Adiposity Phenotypes and Associated Cardiometabolic Risk Profile in the Inuit Population of Nunavik.

The Inuit population of Nunavik is faced with a significant rise in the prevalence of obesity [body mass index (BMI) ≥ 30 kg/m2], but the impact on cardiometabolic health is unclear. The aim of this study was to characterize adiposity phenotypes and explore their associations with cardiometabolic risk factors among Nunavimmiut men and women. We used data obtained from 1296 Inuit who participated in the Qanuilirpitaa? 2017 Nunavik Inuit Health survey. Collected information included demographics, anthropometric measurements including visceral fat level (VFL) measured using electrical bioimpedance, biomarkers, hemodynamics, medical history and medication list. Adjusted population-weighted linear regressions were conducted to assess associations between body fat distribution and cardiometabolic risk factors. The accuracy and cut-off points of anthropometric indices to detect cardiometabolic abnormalities was evaluated by area under the receiver operator characteristic curve (AUROC) and a maximum Youden index analysis. Among Nunavimmiut (mean age 38.8 years [95%CI: 38.4 to 39.3]), obesity was observed in 42.8% of women and 25.6% of men. Compared to men, women presented a higher prevalence of abdominal obesity (78.8% vs. 46.4% in men, p < 0.05) and elevated VFL (54.4% vs. 20.1% with an InBody level ≥ 13, p < 0.05). Indices of global fat distribution and abdominal adiposity including VFL provided poor to moderate ability to detect cardiometabolic abnormalities (AUROC between 0.64 and 0.79). This analysis revealed that despite a high prevalence of abdominal obesity, particularly among women, anthropometric measurements of adiposity are inconsistently associated cardio-metabolic risk factors in Inuit adults of Nunavik.

Using latent class analysis to operationalize a wholistic assessment of Inuit health and well-being.

Many indigenous cultures conceptualize health wholistically, whereby physical, mental, spiritual and relational dimensions of health are interconnected. Yet, quantitative approaches to studying Indigenous health remain anchored in western perspectives, that separate the dimensions of health. This paper aims to operationalize a wholistic indicator of health based on the IQI model of Inuit health. Variables from the 2017 Nunavik Health Survey (N = 1196) were selected based on their representativeness of IQI model. Exploratory Latent Class Analysis (LCA) was used to identify wholistic health profiles. Once participants assigned to their health profile, sociodemographic characteristics were compared across profiles, and multinomial regression models were used to examine the relationship between community-level social determinants of health and the profiles. The LCA revealed three health profiles, labelled as "excellent", "good" and "fair" based on the distribution of answers to the indicators. Nunavimmiut in "excellent" and "good" health were more likely to: rate their health positively; be over 30 years old; be in a relationship; and have participated or volunteered in community events. Nunavimmiut in "fair" health tended to report lower levels of community cohesion, family relationships, and emotional support. Intergrating culturally relevant models of health can support improved health status assessments and identify opportunities for health promotion.

Emerging evidence on selenoneine and its public health relevance in coastal populations: a review and case study of dietary Se among Inuit populations in the Canadian Arctic.

Selenium is an essential mineral yet both deficiency and excess are associated with adverse health effects. Dietary intake of Se in humans varies greatly between populations due to food availability, dietary preferences, and local geological and ecosystem processes impacting Se accumulation into agricultural products and animal populations. We argue there is a need to evaluate and reconsider the relevance of public health recommendations on Se given recent evidence, including the metabolic pathways and health implications of Se. This argument is particularly pertinent for Inuit populations in Northern Canada, who often exceed dietary tolerable upper intake levels and exhibit very high whole blood Se concentrations due to their dependence on local country foods high in the newly discovered Se compound, selenoneine. Since selenoneine appears to have lower toxicity compared to other Se species and does not contribute to the circulating pools of Se for selenoprotein synthesis, we argue that total dietary Se or total Se in plasma or whole blood are poor indicators of Se adequacy for human health in these populations. Overall, this review provides an overview of the current evidence of Se speciation, deficiency, adequacy, and excess and implications for human health and dietary recommendations, with particular reference to Inuit populations in the Canadian Arctic and other coastal populations consuming marine foods.

Wild fish consumption and latitude as drivers of vitamin D status among Inuit living in Nunavik, northern Québec.

OBJECTIVE: To measure vitamin D status and estimate factors associated with serum 25-hydroxyvitamin D (25(OH)D) in Nunavimmiut (Inuit living in Nunavik) adults in 2017. DESIGN: Data were from Qanuilirpitaa? 2017 Nunavik Inuit Health Survey, a cross-sectional study conducted in August-October 2017. Participants underwent a questionnaire, including an FFQ, and blood samples were analysed for total serum 25(OH)D. SETTING: Nunavik, northern Québec, Canada. PARTICIPANTS: A stratified proportional model was used to select respondents, including 1,155 who identified as Inuit and had complete data. RESULTS: Geometric mean serum vitamin D levels were 65·2 nmol/l (95 % CI 62·9-67·6 nmol/l) among women and 65·4 nmol/l (95 % CI 62·3-68·7 nmol/l) among men. The weighted prevalence of serum 25(OH)D < 75 nmol/l, <50 nmol/l <30 nmol/l was 61·2 %, 30·3 % and 7·0 %, respectively. Individuals who were older, female, lived in smaller and/or more southerly communities and/or consumed more country (traditional) foods were at a reduced risk of low vitamin D status. Higher consumption of wild fish was specifically associated with increased serum 25(OH)D concentration. CONCLUSION: It is important that national, regional and local policies and programs are in place to secure harvest, sharing and consumption of nutritious and culturally important country foods like Arctic char and other wild fish species, particularly considering ongoing climate change in the Arctic which impacts the availability, access and quality of fish as food.

Fluoride exposure and thyroid hormone levels in pregnancy: The MIREC cohort.

BACKGROUND: Fluoride exposure may increase the risk of hypothyroidism, but results from previous studies are inconsistent at low-level fluoride exposure (i.e., ≤0.7 mg/L). Human studies of fluoride and thyroid hormone levels in pregnancy are scarce. OBJECTIVES: We examined associations between fluoride exposure and maternal thyroid hormone levels in a Canadian pregnancy cohort, with consideration for fetal sex-specific effects. METHODS: We measured fluoride concentrations in drinking water and spot urine samples collected during each trimester from 1876 pregnant women enrolled in the Maternal-Infant Research on Environmental Chemicals (MIREC) study. We also measured maternal thyroid stimulating hormone (TSH), free thyroxine (FT4), and total thyroxine (TT4) levels during the first trimester of pregnancy. We used linear and non-linear regression models to estimate associations between fluoride exposure and levels of TSH, FT4, and TT4. We explored effect modification by fetal sex and considered maternal iodine status as a potential confounder. RESULTS: A 1 mg/L increase in urinary fluoride was associated with a 0.30 (95 %CI: 0.08, 0.51) logarithmic unit (i.e., 35.0 %) increase in TSH among women pregnant with females, but not males (B = 0.02; 95 %CI: -0.16, 0.19). Relative to women with urinary fluoride concentrations in the first quartile (0.05-0.32 mg/L), those with levels in the third quartile (0.49-0.75 mg/L) had higher FT4 and TT4 (i.e., inverted J-shaped associations), but the association was not statistically significant after adjustment for covariates (p = 0.06). Water fluoride concentration showed a U-shaped association with maternal FT4, whereby women with water fluoride concentrations in the second (0.13-0.52 mg/L) and third (0.52-0.62 mg/L) quartiles had significantly lower FT4 compared to those with levels in the first quartile (0.04-0.13 mg/L). Adjustment for maternal iodine status did not change the results. DISCUSSION: Fluoride exposure was associated with alterations in maternal thyroid hormone levels, the magnitude of which appeared to vary by fetal sex. Given the importance of maternal thyroid hormones for fetal neurodevelopment, replication of findings is warranted.

The Qanuilirpitaa? 2017 Nunavik Health Survey: design, methods, and lessons learned.

OBJECTIVE: To depict the design, methods, sociodemographic characteristics of the population, and lessons learned during the Qanuilirpitaa? 2017 Nunavik Inuit Health Survey, the third major health survey to be conducted among youth and adults residing in Nunavik (Northern Quebec, Canada). METHODS: Qanuilirpitaa? 2017 is a cross-sectional survey that served to update information regarding various aspects of physical health, mental health, and general well-being of Nunavimmiut. The survey was guided by the ethics principles of Ownership, Control, Access, and Possession (OCAP®) ( https://fnigc.ca/ocap ). Questionnaires and clinical tests were administered to residents from the 14 coastal communities onboard the Canadian Coast Guard Ship Amundsen during late summer and early fall 2017. As part of the community component of the survey, qualitative interviews were performed with key respondents, and services and resources supporting health and well-being in the 14 communities were inventoried and characterized. RESULTS: A total of 1326 Nunavimmiut aged 16 and over participated in the survey. Despite difficulties encountered with the recruitment of participants, co-interpretation sessions with Inuit partners revealed that the survey had succeeded in capturing cultural, socio-economic, and lifestyle characteristics of Nunavimmiut. In all, 20 thematic reports have been published covering various aspects of health and well-being of Nunavimmiut. Regional and local reports pertaining to the community component were produced. More in-depth analyses have ensued, and results are presented in articles published in this CJPH supplement issue. CONCLUSION: Information from this survey is being used to update health services and programs in the region and for the development of health policies and public health interventions to tackle key health-related issues faced by Nunavimmiut. Drawing lessons from challenges and successes encountered in Qanuilirpitaa? 2017, this survey paved the way to the upcoming Inuit-led Qanuippitaa? National Inuit Health Survey to be conducted every 5 years throughout Inuit Nunangat.

RéSUMé: OBJECTIF: Décrire la conception, les méthodes, les caractéristiques sociodémographiques de la population et les leçons tirées de l'Enquête sur la santé des Inuits du Nunavik Qanuilirpitaa? 2017, la troisième grande enquête de santé menée auprès de jeunes et d'adultes résidant au Nunavik (Nord du Québec, Canada). MéTHODES: Qanuilirpitaa? 2017 est une enquête transversale qui a permis la mise à jour des informations concernant divers aspects de la santé physique, de la santé mentale et du bien-être général des Nunavimmiut. L'enquête a été guidée par les principes de propriété, de contrôle, d'accès et de possession (OCAP®) ( https://fnigc.ca/ocap ). Des questionnaires et des tests cliniques ont été administrés à des résidents des 14 communautés côtières, à bord du navire Amundsen de la Garde côtière canadienne, à la fin de l'été et au début de l'automne 2017. Des entrevues qualitatives ont également été réalisées avec des répondants clé dans le cadre de la composante communautaire. RéSULTATS: Au total, 1 326 Nunavimmiut âgés de 16 ans et plus ont été recrutés. Malgré les difficultés rencontrées lors du recrutement des participants, les rencontres de co-interprétation ont permis de vérifier que l'enquête avait réussi à capturer les caractéristiques culturelles, socioéconomiques et les habitudes de vie de la population. Au total, 20 rapports thématiques ont été publiés, lesquels couvrent différents aspects de la santé et du bien-être des Nunavimmiut. Un rapport régional et des rapports locaux liés à la composante communautaire ont également été produits. Des analyses plus approfondies ont également été réalisées, dont les résultats sont présentés dans les articles publiés dans ce numéro supplémentaire de la Revue canadienne de santé publique. CONCLUSION: Les informations issues de cette enquête sont utilisées pour la mise à jour des services de santé dans la région et pour le développement de politiques de santé et d'interventions de santé publique, ayant pour cibles les principaux défis auxquels les Nunavimmiut sont confrontés. Grâce aux leçons apprises lors de sa réalisation, cette enquête a pavé la voie aux prochaines enquêtes Qanuippitaa ? qui seront menées tous les 5 ans dans tout l'Inuit Nunangat.

Prevalence and determinants of hypertension in the adult Inuit population of Nunavik (northern Quebec, Canada).

OBJECTIVES: To assess the prevalence of arterial hypertension among Inuit adults living in Nunavik (northern Quebec, Canada) in 2017 and identify its sociodemographic and lifestyle determinants. METHODS: We used data obtained from 1177 Inuit adults aged ≥ 18 years who participated in the cross-sectional Qanuilirpitaa? Nunavik Inuit Health Survey during late summer-early fall of 2017. Resting blood pressure (BP) and anthropometric characteristics were measured during a clinical session, while sociodemographic characteristics and lifestyle habits were documented using validated questionnaires. Information on current medication was retrieved from medical files. Sex-stratified population-weighted log-binomial regressions were conducted to identify determinants of hypertension, adjusting for potential confounders. RESULTS: Hypertension (systolic BP ≥ 140 mm Hg or diastolic BP ≥ 90 mmHg or taking antihypertensive medication) was present in 23% of the adult population and was more frequent in men than women (29% vs. 18%). About a third of hypertensive individuals (34%) were taking antihypertensive medication. These estimates are prone to biases due to the relatively low participation rate (37%). As expected, the prevalence of hypertension increased with age, but values were surprisingly elevated in 18 to 29-year-old men and women (18% and 8%, respectively) compared with 20 to 39-year-old adults of the general Canadian population (3% in both sexes, according to data from the Canadian Health Measures Survey, 2012-2015). Hypertension was associated with obesity and alcohol consumption in both men and women, and with higher socioeconomic status among men. CONCLUSION: This survey revealed a high prevalence of hypertension among young Nunavimmiut adults in 2017 and the need to improve hypertension diagnosis and treatment in the region. Curbing obesity and alcohol consumption, two actionable determinants of hypertension, will require improving food security and addressing the consequences of historical trauma linked to colonization.

RéSUMé: OBJECTIF: Mesurer la prévalence de l'hypertension artérielle chez les adultes vivant au Nunavik (Nord du Québec, Canada) en 2017 et identifier les caractéristiques sociodémographiques et les habitudes de vie qui lui sont associées. MéTHODES: Les données ont été recueillies chez 1177 adultes ≥ 18 ans ayant participé à l'enquête de santé Qanuilirpitaa? auprès des Inuit du Nunavik à la fin de l'été et au début de l'automne 2017. Lors d'une visite en clinique, la tension artérielle au repos et les caractéristiques anthropométriques ont été mesurées, puis des informations concernant les caractéristiques sociodémographiques et les habitudes de vie ont été recueillies à l'aide de questionnaires validés. Une revue des dossiers médicaux a permis de documenter la prise de médicaments antihypertenseurs. Nous avons utilisé des modèles de régression log-binomiale, pondérés pour la population et ajustés pour les co-variables d'intérêt afin d'identifier les déterminants de l'hypertension chez chaque sexe. RéSULTATS: La prévalence globale de l'hypertension était de 23 % et était plus élevée chez les hommes que chez les femmes (29 % vs. 18 %). Le tiers des hypertendus (34 %) recevait une médication antihypertensive. Ces estimés pourraient être biaisés puisque le taux de participation à l'enquête était relativement faible (37 %). Tel qu'attendu, la prévalence d'hypertension était associée à l'âge, mais des valeurs étonnamment élevées ont été notées chez les jeunes hommes et femmes âgés de 18 à 29 ans (18 % et 8 %, respectivement), comparativement aux jeunes adultes âgés de 20 à 39 ans de la population générale canadienne (3 % chez les deux sexes, selon les données de l'Enquête canadienne sur les mesures de santé, 2012­2015). Des associations avec l'obésité et la consommation d'alcool ont été notées chez les deux sexes. On a de plus observé une association avec le statut socio-économique plus élevé chez les hommes seulement. CONCLUSION: Cette étude a révélé une prévalence élevée d'hypertension chez les jeunes Inuit d'âge adulte résidant au Nunavik et un besoin d'améliorer le diagnostic et le traitement de la maladie dans cette région. Elle a de plus permis d'identifier deux facteurs de risque modifiables de l'hypertension dans cette population, soit l'obésité et la consommation d'alcool. Agir sur ces déterminants au Nunavik requiert l'amélioration de la sécurité alimentaire et l'atténuation des conséquences liées aux traumatismes découlant de la colonisation.

Determinants of iron deficiency and anemia among Nunavimmiut: results from the Qanuilirpitaa? 2017 Nunavik Health Survey.

OBJECTIVE: To estimate the prevalence of iron deficiency (ID) and anemia and study their main distal and proximal protective and risk factors among Nunavimmiut 16 years and older in 2017. METHODS: In a cross-sectional participatory survey of 831 women and 436 men from the Qanuilirpitaa? 2017 Nunavik Inuit Health Survey, venous blood samples were collected to measure various indicators of iron status and anemia as well as biomarkers of nutritional and inflammatory status and contaminant exposures. Sociodemographic, food security status, anthropometric, lifestyle, dietary, and health data were collected using questionnaires, clinical sessions, and a medical chart review. ID and anemia diagnoses were based on serum ferritin (SF) and hemoglobin (Hb), respectively. Multiple regressions were used to assess correlates of anemia and iron status. RESULTS: Prevalence of ID was highest among women of childbearing age (16-49 years old, 33%) and anemia among adults aged 50 years and older (31%). These estimates are prone to biases due to the relatively low participation rate (37%). Serum vitamin D, omega-3 polyunsaturated fatty acid content of erythrocyte membranes, blood selenium, inflammation, higher socioeconomic status (SES), obesity, and alcohol consumption were all positively associated with SF, while Helicobacter pylori infection and a recent pregnancy were negatively associated with Hb among women of childbearing age. Among older adults, food insecurity was associated with lower SF. CONCLUSION: While data reported here provide some indication of an improvement since the previous survey conducted in 2004, additional efforts should be devoted to further increasing the SES and access to country foods and nutritious market foods in this population, the two main protective factors against ID and anemia identified in the present study.

RéSUMé: OBJECTIF: Estimer la prévalence de la carence en fer (CF) et de l'anémie et étudier leurs principaux facteurs de protection et de risque distaux et proximaux chez les Nunavimmiut de 16 ans et plus en 2017. MéTHODOLOGIE: Dans le cadre de l'enquête transversale participative Qanuilirpitaa? menée en 2017 auprès de 831 femmes et 436 hommes, des échantillons de sang furent prélevés pour mesurer divers indicateurs de la CF et de l'anémie ainsi que des biomarqueurs de l'état nutritionnel et inflammatoire et de l'exposition aux contaminants environnementaux. Des données sociodémographiques, anthropométriques, sur la sécurité alimentaire, sur le mode de vie, l'alimentation et la santé ont été recueillies à l'aide de questionnaires, de séances cliniques et d'un examen des dossiers médicaux. Les diagnostics de CF et d'anémie furent basés sur la ferritine sérique (SF) et l'hémoglobine (Hb), respectivement. Des régressions multiples ont été utilisées pour évaluer les déterminants de l'anémie et du statut en fer. RéSULTATS: La prévalence de la CF était la plus élevée chez les femmes en âge de procréer (16 à 49 ans, 33 %) et l'anémie chez les adultes âgés de 50 ans et plus (31 %). Ces estimés pourraient être biaisés puisque le taux de participation à l'enquête était relativement faible (37 %). Chez les femmes en âge de procréer, la vitamine D sérique, la teneur en acides gras polyinsaturés oméga-3 des membranes érythrocytaires, le sélénium sanguin, l'inflammation, un statut socio-économique plus élevé, l'obésité et la consommation d'alcool étaient tous associés positivement à la SF, tandis que l'infection à Helicobacter pylori et une grossesse récente étaient associées négativement à l'Hb. Chez les adultes plus âgés, l'insécurité alimentaire était associée à une diminution de la SF. CONCLUSION: Bien que les données de cette enquête suggèrent une amélioration depuis l'enquête précédente réalisée en 2004, des efforts additionnels sont requis pour améliorer le statut socioéconomique et l'accès aux aliments traditionnels et aux aliments de marché de qualité au Nunavik, les deux principaux facteurs protecteurs de la CF et de l'anémie identifiés dans la présente étude.

Respiratory health and its determinants among Nunavimmiut: results from the Qanuilirpitaa? 2017 Nunavik Health Survey.

OBJECTIVES: Respiratory diseases are the leading cause of hospitalization in Nunavik (northern Québec, Canada) and contribute to disparities in life expectancy with the rest of Canada. As part of Qanuilirpitaa? 2017, a cross-sectional population-based health survey, we sought to describe the prevalence of respiratory health indicators, including the first estimate of airway obstruction based on spirometry in an Inuit population, and explore their associated characteristics. METHODS: We analyzed data from 1296 participants aged 16 years and older, using multivariate logistic regression to assess characteristics associated with spirometry-determined airway obstruction and self-reported respiratory symptoms, i.e., wheezing in the last year and chronic cough during at least 3 months. RESULTS: In this relatively young population (83% aged 16 to 54), the prevalences of wheezing, chronic cough, and airway obstruction were, respectively, 27% (95% CI 24-30), 21% (18-23), and 17% (14-20). These estimates are prone to biases due to the relatively low participation rate (about 37%). The most consistent associations were with smoking (≥ 15 pack-years; odds ratio [OR] 3.13, 3.39, and 2.86 for the three indicators, respectively) and food security (OR 0.55 with wheezing and OR 0.26 with chronic cough), as defined in the Household Food Security Survey Module. Wheezing was also associated with allergic sensitization to dogs (2.60) and obesity (2.18). Chronic cough was associated with respiratory infections during childhood (2.12), housing in need of major repairs (1.72), and housing crowding (1.50), and was negatively associated with participation to traditional activities (0.62) and going on the land (0.64). Airway obstruction was associated with being underweight (3.84) and post-secondary education (0.40). Among young adults and women, wheezing was also associated with any inhalation of solvents for recreational purposes during their lifetime (2.62 and 1.56, respectively), while airway obstruction was associated with regular marijuana use (2.22 and 1.84, respectively). CONCLUSION: Smoking and food insecurity are both highly prevalent and strongly associated with respiratory symptoms in Nunavik. Together with essential smoking prevention and cessation programs, our findings suggest that solving food security and housing crises, improving socioeconomic conditions, and promoting traditional lifestyle may improve respiratory health in Nunavik.

RéSUMé: OBJECTIFS: Les maladies respiratoires sont la première cause d'hospitalisation au Nunavik (Nord-du-Québec, Canada) et contribuent aux écarts d'espérance de vie avec le reste du Canada. Dans le cadre de l'enquête transversale et populationnelle Qanuilirpitaa? 2017, cette étude décrit la prévalence d'indicateurs de santé respiratoire et explore les caractéristiques qui leur sont associées. Elle fournit le premier estimé de la prévalence d'obstruction respiratoire par spirométrie dans la population inuite. MéTHODES: Les données de 1 296 participants âgés de 16 ans et plus ont été analysées par régression logistique multivariée pour évaluer les caractéristiques associées avec le wheezing (dans la dernière année), la toux chronique (durant au moins 3 mois) et l'obstruction bronchique (mesurée par spirométrie). RéSULTATS: Dans cette population relativement jeune (83 % entre 16 et 54 ans), les prévalences de wheezing, de toux chronique et d'obstruction bronchique étaient de 27 % (IC95% 24-30), 21 % (18-23) et 17 % (14-20). Ces estimés pourraient être biaisés puisque le taux de participation à l'enquête était relativement faible (environ 37 %). Les associations les plus fortes et consistantes sont observées avec le tabagisme (≥ 15 paquets-années; RC 3,13, 3,39 et 2,86 pour les trois indicateurs, respectivement) et avec la sécurité alimentaire (RC 0,55 avec le wheezing et 0,26 avec la toux chronique), définie à partir du Module d'enquête sur la sécurité alimentaire des ménages. Le wheezing était notamment associé avec la sensibilisation allergique aux chiens (2,60) et l'obésité (2,18). La toux chronique était associée avec les infections respiratoires sévères dans l'enfance (2,12), un logement ayant besoin de réparations majeures (1,72) et un logement surpeuplé (1,50); tandis que participer aux activités traditionnelles (0,62) et aller souvent dans la nature (0,64) semblaient protecteurs. L'obstruction bronchique était associée avec un faible indice de masse corporelle (3,84) et un niveau de scolarité postsecondaire (0,40). Le wheezing était aussi associé avec le fait d'avoir déjà inhalé des solvants chez les jeunes adultes (2,62) et chez les femmes (1,56), tandis que l'obstruction bronchique était associée avec la consommation régulière de cannabis chez les jeunes adultes (2,22) et chez les femmes (1,84). CONCLUSION: Le tabagisme et l'insécurité alimentaire sont fort prévalents et fortement associés avec des symptômes respiratoires au Nunavik. En plus de rappeler l'importance de la prévention du tabagisme, ces résultats supportent la pertinence des efforts communautaires et gouvernementaux pour résoudre les crises de l'insécurité alimentaire et du logement, améliorer les conditions socioéconomiques et promouvoir la culture inuite afin d'améliorer la santé respiratoire au Nunavik.

Simultaneous determination of ergothioneine, selenoneine, and their methylated metabolites in human blood using ID-LC-MS/MS.

Ergothioneine and selenoneine are structurally related dietary antioxidants and cytoprotectants that may help prevent several chronic diseases associated with inflammation and aging. Both compounds share pharmacokinetic characteristics such as cellular uptake through the ergothioneine transporter, accumulation in red blood cells, and biotransformation to methylated metabolites. A rapid, sensitive, specific, precise, and cost-effective analytical method is required to further investigate the potential health benefits of these compounds, individually or combined, in large epidemiological studies. We developed and validated an isotope-dilution liquid chromatography tandem mass spectrometry (ID-LC-MS/MS) method for the simultaneous specific quantification of these analytes in human blood following a simple sample preparation consisting of dilution in aqueous dithiothreitol followed by centrifugal filtration. Chromatographic separation of the analytes is achieved using a reversed-phase chromatography within an 8-min run. Analyte detection is performed using triple quadrupole mass spectrometry in multiple reaction monitoring mode. Each analyte is quantified against its corresponding isotopically labeled internal standard either commercially available or synthesized in-house (77Se-labeled selenoneine compounds). The validated method demonstrates excellent linearity and very good precision (all CV < 10%). Matrix effects are minimal, suggesting that this method could easily be adapted to other matrices. Freeze/thaw cycles have little effect on methylated metabolites but significantly reduced concentrations of the parent compounds. The method was successfully applied to a small set of volunteer blood samples containing low levels of the analytes. The developed ID-LC-MS/MS method opens new avenues for exploring the roles of these bioactive compounds and their metabolites in human health and disease.

Pre- and postnatal exposure to legacy environmental contaminants and sensation seeking in Inuit adolescents from Nunavik.

Despite extensive evidence from cohort studies linking exposure to lead (Pb), mercury (Hg) and polychlorinated biphenyls (PCBs) to numerous cognitive outcomes in children and adolescents, very few studies addressed reward sensitivity, a key dimension of emotional regulation. The present study aimed to examine associations between pre- and postnatal exposure to these environmental neurotoxicants and sensation seeking, a behavioral feature of reward. A total of 207 Inuit adolescents (mean age = 18.5, SD = 1.2) from Nunavik, Canada, completed the Brief Sensation Seeking Scale (BSSS-4) and Sensation Seeking- 2 (SS-2), two self-report questionnaires assessing proneness to sensation seeking. Prenatal, childhood and adolescent exposure to Pb, Hg and PCBs were measured in cord blood at birth and blood samples at 11 years of age and at time of testing. Multiple linear regression models were performed, potential confounders including participants' sociodemographic characteristics and nutrient fish intake were considered. Results showed that higher child blood levels of Pb (b = -0.18, p = 0.01) and PCB-153 (b = -0.16, p = 0.06) were associated with lower BSSS-4 total scores, while cord and adolescent blood PCB-153 levels were significantly related to lower SS2 total scores (b = -0.15, p = 0.04; b = -0.24, p = 0.004). Such associations persisted after further adjustment for co-exposure to concurrent contaminants. These associations were influenced by self-report positive affect and marginally moderated by sex. Sex differences were only observed for child PCB exposure, with the association for risk-taking sensation seeking observed only in girls but not in boys. Further research is warranted to assess the extent to which reduced sensation seeking in chronically exposed individuals affects their behaviors, well-being, and emotional regulation.

Cardiometabolic health and per and polyfluoroalkyl substances in an Inuit population.

INTRODUCTION: The cardiometabolic health status of Inuit in Nunavik has worsened in the last thirty years. The high concentrations of perfluoroalkyl acids (PFAAs) may be contributing to this since PFAAs have been linked with hypercholesterolemia, diabetes, and high blood pressure. The aim of this study was to examine the association between a PFAAs mixture and lipid profiles, Type II diabetes, prediabetes, and high blood pressure in this Inuit population. METHODS: We included 1212 participants of the Qanuilirpitaa? 2017 survey aged 16-80 years. Two mixture models (quantile g-computation and Bayesian Kernel Machine Regression (BKMR)) were used to investigate the associations between six PFAAs (PFHxS, PFOS, PFOA and three long-chain PFAAs (PFNA, PFDA and PFUnDA)) with five lipid profiles and three cardiometabolic outcomes. Non-linearity and interaction between PFAAs were further assessed. RESULTS: An IQR increase in all PFAAs congeners resulted in an increase in total cholesterol (ß 0.15, 95% confidence interval (CI) 0.06, 0.24), low-density lipoprotein cholesterol (LDL) (ß 0.08, 95% CI 0.01, 0.16), high-density lipoprotein cholesterol (HDL) (ß 0.04, 95% CI 0.002, 0.08), apolipoprotein B-100 (ß 0.03, 95% CI 0.004, 0.05), and prediabetes (OR 1.80, 95% CI 1.11, 2.91). There was no association between PFAAs and triglycerides, diabetes, or high blood pressure. Long-chain PFAAs congeners were the main contributors driving the associations. Associations were largely linear, and there was no evidence of interaction between the PFAAs congeners. CONCLUSIONS: Our study provides further evidence of increasing circulating lipids with increased exposure to PFAAs. The increased risk of prediabetes points to the influence of PFAAs on potential clinical outcomes. International regulation of PFAAs is essential to curb PFAAs exposure and related health effects in Arctic communities.

Polybrominated diphenyl ethers in type 2 diabetes mellitus cases and controls: Repeated measurements prior to and after diagnosis.

BACKGROUND: Previous studies have reported associations between certain persistent organic pollutants (POPs) and type 2 diabetes mellitus (T2DM). Polybrominated diphenyl ethers (PBDEs) are a class of POPs that are found in increasing concentrations in humans. Although obesity is a known risk factor for T2DM and PBDEs are fat-soluble, very few studies have investigated associations between PBDEs and T2DM. No longitudinal studies have assessed associations between repeated measurements of PBDE and T2DM in the same individuals and compared time trends of PBDEs in T2DM cases and controls. OBJECTIVES: To investigate associations between pre- and post-diagnostic measurements of PBDEs and T2DM and to compare time trends of PBDEs in T2DM cases and controls. METHODS: Questionnaire data and serum samples from participants in the Tromsø Study were used to conduct a longitudinal nested case-control study among 116 T2DM cases and 139 controls. All included study participants had three pre-diagnostic blood samples (collected before T2DM diagnosis in cases), and up to two post-diagnostic samples after T2DM diagnosis. We used logistic regression models to investigate pre- and post-diagnostic associations between PBDEs and T2DM, and linear mixed-effect models to assess time trends of PBDEs in T2DM cases and controls. RESULTS: We observed no substantial pre- or post-diagnostic associations between any of the PBDEs and T2DM, except for BDE-154 at one of the post-diagnostic time-points (OR = 1.65, 95% CI: 1.00, 2.71). The overall time trends of PBDE concentrations were similar for cases and controls. DISCUSSION: The study did not support PBDEs increasing the odds of T2DM, prior to or after T2DM diagnosis. T2DM status did not influence the time trends of PBDE concentrations.

Fluoride exposure and hypothyroidism in a Canadian pregnancy cohort.

BACKGROUND: While fluoride can have thyroid-disrupting effects, associations between low-level fluoride exposure and thyroid conditions remain unclear, especially during pregnancy when insufficient thyroid hormones can adversely impact offspring development. OBJECTIVES: We evaluated associations between fluoride exposure and hypothyroidism in a Canadian pregnancy cohort. METHODS: We measured fluoride concentrations in drinking water and three dilution-corrected urine samples and estimated fluoride intake based on self-reported beverage consumption. We classified women enrolled in the Maternal-Infant Research on Environmental Chemicals Study as euthyroid (n = 1301), subclinical hypothyroid (n = 100) or primary hypothyroid (n = 107) based on their thyroid hormone levels in trimester one. We used multinomial logistic regression to estimate the association between fluoride exposure and classification of either subclinical or primary hypothyroidism and considered maternal thyroid peroxidase antibody (TPOAb) status, a marker of autoimmune hypothyroidism, as an effect modifier. In a subsample of 466 mother-child pairs, we used linear regression to explore the association between maternal hypothyroidism and child Full-Scale IQ (FSIQ) at ages 3-to-4 years and tested for effect modification by child sex. RESULTS: A 0.5 mg/L increase in drinking water fluoride concentration was associated with a 1.65 (95 % confidence interval [CI]: 1.04, 2.60) increased odds of primary hypothyroidism. In contrast, we did not find a significant association between urinary fluoride (adjusted odds ratio [aOR]: 1.00; 95%CI: 0.73, 1.39) or fluoride intake (aOR: 1.25; 95%CI: 0.99, 1.57) and hypothyroidism. Among women with normal TPOAb levels, the risk of primary hypothyroidism increased with both increasing water fluoride and fluoride intake (aOR water fluoride concentration: 2.85; 95%CI: 1.25, 6.50; aOR fluoride intake: 1.75; 95%CI: 1.27, 2.41). Children born to women with primary hypothyroidism had lower FSIQ scores compared to children of euthyroid women, especially among boys (B coefficient: -8.42; 95 % CI: -15.33, -1.50). DISCUSSION: Fluoride in drinking water was associated with increased risk of hypothyroidism in pregnant women. Thyroid disruption may contribute to developmental neurotoxicity of fluoride.

Perfluoroalkyl acid and bisphenol-A exposure via food sources in four First Nation communities in Quebec, Canada.

OBJECTIVE: To document perfluoroalkyl acids (PFAA) and bisphenol-A (BPA) exposure in four First Nation communities in northern Quebec compared with the Canadian Health Measures Survey (CHMS Cycle 5 2016-2017) and examine the associations between dietary consumption and chemical exposure. DESIGN: We used cross-sectional data from the JES-YEH! project conducted in collaboration with four First Nation communities in 2015. A FFQ collected information on diet, and PFAA and BPA were measured in biological samples. We used generalised linear models to test the associations between food intake and chemical biomarkers. SETTING: Northern Quebec. PARTICIPANTS: Youth aged 3-19 years (n 198). RESULTS: Mean perfluorononanoic acid (PFNA) levels were significantly higher in JES-YEH! than CHMS, and BPA levels were higher among those aged 12-19 years compared with CHMS. Dairy products were associated with PFNA among Anishinabe and Innu participants (geometric mean ratio 95 % CI: 1·53 (95 % CI 1·03, 2·29) and 1·52 (95 % CI 1·05, 2·20), respectively). PFNA was also associated with ultra-processed foods (1·57 (95 % CI 1·07, 2·31)) among Anishinabe, and with wild fish and berries (1·44 (95 % CI 1·07, 1·94); 1·75 (95 % CI 1·30, 2·36)) among Innu. BPA was associated with cheese (1·72 (95 % CI 1·19, 2·50)) and milk (1·53 (95 % CI 1·02, 2·29)) among Anishinabe, and with desserts (1·71 (95 % CI 1·07, 2·74)), processed meats (1·55 (95 % CI 1·00, 2·38)), wild fish (1·64 (95 % CI 1·07, 2·49)) and wild berries (2·06 (95 % CI 1·37, 3·10)) among Innu. CONCLUSIONS: These results highlight the importance of better documenting food-processing and packaging methods, particularly for dairy products, and their contribution to endocrine disruptors exposures as well as to promote minimally processed and unpackaged foods to provide healthier food environments for youth in Indigenous communities and beyond.

Associations between dietary profiles and perfluoroalkyl acids in Inuit youth and adults.

BACKGROUND: Perfluoroalkyl acids (PFAAs), a subset of perfluoroalkyl substances (PFAS), are synthetic chemicals used in industrial and consumer applications. They are exceptionally stable and highly mobile in the environment, and were detected in high concentrations in Arctic wildlife and Nunavik Inuit. The study's objective was to study the association between dietary profiles in Nunavik and plasma PFAAs concentrations. METHODS: The study used data from the Qanuilirpitaa? 2017 Nunavik Inuit Health Survey (Q2017) (N = 1172) on Inuit adults aged 16-80 years. Nine PFAAs congeners were measured in plasma samples (six were detected). Dietary profiles were identified using latent profile analysis. Two sets of dietary profiles were included; the first included market (store-bought) and country foods (harvested/hunted from the land), and the second included only country foods. Multiple linear regression models regressed log-transformed PFAAs concentrations against the dietary profiles, adjusting for sociodemographic variables. RESULTS: We identified statistically significant 24.54-57.55 % increases in all PFAAs congeners (PFOA, PFNA, PFDA, PFUnDA, PFHxS, and PFOS) in the dietary profile defined by frequent country food consumption compared to the dietary profile defined by frequent market food consumption. Individuals defined by low consumption of foods (related to food insecurity) had higher concentrations of six PFAAs compared to individuals with frequent market food consumption. The associations were stronger with profiles defined by more frequent country food consumption, and particularly those with increased marine mammal consumption. PFDA, PFUnDA, and PFOS were particularly associated with high country food consumption frequency, such that their concentrations increased by approximately 67-83 % compared to those reporting no or very little consumption of any country foods. CONCLUSIONS: Increased country food consumption was strongly associated with higher PFAAs concentrations, particularly PFOS, PFDA, and PFUnDA. The results provide further evidence that the quality of country foods is being threatened by PFAAs contamination. Additional national and international regulations are required to protect the Arctic and its inhabitants from these pollutants.