RESUMO
OBJECTIVES: To investigate the use of armspan as a proxy for height in the assessment of nutritional status using body mass index (BMI) for four ethnic groups in Ethiopia. DESIGN: Cross-sectional study. SETTING: Four regions in Ethiopia, namely Oromia, Amhara, Tigre and Somali Region. SUBJECTS: A total of 1706 (884 males and 822 females) Ethiopians aged 18-50 y from four different ethnic groups. METHODS: Anthropometric measurements (weight, height and armspan) were obtained using standard techniques. BMI using height (BMI-ht) and using armspan (BMI-as) were calculated, t-tests were used to compare means, and linear regression to investigate the relationship between BMI-ht and BMI-as. RESULTS: Ethnic and sex differences in the relationship between height and armspan, and their derived variables (BMI-ht and BMI-as), were found. Armspan and height (r=0.83-0.9), and BMI-ht and BMI-as (r=0.89-0.97), were highly correlated in all ethnic groups. BMI-as cut-offs equivalent to the conventional BMI-ht classification of chronic energy deficiency were similar in the Oromo, Amhara and Tigre, but substantially higher in the Somalis. CONCLUSION: Armspan can be used as a proxy for height to estimate BMI, but the relationship between the two measures varies considerably with ethnicity and sex. Unless sex- and ethnicity-specific cut-offs are applied, the use of BMI-as using conventional cut-offs will overestimate the prevalence of underweight in these populations. SPONSORSHIP: HelpAge International.
