isolated and LTL was measured by real-time PCR. Dietary information was collected using a 146-item food frequency questionnaire, and several oxidative stress and damage biomarkers were determined. We found that patients with an inadequate intake of vitamin E according to the European Food Safety Authority, U.S. Food and Nutrition Board, and Spanish dietary recommendation had shorter LTL than those with an adequate intake (p = .004, p = .015, and p = .005, respectively). Moreover, we observed a positive correlation between olive oil, fish consumption and LTL (r2 = .083, p = .010; r2 = .090, p = .006, respectively). Subjects who consumed more than 30 mL olive oil/day had longer LTL than subjects with lower consumption (p = .013). Furthermore, we observed higher glutathione peroxidase activity in subjects consuming less vitamin E (p = .031). Our findings support the importance of an adequate consumption of the antioxidant vitamin E, and the value of the diet as a modulating tool of the senescence process.

Long-term consumption of a Mediterranean diet improves postprandial lipemia in patients with type 2 diabetes: the Cordioprev randomized trial.

Background: Patients with type 2 diabetes (T2D) have an elevated postprandial lipemia (PPL) that has been associated with increased cardiovascular risk. Objective: We aimed to analyze whether the long-term consumption of 2 healthy dietary patterns is associated with an improvement in PPL and remnant cholesterol (RC) concentrations in patients with T2D. Design: We selected patients from the Cordioprev study who underwent oral fat load tests (FLTs) at baseline and the 3-y follow-up (241 patients with and 316 patients without T2D). Subjects were randomly assigned to receive either a Mediterranean diet rich in olive oil (MedDiet; 35% of calories from fat [22% monounsaturated fatty acids (MUFAs)] and 50% from carbohydrates) or a low-fat (LF) diet [<30% fat (12-14% MUFAs) and 55% of calories from carbohydrates]. Lipids were measured in serial bloods drawn at 0, 1, 2, 3, and 4 h after the FLT. Results: After 3 y of dietary intervention, patients with T2D showed an improvement in their PPL measured as postprandial triglycerides (TGs) (P < 0.0001), TG area under the curve (AUC) (P = 0.001), and TG-rich lipoproteins (TRLs-TG; P = 0.001) compared with baseline. Subgroup analysis, based on the type of dietary intervention, showed that those T2D patients randomly assigned to the MedDiet presented a reduction in the TG AUC of 17.3% compared with baseline (P = 0.003). However, there were no differences for T2D patients randomly assigned to the LF diet (P > 0.05) or in patients without T2D (P > 0.05) regardless of the dietary intervention. In addition, the MedDiet induced a significant improvement in the RC AUC in patients with T2D (P = 0.04). However, there was no significant improvement in those following the LF diet. Conclusions: Our findings show that the long-term consumption of a MedDiet rich in olive oil improves PPL and RC concentrations mainly in patients with T2D. This trial was registered at clinicaltrials.gov as NCT00924937.

Influence of gender and menopausal status on gut microbiota.

OBJECTIVES: We explore the differences in the gut microbiota associated with gender and hormonal status. STUDY DESIGN: We included 76 individuals in this study: 17 pre-menopausal women, 19 men matched by age, as a control group for the pre-menopausal women, 20 post-menopausal women and 20 men matched by age as a control group for the post-menopausal women; all 4 groups were also matched by body mass index (BMI) and nutritional background. MAIN MEASUREMENTS: We analyzed the differences in the gut microbiota, endotoxemia, intestinal incretins, pro-inflammatory cytokines, and plasma levels of energy homeostasis regulatory hormones between pre- and post-menopausal women and compared them with their respective male control groups. RESULTS: We found a higher Firmicutes/Bacteroidetes ratio, a higher relative abundance of Lachnospira and Roseburia, and higher GLP-1 plasma levels in pre-menopausal women than in post-menopausal women, who had similar levels to men. In contrast, we observed a lower relative abundance of the Prevotella, Parabacteroides and Bilophila genera, and IL-6 and MCP-1 plasma levels in pre-menopausal women than in post-menopausal women, who had similar levels to the men. We also found higher GiP and leptin plasma levels in women than in men, irrespective of the menopausal status of the women. In addition, adiponectin levels were higher in pre-menopausal women than in their corresponding age-matched male control group. CONCLUSIONS: Our results suggest that the differences in the composition of gut microbiota between genders and between women of different hormonal status may be related to the sexual dimorphism observed in the incidence of metabolic diseases and their co-morbidities.

Circulating miRNAs as Predictive Biomarkers of Type 2 Diabetes Mellitus Development in Coronary Heart Disease Patients from the CORDIOPREV Study.

Circulating microRNAs (miRNAs) have been proposed as type 2 diabetes biomarkers, and they may be a more sensitive way to predict development of the disease than the currently used tools. Our aim was to identify whether circulating miRNAs, added to clinical and biochemical markers, yielded better potential for predicting type 2 diabetes. The study included 462 non-diabetic patients at baseline in the CORDIOPREV study. After a median follow-up of 60 months, 107 of them developed type 2 diabetes. Plasma levels of 24 miRNAs were measured at baseline by qRT-PCR, and other strong biomarkers to predict diabetes were determined. The ROC analysis identified 9 miRNAs, which, added to HbA1c, have a greater predictive value in early diagnosis of type 2 diabetes (AUC = 0.8342) than HbA1c alone (AUC = 0.6950). The miRNA and HbA1c-based model did not improve when the FINDRISC was included (AUC = 0.8293). Cox regression analyses showed that patients with low miR-103, miR-28-3p, miR-29a, and miR-9 and high miR-30a-5p and miR-150 circulating levels have a higher risk of disease (HR = 11.27; 95% CI = 2.61-48.65). Our results suggest that circulating miRNAs could potentially be used as a new tool for predicting the development of type 2 diabetes in clinical practice.

Mediterranean Diet, Glucose Homeostasis, and Inflammasome Genetic Variants: The CORDIOPREV Study.

SCOPE: Insulin resistance (IR) and chronic low-grade inflammation are hallmarks of type 2 diabetes mellitus (T2DM). The "NOD-like receptor pyrin domain containing-3" (NLRP3) inflammasome component of innate immunity is a metabolic stress sensor modulated by dietary and genetics factors. The aim of this study was to evaluate the effects of the consumption of two diets for 3 years, Mediterranean (Med) and low fat, on glucose homeostasis in the 1002 coronary heart disease patients of the CORDIOPREV study, according to a genetic variant of NLRP3 inflammasome. METHODS AND RESULTS: The study was conducted in the framework of the CORDIOPREV study, a randomized dietary intervention with Med and low-fat diets. Single nucleotide polymorphisms (SNPs) located at inflammasome NLRP3 gene were genotyped by OpenArray platform. Nondiabetic CT+TT carriers of the rs4612666 SNP and AG+AA carriers of the rs10733113 SNP increased insulin sensitivity index (ISI) after 3 years of dietary intervention, whereas no effect was observed in diabetic patients. Further analysis by diet showed that the improvement of the ISI in nondiabetic rs10733113 AG+AA carriers was specific to the consumption of the Med diet. CONCLUSION: Our results show that the benefits associated with a Med diet regarding glucose homeostasis in non-T2DM patients depend on genetic variation in the inflammasome.

A plasma circulating miRNAs profile predicts type 2 diabetes mellitus and prediabetes: from the CORDIOPREV study.

We aimed to explore whether changes in circulating levels of miRNAs according to type 2 diabetes mellitus (T2DM) or prediabetes status could be used as biomarkers to evaluate the risk of developing the disease. The study included 462 patients without T2DM at baseline from the CORDIOPREV trial. After a median follow-up of 60 months, 107 of the subjects developed T2DM, 30 developed prediabetes, 223 maintained prediabetes and 78 remained disease-free. Plasma levels of four miRNAs related to insulin signaling and beta-cell function were measured by RT-PCR. We analyzed the relationship between miRNAs levels and insulin signaling and release indexes at baseline and after the follow-up period. The risk of developing disease based on tertiles (T1-T2-T3) of baseline miRNAs levels was evaluated by COX analysis. Thus, we observed higher miR-150 and miR-30a-5p and lower miR-15a and miR-375 baseline levels in subjects with T2DM than in disease-free subjects. Patients with high miR-150 and miR-30a-5p baseline levels had lower disposition index (p = 0.047 and p = 0.007, respectively). The higher risk of disease was associated with high levels (T3) of miR-150 and miR-30a-5p (HRT3-T1 = 4.218 and HRT3-T1 = 2.527, respectively) and low levels (T1) of miR-15a and miR-375 (HRT1-T3 = 3.269 and HRT1-T3 = 1.604, respectively). In conclusion, our study showed that deregulated plasma levels of miR-150, miR-30a-5p, miR-15a, and miR-375 were observed years before the onset of T2DM and pre-DM and could be used to evaluate the risk of developing the disease, which may improve prediction and prevention among individuals at high risk for T2DM.

Endotoxemia is modulated by quantity and quality of dietary fat in older adults.

BACKGROUND: Aging is an important determinant of the rate of atherosclerosis development, mainly through low-grade inflammation. Diet, and particularly its fat content, modulates the inflammatory response in fasting and postprandial states. OBJECTIVE: We aimed to study the effects of dietary fat on endotoxemia in healthy older adults. MATERIALS AND METHODS: Twenty healthy older adults were randomized to three diets, lasting three-weeks each, using a crossover design: 1. A Mediterranean diet enriched in MUFA with virgin olive oil. 2. An SFA-rich diet. 3. A low-fat high-carbohydrate diet enriched in n-3 PUFA (α-linolenic acid of plant origin) (CHO-PUFA diet). At the end of each period, after a 12-h fast, the subjects received a meal with a composition similar to the dietary period just completed. We determined the fasting and the postprandial plasma levels of lipopolysaccharide (LPS) and LPS-binding protein (LBP). RESULTS: In the fasting state, we observed lower LPS plasma levels after the consumption of the CHO-PUFA diet (P=0.046) in comparison with the consumption of the Med and SFA-rich diets. In the postprandial measurements, we observed a statistically significant increase in plasma levels of LPS (P=0.044) and a decrease in LBP (P=0.003) after the intake of the CHO-PUFA meal, whereas no postprandial changes were observed after the ingestion of the Med and SFA-rich meals. CONCLUSION: Our results, together with those obtained in a previous study, support the concept that the consumption of the Med Diet, in contrast to a low-fat PUFA diet, constitutes a more suitable dietary lifestyle for preventing the development of atherosclerosis in a population at risk, such as older adults.

Effect of Dietary Lipids on Endotoxemia Influences Postprandial Inflammatory Response.

Metabolic syndrome (MetS) results in postprandial metabolic alterations that predisposes one to a state of chronic low-grade inflammation and increased oxidative stress. We aimed to assess the effect of the consumption of the quantity and quality of dietary fat on fasting and postprandial plasma lipopolysaccharides (LPS). A subgroup of 75 subjects with metabolic syndrome was randomized to receive 1 of 4 diets: HSFA, rich in saturated fat; HMUFA, rich in monounsaturated fat; LFHCC n-3, low-fat, rich in complex carbohydrate diet supplemented with n-3 polyunsaturated fatty acids; LFHCC low-fat, rich in complex carbohydrate diet supplemented with placebo, for 12 weeks each. We administered a fat challenge reflecting the fatty acid composition of the diets at postintervention. We determined the plasma lipoproteins and glucose and gene expression in peripheral blood mononuclear cells (PBMC) and adipose tissue. LPS and LPS binding protein (LBP) plasma levels were determined by ELISA, at fasting and postprandial (4 h after a fat challenge) states. We observed a postprandial increase in LPS levels after the intake of the HSFA meal, whereas we did not find any postprandial changes after the intake of the other three diets. Moreover, we found a positive relationship between the LPS plasma levels and the gene expression of IkBa and MIF1 in PBMC. No statistically significant differences in the LBP plasma levels at fasting or postprandial states were observed. Our results suggest that the consumption of HSFA diet increases the intestinal absorption of LPS which, in turn, increases postprandial endotoxemia levels and the postprandial inflammatory response.

Dietary fat quantity and quality modifies advanced glycation end products metabolism in patients with metabolic syndrome.

SCOPE: Advanced glycation end products (AGEs) increase in dysmetabolic conditions. Lifestyle, including diet, has shown be effective in preventing the development of metabolic syndrome (MetS). We investigated whether AGE metabolism is affected by diets with different fat quantity and quality in MetS patients. METHODS AND RESULTS: A randomized, controlled trial assigned 75 MetS patients to one of four diets: high SFA (HSFA), high MUFA (HMUFA), and two low-fat, high-complex carbohydrate diets (LFHCC) supplemented with long-chain n-3 PUFA or placebo for 12-weeks each. Dietary and serum AGE [methylglyoxal (MG: lysine-MG-H1) and N-carboxymethyllysine] levels and gene expression related to AGE metabolism in peripheral blood mononuclear cells (AGER1, RAGE, GloxI, and Sirt1 mRNA) were determined. HMUFA diet reduced serum AGE (sAGE) and RAGE mRNA, increased AGER1 and GloxI mRNA levels compared to the other diets. LFHCC n-3 diet reduced sAGE levels and increased AGER1 mRNA levels compared to LFHCC and HSFA diets. Multiple regression analyses showed that sMG and AGER1 mRNA appeared as significant predictors of oxidative stress/inflammation-related parameters. CONCLUSIONS: Low AGE content in HMUFA diet reduces sAGEs and modulates the gene expression related to AGE metabolism in MetS patients, which may be used as a therapeutic approach to reduce the incidence of MetS and related chronic diseases.

TNFA gene variants related to the inflammatory status and its association with cellular aging: From the CORDIOPREV study.

BACKGROUND: Several single nucleotide polymorphisms have been proposed as potential predictors of the development of age-related diseases. OBJECTIVE: To explore whether Tumor Necrosis Factor Alpha (TNFA) gene variants were associated with inflammatory status, thus facilitating the rate of telomere shortening and its relation to cellular aging in a population with established cardiovascular disease from the CORDIOPREV study (NCT00924937). MATERIALS AND METHODS: SNPs (rs1800629 and rs1799964) located at the TNFA gene were genotyped by OpenArray platform in 840 subjects with established cardiovascular disease. Relative telomere length was determined by real time PCR and plasma levels of C-reactive protein by ELISA. In a subgroup of 90 subjects, the gene expression profiles of TNFA, IKKß, p47phox, p40phox, p22phox and gp91phox were determined by qRT-PCR. RESULTS: GG subjects for the SNP rs1800629 at the TNFA gene showed shorter relative telomere length and higher plasma levels of hs-CRP than A-allele subjects (p<0.05). Consistent with these findings, the expression of pro-inflammatory (TNFA) and pro-oxidant (p47phox and the gp91phox) genes was higher in GG subjects than A allele subjects (p<0.05). CONCLUSION: Subjects carrying the GG genotype for the SNP rs1800629 at the TNFA gene show a greater activation of the proinflammatory status than A-allele carriers, which is related to ROS formation. These ROS could induce DNA damage especially in the telomeric sequence, by decreasing the telomere length and inducing cellular aging. This effect may also increase the risk of the development of age-related diseases.