Obesity and relative subcutaneous fat distribution among Canadians of First Nation and European ancestry

OBJECTIVE: To compare Canadians of Aboriginal (First Nation, FN) and European ancestry (EA), with respect to obesity, subcutaneous fatness and relative subcutaneous fat distribution. DESIGN: Cross-sectional comparison. SUBJECTS: 118 First Nation and 472 European ancestry Canadians from Northern Ontario, youth (5-19y) and adults (20-75y). MEASUREMENTS: Stature, mass and skinfold thicknesses at the triceps, biceps, medial calf, subscapular, suprailiac and abdominal sites. ANALYSIS: Prevalence of obesity was determined using the 85(th) percentile of body mass index (BMI) from NHANES II as the cut-off. Principal components (PC) analyses were performed on the six skinfolds. The first component (PC1) represented a trunk-extremity skinfold contrast. Differences in mean component scores between FN and EA were assessed using independent samples t-tests. RESULTS: Prevalence of obesity among FN was high, ranging from 29% in youth to 60% in adult females. FN demonstrated greater subcutaneous adiposity and greater values for PC1, with the exception of adult males, where the difference is in the expected direction, but is not significant. The direction of the differences indicates that the FN have a greater centralization of subcutaneous fat, CONCLUSIONS: FN Canadians generally have a greater prevalence of obesity, greater subcutaneous fatness and a more centralized distribution of body fat than those of European ancestry.