Does sitting height ratio affect estimates of obesity prevalence among Canadian Inuit? Results from the 2007-2008 Inuit Health Survey

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.

How to account for Inuit ancestry in lung function prediction

Rigorous lung function prediction equations for the Inuit are lacking. We used spirometry from 351 Inuit and 29 people of other ancestry obtained during an occupational survey in Greenland to determine how to obtain valid lung function predictions for the Inuit using Global Lung Function Initiative (GLI) equations for Europeans. Standing height for the Inuit was used in the predictions as well as their height modified in line with the known differences in standing to sitting height ratio (SHR) for the Inuit. With recorded height in predicting lung function, mean±SD Inuit z-scores for FVC and FEV1 were significantly higher than predicted (0.81±1.20 and 0.53±1.36, respectively, p<0.0001) which was not true for the non-Inuit participants (-0.01±1.04 and 0.15±1.17, respectively). When using height modified for SHR the mean±SD Inuit z-scores for FVC and FEV1 were no longer significantly different from predicted (0.10±1.10 and -0.12±1.24, respectively). The mean±SD Inuit FEV1/FVC z-scores were not significantly different from the non-Inuit, being respectively -0.45±0.98 and -0.01±1.04. Modified height changed the mean±SD Inuit FEV1/FVC z-scores to -0.39±0.99. Representative lung function predictions from GLI equations can be made for Inuit by using standing height modified for the known differences in SHR between Inuit and those of European ancestry.

Rhino Conjunctivitis and Asthma Among Seafood Processing Workers in Greenland. A Cross-Sectional Study

Introduction: The fishing- and the seafood processing industries are the largest industrial sectors in Greenland. Despite this, only a few cases of occupational diseases in this industry have been reported to the Danish Labor Market Insurance. Occupational asthma and allergy are well-known occupational diseases in the seafood processing industry worldwide and underreporting of occupational diseases in Greenland is suspected.

Objective: The aim of the current study was to examine the associations between job exposures and occupational asthma and rhino conjunctivitis in workers in the Greenlandic seafood processing industry and to compare the prevalence of sensitization by type and degree of exposure to snow crab, shrimp, fish, and the fish parasite, Anisakis simplex.

Methods: Data from 382 Greenlandic seafood processing workers were collected during 2016–2018. Data included questionnaire answers, lung function measurements, skin prick tests, and blood samples with ImmunoCAP. For all analyses, p < 0.05 was considered the level of significance.

Results: 5.5% of the workers had occupational asthma and 4.6% had occupational rhino conjunctivitis. A large proportion of the workers were sensitized to allergens specific to the workplace; 18.1% to snow crab, 13.6% to shrimp, 1.4% to fish, and 32.6% to the fish parasite, A. simplex. We found a dose-response relationship between the risk of being sensitized to snow crab and A. simplex and years of exposure to the allergens in the seafood processing industry.

Conclusion: This study showed that a considerable proportion of workers in the Greenlandic seafood processing industry had occupational asthma and rhino conjunctivitis. Additionally, the study showed high sensitization levels toward snow crab, shrimp, and the fish parasite, A. simplex. This supports the hypothesis of a considerable degree of underreporting of occupational allergic airway disease in the Greenlandic seafood processing industry. Prospectively, it is important to inform workers, leaders, and health care professionals of the health problems and the law on worker's compensation, and to initiate preventive actions at factory and trawler level.

Comparison of Anthropometric Indicators That Assess Nutritional Status From Infancy to Old Age and Proposal of Percentiles for a Regional Sample of Chile

Objectives: Anthropometric variables are used to evaluate health, dietary status, disease risks, and changes in body composition. The purpose of this study was to compare weight, height, and Body Mass Index (BMI) with American references from the National Center for Health Statistics (NCHS-2012), using BMI and Tri-Ponderal Mass Index (TMI) to propose percentiles for evaluating nutritional status of children, adolescents, and adults, ages 5-80 years old. Methods: A descriptive cross-sectional study was conducted in 15,436 (8,070 males and 7,366 females) children, youths and adults in the Maule region (Chile). The age range ranged from 5.0 to ~80 years of age. Weight and height were assessed. Body mass index BMI and tri-ponderal mass index (TMI) were calculated. The LMS method was used to generate percentiles. Results: The results illustrated that children were heavier and had more BMI during childhood compared to the NCHS references. During adolescence, reference values were greater until approximately ages 70-79. For height, children were relatively similar to those of the NCHS references, but during adolescence, differences became evident. Adolescence until approximately age 80, the population showed lower values for height. Percentiles were calculated using BMI and TMI by age range and sex. Differences occurred between the American NCHS references and the population with regard to the anthropometric variables of weight, height, and in BMI. Conclusion: Discrepancies with the American NCHS reference were verified in the anthropometric variables of weight, height and BMI. Reference percentiles of BMI and TMI were developed for the evaluation of the nutritional status of the regional population of Maule (Chile). Its use is suggested in clinical and epidemiological contexts.

Community-driven research in the canadian arctic: dietary exposure to methylmercury and gastric health outcomes

Indigenous Arctic Canadians have a higher prevalence of gastric neoplasms relative to North Americans of European ancestry. We investigated the hypothesis that low-dose methylmercury exposure from eating fish/whale increases the risk of gastric cancer in Arctic communities. We used intermediate endpoints from an established model of gastric carcinogenesis: intestinal metaplasia, atrophy, and severe chronic gastritis. During 2008-2012, we obtained gastric biopsies from participants of community-driven projects in 3 communities. In 2016, we collected hair samples to measure methylmercury levels and interviewed them about diet. In cross-sectional analysis, logistic regression estimated odds ratios for the estimated effect of hair-methylmercury concentration on the prevalence of each pathology outcome stratified by selenium intake. Among 80 participants, prevalence of intestinal metaplasia, atrophy and severe chronic gastritis was 17, 29 and 38%, respectively. Adjusted Odds of severe chronic gastritis and atrophy were highest at hair-methylmercury concentrations ≥1μg/g when estimated selenium intake was 0, and approached 0 for all methylmercury levels as estimated selenium intake increased. Gastric pathology increased with methylmercury exposure when selenium intake was low. Though limited by small numbers, these findings suggest selenium ingested by eating fish/whale may counter harmful effects of methylmercury exposure in Arctic populations.

A Scoping Review of Obesity among Indigenous Peoples in Canada

Indigenous populations in Canada are heavily affected by the burden of obesity, and certain communities, such as First Nations on reserve, are not included in the sampling framework of large national health surveys. A scoping review of ever published original research reporting obesity rates (body mass index ≥ 30), among adult Indigenous peoples in Canada, was conducted to identify studies that help close the Canadian Community Health Survey (CCHS) data gap for obesity prevalence in Indigenous populations in Canada and to make comparisons based on ethnicity, sex, time, and geography. First Nations on reserve with self-reported height and weight had higher rates of obesity (30%-51%) than First Nations off reserve (21%-42%) and non-Indigenous populations (12%-31%) in their respective province or territory, with the exception of Alberta, where rates in First Nations on reserve (30% and 36%) were lower or similar to those reported in First Nations off reserve (38%). First Nations on reserve with predominantly measured height and weight (42%-66%) had higher rates of obesity compared to Inuit in Quebec (28%), Nunavut (33%), and Newfoundland and Labrador (41%), while the rates were similar to those in Inuit in Northwest Territories (49%). Obesity in these large studies conducted among Inuit was based solely on measured height and weight. Studies in First Nations and Inuit alike showed higher prevalence of obesity in women, as well as an increase with time. No recent studies measured the obesity rates for First Nations in Yukon and Northwest Territories and for Métis living in settlements of Northern Alberta. Researchers are encouraged to conduct total diet studies in these regions, and to use existing data to analyze the associations between obesity, road access, latitude, food environment, and traditional food intake, to further inform community planning and development.

The association of household food security, household characteristics and school environment with obesity status among off-reserve First Nations and Métis children and youth in Canada: results from the 2012 Aboriginal Peoples Survey

INTRODUCTION

Indigenous children are twice as likely to be classified as obese and three times as likely to experience household food insecurity when compared with non- Indigenous Canadian children. The purpose of this study was to explore the relationship between food insecurity and weight status among Métis and off-reserve First Nations children and youth across Canada.

METHODS

We obtained data on children and youth aged 6 to 17 years (n = 6900) from the 2012 Aboriginal Peoples Survey. We tested bivariate relationships using Pearson chi-square tests and used nested binary logistic regressions to examine the food insecurity-weight status relationship, after controlling for geography, household and school characteristics and cultural factors.

RESULTS

Approximately 22% of Métis and First Nations children and youth were overweight, and 15% were classified as obese. Over 80% of the sample was reported as food secure, 9% experienced low food security and 7% were severely food insecure. Off-reserve Indigenous children and youth from households with very low food security were at higher risk of overweight or obese status; however, this excess risk was not independent of household socioeconomic status, and was reduced by controlling for household income, adjusted for household size. Negative school environment was also a significant predictor of obesity risk, independent of demographic, household and geographic factors.

CONCLUSION

Both food insecurity and obesity were prevalent among the Indigenous groups studied, and our results suggest that a large proportion of children and youth who are food insecure are also overweight or obese. This study reinforces the importance of including social determinants of health, such as income, school environment and geography, in programs or policies targeting child obesity.

Prevalence of overweight and obesity among indigenous populations in Canada: A systematic review and meta-analysis

Previous studies on overweight and obesity among indigenous peoples in Canada have been inconclusive. A systematic review was conducted on the prevalence of overweight and obesity among Canadian indigenous populations. Major bibliographic databases were searched for relevant studies published between January 1990 and June 2013. We reviewed 594 abstracts and included 41 studies in the meta-analyses. Using the heterogeneity test (Cochrane Q) results, the overall prevalence was estimated using fixed- or random-effects model. Nonadults (<18 years) had a pooled prevalence of overweight and obesity at 29.8% (95% CI: 25.2-34.4) and 26.5% (95% CI: 21.8-31.3), respectively. The pooled prevalence of overweight and obesity among adults were 29.7% (95% CI: 28.2-31.2) and 36.6% (95% CI: 32.9-40.2), respectively. Adult males had higher overweight prevalence than females (34.6% vs. 26.6%), but lower obesity prevalence (31.6% vs. 40.6%). Nonadult girls had higher prevalence than boys [overweight: 27.6%; 95% CI: 22.6-32.7 vs. 24.7%; 95% CI: 19.0-30.5; obesity: 28.6%; 95% CI: 20.3-36.9 vs. 25.1%; 95% CI: 13.8-36.4]. Nonadult Inuit had the highest overweight and lowest obesity prevalence. Although Inuit adult had the lowest prevalence of overweight (28.7%; 95% CI: 27.3-30.2) and obesity (32.3%; 95% CI: 25.5-39.1), it was relatively high. This study highlights the need for nutritional intervention programs for obesity prevention among indigenous populations in Canada.

Total and central obesity in elderly associated with a marker of undernutrition in early life - sitting height-to-stature ratio: A nutritional paradox

OBJECTIVES

The purpose of this study was to investigate whether sitting height-to-stature ratio (SHSR) is associated with total and central obesity in the elderly.

METHODS

This was a cross-sectional study with 133 noninstitutionalized elderly. High SHSR (≥ 1SD above the mean) was used as a marker of undernutrition (MU) in early life. Poisson's multiple regression was used to determine the association between variables.

RESULTS

The prevalence of high SHSR was 21.0%, total obesity 43.6% and central obesity 50.4%. Elderly with high SHSR presented a statistically significant association with total obesity (PR 1.50; 95% CI 1.04-2.18) and central obesity (PR 1.42; 95% CI 1.03-1.95) after adjustment for sex, age, educational level and income in the multivariate analysis.

CONCLUSION

The occurrence of total and central obesity in the elderly was associated with a MU in early life. This result indicates that nutritional deficiencies in childhood may increase the risk of obesity in the elderly, a nutritional paradox.

Cardiovascular Disease Susceptibility and Resistance in Circumpolar Inuit Populations

Cardiovascular disease (CVD) is a major public health issue in indigenous populations in the Arctic. These diseases have emerged concomitantly with profound social changes over the past 60 years. The aim of this study was to summarize the literature on CVD risk among Arctic Inuit. Literature on prevalence, incidence, and time trends for CVD and its risk factors in Arctic Inuit populations was reviewed. Most evidence supports a similar incidence of coronary heart disease and a higher incidence of cerebrovascular disease among Arctic Inuit than seen in western populations. Factors that may increase CVD risk include aging of the population, genetic susceptibility, and a rapid increase in obesity, diabetes, and hypertension in parallel with decreasing physical activity and deterioration of the lipid profile. In contrast, and of great importance, there has been a decrease in smoking and alcohol intake (at least documented in Greenland), and contaminant levels are declining. Although there have been marked socioeconomic and dietary changes, it remains unsolved and to some extent controversial how this may have influenced cardiovascular risk among Arctic Inuit. The increase in life expectancy, in combination with improved prognosis for patients with manifest CVD, will inevitably lead to a large increase in absolute numbers of individuals affected by CVD in Arctic Inuit populations, exacerbated by the rise in most CVD risk factors over the past decades. For preventive purposes and for health care planning, it is crucial to carefully monitor disease incidence and trends in risk factors in these vulnerable Arctic populations.

Interrelationships between anthropometric variables and overweight in childhood and adolescence

Objectives

To answer the questions: how does body mass index (BMI) correlate to five overweight related anthropometric variables during different ages in childhood, and which anthropometric variables contribute most to variation in BMI during childhood?

Methods

Data on BMI, height (H), sitting height (SH), waist circumference (WC), waist to height ratio (WHtR), waist to sitting height ratio (WSHtR), subscapular skinfold (SSF), and triceps skinfold (TSF), from 4,576 Norwegian children 4.00–15.99 years of age, were transformed to standard deviation scores (SDS) and studied using correlation and multiple regression analyses.

Results

The correlations between BMI SDS and the standardized anthropometric variables were in general strong and positive. For all variables, the correlations were weakest in the youngest age group and highest between 7 and 12 years. WC SDS and WHtR SDS were most strongly correlated with BMI SDS through all ages and in both sexes. A model with seven anthropometric variables adjusted for age and sex explained 81.4% of the variation in BMI SDS. When adjusted for all other variables, WC SDS contributed most to the variation in BMI SDS (b = 0.467, CI [0.372, 0.562]). Age group, but not sex, contributed significantly to variation in BMI SDS.

Conclusion

The interrelationships between BMI SDS and five standardized overweight related anthropometric variables were dependent on age, being weakest in the youngest age group. Independent of sex and age, WC SDS was in this study superior to other anthropometric variables in contributing to variation in BMI SDS during childhood. Am. J. Hum. Biol. 26:502–510, 2014. © 2014 The Authors American Journal of Human Biology Published by Wiley Periodicals, Inc.

Raised BMI cut-off for overweight in Greenland Inuit--a review

Background

Obesity is associated with increased morbidity and premature death. Obesity rates have increased worldwide and the WHO recommends monitoring. A steep rise in body mass index (BMI), a measure of adiposity, was detected in Greenland from 1963 to 1998. Interestingly, the BMI starting point was in the overweight range. This is not conceivable in a disease-free, physically active, pre-western hunter population.

Objective

This led us to reconsider the cut-off point for overweight among Inuit in Greenland.

Design and findings

We found 3 different approaches to defining the cut-off point of high BMI in Inuit. First, the contribution to the height by the torso compared to the legs is relatively high. This causes relatively more kilograms per centimetre of height that increases the BMI by approximately 10% compared to Caucasian whites. Second, defining the cut-off by the upper 90-percentile of BMI from height and weight in healthy young Inuit surveyed in 1963 estimated the cut-off point to be around 10% higher compared to Caucasians. Third, if similar LDL-cholesterol and triglycerides are assumed for a certain BMI in Caucasians, the corresponding BMI in Inuit in both Greenland and Canada is around 10% higher. However, genetic admixture of Greenland Inuit and Caucasian Danes will influence this difference and hamper a clear distinction with time.

Conclusion

Defining overweight according to the WHO cut-off of a BMI above 25 kg/m² in Greenland Inuit may overestimate the number of individuals with elevated BMI.

Design and methods of the Adult Inuit Health Survey 2007-2008

Background

The Canadian International Polar Year (IPY) program made it possible to undertake much needed health research in 3 jurisdictions within the Canadian Inuit Nunangat (homeland) over a 2-year period: Inuvialuit Settlement Region (ISR), Nunavut Territory, and Nunatsiavut.

Design

The Adult Inuit Health Survey (IHS) was a cross-sectional survey and provides baseline data upon which future comparisons can be made for prospectively assessing factors leading to the progression of chronic diseases among Canadian Inuit. With the help of the Canadian Coast Guard Ship Amundsen, which was equipped with research and laboratory facilities, 33 coastal communities were visited; land survey teams visited 3 inland communities.

Results

The Adult IHS succeeded in obtaining important baseline information concerning the health status and living conditions of 2,595 adults living in ISR, Nunavut and Nunatsiavut.

Conclusion

Information from this survey will be useful for future comparisons and the opportunity to link with the International Inuit Cohort, a follow-up evaluation, and for the development of future health policies and public health interventions.

Growth measures among preschool-age Inuit children living in Canada and Greenland

Aim: The present study reports findings from a study of preschool-age Inuit children living in the Arctic regions of Canada and Greenland. Methods: We compare stature and obesity measures using cutoffs from the Centers for Disease Control and the International Obesity Task Force references. The sample is comprised of 1121 Inuit children (554 boys and 567 girls) aged 3–5 years living in Nunavut ( n=376) and Nunavik ( n=87), Canada, in the capital city of Nuuk, Greenland ( n=86), and in Greenland’s remaining towns and villages ( n=572). Results: Greenland Inuit children were significantly taller than their Canadian counterparts, with greatest height and weight observed among children from Nuuk. Overall prevalence of stunting was low with the three cutoffs yielding similar values for height-for-age z-scores. Obesity prevalence was higher among Canadian Inuit children than their Greenland counterparts. Conclusions: Inuit children have stature values consistent with those of the Centers for Disease Control reference and low prevalence of stunting, though geographic variability in mean stature values between Canadian and Greenlandic samples likely reflects differences in both socioeconomic status and genetic admixture. Obesity prevalence is high among both Canadian and Greenland Inuit preschoolers, with children living in the city of Nuuk exhibiting lower obesity prevalence than children living in either Nunavut or Nunavik, Canada or Greenland’s towns and villages. Varying obesity prevalence may reflect varying degrees of food security in remote locations as well as the influence of stature and sitting height which have not been well studied in young Inuit children.

Association between socioeconomic status and overweight and obesity among Inuit adults: International Polar Year Inuit Health Survey, 2007-2008

OBJECTIVES

To evaluate the socio-economic correlates of overweight and obesity among Inuit undergoing rapid cultural changes.

STUDY DESIGN

A cross-sectional health survey of 2,592 Inuit adults from 36 communities in the Canadian Arctic.

METHODS

Main outcome measures were overweight and obesity (BMI>25 kg/m2 and >30 kg/m2, respectively) and as characteristics were similar, groups were combined into an at-risk BMI category (BMI>25 kg/m2). Logistic regression was used to determine the association between various sociodemographic characteristics and physical activity with overweight and obesity.

RESULTS

The prevalence of overweight and obesity was 28 and 36%, respectively, with a total prevalence of overweight and obesity of 64%. In analyses of sociodemographic variables adjusted for age, gender and region, higher education, any employment, personal income, and private housing were all significantly positively correlated with an at-risk BMI (p≤0.001). Smoking, Inuit language as primary language spoken at home, and walking were inversely associated with overweight and obesity.

CONCLUSIONS

The current findings highlight the social disparities in overweight and obesity prevalence in an ethnically distinct population undergoing rapid cultural changes.