Modernization of lifestyle, body fat content and body fat distribution: a comparison of Igloolik Inuit and Volochanka nGanasan.

OBJECTIVE

To compare two circumpolar populations at different stages in adoption of a modern lifestyle with respect to body fat content, fat distribution, blood lipids and blood pressures.

DESIGN

Cross-sectional comparison between Inuit and nGanasan.

SUBJECTS

141 male and 107 female Inuit (aged 17-49 years) living in the modern settlement of Igloolik (69 degrees 40'N, 81 degrees W) and 38 male and 39 female nGanasan living a more traditional lifestyle in Volochanka (71 degrees N, 94 degrees E).

MEASUREMENT

Triceps, subscapular and suprailiac skinfold thicknesses, chest and waist circumferences, blood pressures, plasma total cholesterol, plasma HDL-cholesterol and triglyceride concentrations.

RESULTS

Igloolik Inuit now have similar subcutaneous fat readings to their urban counterparts, average values increasing with age from 10 to 16 mm in males, and from 15 to 29 mm in females. In Volochanka, the men retain low readings (6-8 mm), but the women (13-25 mm) almost match their Inuit counterparts. Individual skinfolds, chest and waist circumferences all show substantial correlations with blood pressure (nGanasan > Inuit). The subscapular/triceps ratio is also high (Igloolik, 1.55 to 1.74 in men, 1.06 to 1.15 in women; Volochanka, 1.45 to 1.70 in men and 1.20 to 1.70 in women), but this ratio is only weakly correlated with plasma lipids and blood pressures.

CONCLUSIONS

Internal fat deposition may reduce correlations between skinfolds and other cardiac risk factors. Nevertheless, the Inuit have accumulated fat in adopting a modern, sedentary lifestyle, with adverse implications for their future health.