Impact of mediterranean diet promotion on environmental sustainability: a longitudinal analysis.

OBJECTIVE: This article aims to estimate the differences in environmental impact (greenhouse gas [GHG] emissions, land use, energy used, acidification and potential eutrophication) after one year of promoting a Mediterranean diet (MD). METHODS: Baseline and 1-year follow-up data from 5800 participants in the PREDIMED-Plus study were used. Each participant's food intake was estimated using validated semi-quantitative food frequency questionnaires, and the adherence to MD using the Dietary Score. The influence of diet on environmental impact was assessed through the EAT-Lancet Commission tables. The influence of diet on environmental impact was assessed through the EAT-Lancet Commission tables. The association between MD adherence and its environmental impact was calculated using adjusted multivariate linear regression models. RESULTS: After one year of intervention, the kcal/day consumed was significantly reduced (-125,1 kcal/day), adherence to a MD pattern was improved (+0,9) and the environmental impact due to the diet was significantly reduced (GHG: -361 g/CO2-eq; Acidification:-11,5 g SO2-eq; Eutrophication:-4,7 g PO4-eq; Energy use:-842,7 kJ; and Land use:-2,2 m2). Higher adherence to MD (high vs. low) was significantly associated with lower environmental impact both at baseline and one year follow-up. Meat products had the greatest environmental impact in all the factors analysed, both at baseline and at one-year follow-up, in spite of the reduction observed in their consumption. CONCLUSIONS: A program promoting a MD, after one year of intervention, significantly reduced the environmental impact in all the factors analysed. Meat products had the greatest environmental impact in all the dimensions analysed.

Intensive Weight-Loss Lifestyle Intervention Using Mediterranean Diet and COVID-19 Risk in Older Adults: Secondary Analysis of PREDIMED-Plus Trial.

OBJECTIVES: We tested the effects of a weight-loss intervention encouraging energy-reduced MedDiet and physical activity (PA) in comparison to ad libitum MedDiet on COVID-19 incidence in older adults. DESIGN: Secondary analysis of PREDIMED-Plus, a prospective, ongoing, multicentre randomized controlled trial. SETTING: Community-dwelling, free-living participants in PREDIMED-Plus trial. PARTICIPANTS: 6,874 Spanish older adults (55-75 years, 49% women) with overweight/obesity and metabolic syndrome. INTERVENTION: Participants were randomised to Intervention (IG) or Control (CG) Group. IG received intensive behavioural intervention for weight loss with an energy-reduced MedDiet intervention and PA promotion. CG was encouraged to consume ad libitum MedDiet without PA recommendations. MEASUREMENTS: COVID-19 was ascertained by an independent Event Committee until December 31, 2021. COX regression models compared the effect of PREDIMED-Plus interventions on COVID-19 risk. RESULTS: Overall, 653 COVID-19 incident cases were documented (IG:317; CG:336) over a median (IQR) follow-up of 5.8 (1.3) years (inclusive of 4.0 (1.2) years before community transmission of COVID-19) in both groups. A significantly lowered risk of COVID-19 incidence was not evident in IG, compared to CG (fully-adjusted HR (95% CI): 0.96 (0.81,1.12)). CONCLUSIONS: There was no evidence to show that an intensive weight-loss intervention encouraging energy-reduced MedDiet and PA significantly lowered COVID-19 risk in older adults with overweight/obesity and metabolic syndrome in comparison to ad libitum MedDiet. Recommendations to improve adherence to MedDiet provided with or without lifestyle modification suggestions for weight loss may have similar effects in protecting against COVID-19 risk in older adults with high cardiovascular risks.

Hepatic insulin resistance both in prediabetic and diabetic patients determines postprandial lipoprotein metabolism: from the CORDIOPREV study.

BACKGROUND/AIMS: Previous evidences have shown the presence of a prolonged and exaggerated postprandial response in type 2 diabetes mellitus (T2DM) and its relation with an increase of cardiovascular risk. However, the response in prediabetes population has not been established. The objective was to analyze the degree of postprandial lipemia response in the CORDIOPREV clinical trial (NCT00924937) according to the diabetic status. METHODS: 1002 patients were submitted to an oral fat load test meal (OFTT) with 0.7 g fat/kg body weight [12 % saturated fatty acids (SFA), 10 % polyunsaturated fatty acids (PUFA), 43 % monounsaturated fatty acids (MUFA), 10 % protein and 25 % carbohydrates]. Serial blood test analyzing lipid fractions were drawn at 0, 1, 2, 3 and 4 h during postprandial state. Postprandial triglycerides (TG) concentration at any point >2.5 mmol/L (220 mg/dL) has been established as undesirable response. We explored the dynamic response in 57 non-diabetic, 364 prediabetic and 581 type 2 diabetic patients. Additionally, the postprandial response was evaluated according to basal insulin resistance subgroups in patients non-diabetic and diabetic without pharmacological treatment (N = 642). RESULTS: Prevalence of undesirable postprandial TG was 35 % in non-diabetic, 48 % in prediabetic and 59 % in diabetic subgroup, respectively (p < 0.001). Interestingly, prediabetic patients displayed higher plasma TG and large triacylglycerol-rich lipoproteins (TRLs-TG) postprandial response compared with those non-diabetic patients (p < 0.001 and p = 0.003 respectively). Moreover, the area under the curve (AUC) of TG and AUC of TRLs-TG was greater in the prediabetic group compared with non-diabetic patients (p < 0.001 and p < 0.005 respectively). Patients with liver insulin resistance (liver-IR) showed higher postprandial response of TG compared with those patients with muscle-IR or without any insulin-resistance respectively (p < 0.001). CONCLUSIONS: Our findings demonstrate that prediabetic patients show a lower phenotypic flexibility after external aggression, such as OFTT compared with nondiabetic patients. The postprandial response increases progressively according to non-diabetic, prediabetic and type 2 diabetic state and it is higher in patients with liver insulin-resistance. To identify this subgroup of patients is important to treat more intensively in order to avoid future cardiometabolic complications.

Alarmin high-mobility group B1 (HMGB1) is regulated in human adipocytes in insulin resistance and influences insulin secretion in ß-cells.

BACKGROUND: The nuclear protein high-mobility group box 1 (HMGB1) can be passively released by necrotic cells or secreted actively by several cell types to regulate immune and inflammatory responses, as well as tissue remodeling. We herein aimed to characterize the effect of insulin resistance on HMGB1 in adipose tissue and to examine its potential role as a metabolic regulator in ß-pancreatic cells. DESIGN: Plasma HMGB1 concentration and adipose HMGB1 expression were assessed in relation to obesity and insulin resistance. Cultured adipocytes from lean and obese patients were used to investigate the intracellular distribution and factors regulating HMGB1 release, as well as to test its effects on adipogenesis and lipid metabolism. A regulatory role for HMGB1 in insulin secretion was also investigated. RESULTS: Circulating HMGB1 was positively associated with body mass index, while adipose HMGB1 mRNA levels correlated with the expression of inflammatory markers. Insulin resistance modified the intracellular distribution of HMGB1 in human adipocytes, with HMGB1 being predominantly nuclear in lean and obese normoglycemic individuals while localized to the cytosol in obese patients with type 2 diabetes. Adipocytes from lean individuals exposed to conditioned media from lipopolysaccharide-stimulated macrophages induced HMGB1 redistribution to the cytoplasm and release. HMGB1 treatment had no effect on differentiation and lipid metabolism in adipocytes. However, HMGB1, whose circulating levels correlated with postload insulin concentration, increased both insulin release and intracellular Ca(2+) concentration in INS-1 cells. CONCLUSIONS: These findings show, for the first time, that HMGB1 expression and release by human adipocytes is altered by inflammatory conditions as those imposed by obesity and insulin resistance. Our data reveal a novel role for HMGB1 as a stimulatory factor of insulin secretion of ß-pancreatic cells.

A gene variation (rs12691) in the CCAT/enhancer binding protein α modulates glucose metabolism in metabolic syndrome.

BACKGROUND AND AIMS: CCAAT/enhancer-binding protein alpha (CEBPA) is a transcription factor involved in adipogenesis and energy homeostasis. Caloric restriction reduces CEBPA protein expression in patients with metabolic syndrome (MetS). A previous report linked rs12691 SNP in CEBPA to altered concentration of fasting triglycerides. Our objective was to assess the effects of rs12691 in glucose metabolism in Metabolic Syndrome (MetS) patients. METHODS AND RESULTS: Glucose metabolism was assessed by static (glucose, insulin, adiponectin, leptin and resistin plasma concentrations) and dynamic (disposition index, insulin sensitivity index, HOMA-IR and acute insulin response to glucose) indices, performed at baseline and after 12 weeks of 4 dietary interventions (high saturated fatty acid (SFA), high monounsaturated fatty acid (MUFA), low-fat and low-fat-high-n3 polyunsaturated fatty acid (PUFA)) in 486 subjects with MetS. Carriers of the minor A allele of rs12691 had altered disposition index (p = 0.0003), lower acute insulin response (p = 0.005) and a lower insulin sensitivity index (p = 0.025) indicating a lower insulin sensitivity and a lower insulin secretion, at baseline and at the end of the diets. Furthermore, A allele carriers displayed lower HDL concentration. CONCLUSION: The presence of the A allele of rs12691 influences glucose metabolism of MetS patients.

Consumption of diets with different type of fat influences triacylglycerols-rich lipoproteins particle number and size during the postprandial state.

BACKGROUND AND AIMS: Previous evidence suggests that dietary fat could influence the composition and size of triacylglycerols-rich lipoproteins (TRL). In a controlled intervention study on healthy subjects, we evaluated the influence of 3 dietary interventions, with different types of fat on postprandial TRL particle size and number. METHODS AND RESULTS: Volunteers followed three different diets for four weeks each, according to a randomized crossover design. Western diet: 15% protein, 47% carbohydrates (CHO), 38% fat (22% saturated fatty acid (SFA)); Mediterranean diet: 15% protein, 47% CHO, 38% fat (24% monounsaturated fatty acid (MUFA)); high CHO enriched with ALNA diet: 15% protein, 55% CHO, <30% fat (8% polyunsaturated fatty acid (PUFA)). After a 12-h fast, volunteers consumed a breakfast with 1g fat and 7 mg cholesterol per kg body weight and a fat composition similar to that consumed in each of the diets: Butter meal: 35% SFA; Olive oil meal: 36% MUFA; Walnut meal: 16% PUFA, 4% α-linolenic acid. Tryglicerides (TG) in TRL (large and small TRL) were determined by ultracentrifugation and size and number of lipoprotein particles were measured with Nuclear Magnetic Resonance Spectroscopy at different time points. The olive oil meal reduced the number of total TRL postprandial particles compared with the other meals (P=0.002). Moreover, the olive oil meal also increased the TRL particle size compared with the walnut meal (P=0.001). CONCLUSION: Our data showed that short-term intake of the Mediterranean diet and the acute intake of an olive oil meal lead to the formation of a reduced number and higher-size TRL particle compared with other fat sources. These novel findings have implications for understanding the postprandial lipoprotein mechanisms, and could favour the lower cardiovascular risk in Mediterranean countries.

Association between the APOA2 promoter polymorphism and body weight in Mediterranean and Asian populations: replication of a gene-saturated fat interaction.

OBJECTIVE: The APOA2 gene has been associated with obesity and insulin resistance (IR) in animal and human studies with controversial results. We have reported an APOA2-saturated fat interaction determining body mass index (BMI) and obesity in American populations. This work aims to extend our findings to European and Asian populations. METHODS: Cross-sectional study in 4602 subjects from two independent populations: a high-cardiovascular risk Mediterranean population (n = 907 men and women; aged 67 ± 6 years) and a multiethnic Asian population (n = 2506 Chinese, n = 605 Malays and n = 494 Asian Indians; aged 39 ± 12 years) participating in a Singapore National Health Survey. Anthropometric, clinical, biochemical, lifestyle and dietary variables were determined. Homeostasis model assessment of insulin resistance was used in Asians. We analyzed gene-diet interactions between the APOA2 -265T>C polymorphism and saturated fat intake (C polymorphism on body-weight-related measures was modulated by saturated fat in Mediterranean and Asian populations.

Pleiotropic effects of TCF7L2 gene variants and its modulation in the metabolic syndrome: from the LIPGENE study.

AIMS/HYPOTHESIS: Variants of the TCF7L2 gene predict the development of type 2 diabetes mellitus (T2DM). We investigated the associations between gene variants of TCF7L2 and clinical features of the metabolic syndrome (MetS) (an entity often preceding T2DM), and their interaction with non-genetic factors, including plasma saturated fatty acids (SFA) concentration and insulin resistance (IR). METHODS: Fasting lipid profiles, insulin sensitivity, insulin secretion, anthropometrics, blood pressure and 10 gene variations of the TCF7L2 gene were determined in 450 subjects with MetS. RESULTS: Several single nucleotide polymorphisms (SNP) showed phenotypic associations independent of SFA or IR. Carriers of the rare T allele of rs7903146, and of three other SNPs in linkage disequilibrium with rs7903146, had lower blood pressure and insulin secretion. High IR and the presence of the T-allele of rs7903146 acted synergistically to define those with reduced insulin secretion. Carriers of the minor allele of rs290481 exhibited an altered lipid profile, with increased plasma levels of apolipoprotein B, non-esterified fatty acids, cholesterol and apolipoprotein B in triglyceride rich lipoproteins, and LDL cholesterol. Carriers of the minor allele of rs11196224 that had higher plasma SFA levels showed elevated procoagulant/proinflammatory biomarkers, impaired insulin secretion and increased IR, whereas carriers of the minor allele of rs17685538 with high plasma SFA levels exhibited higher blood pressure. CONCLUSIONS/INTERPRETATION: SNP in the TCF7L2 gene are associated with differences in insulin secretion, blood pressure, blood lipids and coagulation in MetS patients, and may be modulated by SFA in plasma or IR.

Polymorphism at the TRIB1 gene modulates plasma lipid levels: insight from the Spanish familial hypercholesterolemia cohort study.

BACKGROUND AND AIMS: rs17321515 SNP has been associated with variation in LDL-C, high density lipoprotein cholesterol and triglycerides concentrations. This effect has never been studied in patients with severe hypercholesterolemia. Therefore, our aims were to assess the association of the rs17321515 (TRIB1) SNP with plasma lipids concentrations and anthropometric variables and to explore the interaction between this SNP and some classic risk factors in patients with familial hypercholesterolemia (FH). METHODS AND RESULTS: rs17321515 SNP was genotyped in 531 subjects with genetic diagnosis of FH. Homozygous A/A had significantly higher waist circumference compared with G/G subjects (P = 0.006) and carriers of the minor allele G (P = 0.039). Interestingly, smokers homozygous for the A allele displayed higher plasma triglycerides concentrations (P = 0.029), higher VLDL-C levels (P = 0.023) and higher TC/HDL-C ratio (P = 0.035) than carriers of the minor allele G. In addition, homozygous A/A with the presence of arcus cornealis displayed lower plasma ApoA-I levels (P = 0.024) and higher TC/HDL-C ratio (P = 0.046) than carriers of the minor allele G. CONCLUSIONS: Smoking status and presence of arcus cornealis modulate the effect of rs17321515 (TRIB1) polymorphism on plasma lipids levels in patients with FH. These results could explain the differences in the susceptibility to coronary heart disease in these patients.

Genetic variations at ABCG5/G8 genes modulate plasma lipids concentrations in patients with familial hypercholesterolemia.

OBJECTIVE: To investigate the association of four common single nucleotide polymorphisms (SNPs) at ABCG5 (i7892A>G, i18429C>T, Gln604GluC>G, i11836G>A) and five at ABCG8 (5U145T>G, Tyr54CysA>G, Asp19HisG>C, i14222T>C, and Thr400LysG>T) with plasma lipids concentrations and to explore the interaction between those SNPs and smoking in patients with FH. METHODS AND RESULTS: ABCG5/G8 SNPs were genotyped in 500 subjects with genetic diagnosis of FH. Carriers of the minor A allele at the ABCG5_i11836G>A SNP displayed significantly higher HDL-C concentrations (P=0.023) than G/G subjects. In addition, carriers of the minor G allele at the ABCG5_Gln604GluC>G SNP had significantly lower VLDL-C (P=0.011) and lower TG (P=0.017) concentrations than homozygous C/C. Interestingly, a significant gene-smoking interaction was found, in which carriers of the minor alleles at ABCG5 (i7892A>G, i18429C>T, i11836G>A) SNPs displayed significantly lower HDL-C, higher TC and higher TG respectively, only in smokers. On the other hand, nonsmokers carriers of the minor alleles at ABCG5 (i18429C>T and Gln604GluC>G) SNPs had significantly lower TG concentrations (P=0.012 and P=0.035) compared with homozygous for the major allele. CONCLUSIONS: Our data support the notion that ABCG5/G8 genetic variants modulate plasma lipids concentrations in patients with FH and confirm that this effect could be influenced by smoking. Therefore, these results suggest that gene-environmental interactions can affect the clinical phenotype of FH.