January 2000, Volume 24, Issue 1, Pages 88 - 92

Paper

Body mass index in 17-year-old Israeli males of different ethnic backgrounds; national or ethnic-specific references? A Lusky1, F Lubin2, V Barell1, G Kaplan1, V Layani1, B Lev3 & M Wiener3 1Health Services Research Unit, Ministry of Health, Sheba Medical Center, Tel Hashomer, 52621, Israel     2Department of Clinical Epidemiology, Sheba Medical Center, Tel Hashomer, 52621, Israel     3Israel Defense Force Medical Corps, Israel     Correspondence to: A Lusky , Health Services Research Unit, Gertner Institute, Sheba Medical Center, Tel Hashomer 52621, Israel.

Keywords

body mass index;   ethnic-specific reference;   national reference

Abstract

OBJECTIVE: To evaluate whether a single national reference is appropriate for assessing prevalence of overweight in heterogeneous populations, or whether ethnic-specific references are needed. DESIGN: A population-based study of Israeli Jewish males who underwent routine physical and clinical examinations prior to army recruitment served as the basis for the development of two types of references for body mass index (BMI): a national reference (NR) and an ethnic-specific reference (ER). SUBJECTS: Consecutive cohorts of all 17-y-old Jewish male recruits (n=109, 570). MEASUREMENTS: Weight, height and blood pressure values were obtained. BMI was calculated, and the 85th percentile of BMI was used as a cut-off point for overweight, using both types of references. Prevalence of hypertension among recruits was used as a biomarker to support the reliability of the ER when discrepancy in classification between the two references was found. RESULTS: As compared to the NR, three ethnic groups had a BMI distribution shifted to the left (light sub-population) and five were shifted to the right (heavy sub-population). In the light sub-population, 7% of the inductees who were classified as having normal weight by the NR were considered overweight by the ER and had a hypertension rate similar to that of those defined as overweight by both references (3.1 per 1000). In the heavy sub-population the 4% of subjects who were overweight by NR and normal by ER had hypertension rates similar to those defined as normal weight by both references (2.7/1000), and significantly lower than that of those classified as overweight by both references (10.8/1000). CONCLUSION: In heterogeneous populations, ethnic references should be used to evaluate prevalence of overweight, rather than one national reference. International Journal of Obesity (2000)24, 88-92

Received 26 September 1998; Revised 16 June 1999; Accepted 27 February 1999

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