Objective: To ascertain whether constant body mass index (BMI) standards are appropriate in genetically similar populations.
Design: Data are taken from the International Collaborative Study of Hypertension in Blacks (ICSHIB), an observational study.
Subjects: Individuals of African descent who were included in ICSHIB. Subjects lived in eight different sites: Barbados; Cameroon (urban and rural); Jamaica; Manchester, UK; Maywood, IL; urban Nigeria; and St Lucia.
Measurements: Weight and height.
Results: Constant BMI standards effectively argue for the constancy of slope of the linear regression equations of In(weight) on In(height) across populations. Linear regression results indicate that the height/weight relationship implied by the use of constant BMI standards, is not found in these populations and that there is much variation across groups.
Conclusion: The use of constant BMI standards in classifying individuals prognostically may be unwise, even in genetically similar populations.