Using Capillary Whole Blood to Quantitatively Measure Ferritin: A Validation Trial of a Point-of-Care System.

Iron deficiency is a public health problem with devastating health, developmental and behavioral effects which often exacerbated due to affordability and access to screening and diagnosis. Using IronScan™ a portable, point-of-care diagnostic system capable of quantitatively measuring ferritin in blood, we validated IronScan™ ferritin measurements using whole blood and serum with a lab-based, regulator-approved analytical device for measuring ferritin in venous serum. Capillary (finger stick) and venous whole blood samples were obtained from 44 male and female volunteers. Venous serum (vSer) ferritin concentrations were measured on Immulite 2000 Xpi (gold standard). Capillary whole blood (cWB), venous whole blood (vWB), and vSer ferritin levels were measured by IronScan™. cWB ferritin concentrations from IronScan™ were significantly correlated (R2 = 0.86) with vSer measured with the FDA-approved Immulite system. The results from the multiple regression analysis indicate that 10% of the variability was due to the method of blood collection (venous vs. capillary) and 6% was due to the form of blood analysis (whole blood vs. serum). The sensitivity of diagnosing iron deficiency using the WHO cutoff of <30 ng/mL is 90%, with a specificity of 96%. In conclusion, IronScan™ is a rapid viable option for measuring ferritin as a point-of-care system.

Lower omega-3 status associated with higher erythrocyte distribution width and neutrophil-lymphocyte ratio in UK Biobank cohort.

High red blood distribution width (RDW) is associated with decreased red blood cell deformability, and high neutrophil-lymphocyte ratio (NLR) is a biomarker of systemic inflammation and innate-adaptive immune system imbalance. Both RDW and NLR are predictors of chronic disease risk and mortality. Omega-3 index (O3I) values have previously been shown to be inversely associated with RDW and NLR levels. Our objective was to determine if total plasma long chain omega-3 fatty acids (Omega3%) measured in the UK Biobank cohort were associated with RDW and NLR values. RDW- and NLR- relationships with Omega3% were characterized in 109,191 adults (58.4% female). RDW- and NLR-Omega3% relationships were inversely associated with Omega3% (both p < 0.0001). These cross-sectional associations confirm previous findings that increasing RDW and NLR values are associated with low O3I. The hypothesis that RDW and/or NLR values can be reduced in individuals with less-than optimal long chain omega 3 values need to be tested in randomized controlled intervention trials using EPA and/or DHA.

Are professors of human nutrition faculty at Canadian universities representative with respect to common social constructs of gender and race?

Attributes such as sex and race/ethnicity are associated with inequities in representation. The objective of this study was to assess representation of 2 social constructs, gender and race, of professors of human nutrition in Canada. Using information publicly available October 2021, individuals with the title of assistant, associate, or full professor were identified on websites of 20 Canadian universities offering undergraduate and/or graduate degrees in human nutrition. Individuals were subjectively stratified to social constructs, i.e., white, racialized, or Indigenous, based on photographs, ethnic origin of a surname, and regional and ethnic origin disclosures on university websites, LinkedIn, social media, etc. Gender was assigned based on publicly available photographs and self-disclosed pronouns (when available). Of the 190 individuals, 80% were white, 16.4% were racialized, and 2.6% were Indigenous peoples. The majority (65.3%) were women. In a subset with established doctoral thesis dates and dates of hire at their current institution (n = 153), racialized and Indigenous professors, especially assistant and associate, had earned their doctorate and been hired more recently than their white peers. This study is limited because only individuals with professorial titles were included and the assignment of social constructs for race and gender was subjective. Nevertheless, it establishes an understanding of the proportions of professors of human nutrition who are white, racialized, Indigenous, women, and men. Novelty: Canadian universities strive to be equitable, diverse, and inclusive. One hundred and ninety professors of human nutrition were stratified using social constructs for race and gender. Findings: 65% Women, 80% white, 16.4% racialized, and 2.6% Indigenous.

The omega-3 index is inversely associated with the neutrophil-lymphocyte ratio in adults'.

The neutrophil-lymphocyte ratio (NLR) is a biomarker of systemic inflammation and measures innate-adaptive immune system balance. The omega-3-index (O3I) measures the amount of EPA+DHA in blood. Both a low O3I and an elevated NLR are associated with increased risk for chronic disease and mortality, including cardiovascular diseases and cancer. Hypothesizing that low O3I may partly contribute to systemic chronic inflammation, we asked if a relationship existed between O3I and NLR in healthy adults (≥18 y, n = 28,871, 51% female) without inflammation [C-reactive protein (CRP) <3 mg/mL)] who underwent a routine clinical assessment. NLR was inversely associated with O3I before (p < 0.0001) and after adjusting for age, sex, BMI, and CRP (p < 0.0001). Pearson correlations of other variables with NLR were r = 0.06 (CRP), r = 0.14 (age), and r = 0.01(BMI). In this healthy population, an O3I < 6.6% was associated with increasing NLR whereas NLR remained relatively constant (low) when O3I > 6.6%, suggestive of a quiescent, balanced immune system.

Omega-3 index is directly associated with a healthy red blood cell distribution width.

Low red blood cell (RBC) membrane content of EPA and DHA, i.e., the omega-3 index (O3I), and elevated RBC distribution width (RDW) are risk factors for all-cause mortality. O3I and RDW are related with membrane fluidity and deformability. Our objective was to determine if there is a relationship between O3I and RDW in healthy adults. Subjects without inflammation or anemia, and with values for O3I, RDW, high-sensitivity C-reactive protein (CRP), body mass index (BMI), age and sex were identified (n = 25,485) from a clinical laboratory dataset of  > 45,000 individuals. RDW was inversely associated with O3I in both sexes before and after (both p < 0.00001) adjusting models for sex, age, BMI and CRP. Stratification by sex revealed a sex-O3I interaction with the RDW-O3I slope (p < 0.00066) being especially steep in females with O3I ≤ 5.6%. In healthy adults of both sexes, the data suggested that an O3I of > 5.6% may help maintain normal RBC structural and functional integrity.

Beyond Nutrient Deficiency-Opportunities to Improve Nutritional Status and Promote Health Modernizing DRIs and Supplementation Recommendations.

The US Dietary Guidelines for Americans (DGA) provide dietary recommendations to meet nutrient needs, promote health, and prevent disease. Despite 40 years of DGA, the prevalence of under-consumed nutrients continues in the US and globally, although dietary supplement use can help to fill shortfalls. Nutrient recommendations are based on Dietary Reference Intakes (DRIs) to meet the nutrient requirements for nearly all (97 to 98 percent) healthy individuals in a particular life stage and gender group and many need to be updated using current evidence. There is an opportunity to modernize vitamin and mineral intake recommendations based on biomarker or surrogate endpoint levels needed to 'prevent deficiency' with DRIs based on ranges of biomarker or surrogate endpoints levels that support normal cell/organ/tissue function in healthy individuals, and to establish DRIs for bioactive compounds. We recommend vitamin K and Mg DRIs be updated and DRIs be established for lutein and eicosapentaenoic and docosahexaenoic acid (EPA + DHA). With increasing interest in personalized (or precision) nutrition, we propose greater research investment in validating biomarkers and metabolic health measures and the development and use of inexpensive diagnostic devices. Data generated from such approaches will help elucidate optimal nutrient status, provide objective evaluations of an individual's nutritional status, and serve to provide personalized nutrition guidance.

Using an erythrocyte fatty acid fingerprint to predict risk of all-cause mortality: the Framingham Offspring Cohort.

BACKGROUND: RBC long-chain omega-3 (n-3) fatty acid (FA) percentages (of total fatty acids) are associated with lower risk for total mortality, but it is unknown if a suite of FAs could improve risk prediction. OBJECTIVES: The objective of this study was to compare a combination of RBC FA levels with standard risk factors for cardiovascular disease (CVD) in predicting risk of all-cause mortality. METHODS: Framingham Offspring Cohort participants without prevalent CVD having RBC FA measurements and relevant baseline clinical covariates (n = 2240) were evaluated during 11 y of follow-up. A forward, stepwise approach was used to systematically evaluate the association of 8 standard risk factors (age, sex, total cholesterol, HDL cholesterol, hypertension treatment, systolic blood pressure, smoking status, and prevalent diabetes) and 28 FA metrics with all-cause mortality. A 10-fold cross-validation process was used to build and validate models adjusted for age and sex. RESULTS: Four of 28 FA metrics [14:0, 16:1n-7, 22:0, and omega-3 index (O3I; 20:5n-3 + 22:6n-3)] appeared in ≥5 of the discovery models as significant predictors of all-cause mortality. In age- and sex-adjusted models, a model with 4 FA metrics was at least as good at predicting all-cause mortality as a model including the remaining 6 standard risk factors (C-statistic: 0.778; 95% CI: 0.759, 0.797; compared with C-statistic: 0.777; 95% CI: 0.753, 0.802). A model with 4 FA metrics plus smoking and diabetes (FA + Sm + D) had a higher C-statistic (0.790; 95% CI: 0.770, 0.811) compared with the FA (P < 0.01) or Sm + D models alone (C-statistic: 0.766; 95% CI: 0.739, 0.794; P < 0.001). A variety of other highly correlated FAs could be substituted for 14:0, 16:1n-7, 22:0, or O3I with similar predicted outcomes. CONCLUSIONS: In this community-based population in their mid-60s, RBC FA patterns were as predictive of risk for death during the next 11 y as standard risk factors. Replication is needed in other cohorts to validate this FA fingerprint as a predictor of all-cause mortality.

Resveratrol Inhibits Neointimal Growth after Arterial Injury in High-Fat-Fed Rodents: The Roles of SIRT1 and AMPK.

We have shown that both insulin and resveratrol (RSV) decrease neointimal hyperplasia in chow-fed rodents via mechanisms that are in part overlapping and involve the activation of endothelial nitric oxide synthase (eNOS). However, this vasculoprotective effect of insulin is abolished in high-fat-fed insulin-resistant rats. Since RSV, in addition to increasing insulin sensitivity, can activate eNOS via pathways that are independent of insulin signaling, such as the activation of sirtuin 1 (SIRT1) and AMP-activated kinase (AMPK), we speculated that unlike insulin, the vasculoprotective effect of RSV would be retained in high-fat-fed rats. We found that high-fat feeding decreased insulin sensitivity and increased neointimal area and that RSV improved insulin sensitivity (p < 0.05) and decreased neointimal area in high-fat-fed rats (p < 0.05). We investigated the role of SIRT1 in the effect of RSV using two genetic mouse models. We found that RSV decreased neointimal area in high-fat-fed wild-type mice (p < 0.05), an effect that was retained in mice with catalytically inactive SIRT1 (p < 0.05) and in heterozygous SIRT1-null mice. In contrast, the effect of RSV was abolished in AMKPα2-null mice. Thus, RSV decreased neointimal hyperplasia after arterial injury in both high-fat-fed rats and mice, an effect likely not mediated by SIRT1 but by AMPKα2.

Measuring health promotion: translating science into policy.

Commonly, it is the end of life when our health is deteriorating, that many will make drastic lifestyle changes to improve their quality of life. However, it is increasingly recognized that bringing good health-promoting behaviors into practice as early in life as possible has the most significant impact across the maximal healthspan. The WHO has brought clarity to health promotion over the last fifteen years, always centering on language relating to a process of enabling people to increase control over, and to improve, their physical, mental and social health. A good healthspan is not just freedom from morbidity and mortality, it is that joie de vivre ("joy of living") that should accompany every day of our lifespan. Therefore, health promotion includes not only the health sector, but also needs individual commitment to achieve that target of a healthspan aligned with the lifespan. This paper explores health promotion and health literacy, and how to design appropriate nutritional studies to characterize contributors to a positive health outcome, the role the human microbiome plays in promoting health and addressing and alleviating morbidity and diseases, and finally how to characterize phenotypic flexibility and a physiologic resilience that we must maintain as our structural and functional systems are bombarded with the insults and perturbations of life.

Modeling Possible Outcomes of Updated Daily Values on Nutrient Intakes of the United States Adult Population.

The United States (US) Food and Drug Administration has updated the Daily Values (DVs) for the Nutrition Facts Label on packaged foods. We used the National Health and Nutrition Examination Survey 2009-2012 data with the International Life Sciences Institute, North America Fortification Database, which identifies intrinsic, mandatory enriched, and fortified sources of nutrients in foods and beverages, to model the new DVs' potential impact on adult (≥19 years of age) intake. We assumed that manufacturers will adjust voluntary fortification to maintain percent DV claims. We assessed the percent of the US population whose usual intake (UI) was < the Estimated Average Requirement (EAR), and ≥ the Upper Limit (UL) based on the current DVs, and modeled estimated UI and %

Establishing What Constitutes a Healthy Human Gut Microbiome: State of the Science, Regulatory Considerations, and Future Directions.

On December 17, 2018, the North American branch of the International Life Sciences Institute (ILSI North America) convened a workshop "Can We Begin to Define a Healthy Gut Microbiome Through Quantifiable Characteristics?" with >40 invited academic, government, and industry experts in Washington, DC. The workshop objectives were to 1) develop a collective expert assessment of the state of the evidence on the human gut microbiome and associated human health benefits, 2) see if there was sufficient evidence to establish measurable gut microbiome characteristics that could serve as indicators of "health," 3) identify short- and long-term research needs to fully characterize healthy gut microbiome-host relationships, and 4) publish the findings. Conclusions were as follows: 1) mechanistic links of specific changes in gut microbiome structure with function or markers of human health are not yet established; 2) it is not established if dysbiosis is a cause, consequence, or both of changes in human gut epithelial function and disease; 3) microbiome communities are highly individualized, show a high degree of interindividual variation to perturbation, and tend to be stable over years; 4) the complexity of microbiome-host interactions requires a comprehensive, multidisciplinary research agenda to elucidate relationships between gut microbiome and host health; 5) biomarkers and/or surrogate indicators of host function and pathogenic processes based on the microbiome need to be determined and validated, along with normal ranges, using approaches similar to those used to establish biomarkers and/or surrogate indicators based on host metabolic phenotypes; 6) future studies measuring responses to an exposure or intervention need to combine validated microbiome-related biomarkers and/or surrogate indicators with multiomics characterization of the microbiome; and 7) because static genetic sampling misses important short- and long-term microbiome-related dynamic changes to host health, future studies must be powered to account for inter- and intraindividual variation and should use repeated measures within individuals.

Unconventional Secretion of Adipocyte Fatty Acid Binding Protein 4 Is Mediated By Autophagic Proteins in a Sirtuin-1-Dependent Manner.

Fatty acid binding protein 4 (FABP4) is a leaderless lipid carrier protein primarily expressed by adipocytes and macrophages that not only functions intracellularly but is also secreted. The secretion is mediated via unconventional mechanism(s), and in a variety of species, metabolic dysfunction is correlated with elevated circulating FABP4 levels. In diabetic animals, neutralizing antibodies targeting serum FABP4 increase insulin sensitivity and attenuate hepatic glucose output, suggesting the functional importance of circulating FABP4. Using animal and cell-based models, we show that FABP4 is secreted from white, but not brown, adipose tissue in response to lipolytic stimulation in a sirtuin-1 (SIRT1)-dependent manner via a mechanism that requires some, but not all, autophagic components. Silencing of early autophagic genes such as Ulk1/2, Fip200, or Beclin-1 or chemical inhibition of ULK1/2 or VPS34 attenuated secretion, while Atg5 knockdown potentiated FABP4 release. Genetic knockout of Sirt1 diminished secretion, and serum FABP4 levels were undetectable in Sirt1 knockout mice. In addition, blocking SIRT1 by EX527 attenuated secretion while activating SIRT1 by resveratrol-potentiated secretion. These studies suggest that FABP4 secretion from adipocytes is regulated by SIRT1 and requires early autophagic components.

US Family Physicians Overestimate Personal ω-3 Fatty Acid Biomarker Status: Associations with Fatty Fish and ω-3 Supplement Intake.

BACKGROUND: The health benefits of ω-3 (n-3) fatty acids are well established. Only a small percentage of Americans consume the recommended amounts of fatty fish, the main dietary source of ω-3 fatty acids, and most have low ω-3 fatty acid blood concentrations. OBJECTIVE: We aimed to measure biomarkers of long-chain ω-3 fatty acid (EPA and DHA) status among family physicians, and determine whether having their ω-3 status tested would influence attitudes and patient recommendations. METHODS: Family physicians attending a medical conference (n = 340) completed an ω-3 intake survey and had a finger stick blood sample taken. ω-3 Index, percentage of ω-6 (%n-6) in highly unsaturated fatty acids (HUFAs), and EPA:arachidonic acid (AA) ratio were calculated from whole blood fatty acid profiles. Post-conference, a subsample of participants (n = 100) responded to a survey regarding attitudes and recommendations about ω-3s. RESULTS: Average age (mean ± SEM) of participants was 48.0 ± 0.7 y and 59% were women. Average ω-3 Index was 5.2% ± 0.1%, %n-6 in HUFA was 75% ± 0.4%, and EPA:AA ratio was 0.076 ± 0.004. 57% of family physicians reported consuming <2 servings/wk of fatty fish, and 78% reported using ω-3 supplements ≤1/wk. Although 51% believed ω-3 status was in a desirable range, only 5% had an ω-3 Index ≥8%. Biomarkers of ω-3 status were significantly associated with fatty fish intake and supplement use, and were correlated (R2 ranging from 0.59 to 0.77). Physicians who had ω-3 status tested (n = 65) were more likely to agree with statements affirming the health benefits of ω-3 fatty acids and more willing to recommend ω-3 fatty acids to their patients (P = 0.004). CONCLUSIONS: Blood concentrations of ω-3 fatty acids in family physicians were below recommendations, and were associated with fatty fish intake and ω-3 supplement use. There was a discrepancy between perceived and actual ω-3 status. Increased awareness of personal ω-3 status among physicians may facilitate patient communication and recommendations about ω-3 fatty acid intake. This trial was registered at clinicaltrials.gov as, NCT03056898.

Contribution of NK cells to immunotherapy mediated by PD-1/PD-L1 blockade.

Checkpoint blockade immunotherapy targeting the PD-1/PD-L1 inhibitory axis has produced remarkable results in the treatment of several types of cancer. Whereas cytotoxic T cells are known to provide important antitumor effects during checkpoint blockade, certain cancers with low MHC expression are responsive to therapy, suggesting that other immune cell types may also play a role. Here, we employed several mouse models of cancer to investigate the effect of PD-1/PD-L1 blockade on NK cells, a population of cytotoxic innate lymphocytes that also mediate antitumor immunity. We discovered that PD-1 and PD-L1 blockade elicited a strong NK cell response that was indispensable for the full therapeutic effect of immunotherapy. PD-1 was expressed on NK cells within transplantable, spontaneous, and genetically induced mouse tumor models, and PD-L1 expression in cancer cells resulted in reduced NK cell responses and generation of more aggressive tumors in vivo. PD-1 expression was more abundant on NK cells with an activated and more responsive phenotype and did not mark NK cells with an exhausted phenotype. These results demonstrate the importance of the PD-1/PD-L1 axis in inhibiting NK cell responses in vivo and reveal that NK cells, in addition to T cells, mediate the effect of PD-1/PD-L1 blockade immunotherapy.

Modulating SIRT1 activity variously affects thymic lymphoma development in mice.

SIRT1 is a protein deacetylase with a broad range of biological functions, many of which are known to be important in carcinogenesis, however much of the literature regarding the role of SIRT1 in cancer remains conflicting. In this study we assessed the effect of SIRT1 on the initiation and progression of thymic T cell lymphomas. We employed mouse strains in which SIRT1 activity was absent or could be reversibly modulated in conjunction with thymic lymphoma induction using either the N-nitroso-N-methylurea (NMU) carcinogenesis or the nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) transgene. Decreased SIRT1 activity reduced the development of thymic lymphomas in the NMU-treated mice but was permissive for the formation of lung adenomas. Conversely, in the NPM-ALK transgenic mice, decreased SIRT1 activity had a modest promoting effect in the development of thymic lymphomas. The results of the work presented here add to the growing body of evidence that sirt1 is neither an outright oncogene nor a tumor suppressor. These opposing results in two models of the same disease suggest that the influence of sirt1 on carcinogenesis may lie in a role in tumor surveillance.