Appropriateness of current thresholds for obesity-related measures among Aboriginal people.

BACKGROUND: Despite the high prevalence of obesity and diabetes in the Canadian Aboriginal population, it is unknown whether the current thresholds for body mass index and waist circumference derived from white populations are appropriate for Aboriginal people. We compared the risk of cardiovascular disease among Canadian Aboriginal and European populations using the current thresholds for body mass index and waist circumference.

METHODS: Healthy Aboriginal (n = 195) and European (n = 201) participants (matched for sex and body mass index range) were assessed for demographic characteristics, lifestyle factors, total and central adiposity and risk factors for cardiovascular disease. Among Aboriginal and European participants, we compared the relation between body mass index and each of the following 3 factors: percent body fat, central adiposity and cardiovascular disease risk factors. We also compared the relation between waist circumference and the same 3 factors.

RESULTS: The use of body mass index underestimated percent body fat by 1.3% among Aboriginal participants compared with European participants (p = 0.025). The use of waist circumference overestimated abdominal adipose tissue by 26.7 cm2 among Aboriginal participants compared with European participants (p = 0.007). However, there was no difference in how waist circumference estimated subcutaneous abdominal and visceral adipose tissue among the 2 groups. At the same body mass index and waist circumference, we observed no differences in the majority of cardiovascular disease risk factors among Aboriginal and European participants. The prevalence of dyslipidemia, hypertension, impaired fasting glucose and metabolic syndrome was similar among participants in the 2 groups after adjustment for body mass index, waist circumference, age and sex.

INTERPRETATION: We found no difference in the relation between body mass index and risk of cardiovascular disease between men and women of Aboriginal and European descent. We also found no difference between waist circumference and cardiovascular disease risk among these groups. These data support the use of current anthropometric thresholds in the Canadian Aboriginal population.