Linkage and association analysis of obesity traits reveals novel loci and interactions with dietary n-3 fatty acids in an Alaska Native (Yup'ik) population

Electronic health record reveals community-level cardiometabolic health benefits associated with 10 years of community-based participatory research

BACKGROUND

While a major goal of community-based participatory research (CBPR) is to improve community health; it is unclear how to measure longstanding success of CBPR.

OBJECTIVE

We sought to determine the impact of ongoing CBPR on cardiometabolic health of participating communities, including in people not directly participating in research.

METHODS

We used linear mixed-effects modelling with electronic medical records from 2002 to 2012 from the Yukon-Kuskokwim Health Corporation, which provides health care to all Alaska Native people in southwestern Alaska, to compare rates of change in cardiometabolic risk factors between communities that did and did not participate in ongoing CBPR beginning in 2003.

RESULTS

We analysed 1,262,035 medical records from 12,402 individuals from 10 study and 38 control communities. Blood pressure declined faster in study than in control communities: systolic blood pressure (0.04 mmHg/year; 95% confidence interval [CI]: 0.01, 0.08); diastolic blood pressure (DBP) (0.07 mmHg/year; 95% CI: 0.04, 0.09). Body mass index increased 0.04 units/year faster in study communities than in control communities (95% CI: 0.03, 0.05). More study visits were associated with faster reduction of DBP and triglyceride levels in study communities.

CONCLUSIONS

Ongoing CBPR may improve overall cardiometabolic health in communities, perhaps by increasing engagement in health and advocacy.

Cancer statistics for American Indian and Alaska Native individuals, 2022: Including increasing disparities in early onset colorectal cancer

American Indian and Alaska Native (AIAN) individuals are diverse culturally and geographically but share a high prevalence of chronic illness, largely because of obstacles to high-quality health care. The authors comprehensively examined cancer incidence and mortality among non-Hispanic AIAN individuals, compared with non-Hispanic White individuals for context, using population-based data from the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries. Overall cancer rates among AIAN individuals were 2% higher than among White individuals for incidence (2014 through 2018, confined to Purchased/Referred Care Delivery Area counties to reduce racial misclassification) but 18% higher for mortality (2015 through 2019). However, disparities varied widely by cancer type and geographic region. For example, breast and prostate cancer mortality rates are 8% and 31% higher, respectively, in AIAN individuals than in White individuals despite lower incidence and the availability of early detection tests for these cancers. The burden among AIAN individuals is highest for infection-related cancers (liver, stomach, and cervix), for kidney cancer, and for colorectal cancer among indigenous Alaskans (91.3 vs. 35.5 cases per 100,000 for White Alaskans), who have the highest rates in the world. Steep increases for early onset colorectal cancer, from 18.8 cases per 100,000 Native Alaskans aged 20-49 years during 1998 through 2002 to 34.8 cases per 100,000 during 2014 through 2018, exacerbated this disparity. Death rates for infection-related cancers (liver, stomach, and cervix), as well as kidney cancer, were approximately two-fold higher among AIAN individuals compared with White individuals. These findings highlight the need for more effective strategies to reduce the prevalence of chronic oncogenic infections and improve access to high-quality cancer screening and treatment for AIAN individuals. Mitigating the disparate burden will require expanded financial support of tribal health care as well as increased collaboration and engagement with this marginalized population.

In the context of the triple burden of malnutrition: A systematic review of gene-diet interactions and nutritional status

Genetic background interacts with dietary components to modulate nutritional health status. This study aimed to review the evidence for gene-diet interactions in all forms of malnutrition. A comprehensive systematic literature search was conducted through April 2021 to identify observational and intervention studies reporting the effects of gene-diet interactions in over-nutrition, under-nutrition and micronutrient status. Risk of publication bias was assessed using the Quality Criteria Checklist and a tool specifically designed for gene-diet interaction research. 167 studies from 27 populations were included. The majority of studies investigated single nucleotide polymorphisms (SNPs) in overnutrition (n = 158). Diets rich in whole grains, vegetables, fruits and low in total and saturated fats, such as Mediterranean and DASH diets, showed promising effects for reducing obesity risk among individuals who had higher genetic risk scores for obesity, particularly the risk alleles carriers of FTO rs9939609, rs1121980 and rs1421085. Other SNPs in MC4R, PPARG and APOA5 genes were also commonly studied for interaction with diet on overnutrition though findings were inconclusive. Only limited data were found related to undernutrition (n = 1) and micronutrient status (n = 9). The findings on gene-diet interactions in this review highlight the importance of personalized nutrition, and more research on undernutrition and micronutrient status is warranted.

Artificial Intelligence-Assisted Identification of Genetic Factors Predisposing High-Risk Individuals to Asymptomatic Heart Failure

Heart failure (HF) is a global pandemic public health burden affecting one in five of the general population in their lifetime. For high-risk individuals, early detection and prediction of HF progression reduces hospitalizations, reduces mortality, improves the individual’s quality of life, and reduces associated medical costs. In using an artificial intelligence (AI)-assisted genome-wide association study of a single nucleotide polymorphism (SNP) database from 117 asymptomatic high-risk individuals, we identified a SNP signature composed of 13 SNPs. These were annotated and mapped into six protein-coding genes (GAD2, APP, RASGEF1C, MACROD2, DMD, and DOCK1), a pseudogene (PGAM1P5), and various non-coding RNA genes (LINC01968, LINC00687, LOC105372209, LOC101928047, LOC105372208, and LOC105371356). The SNP signature was found to have a good performance when predicting HF progression, namely with an accuracy rate of 0.857 and an area under the curve of 0.912. Intriguingly, analysis of the protein connectivity map revealed that DMD, RASGEF1C, MACROD2, DOCK1, and PGAM1P5 appear to form a protein interaction network in the heart. This suggests that, together, they may contribute to the pathogenesis of HF. Our findings demonstrate that a combination of AI-assisted identifications of SNP signatures and clinical parameters are able to effectively identify asymptomatic high-risk subjects that are predisposed to HF.

Marine n-3 polyunsaturated fatty acids: Efficacy on inflammatory-based disorders

Inflammation is a physiological response to injury, stimulating tissue repair and regeneration. However, the presence of peculiar individual conditions can negatively perturb the resolution phase eventually leading to a state of low-grade systemic chronic inflammation, characterized by tissue and organ damages and increased susceptibility to non-communicable disease. Marine n-3 polyunsaturated fatty acids (n-3 PUFAs), mainly eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), are able to influence many aspects of this process. Experiments performed in various animal models of obesity, Alzheimer's disease and multiple sclerosis have demonstrated that n-3 PUFAs can modulate the basic mechanisms as well as the disease progression. This review describes the available data from experimental studies to the clinical trials.

Quantile-dependent expressivity of plasma adiponectin concentrations may explain its sex-specific heritability, gene-environment interactions, and genotype-specific response to postprandial lipemia

Background

"Quantile-dependent expressivity" occurs when the effect size of a genetic variant depends upon whether the phenotype (e.g. adiponectin) is high or low relative to its distribution. We have previously shown that the heritability (h² ) of adiposity, lipoproteins, postprandial lipemia, pulmonary function, and coffee and alcohol consumption are quantile-specific. Whether adiponectin heritability is quantile specific remains to be determined.

Methods

Plasma adiponectin concentrations from 4,182 offspring-parent pairs and 1,662 sibships from the Framingham Heart Study were analyzed. Quantile-specific heritability from offspring-parent (β _OP,h² = 2β _OP/(1 + r_spouse)) and full-sib regression slopes (β _FS, h² = {(1 + 8r_spouse β _FS)^0.05-1}/(2r_spouse)) were robustly estimated by quantile regression with nonparametric significance assigned from 1,000 bootstrap samples.

Results

Quantile-specific h² (± SE) increased with increasing percentiles of the offspring's age- and sex-adjusted adiponectin distribution when estimated from β _OP (P _trend = 2.2 × 10^-6): 0.30 ± 0.03 at the 10th, 0.33 ± 0.04 at the 25th, 0.43 ± 0.04 at the 50th, 0.55 ± 0.05 at the 75th, and 0.57 ± 0.08 at the 90th percentile, and when estimated from β _FS (P _trend = 7.6 × 10^-7): 0.42 ± 0.03 at the 10th, 0.44 ± 0.04 at the 25th, 0.56 ± 0.05 at the 50th, 0.73 ± 0.08 at the 75th, and 0.79 ± 0.11 at the 90th percentile. Consistent with quantile-dependent expressivity, adiponectin's: (1) heritability was greater in women in accordance with their higher adiponection concentrations; (2) relationships to ADIPOQ polymorphisms were modified by adiposity in accordance with its adiponectin-lowering effect; (3) response to rosiglitazone was predicted by the 45T> G ADIPOQ polymorphism; (4) difference by ADIPOQ haplotypes increased linearly with increasing postprandial adiponectin concentrations.

Conclusion

Adiponectin heritability is quantile dependent, which may explain sex-specific heritability, gene-environment and gene-drug interactions, and postprandial response by haplotypes.

Potential Cardiovascular and Metabolic Beneficial Effects of ω-3 PUFA in Male Obesity Secondary Hypogonadism Syndrome

Long-chain ω-3 polyunsaturated fatty acids (PUFAs) are fundamental biocomponents of lipids and cell membranes. They are involved in the maintenance of cellular homeostasis and they are able to exert anti-inflammatory and cardioprotective actions. Thanks to their potential beneficial effects on the cardiovascular system, metabolic axis and body composition, we have examined their action in subjects affected by male obesity secondary hypogonadism (MOSH) syndrome. MOSH syndrome is characterized by the presence of obesity associated with the alteration of sexual and metabolic functions. Therefore, this review article aims to analyze scientific literature regarding the possible benefits of ω-3 PUFA administration in subjects affected by MOSH syndrome. We conclude that there are strong evidences supporting ω-3 PUFA administration and/or supplementation for the treatment and management of MOSH patients.

Alaska Native Traditional Food and Harvesting Activity Patterns over 10 Years of Follow-Up

BACKGROUND

Alaska Native (AN) traditional foods and associated harvesting activities are beneficial to human health.

OBJECTIVE

This study assessed longitudinal self-reported traditional food use and harvesting activities among Alaska Native and American Indian (AN/AI) participants in the Alaska Education and Research Towards Health (EARTH) study.

METHODS

In 2004-2006, southcentral Alaska EARTH study participants (n = 1320) completed diet and activity questionnaires which were repeated in 2015-2017; results were compared between participants who completed both questionnaires (n = 388).

RESULTS

In the follow-up questionnaire, >93% of participants reported eating ≥1 traditional food in the past year. The top 3 traditional foods were fish (75%), moose (42%), and shellfish (41%). Women were more likely than men to consume traditional foods, especially fish, gathered berries, shellfish, and seal oil (P < 0.05). Participants aged ≥60 y in the original cohort were significantly more likely to consume fish and shellfish at follow-up, whereas those aged 40-59 y were the most likely of the 3 age groups to consume seal oil (P < 0.05). Between the original cohort and follow-up, there was a significant decline in the mean number of traditional foods eaten from 6.3 to 5.5, as well as reduced consumption of multiple traditional foods (P < 0.001). Over 59% of participants reported ≥1 traditional harvesting activity in the past year; this proportion did not significantly change between baseline and follow-up. Picking berries/greens (44%), cutting/smoking fish or meat (33%), and fishing (30%) were the most common activities. Participation in traditional harvesting activities was greater among women than men (P < 0.05), but did not differ by age.

CONCLUSIONS

Longitudinal follow-up demonstrated that AN/AI people maintained participation in traditional harvesting activities, but the variety of traditional foods declined significantly among both men and women. Promotion of traditional foods and harvesting activities that serve as protective factors against chronic diseases may benefit this population.

First Genome-wide Association Analysis for Growth Traits in the Largest Coral Reef-Dwelling Bony Fishes, the Giant Grouper (Epinephelus lanceolatus)

The giant grouper, Epinephelus lanceolatus, is the largest coral reef-dwelling bony fish species. However, despite extremely fast growth performance and the considerable economic importance in this species, its genetic regulation of growth remains unknown. Here, we performed the first genome-wide association study (GWAS) for five growth traits in 289 giant groupers using 42,323 single nucleotide polymorphisms (SNPs) obtained by genotyping-by-sequencing (GBS). We identified a total of 36 growth-related SNPs, of which 11 SNPs reached a genome-wide significance level. The phenotypic variance explained by these SNPs varied from 7.09% for body height to 18.42% for body length. Moreover, 22 quantitative trait loci (QTLs) for growth traits, including nine significant QTLs and 13 suggestive QTLs, were found on multiple chromosomes. Interestingly, the QTL (LG17: 6934451) was shared between body weight and body height, while two significant QTLs (LG7: 22596399 and LG15: 11877836) for body length were consistent with the associated regions of total length at the genome-wide suggestive level. Eight potential candidate genes close to the associated SNPs were selected for expression analysis, of which four genes (phosphatidylinositol transfer protein cytoplasmic 1, protein tyrosine phosphatase receptor type E, alpha/beta hydrolase domain-containing protein 17C, and vascular endothelial growth factor A-A) were differentially expressed and involved in metabolism, development, response stress, etc. This study improves our understanding of the complex genetic architecture of growth in the giant grouper. The results contribute to the selective breeding of grouper species and the conservation of coral reef fishes.

Habitual consumption of long-chain n-3 PUFAs and fish attenuates genetically associated long-term weight gain

BACKGROUND

A growing amount of data suggests that n-3 (ω-3) polyunsaturated fatty acid (PUFA) intake may modify the genetic association with weight change.

OBJECTIVES

We aimed to prospectively test interactions of habitual consumption of n-3 PUFAs or fish, the major food source, with overall genetic susceptibility on long-term weight change.

DESIGN

Gene-diet interactions were examined in 11,330 women from the Nurses' Health Study (NHS), 6773 men from the Health Professionals Follow-Up Study (HPFS), and 6254 women from the Women's Health Initiative (WHI).

RESULTS

In the NHS and HPFS cohorts, food-sourced long-chain n-3 PUFA intake showed directionally consistent interactions with genetic risk score on long-term changes in BMI (P-interaction = 0.01 in the HPFS, 0.15 in the NHS, and 0.01 in both cohorts combined). Such interactions were successfully replicated in the WHI, an independent cohort (P-interaction = 0.02 in the WHI and 0.01 in the combined 3 cohorts). The genetic associations with changes in BMI (in kg/m2) consistently decreased (0.15, 0.10, 0.07, and -0.14 per 10 BMI-increasing alleles) across the quartiles of long-chain n-3 PUFAs in the combined cohorts. In addition, high fish intake also attenuated the genetic associations with long-term changes in BMI in the HPFS (P-interaction = 0.01), NHS (P-interaction = 0.03), WHI (P-interaction = 0.10), and the combined cohorts (P-interaction = 0.01); and the differences in BMI changes per 10 BMI-increasing alleles were 0.16, 0.06, -0.08, and -0.18, respectively, across the categories (≤1, 1∼4, 4∼6, and ≥7 servings/wk) of total fish intake. Similar interactions on body weight were observed for fish intake (P-interaction = 0.003) and long-chain n-3 PUFA intake (P-interaction = 0.12).

CONCLUSION

Our study provides replicable evidence to show that high intakes of fish and long-chain n-3 PUFAs are associated with an attenuation of the genetic association with long-term weight gain based on results from 3 prospective cohorts of Caucasians.

Moderating effect of PLIN4 genetic variant on impulsivity traits in 5-year-old-children born small for gestational age

Poor fetal growth is associated with long-term behavioral, metabolic and psychiatric alterations, including impulsivity, insulin resistance, and mood disorders. However, the consumption of omega-3 polyunsaturated fatty acid (n-3 PUFA) seems to be protective for this population, improving inhibitory control and behavioral reactivity. We investigated whether the presence of the A allele of rs8887 SNP (PLIN4 gene), known to be associated with increased sensitivity to the consumption of n-3 PUFAs, interacts with fetal growth influencing inhibitory control. 152 five-year-old children were genotyped and performed the Stop Signal Task (SSRT). There was a significant interaction between birth weight and the presence of the A allele on SSRT performance, in which lower birth weight associated with poorer inhibitory control only in non-carriers. These results suggest that a higher responsiveness to n-3 PUFAS protects small for gestational age children from developing poor response inhibition, highlighting that optimizing n-3 PUFA intake may benefit this population.

Genetic polymorphisms are associated with exposure biomarkers for metals and persistent organic pollutants among Inuit from the Inuvialuit Settlement Region, Canada

BACKGROUND

Inuit are exposed to some of the highest levels of contaminants worldwide. Studies suggest that several genes that mediate the metabolism of these contaminants are polymorphic. We hypothesize that single nucleotide polymorphisms (SNPs) in such genes may underline differences in biomarker concentrations and/or modify exposure-biomarker associations.

METHODS

Members from the Inuvialuit Settlement Region (Canada) were recruited. Blood concentrations of mercury (Hg), cadmium (Cd), lead (Pb), dichlorodiphenyldichloroethylene (DDE), and polychlorinated biphenyl (PCB-153) were measured. SNPs from pathways such as glutathione, metallothionein, oxidative stress, and xenobiotic transport were genotyped in 281 participants, and data from 112 SNPs were included in the analyses. Surveys were administered to obtain information on demographics, and key sources of Hg (diet) and Cd (smoking) exposure. ANOVA and linear regressions were used for data analyses.

RESULTS

Geometric mean concentrations of metals were 4.6μg/L for Hg, 1.3μg/L for Cd, and 32.2μg/L for Pb. Concentrations of organic pollutants were 2.0μg/L for DDE and 0.6μg/L for PCB-153. Biomarker levels for Hg, Cd, Pb, DDE, and PCB-153 differed (p<0.05) by genotype for 4, 3, 4, 3, and 3 SNPs, respectively. In multivariable analyses (for Pb, DDE, PCB-153) adjusting age, sex and body mass index (BMI), only 2 associations (one for Pb and one for DDE) remained significant. In multivariable analyses accounting for sources of Hg or Cd exposure, 24 SNPs (9 for Hg, 15 for Cd with 4 overlapping) had significant (p<0.05) main effects on biomarker levels and/or modified exposure-biomarker associations.

CONCLUSION

The findings suggest that polymorphisms in key environmentally responsive genes can influence biomarker levels and/or modify exposure-biomarker associations for contaminants of concern to Arctic populations. Consideration of such gene-environment results may help improve the ability to conduct exposure (and ultimately risk) assessments of country foods and Inuit health.

Identification of novel genes significantly affecting growth in catfish through GWAS analysis

Growth is the most important economic trait in aquaculture. Improvements in growth-related traits can enhance production, reduce costs and time to produce market-size fish. Catfish is the major aquaculture species in the United States, accounting for 65% of the US finfish production. However, the genes underlying growth traits in catfish were not well studied. Currently, the majority of the US catfish industry uses hybrid catfish derived from channel catfish female mated with blue catfish male. Interestingly, channel catfish and blue catfish exhibit differences in growth-related traits, and therefore the backcross progenies provide an efficient system for QTL analysis. In this study, we conducted a genome-wide association study for catfish body weight using the 250 K SNP array with 556 backcross progenies generated from backcross of male F1 hybrid (female channel catfish × male blue catfish) with female channel catfish. A genomic region of approximately 1 Mb on linkage group 5 was found to be significantly associated with body weight. In addition, four suggestively associated QTL regions were identified on linkage groups 1, 2, 23 and 24. Most candidate genes in the associated regions are known to be involved in muscle growth and bone development, some of which were reported to be associated with obesity in humans and pigs, suggesting that the functions of these genes may be evolutionarily conserved in controlling growth. Additional fine mapping or functional studies should allow identification of the causal genes for fast growth in catfish, and elucidation of molecular mechanisms of regulation of growth in fish.

Marine collagen peptides reduce endothelial cell injury in diabetic rats by inhibiting apoptosis and the expression of coupling factor 6 and microparticles

The present study aimed to elucidate the role of marine collagen peptides (MCPs) in protection of carotid artery vascular endothelial cells (CAVECs) in type 2 diabetes mellitus (T2DM), and the mechanism underlying this process. In an in vivo experiment, diabetic Wistar rats were divided randomly into four groups (n=10/group): Diabetes control, and three diabetes groups administered low, medium and high doses of MCPs (2.25, 4.5 and 9.0 g/kg body weight/day, respectively). Another 10 healthy rats served as the control. In an in vitro experiment, human umbilical‑vein endothelial cells (HUVECs) were incubated in normal and high concentrations of glucose with or without MCPs (3.0, 15.0 and 30.0 mg/ml, respectively) for 24, 48 or 72 h. Blood vessel/endothelial construction, inflammatory exudation and associated molecular biomarkers in CAVECs were detected and analyzed. The results of the present study demonstrated that in rats, MCP treatment for 4 weeks significantly lowered blood glucose and attenuated endothelial thinning and inflammatory exudation in carotid‑artery vascular endothelial cells. In vitro, the high‑glucose intervention significantly increased cell apoptosis in HUVECs, and medium and high doses of MCPs (4.5 and 9.0 g/kg body weight/day, respectively) partially ameliorated this high glucose‑mediated apoptosis and decreased levels of apoptosis biomarkers. In conclusion, a moderate oral MCP dose (≥4.5 g/kg body weight/day) may be a novel therapeutic tool to protect against early cardiovascular complications associated with T2DM by inhibiting apoptosis and reducing the expression of coupling factor 6 and microparticles.

Functional and clinical relevance of novel and known PCSK1 variants for childhood obesity and glucose metabolism

Objective

Variants in Proprotein Convertase Subtilisin/Kexin Type 1 (PCSK1) may be causative for obesity as suggested by monogenic cases and association studies. Here we assessed the functional relevance in experimental studies and the clinical relevance through detailed metabolic phenotyping of newly identified and known PCSK1 variants in children.

Results

In 52 obese children selected for elevated proinsulin levels and/or impaired glucose tolerance, we found eight known variants and two novel heterozygous variants (c.1095 + 1G > A and p.S24C) by sequencing the PCSK1 gene. Patients with the new variants presented with extreme obesity, impaired glucose tolerance, and PCOS. Functionally, c.1095 + 1G > A caused skipping of exon8 translation and a complete loss of enzymatic activity. The protein was retained within the endoplasmic reticulum (ER) causing ER stress. The p.S24C variant had no functional effect on protein size, cell trafficking, or enzymatic activity. The known variants rs6230, rs35753085, and rs725522 in the 5′ end did not affect PCSK1 promoter activity.

In clinical association studies in 1673 lean and obese children, we confirmed associations of rs6232 and rs6234 with BMI-SDS and of rs725522 with glucose stimulated insulin secretion and Matsuda index. We did not find the new variants in any other subjects.

Conclusions

We identified and functionally characterized two rare novel PCSK1 variants of which c.1095 + 1G > A caused complete loss of protein function. In addition to confirming rs6232 and rs6234 in PCSK1 as polygenic risk variants for childhood obesity, we describe an association of rs725522 with insulin metabolism. Our results support the contribution of PCSK1 variants to obesity predisposition in children.

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We identified two novel variants in PCSK1 in severely obese adolescents.

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The phenotype of these two heterozygous carriers is more severe than in “common childhood obesity”.

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The ΔEx8 variant leads to a truncated protein with a complete loss of function, which is retained within the ER.

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For common variant rs725522 detailed metabolic phenotyping revealed impaired glucose dynamics.

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Overall, variants in PCSK1 are not only associated with childhood obesity, but a more severe phenotype than in BMI-matched controls.

Linkage and association analysis of circulating vitamin D and parathyroid hormone identifies novel loci in Alaska Native Yup'ik people

BACKGROUND

Vitamin D deficiency is a well-documented public health issue with both genetic and environmental determinants. Populations living at far northern latitudes are vulnerable to vitamin D deficiency and its health sequelae, although consumption of traditional native dietary pattern rich in fish and marine mammals may buffer the effects of reduced sunlight exposure. To date, few studies have investigated the genetics of vitamin D metabolism in circumpolar populations or considered genediet interactions with fish and n-3 fatty acid intake.

METHODS

We searched for genomic regions exhibiting linkage and association with circulating levels of vitamin D and parathyroid hormone (PTH) in 982 Yup'ik individuals from the Center for Alaska Native Health Research Study. We also investigated potential interactions between genetic variants and a biomarker of traditional dietary intake, the δ15N value.

RESULTS

We identified several novel regions linked with circulating vitamin D and PTH as well as replicated a previous linkage finding on 2p16.2 for vitamin D. Bioinformatic analysis revealed multiple candidate genes for both PTH and vitamin D, including CUBN, MGAT3, and NFKBIA. Targeted association analysis identified NEBL as a candidate gene for vitamin D and FNDC3B for PTH. We observed significant associations between a variant in MXD1 and vitamin D only when an interaction with the δ15N value was included. Finally, we integrated pathway level information to illustrate the biological validity of the proposed candidate genes.

CONCLUSION

We provide evidence of linkage between several biologically plausible genomic regions and vitamin D metabolism in a circumpolar population. Additionally, these findings suggest that a traditional dietary pattern may modulate genetic effects on circulating vitamin D.