Body proportions in healthy adult Inuit in East Greenland in 1963

A national study on weight classes among children in Greenland at school entry

OBJECTIVES

To estimate the proportion of gender-specific thinness, overweight and obesity among children born in 2005 at school entry in Greenland and to compare figures between the capital, Nuuk, with the rest of Greenland.

STUDY DESIGN

A cross-sectional study based on data from Electronic Medical Records (EMR).

METHODS

All children born in 2005 with permanent address in Greenland at the time of data extraction with a registered weight and height in EMR from January 1st 2011 to January 31st 2013 were included in the study. Information about height without shoes and weight in light indoor clothing was obtained. Body Mass Index (BMI) was calculated. Participants were categorized into age and gender-specific weight classes based on the International Obesity Task Force (IOTF) cut-offs for child overweight, obesity and thinness.

RESULTS

A total of 842 children born in 2005 were identified. Of those, 72% (N=607, 308 boys and 299 girls) had a recorded weight and height in the study period. In total, 74.6% (71.2-78.1) were categorized as of normal weight. The proportion of children with overweight was 15.8% (12.9-18.7) while 6.8% (4.8-8.8) were obese. In all, 2.9% were categorized as thin. The proportion of overweight among boys (12.7%) was lower (p=0.031) than among girls (19.1%), and boys in Nuuk had a lower median BMI compared to the rest of Greenland. No differences in distribution of age and gender-specific overweight and obesity were observed between the capital and the rest of Greenland.

CONCLUSION

Nearly 1 quarter of Greenlandic children are overweight or obese at school entry. No differences were observed between Nuuk and the rest of Greenland. Information about weight and height is available in the EMR for the majority of all children at school entry in Greenland. Continuous monitoring of the proportion of overweight and obesity among children using data from the EMR in Greenland is recommended.

Forty-five year trends in overweight and obesity in an indigenous arctic Inuit Society in transition and spatiotemporal trends

OBJECTIVES

Overweight and obesity associate with increased morbidity and premature death. Westernization of societies heralds rising obesity rates. A steep increase in body mass index (BMI) and overweight in Greenland from 1963 to 1998 led us to follow-up on height, weight, BMI, and rates of overweight among populations in Greenland and assess time trends between different stages of transition.

METHODS

BMI was calculated from height and weight measured on Inuit and non-Inuit aged 50 through 69 years surveyed in 1963, 1998, and 2008 in Ammassalik district in East Greenland and in 1998 and 2008 in the capital Nuuk in West Greenland.

RESULTS

A total of 1,186 were surveyed in 1963 (52 men/63 women), 1998 (309/226), and 2008 (297/239). BMI increased with time (P < 0.001; 1963/1998/2008 23.3/24.3/26.2 kg/m(2) ). In addition, BMI increased with urbanization in Inuit men (P = 0.001; settlements/town/city, in 1998, 23.9/24.9/25.5 kg/m(2) ; in 2008, 25.0/26.0/27.0 kg/m(2) ) while not in Inuit women (P = 0.18). The number of overweight Inuit (BMI >27 kg/m(2) ) increased with time in men (4.0/25.6/33.2% in 1963/1998/2008, P = 0.001) and in women (13.6/30.7/37.3%, P = 0.001). BMI was above 30 kg/m(2) in 2.0/10.8/17.5% of all Inuit men in 1963/1998/2008 (P = 0.003) and in 8.3%/23.0/24.5% of all Inuit women (P = 0.02) respectively.

CONCLUSIONS

Overweight and obesity rates rise with time and with societal transition in Greenland. Settlements and town are catching up with the city where the rate of increase is diminishing, although there were gender differences.

Estimation of health risk by using toxicokinetic modelling: a case study of polychlorinated biphenyl PCB153

To assess potential PCB153-associated human health effects and risks, it is necessary to model past exposure. PCB153 blood concentrations, obtained from the AMAP biomonitoring programme, in Inuit women covering the years 1994-2006 at Disko Bay, 1999-2005 at Nuuk, and 1992-2007 at Nunavik were used to extrapolate body burden and exposure to the whole lifespan of the population by the one-compartment toxicokinetic model. By using risk characterisation modelling, calculated Hazard Quotients were higher than 1 between the years 1955 and 1987 for the 90th population percentile and during 1956-1984 for the 50th population percentile. Cancer risk for overall exposure of PCB153 ranged from 4.6×10(-5) to 1.8×10(-6) for the 90th percentile and 3.6×10(-5) to 1.4×10(-10) for the 50th percentile between 1930 and 2049, when central estimates or upper-bound slope factors were applied. Cancer risk was below 1×10(-6) for the same time period when a lower slope factor was applied. Significant future research requirements to improve health risk characterisation include, among others, larger sample sizes, better analytical accuracy, fewer assumptions in exposure assessment, and consequently, a better choice of the toxicity benchmark used to develop the hazard quotient.

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.

Frequent left ventricular hypertrophy independent of blood pressure in 1851 pre-western Inuit

BACKGROUND

Elevated blood pressure is a risk factor for cardiovascular disease and may be detected by left ventricular hypertrophy (LVH) in electrocardiogram (ECG). Pre-western Inuit had frequent signs of LVH in ECG predominantly in the 3rd decade while a low occurrence of ischemic heart disease.

METHODS

We evaluated the association between blood pressures and ECG signs of LVH, cardiac auscultation, and symptoms related to heart disease in the recently recovered data from the survey of 1851 Inuit conducted in 1962-1964 in East Greenland.

RESULTS

The participation rate was 97%. Among the 812 Inuit aged 18 years or above blood pressure was unaltered until the age of 39 years (systolic, p=76; diastolic, p=0.36) and increased subsequently (both, p<0.001). Systolic blood pressure >140 mmHg was more frequent when aged >40 years (p<0.001) and diastolic blood pressure >90 mmHg was more common in men (p<0.001) and in men and women aged >40 years (p<0.001). ECG signs of LVH were more frequent in men (p<0.01) but the occurrence decreased from the age of 40 years (p<0.01), and were not influenced by systolic (p=0.97), diastolic (p=0.87) or pulse pressure (p=0.69).

CONCLUSIONS

Blood pressure rose only after the age of 40 years in pre-western Inuit. Left ventricular hypertrophy peaked among 30-year olds and was independent of elevated blood pressure. It may be speculated that the common left ventricular hypertrophy was due to marked physical activity that contributed to the low occurrence of ischemic heart disease among pre-western Inuit.

Low occurrence of ischemic heart disease among Inuit around 1963 suggested from ECG among 1851 East Greenland Inuit

BACKGROUND

The prevalence of coronary heart disease among Greenland Inuit today is similar to that of western populations. The cardiovascular risk profile among Inuit has changed over the past four decades with the introduction of a western life style. An unaltered prevalence of coronary heart disease has been proposed, but no pre-westernisation data exist.

AIM

To describe pre-westernisation prevalence of coronary heart disease among East Greenland Inuit.

DESIGN

A population study of 1851 Inuit living in East Greenland was conducted in 1962-1964. It included ECG, cardiac auscultation and recording of symptoms. ECGs were evaluated for ischemic signs, arrhythmia, hypertrophy, and conduction abnormalities.

RESULTS

The participation rate was 97%. A12-lead ECG was performed in 181 adults, including 65% of men aged 40 years and above. Hypertrophy was seen in 15% and peaked in 30-39 year olds. Pathological conduction disturbances were seen in 4% and 1% had ischemic signs. The age-standardised prevalence of ischemic ECG findings was 5.5%. Abnormal ECG findings did not correlate with pathologic findings on cardiac auscultation or symptoms related to heart disease.

CONCLUSIONS

Hypertrophy peaked among 30 years olds. Ischemic ECG findings were present in East Greenland Inuit before westernisation, the prevalence clearly lower than today.

Ethnic differences in bone mineral density between inuit and Caucasians in north Greenland are caused by differences in body size

Data on bone mineral density (BMD) in living Inuit are limited and BMD measurements in Arctic Inuit using Dualenergy X-ray Absorptiometry (DXA) are lacking. Ethnicity may be important for bone mass. The aim of this study was to validate DXA in rural Arctic Greenland, to measure BMD in Greenland Inuit and Caucasians, and to estimate the importance of ethnicity for BMD. We measured the BMD in 80 healthy subjects living in Ilulissat and Saqqaq in North Greenland twice in both distal forearms and in both heels using peripheral DXA (pDXA). Participants were stratified by origin (Inuit[settlement])/Caucasians, n = 33 [19]/28), gender (men/women, n = 37/43), and age (30-39/40-49, n = 32/48). Caucasians were bigger than Inuit (men/women, height p < 0.001/p < 0.001; weight p = 0.01/ p = 0.026), but had similar BMI (p = 0.42/0.70). Triplicate pDXA measurements showed individual CV% = 0.16-1.79%; overall CV% = 1.1% (forearm)/1.0% (heel). Data followed the normal distribution (p = 0.65-0.99) with identical variances between Inuit and Caucasians (p = 0.12-0.63). Mean BMD in right forearm/left forearm/right heel/left heel was: Inuit men 0.570/0.568/0.549/0.536 g/cm2; Inuit women 0.484/0.474/0.473/0.464 g/cm2; Caucasian men 0.580/0.570/0.646/0.638 g/cm2; Caucasian women 0.495/0.496/0.552/0.553 g/cm2. An ethnic difference in heel BMD (p < 0.001) disappeared when adjusted for weight (p = 0.30). No difference was found in forearm BMD. In conclusion, pDXA is feasible and reliable in rural Greenland. Ethnic differences in BMD are small and may reflect differences in body size.