A High Intake of Saturated Fatty Acids Strengthens the Association between the Fat Mass and Obesity-Associated Gene and BMI123

Evidence that physical activity (PA) modulates the association between the fat mass and obesity-associated gene (FTO) and BMI is emerging; however, information about dietary factors modulating this association is scarce. We investigated whether fat and carbohydrate intake modified the association of FTO gene variation with BMI in two populations, including participants in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) study (n = 1069) and in the Boston Puerto Rican Health (BPRHS) study (n = 1094). We assessed energy, nutrient intake, and PA using validated questionnaires. Genetic variability at the FTO locus was characterized by polymorphisms rs9939609 (in the GOLDN) and rs1121980 (in the GOLDN and BPRHS). We found significant interactions between PA and FTO on BMI in the GOLDN but not in the BPRHS. We found a significant interaction between SFA intake and FTO on BMI, which was stronger than that of total fat and was present in both populations (P-interaction = 0.007 in the GOLDN and P-interaction = 0.014 in BPRHS for categorical; and P-interaction = 0.028 in the GOLDN and P-interaction = 0.041 in BPRHS for continuous SFA). Thus, homozygous participants for the FTO-risk allele had a higher mean BMI than the other genotypes only when they had a high-SFA intake (above the population mean: 29.7 ± 0.7 vs. 28.1 ± 0.5 kg/m2; P = 0.037 in the GOLDN and 33.6. ± 0.8 vs. 31.2 ± 0.4 kg/m2; P = 0.006 in BPRHS). No associations with BMI were found at lower SFA intakes. We found no significant interactions with carbohydrate intake. In conclusion, SFA intake modulates the association between FTO and BMI in American populations

Sedimentological and palaeohydrological characterization of Late Pleistocene and Holocene tufa mound palaeolakes using trenching methods in the Spanish Pyrenees

Lakes developed in the inner depressions of tufa mounds are rare geomorphic features and still poorly understood. Sedimentation in this unusual type of endorheic lake with a very restricted catchment area is highly sensitive to environmental and hydrological changes. The Isona tufa mound complex, north-eastern Iberian Peninsula, is associated with the discharge zone of a confined artesian aquifer and comprises 11 tufa mounds consisting of an annular rimstone enclosing a central depression filled with lake deposits. Data gathered from trenches excavated in four palaeolakes located within three different morphostratigraphic units permitted a precise analysis of the geometrical characteristics and stratigraphic relationships of the deposits and provided a sedimentation model for the Late Quaternary infilling of the spring-fed lakes. The work illustrates that trenches allow a precise characterization of the stratigraphic arrangements, lateral facies changes and deformation structures, which are not apparent in studies relying solely on borehole records, and facilitate sampling for dating and geochemical analyses. The five sedimentary facies described represent different evolutionary stages of the lakes, including: (i) carbonate-rich palustrine deposits probably related to periods with strong hydrological seasonality; (ii) massive highly bioturbated organic ooze; (iii) banded organic carbonate-rich facies associated with an increase in the regional effective moisture; (iv) finegrained quartz-rich aeolian/slope-wash sediments; and (v) colluvial facies deposited following the desiccation of the lakes located at higher altitudes. Geochemical and sedimentological analyses of the lacustrine sequences provided information on the palaeohydrological evolution of the Isona tufa mound complex and the palaeoenvironmental conditions of the area over the last 28 ka. Radiometric dating suggests that deposition occurred simultaneously at ca 22 ka in palaeolakes situated at different elevations. A drop in the piezometric level prompted by the opening of springs at lower altitudes probably caused the deactivation of the upper springs and the desiccation of the lakes. Arid conditions prevailed in the area during the Late Glacial and the early Holocene (28·0 to 8·5 ka BP). More humid conditions recorded from 8·5 to 4·2 ka and again since 1·7 ka are in accordance with palaeoenvironmental reconstructions available in the Western Mediterranean since the Last Glacial Maximum

Association between a SLC23A2 gene variation, plasma vitamin C levels, and risk of glaucoma in a Mediterranean population

PurposeSeveral dietary factors have been associated with glaucoma. Among them, dietary antioxidant intake (i.e., vitamin C and vitamin A) in association with glaucoma has been analyzed, but with mixed results. Genetic factors may play a role in modulating the effect of dietary antioxidant intake on glaucoma; however, nutrigenetic studies in this field are scarce. Our aim was to study the association between selected polymorphisms in key proteins related to vitamin C and vitamin A concentrations and primary open-angle glaucoma (POAG).MethodsWe performed a case-control study matched for age, sex, and bodyweight. We recruited 300 subjects (150 POAG cases and 150 controls) from a Mediterranean population and determined the plasma concentrations of vitamin C and vitamin A for each subject. We selected the following single-nucleotide polymorphisms (SNPs) in genes related to vitamin A and vitamin C concentrations: rs176990 and rs190910 in the retinol-binding protein 1 (RBP1) gene; and rs10063949 and rs1279683 in the Na+-dependent L-ascorbic acid transporters 1 and 2, respectively (encoded by the SLC23A1 and SLC23A2 genes).ResultsWe found a statistically significant association between the rs1279386 (A>G) SNP in SLC23A2 and POAG risk. In the crude analysis, homozygous subjects for the G allele (GG subjects) had higher risk of POAG than other genotypes (OR: 1.67; 95% CI: 1.03–2.71). This association remained statistically significant (p=0.010) after multivariate adjustment for potential confounders. We also found that POAG patients had lower plasma vitamin C concentrations than control subjects (9.9±1.7 µg/ml versus 11.7±1.8 µg/ml, p<0.001). Moreover, we consistently detected a significant association between the rs1279386 SNP in SLC23A2 and plasma vitamin C concentrations: GG subjects had significantly lower plasma vitamin C concentrations than the other genotypes (9.0±1.4 µg/ml versus 10.5±1.6 µg/ml, p<0.001 in POAG cases and 10.9±1.6 µg/ml versus 12.1±1.8 µg/ml, p<0.001 in controls). The rs10063949 SNP in SLC23A1 was not associated with either plasma vitamin C concentrations or POAG risk. Similarly, SNPs in RBP1 were not associated with vitamin A concentrations or POAG risk.ConclusionsThe rs1279683 SNP in SLC23A2 was significantly associated with lower plasma concentrations of vitamin C and with higher risk of POAG in GG subjects

The Mediterranean diet protects against waist circumference enlargement in 12Ala carriers for the PPARgamma gene: 2 years' follow-up of 774 subjects at high cardiovascular risk.

The PPARgamma gene regulates insulin sensitivity and adipogenesis. The Pro12Ala polymorphism of this gene has been related to fat accumulation. Our aim was to analyse the effects of a 2-year nutritional intervention with Mediterranean-style diets on adiposity in high-cardiovascular risk patients depending on the Pro12Ala polymorphism of the PPARgamma gene. The population consisted of a substudy (774 high-risk subjects aged 55-80 years) of the Prevención con Dieta Mediterránea (PREDIMED) randomised trial aimed at assessing the effect of the Mediterranean diet for CVD prevention. There were three nutritional intervention groups: two of them of a Mediterranean-style diet and the third was a control group advised to follow a conventional low-fat diet. All the participants were genotyped by PCR-restriction fragment length polymorphism (RFLP). The results showed that carriers of the 12Ala allele allocated to the control group had a statistically significant higher change in waist circumference (adjusted difference coefficient = 2.37 cm; P = 0.014) compared with wild-type subjects after 2 years of nutritional intervention. This adverse effect was not observed among 12Ala carriers allocated to both Mediterranean diet groups. In diabetic patients a statistically significant interaction between Mediterranean diet and the 12Ala allele regarding waist circumference change was observed ( - 5.85 cm; P = 0.003). In conclusion, the Mediterranean diet seems to be able to reduce waist circumference in a high-cardiovascular risk population, reversing the negative effect that the 12Ala allele carriers of the PPARgamma gene appeared to have. The beneficial effect of this dietary pattern seems to be higher among type 2 diabetic subjects

Dietary Intake of n-6 Fatty Acids Modulates Effect of Apolipoprotein A5 Gene on Plasma Fasting Triglycerides, Remnant Lipoprotein Concentrations, and Lipoprotein Particle Size

Background— Apolipoprotein A5 gene (APOA5) variation is associated with plasma triglycerides (TGs). However, little is known about whether dietary fat modulates this association. Methods and Results— We investigated the interaction between APOA5 gene variation and dietary fat in determining plasma fasting TGs, remnant-like particle (RLP) concentrations, and lipoprotein particle size in 1001 men and 1147 women who were Framingham Heart Study participants. Polymorphisms –1131T>C and 56C>G, representing 2 independent haplotypes, were analyzed. Significant gene–diet interactions between the –1131T>C polymorphism and polyunsaturated fatty acid (PUFA) intake were found (PG polymorphism. The –1131C allele was associated with higher fasting TGs and RLP concentrations (P6% of total energy). No heterogeneity by sex was found. These interactions showed a dose-response effect when PUFA intake was considered as a continuous variable (P<0.01). Similar interactions were found for the sizes of VLDL and LDL particles. Only in carriers of the –1131C allele did the size of these particles increase (VLDL) or decrease (LDL) as PUFA intake increased (P<0.01). We further analyzed the effects of n-6 and n-3 fatty acids and found that the PUFA–APOA5 interactions were specific for dietary n-6 fatty acids. Conclusions— Higher n-6 (but not n-3) PUFA intake increased fasting TGs, RLP concentrations, and VLDL size and decreased LDL size in APOA5 –1131C carriers, suggesting that n-6 PUFA–rich diets are related to a more atherogenic lipid profile in these subjects.Corella Piquer, Maria Dolores, [email protected]

Epigenomics and Metabolomics Reveal the Mechanism of the \u3cem\u3eAPOA2\u3c/em\u3e-Saturated Fat Intake Interaction Affecting Obesity

Background: The putative functional variant −265T \u3e C (rs5082) within the APOA2 promoter has shown consistent interactions with saturated fatty acid (SFA) intake to influence the risk of obesity. Objective: The aim of this study was to implement an integrative approach to characterize the molecular basis of this interaction. Design: We conducted an epigenome-wide scan on 80 participants carrying either the rs5082 CC or TT genotypes and consuming either a low-SFA (\u3c 22 g/d) or high-SFA diet (≥ 22 g/d), matched for age, sex, BMI, and diabetes status in the Boston Puerto Rican Health Study (BPRHS). We then validated the findings in selected participants in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) Study (n = 379) and the Framingham Heart Study (FHS) (n = 243). Transcription and metabolomics analyses were conducted to determine the relation between epigenetic status, APOA2 mRNA expression, and blood metabolites. Results: In the BPRHS, we identified methylation site cg04436964 as exhibiting significant differences between CC and TT participants consuming a high-SFA diet, but not among those consuming low-SFA. Similar results were observed in the GOLDN Study and the FHS. Additionally, in the FHS, cg04436964 methylation was negatively correlated with APOA2 expression in the blood of participants consuming a high-SFA diet. Furthermore, when consuming a high-SFA diet, CC carriers had lower APOA2 expression than those with the TT genotype. Lastly, metabolomic analysis identified 4 pathways as overrepresented by metabolite differences between CC and TT genotypes with high-SFA intake, including tryptophan and branched-chain amino acid (BCAA) pathways. Interestingly, these pathways were linked to rs5082-specific cg04436964 methylation differences in high-SFA consumers. Conclusions: The epigenetic status of the APOA2 regulatory region is associated with SFA intake and APOA2 -265T \u3e C genotype, promoting an APOA2 expression difference between APOA2 genotypes on a high-SFA diet, and modulating BCAA and tryptophan metabolic pathways. These findings identify potential mechanisms by which this highly reproducible gene-diet interaction influences obesity risk, and contribute new insights to ongoing investigations of the relation between SFA and human health. This study was registered at clinicaltrials.gov as NCT03452787

Epigenomics and metabolomics reveal the mechanism of the APOA2-saturated fat intake interaction affecting obesity

Background: The putative functional variant -265T\u3eC (rs5082) within the APOA2 promoter has shown consistent interactions with saturated fatty acid (SFA) intake to influence the risk of obesity. Objective: The aim of this study was to implement an integrative approach to characterize the molecular basis of this interaction. Design: We conducted an epigenome-wide scan on 80 participants carrying either the rs5082 CC or TT genotypes and consuming either a low-SFA (\u3c22 g/d) or high-SFA diet (≥22 g/d), matched for age, sex, BMI, and diabetes status in the Boston Puerto Rican Health Study (BPRHS). We then validated the findings in selected participants in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) Study (n = 379) and the Framingham Heart Study (FHS) (n = 243). Transcription and metabolomics analyses were conducted to determine the relation between epigenetic status, APOA2 mRNA expression, and blood metabolites. Results: In the BPRHS, we identified methylation site cg04436964 as exhibiting significant differences between CC and TT participants consuming a high-SFA diet, but not among those consuming low-SFA. Similar results were observed in the GOLDN Study and the FHS. Additionally, in the FHS, cg04436964 methylation was negatively correlated with APOA2 expression in the blood of participants consuming a high-SFA diet. Furthermore, when consuming a high-SFA diet, CC carriers had lower APOA2 expression than those with the TT genotype. Lastly, metabolomic analysis identified 4 pathways as overrepresented by metabolite differences between CC and TT genotypes with high-SFA intake, including tryptophan and branched-chain amino acid (BCAA) pathways. Interestingly, these pathways were linked to rs5082-specific cg04436964 methylation differences in high-SFA consumers. Conclusions: The epigenetic status of the APOA2 regulatory region is associated with SFA intake and APOA2 -265T\u3eC genotype, promoting an APOA2 expression difference between APOA2 genotypes on a high-SFA diet, and modulating BCAA and tryptophan metabolic pathways. These findings identify potential mechanisms by which this highly reproducible gene-diet interaction influences obesity risk, and contribute new insights to ongoing investigations of the relation between SFA and human health. This study was registered at clinicaltrials.gov as NCT03452787

Spatial heterogeneity of benthic methane dynamics in the subaquatic canyons of the Rhone River Delta (Lake Geneva)

Heterogeneous benthic methane (CH4) dynamics from river deltas with important organic matter accumulation have been recently reported in various aquatic and marine environments. The spatial heterogeneity of dissolved CH4 concentrations and associated production and diffusion rates were investigated in the Rhone River Delta of Lake Geneva (Switzerland/France) using sediment cores taken as part of the éLEMO Project. Benthic CH4 dynamics within the complex subaquatic canyon structure of the Rhone Delta were compared (1) between three canyons of different sedimentation regimes, (2) along a longitudinal transect of the ‘active' canyon most influenced by the Rhone River, and (3) laterally across a canyon. Results indicated higher CH4 diffusion and production rates in the ‘active' compared to the other canyons, explained by more allochthonous carbon deposition. Within the active canyon, the highest diffusion and production rates were found at intermediate sites further along the canyon. Stronger resuspension of sediments directly in front of the river inflow was likely the cause for the variable emission rates found there. Evidence also suggests more CH4 production occurs on the levees (shoulders) of canyons due to preferred sedimentation in those locations. Our results from the heterogeneous Rhone delta in Lake Geneva further support the concept that high sedimentary CH4 concentrations should be expected in depositional environments with high inputs of allochthonous organic carbon