Cardiometabolic correlates of low type 2 diabetes incidence in western Alaska Native people - The WATCH study

An assessment of cardiovascular disease hospitalizations and disparities by race in patients with rheumatic disease hospitalizations in Alaska, 2015-2018

BACKGROUND

There is an increased risk of cardiovascular disease in people with many rheumatic diseases. The primary objective of this study was to evaluate cardiovascular disease hospitalizations in Alaska for people with and without a rheumatic disease diagnosis and assess disparities by race, with a focus on Alaska Native and American Indian people.

METHODS

This study used the Alaska Health Facilities Data Reporting Program data on inpatient hospitalizations from 2015 to 2018. We identified people with a rheumatic disease diagnosis based on any hospitalization with a set of rheumatic disease diagnoses and compared them to people hospitalized but without a rheumatic disease diagnosis. We determined the odds of cardiovascular disease hospitalization by rheumatic disease diagnosis and assessed the influence of race and other factors, using univariate analyses and multivariable models.

RESULTS

People with a rheumatic disease diagnosis other than osteoarthritis had higher odds of cardiovascular disease hospitalization. The odds ratio was highest in people with gout compared to other rheumatic diseases. In multivariable models, there was an interaction between race and rheumatic disease status. Specifically, having gout increased the odds of cardiovascular disease hospitalization for people of all races, while having a rheumatic disease other than gout or osteoarthritis increased the odds of cardiovascular disease hospitalization in Alaska Native/American Indian people but not in people of other races.

CONCLUSIONS

The association between rheumatic disease status and cardiovascular disease hospitalization in Alaska varied by type of rheumatic disease and race. This adds substantially to the literature on associations between rheumatic disease and cardiovascular disease in Indigenous North American populations.

Alaska Native Parents' Decision-Making About Food, Beverages, and Screen Time for Young Children: Formative Insights From the "Got Neqpiaq?" Project

With rising childhood obesity rates, ensuring children adopt healthy habits early is imperative. Given the unique context for Alaska Native families living in rural remote communities, who are concurrently experiencing changes in traditional practices, we investigated what impacts parents' decisions as they relate to daily living before revising a preschool curriculum focused on healthy habits. The objective of this study was to explore factors influencing parents' decisions about their children's foods, beverages, and activities. In focus group discussions with AN parents of young children across 12 communities, we asked about meals, traditional foods, beverages, physical activity, and screen time. All sessions were recorded, transcribed, and analyzed using open and selective coding to allow the most important themes to emerge. As parents discussed how they make decisions, several trends emerged related to adults' and children's food and beverage preferences; the impact of adult modeling on children; and how convenience, seasonality, access, and a reluctance to engage in conflict all impact decision-making. Parents and other community members shared important perspectives on exposing children to traditional subsistence foods and activities and passing important traditional knowledge to them at an early age. These perspectives will form the basis for preschool curricula in these communities.

Obesity Prevalence and Dietary Factors Among Preschool-Aged Head Start Children in Remote Alaska Native Communities: Baseline Data from the "Got Neqpiaq?" Study

Background: American Indian and Alaska Native preschool-aged children experience a high prevalence of obesity, yet are under-represented in obesity prevention research. This study examined obesity prevalence and dietary risk factors among Alaska Native preschool-aged children in southwest Alaska. Methods: The study used baseline data from "Got Neqpiaq?" a culturally centered multilevel intervention focused on Yup'ik Alaska Native children, aged 3-5 years, enrolled in Head Start in 12 communities in southwest Alaska (n = 155). The primary outcomes were BMI percentile, overweight, and obesity. Dietary factors of interest were measured using biomarkers: traditional food intake (nitrogen stable isotope ratio biomarker), ultraprocessed food intake (carbon stable isotope ratio biomarker), and vegetable and fruit intake (skin carotenoid status biomarker measured by the Veggie Meter). Cardiometabolic markers (glycated hemoglobin [HbA1c] and blood cholesterol) were also measured. Results: Among the Yup'ik preschool-aged children in the study, the median BMI percentile was 91, and the prevalence of overweight or obesity was 70%. The traditional food intake biomarker was negatively associated with BMI, whereas the ultraprocessed foods and vegetable and fruit biomarkers were not associated with BMI. HbA1c and blood cholesterol were within healthy levels. Conclusions: The burden of overweight and obesity is high among Yup'ik preschool-aged children. Traditional food intake is inversely associated with BMI, which underscores the need for culturally grounded interventions that emphasize traditional values and knowledge to support the traditional food systems in Alaska Native communities in southwest Alaska. Registered with ClinicalTrials.gov #NCT03601299.

Obesity-Associated Dyslipidemia Is Moderated by Habitual Intake of Marine-Derived n-3 Polyunsaturated Fatty Acids in Yup'ik Alaska Native People: A Cross-Sectional Mediation-Moderation Analysis

BACKGROUND

Obesity leads to insulin resistance, altered lipoprotein metabolism, dyslipidemia, and cardiovascular disease. The relationship between long-term intake of n-3 polyunsaturated fatty acids (n-3 PUFAs) and prevention of cardiometabolic disease remains unresolved.

OBJECTIVES

The aim of this study was to explore direct and indirect pathways between adiposity and dyslipidemia, and the degree to which n-3 PUFAs moderate adiposity-induced dyslipidemia in a population with highly variable n-3 PUFA intake from marine foods.

METHODS

In total, 571 Yup'ik Alaska Native adults (18-87 y) were enrolled in this cross-sectional study. The red blood cell (RBC) nitrogen isotope ratio (15N/14N, or NIR) was used as a validated objective measure of n-3 PUFA intake. EPA and DHA were measured in RBCs. Insulin sensitivity and resistance were estimated by the HOMA2 method. Mediation analysis was conducted to evaluate the contribution of the indirect causal path between adiposity and dyslipidemia mediated through insulin resistance. Moderation analysis was used to assess the influence of dietary n-3 PUFAs on the direct and indirect paths between adiposity and dyslipidemia. Outcomes of primary interest included plasma total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), non-HDL-C, and triglycerides (TG).

RESULTS

In this Yup'ik study population, we found that up to 21.6% of the total effects of adiposity on plasma TG, HDL-C, and non-HDL-C are mediated through measures of insulin resistance or sensitivity. Moreover, RBC DHA and EPA moderated the positive association between waist circumference (WC) and TC or non-HDL-C, whereas only DHA moderated the positive association between WC and TG. However, the indirect path between WC and plasma lipids was not significantly moderated by dietary n-3 PUFAs.

CONCLUSIONS

Intake of n-3 PUFAs may independently reduce dyslipidemia through the direct path resulting from excess adiposity in Yup'ik adults. NIR moderation effects suggest that additional nutrients contained in n-3 PUFA-rich foods may also reduce dyslipidemia.

Smoking Patterns Among Urban Alaska Native and American Indian Adults: The Alaska EARTH 10-Year Follow-up Study

INTRODUCTION

Data on cigarette smoking prevalence among Alaska Native and American Indian (ANAI) people are limited to cross-sectional studies or specific subpopulations. Using data from the Alaska Education and Research toward Health (EARTH) Study 10-year follow-up, this study assessed patterns of smoking from baseline and factors associated with current use.

AIMS AND METHODS

EARTH Study urban south central ANAI participants (N = 376; 73% women) provided questionnaire data on smoking at baseline and 10-year follow-up. Multivariable-adjusted logistic regression assessed whether gender, cultural factors (Tribal identity, language spoken in the home), depressive symptoms (PHQ-9), baseline smoking status, and baseline cigarettes per day (CPD) were associated with current smoking at follow-up.

RESULTS

Current smoking was 27% and 23% at baseline and follow-up, respectively. Of baseline smokers, 60% reported smoking at follow-up (77% men, 52% women). From multivariable-adjusted analyses, the odds of current smoking at follow-up were lower among women than men, those who never or formerly smoked versus currently smoked at baseline, and smoking <10 CPD compared with ≥10 CPD at baseline. PHQ-9 score or cultural variables were not associated with smoking at follow-up. Smoking fewer baseline CPD was associated with former smoking status (ie, quitting) at follow-up among women, but not men.

CONCLUSIONS

Our project is among the first to longitudinally explore smoking within an ANAI cohort. While we observed persistent smoking during a 10-year period, there were important differences by gender and CPD in quitting. These differences may be important to enhance the reach and efficacy of cessation interventions for ANAI people.

IMPLICATIONS

This study contributes novel longitudinal information on cigarette smoking prevalence during a 10-year period among Alaska Native and American Indian (ANAI) people. Prior data on smoking prevalence among ANAI people are limited to cross-sectional studies or specific subpopulations. Our project is among the first to longitudinally explore smoking prevalence within an ANAI cohort. We observed persistent smoking during a 10-year period. The study also contributes information on differences by gender and cigarettes smoked per day in quitting. These findings have implications for enhancing the reach and efficacy of cessation interventions for ANAI people.

Habitual Intake of Marine-Derived n-3 PUFAs is Inversely Associated with a Cardiometabolic Inflammatory Profile in Yup'ik Alaska Native People

BACKGROUND

The relationship between dietary n-3 PUFAs and the prevention of cardiometabolic diseases, including type 2 diabetes, is unresolved. Examination of the association between n-3 PUFAs and chronic low-grade inflammation in a population where many individuals have had an extremely high intake of marine mammals and fish throughout their lifespan may provide important clues regarding the impact of n-3 PUFAs on health.

OBJECTIVES

The aim of this study was to explore associations between concentrations of n-3 PUFAs resulting from habitual intake of natural food sources high in fish and marine mammals with immune biomarkers of metabolic inflammation and parameters of glucose regulation.

METHODS

A total of 569 Yup'ik Alaska Native adults (18-87 years old) were enrolled in this cross-sectional study between December 2016 and November 2019. The RBC nitrogen isotope ratio (NIR; 15N/14N) was used as a validated measure of n-3 PUFA intake to select 165 participant samples from the first and fourth quartiles of n-3 PUFA intakes. Outcomes included 38 pro- and anti-inflammatory cytokines and 8 measures of glucose homeostasis associated with type 2 diabetes risks. These outcomes were evaluated for their associations with direct measurements of EPA, DHA, and arachidonic acid in RBCs.

ANALYSIS

Linear regression was used to detect significant relationships with cytokines and n-3 PUFAs, adiposity, and glucose-related variables.

RESULTS

The DHA concentration in RBC membranes was inversely associated with IL-6 (β = -0.0066; P < 0.001); EPA was inversely associated with TNFα (β = -0.4925; P < 0.001); and the NIR was inversely associated with Monocyte chemoattractant protein-1 (MCP-1) (β = -0.8345; P < 0.001) and IL-10 (β = -1.2868; P < 0.001).

CONCLUSIONS

Habitual intake of marine mammals and fish rich in n-3 PUFAs in this study population of Yup'ik Alaska Native adults is associated with reduced systemic inflammation, which may contribute to the low prevalence of diseases in which inflammation plays an important role.

Ten-year weight gain is not associated with multiple cardiometabolic measures in Alaska EARTH study participants

BACKGROUND AND AIMS

Alaska Native (AN) traditional lifestyle may be protective against chronic disease risk. Weight gain in adulthood has been linked to increases in chronic disease risk among other populations; yet, its impact among Alaska Native people has never been evaluated. We aimed to evaluate changes in obesity-related metrics over time, and determine associations of changes with cardiometabolic markers of chronic disease risk among AN people.

METHODS AND RESULTS

Study participants enrolled in the southcentral Alaska Education and Research Towards Health Study in 2004-2006 were invited to participate in a follow-up study conducted 2015-2017. Of the original 1320 participants, 388 completed follow-up health assessments consisting of multiple health surveys, anthropometric measurements, and cardiometabolic measures including blood sugars, blood lipids, and blood pressure. Differences in measurements between visits were determined and associations of weight change with cardiometabolic measures evaluated. Body mass index increased by 3.7 kg/m2 among men and 4.8 kg/m2 among women. Hip circumference (1.1 cm, p < 0.01) and waist circumference (0.7 cm, p < 0.01) increased among women; only waist circumference increased among men (1.6 cm, p < 0.01). Among men, there were no associations of weight change with cardiometabolic measures. Among women, there was an inverse association between weight gain and high-density lipoprotein cholesterol only (0.17 mg/dL (CI: -3.1, -0.03), p = 0.02).

CONCLUSIONS

While weight increase over a 10-year period was not associated with substantive changes in cardiometabolic measures among AN men, there was a decrease in high density lipid cholesterol associated with weight gain among AN women.

Increase in diabetes among urban Alaska Native people in the Alaska EARTH follow-up study: A call for prediabetes screening, diagnosis, and referral for intervention

AIMS

This study estimates incidence of diabetes (DM) and pre-DM relative to DM risk factors among relatively healthy Alaska Native and American Indian (henceforth AN) adults living in urban south central Alaska.

METHODS

Baseline (2004-2006) and follow-up (2014-2017) surveys, blood samples, and medical chart review data were collected from AN adults living in south central Alaska. We analyzed associations between prevalent risk factors and incident DM and pre-DM using Cox proportional hazards and used multivariable models to identify independent predictors for both DM and pre-DM.

RESULTS

Among 379 participants with follow-up data, overall DM incidence was 16.5/1,000 PY; overall pre-DM incidence was 77.6/1,000 PY, with marked differences between men and women. Prevalent cardiometabolic risk factors also varied with greater amounts of overweight in men and greater amounts of obesity in women. Controlling for age and sex, obesity, abdominal adiposity, pre-DM, and metabolic syndrome independently increased DM risk.

CONCLUSION

Health care providers of AN populations must seize the opportunity to screen, refer, and treat individuals with pre-DM and other modifiable DM risk factors prior to DM diagnosis if we are to alter the epidemiologic course of disease progression in this urban AN population.

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.

Associations between food insecurity and prediabetes in a representative sample of U.S. Adults (NHANES 2005-2014)

AIMS

The primary aim of this research was to investigate the association between food insecurity and prediabetes and to identify specific subgroups for early clinical intervention.

METHODS

Cross-sectional data from 25,814 participants were analyzed from the National Health and Nutrition Examination Survey for years 2005-2014. Multivariable logistic regression was used to explore the association between food security status and laboratory-confirmed prediabetes. All models were adjusted for age, sex, race, and body mass index.

RESULTS

When compared to participants with full and marginal food security, participants with low/very food security were 1.35 (95% CI: 1.17-1.55) times more likely to have prediabetes. Younger individuals with low/very low food security had a greater likelihood of prediabetes, 1.50 (95% CI: 1.19-1.81), when compared with their food secure counterparts.

CONCLUSIONS

Food insecurity at any level, whether low or very low, is positively associated with prediabetes in the U.S. general adult population. Food insecure young adults, particularly those aged 20-34 years, should be targeted for early clinical intervention.

Fasting triglycerides as a predictor of incident diabetes, insulin resistance and β-cell function in a Canadian First Nation

Background: Diabetes prevalence is substantially higher among Canadian First Nations populations than the non-First Nation population. Fasting serum triglycerides have been found to be an important predictor of incident diabetes among non-indigenous populations. However, there is a great need to understand diabetes progression within specific ethnic groups, particularly First Nations populations.

Objective: The purpose of this study was to test for an association between fasting serum triglycerides and incident diabetes, changes in insulin resistance and changes in β-cell function in a Manitoba First Nation cohort.

Methods: Study data were from two diabetes screening studies in Sandy Bay First Nation in Manitoba, Canada, collected in 2002/2003 and 2011/2012. The cohort was composed of respondents to both screening studies (n=171). Fasting blood samples and anthropometric, health and demographic data were collected. A generalised linear model with Poisson distribution was used to test for an association between fasting triglycerides and incident diabetes.

Results: There were 35 incident cases of diabetes among 128 persons without diabetes at baseline. Participants who developed incident type 2 diabetes were significantly older and had significantly higher body mass index (BMI; p=0.012), total cholesterol (p=0.007), fasting triglycerides (p<0.001), and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) (p<0.001). Fasting triglyceride level was found to be a statistically significant positive predictor of incident diabetes independent of age, sex and waist circumference at baseline. Participants with triglycerides in the highest tertile (≥2.11 mmol/l) had a 4.0-times higher risk of developing incident diabetes compared to those in the lowest tertile (p=0.03). Notably, neither waist circumference nor BMI were significant predictors of incident diabetes independent of age, sex and triglycerides.

Conclusion: Fasting triglycerides may be useful as a clinical predictor of insulin resistance and diabetes development among First Nations populations. Unlike other ethnic groups, BMI and waist circumference may be less important factors in diabetes development.

Bi-cultural dynamics for risk and protective factors for cardiometabolic health in an Alaska Native (Yup'ik) population

Alaska Native people experience disparities in mortality from heart disease and stroke. This work attempts to better understand the relationships between socioeconomic, behavioral, and cardiometabolic risk factors among Yup'ik people of southwestern Alaska, with a focus on the role of the socioeconomic, and cultural components. Using a cross-sectional sample of 486 Yup'ik adults, we fitted a Partial Least Squares Path Model (PLS-PM) to assess the associations between components, including demographic factors [age and gender], socioeconomic factors [education, economic status, Yup'ik culture, and Western culture], behavioral factors [diet, cigarette smoking and smokeless tobacco use, and physical activity], and cardiometabolic risk factors [adiposity, triglyceride-HDL and LDL lipids, glycemia, and blood pressure]. We found relatively mild associations of education and economic status with cardiometabolic risk factors, in contrast with studies in other populations. The socioeconomic factor and participation in Yup'ik culture had potentially protective associations with adiposity, triglyceride-HDL lipids, and blood pressure, whereas participation in Western culture had a protective association with blood pressure. We also found a moderating effect of participation in Western culture on the relationships between Yup'ik culture participation and both blood pressure and LDL lipids, indicating a potentially beneficial additional effect of bi-culturalism. Our results suggest that reinforcing protective effects of both Yup'ik and Western cultures could be useful for interventions aimed at reducing cardiometabolic health disparities.

Carnitine palmitoyltransferase 1A P479L and infant death: policy implications of emerging data

Carnitine palmitoyltransferase 1 isoform A (CPT1A) is a crucial enzyme for the transport of long-chain fatty acids into the mitochondria. The CPT1A p.P479L variant is found in high frequencies among indigenous populations residing on the west and north coasts of Alaska and Canada and in northeast Siberia and Greenland. Epidemiological studies have reported a statistical association between P479L homozygosity and infant death in Alaska Native and Canadian Inuit populations. Here, we review the available evidence about the P479L variant and apply to these data the epidemiological criteria for assessing causal associations. We found insufficient evidence to support a causal association with infant death and, further, that if a causal association is present, then the genotype is likely to be only one of a complex set of factors contributing to an increased risk of infant death. We conclude that additional research is needed to clarify the observed association and to inform effective preventative measures for infant death. In light of these findings, we discuss the policy implications for public health efforts because policies based on the observed association between P479L homozygosity and infant death data are premature.Genet Med advance online publication 26 January 2017.