There is a high prevalence of hyperhomocysteinemia that has been linked to high cardiovascular risk in obese individuals and could be attributed to poor nutritional status of folate and vitamin B12. We sought to examine the association between blood homocysteine (Hcy) folate, and vitamin B12 levels and vascular dysfunction in morbidly obese adults using novel ex vivo flow-induced dilation (FID) measurements of isolated adipose tissue arterioles. Brachial artery flow-mediated dilation (FMD) was also measured. Subcutaneous and visceral adipose tissue biopsies were obtained from morbidly obese individuals and non-obese controls. Resistance arterioles were isolated in which FID, acetylcholine-induced dilation (AChID), and nitric oxide (NO) production were measured in the absence or presence of the NO synthase inhibitor, L-NAME, Hcy, or the superoxide dismutase mimetic, TEMPOL. Our results demonstrated that plasma Hcy concentrations were significantly higher, while folate, vitamin B12, and NO were significantly lower in obese subjects compared to controls. Hcy concentrations correlated positively with BMI, fat %, and insulin levels but not with folate or vitamin B12. Brachial and arteriolar vasodilation were lower in obese subjects, positively correlated with folate and vitamin B12, and inversely correlated with Hcy. Arteriolar NO measurements and sensitivity to L-NAME were lower in obese subjects compared to controls. Finally, Hcy incubation reduced arteriolar FID and NO sensitivity, an effect that was abolished by TEMPOL. In conclusion, these data suggest that high concentrations of plasma Hcy and low concentrations of folate and vitamin B12 could be independent predictors of vascular dysfunction in morbidly obese individuals.

We thank the editor and the reviewers for their thoughtful review of our manuscript and for the opportunity to improve and resubmit. The detailed comments the authors received are indeed beneficial and improve the quality of our data presentation and interpretation. We have responded to the reviewers' comments/critiques below and have incorporated the recommended changes in the manuscript. Major concernsComment # 1: Do you have information on dietary preferences in your sample? Are there omnivores, vegetarian or vegans? This is important due to the potential use of vitamin supplements with vitamin B12. The authors did not discuss the differences in folate and vitamin B12 between controls and subjects with obesity, and how this is related with the observed methylation patterns… this should be addressed due to its one of the strengths of this study. Response to comment # 1:We agree with the reviewer and we obtained questionnaires about supplementations however, most subjects were not able to recall taking supplements that specifically rich in folate or vitamin B12. Accordingly, we decided to measure actual concentrations of folate and B12 in plasma. Also, we do not have specific information about dietary preferences of our subjects but realizing the importance of this information, we will start to implement this questionnaire in our future studies. We also agree that the part about vitamin B12 and folate in obese and non-obese subjects and the relation to methylation was missing in the discussion. Per your recommendation, we added a new paragraph that discusses this part (lines 341-360).Comment # 2: The data in table 2 was analyzed by sex? Considering that HDL-C cut-off is different among men and women…Response to comment # 2: Results for HDL-C did not show significant differences between males and females within each group (obese and non-obese). When compared, the p value was higher than 0.7 in both groups. Comment # 3:The authors show interesting data in Table 2, where HOMA index and FPI is higher in obese subjects in comparison to controls, however, FPG and HbA1c are not different among groups as expected. Please discuss about these result.Response to comment # 3: Insulin can be higher in obese individuals which results in higher HOMA-IR at earlier stages of insulin resistance before the conditions mature to full-blown diabetes where glucose metabolism is actually compromised and manifested as high blood glucose. We believe that some of subjects in the obese group are at early stages of insulin resistance but since they are young (mid 30s in average), a complete picture of diabetes might not have been developed yet. A statement that explain this was added to the discussion (lines 260-263)Comment # 4: Alcohol consumption was measured by a questionnaire, is this validated? This information is not described in methods, fix this issue. In table 2 the data appears as "alcohol drinkers %", however, in the discussion, the authors mentioned that they have classified into none, mild, moderate and heavy drinking, but this...

Background This study examines the relationships between childhood food allergy and parental unhealthy food choices for their children across attitudes towards childhood obesity as mediators and parental gender, income and education as potential moderators. Methods We surveyed parents with at least one child between the ages of 6 and 12 living in Canada and the United States. We received 483 valid responses that were analysed using structural equation modelling approach with bootstrapping to test the hypothetical path model and its invariance across the moderators. Results The analysis revealed that pressure to eat fully mediated the effects of childhood food allergy and restriction on parental unhealthy food choices for their children. Finally, we found that parental gender moderated the relationship between childhood food allergy and the pressure to eat. Conclusions The paper contributes to the literature on food allergies among children and the marginalisation of families with allergies. Our explorative model is a first of its kind and offers a fresh perspective on complex relationships between variables under consideration. Although our data collection took place prior to Covid-19 outbreak, this paper bears yet particular significance as it casts light on how families with allergies should be part of the priority groups to have access to food supply during crisis periods.

Obesity is characterized by the accumulation of dysfunctional adipose tissues, which predisposes to cardiometabolic diseases. Our previous in vitro studies demonstrated a role of hypoxia in inducing adipokine hypomethylation in adipocytes. We sought to examine this mechanism in visceral adipose tissues (VATs) from obese individuals and its correlation with cardiometabolic risk factors. We propose an involvement of the hypoxia-inducible factor, HIF1α, and the DNA hydroxymethylase, TET1. Blood samples and VAT biopsies were obtained from obese and non-obese subjects (n = 60 each) having bariatric and elective surgeries, respectively. The analyses of VAT showed lower vascularity, and higher levels of HIF1α and TET1 proteins in the obese subjects than controls. Global hypomethylation and hydroxymethylation were observed in VAT from obese subjects along with promoter hypomethylation of several pro-inflammatory adipokines. TET1 protein was enriched near the promotor of the hypomethylated adipokines. The average levels of adipokine methylation correlated positively with vascularity and arteriolar vasoreactivity and negatively with protein levels of HIF1α and TET1 in corresponding VAT samples, serum and tissue inflammatory markers, and other cardiometabolic risk factors. These findings suggest a role for adipose tissue hypoxia in causing epigenetic alterations, which could explain the increased production of adipocytokines and ultimately, vascular dysfunction in obesity.

Previous reports demonstrated that severe acute respiratory syndrome coronavirus (SARS-CoV-2) binding immunoglobulin G levels did not increase significantly between the first and second doses of the BNT162b2 vaccine in previously infected individuals. We tested neutralizing antibodies (nAbs) against SARS-CoV-2 Delta and Omicron variants after the first and second doses of this vaccine in infection-naive and previously infected individuals. Delta, but not Omicron, nAb titers significantly increased from the first to the second dose in both groups of individuals. Importantly, we found that Omicron nAb titers were much lower than Delta nAb titers and that even after 2 doses of vaccine, 17 of 29 individuals in the infection-naive group and 2 of 27 in the previously infected group did not have detectable Omicron nAb titers. Infection history alone did not adequately predict whether a second dose resulted in adequate nAb. For future variants of concern, the discussion on the optimal number of vaccine doses should be based on studies testing for nAb against the specific variant.