ARE THERE ETHNIC-DIFFERENCES IN THE ASSOCIATION BETWEEN BODY-WEIGHT AND RESISTANCE, MEASURED BY BIOELECTRICAL-IMPEDANCE

OBJECTIVE: To describe ethnic differences in the relationship between body size and body composition. Knowledge about such differences is im portant when studying obesity-related complications, such as hypertens ion and noninsulin dependent diabetes, because it may not be possible to generalize results from one study population to other populations. DESIGN: Cross-sectional study. SUBJECTS: Four groups of different ethn ic identity (2987 Caucasians (Danes), 243 predominantly Melanesian (To rres Strait Islanders from northern Australia), 206 Australian Aborigi nes and 146 Polynesians (New Zealand Samoans)), aged 30-70 y, were stu died. MEASUREMENTS: We examined associations between body weight and b ioelectrical impedance, as a measure of body composition. RESULTS: Exc ept for Australian Aborigines, associations (slopes) between body weig ht and resistance were generally constant in the different ethnic grou ps, once height and age differences had been considered, indicating th at this relationship may involve a certain universality, that is indep endent of the population specificity for impedance measurement. System atic differences in instrument readings or electrodes did not seem to be responsible for the differences found. CONCLUSION: With the excepti on of Australian Aborigines, there may be a constant relation between body size and body composition (total body water or fat free mass) of different ethnic groups, that depends on gender and age category only.