Differences in the relationship between body fat and body mass index between two different Indonesian ethnic groups: The effect of body build

Self Cite

Objectives: To test the impact of body build factors on the validity of impedance-based body composition predictions across (ethnic) population groups and to study the suitability of segmental impedance measurements. Design: Cross-sectional observational study. Settings: Ministry of Health and School of Physical Education, Nanyang Technological University, Singapore. Subjects: A total of 291 female and male Chinese, Malays and Indian Singaporeans, aged 18 -69, body mass index (BMI) 16.0 -40.2 kg= m 2 . Methods: Anthropometric parameters were measured in addition to impedance (100 kHz) of the total body, arms and legs. Impedance indexes were calculated as height 2 =impedance. Arm length (span) and leg length (sitting height), wrist and knee width were measured from which body build indices were calculated. Total body water (TBW) was measured using deuterium oxide dilution. Extra cellular water (ECW) was measured using bromide dilution. Body fat percentage was determined using a chemical four-compartment model. Results: The bias of TBW predicted from total body impedance index (bias: measured minus predicted TBW) was different among the three ethnic groups, TBW being significantly underestimated in Indians compared to Chinese and Malays. This bias was found to be dependent on body water distribution (ECW=TBW) and parameters of body build, mainly relative (to height) arm length. After correcting for differences in body water distribution and body build parameters the differences in bias across the ethnic groups disappeared. The impedance index using total body impedance was better correlated with TBW than the impedance index of arm or leg impedance, even after corrections for body build parameters. Conclusions: The study shows that ethnic-specific bias of impedance-based prediction formulas for body composition is due mainly to differences in body build among the ethnic groups. This means that the use of 'general' prediction equations across different (ethnic) population groups without prior testing of their validity should be avoided. Total body impedance has higher predictive value than segmental impedance.

Section: Discussionmentioning

confidence: 87%

Validity of total and segmental impedance measurements for prediction of body composition across ethnic population groups

Deurenberg¹,

Deurenberg-Yap

Schouten

2002

Self Cite

“…Those who have a higher relative leg/arm length will have a higher resistance/impedance, and thus have a lower RI at a given FFM and an underestimation of TBW and FFM (Snijder et al, 1999). Data on differences in relative leg length among Asian children from different origins are limited, but these differences have been found among Asian adults (Gurrici et al, 1999;Deurenberg et al, 2002b) and between Asians, blacks and Caucasians (Gallagher et al, 1996;Norgan, 1994;Deurenberg et al, 1999). Furthermore, the ethnic difference in TBW distribution can also influence the estimation of TBW and FFM by single frequency BIA.…”

Section: Development Of Bia Equationsmentioning

confidence: 96%

Validation of bioelectrical impedance analysis for total body water assessment against the deuterium dilution technique in Asian children

Liu

Byrne

et al. 2011

Background/Objectives: To develop and cross-validate bioelectrical impedance analysis (BIA) prediction equations of total body water (TBW) and fat-free mass (FFM) for Asian pre-pubertal children from China, Lebanon, Malaysia, Philippines and Thailand. Subjects/Methods: Height, weight, age, gender, resistance and reactance measured by BIA were collected from 948 Asian children (492 boys and 456 girls) aged 8-10 years from the five countries. The deuterium dilution technique was used as the criterion method for the estimation of TBW and FFM. The BIA equations were developed using stepwise multiple regression analysis and cross-validated using the Bland-Altman approach. Results: The BIA prediction equation for the estimation of TBW was as follows: TBW ¼ 0.231 Â height 2 / resistance þ 0.066 Â height þ 0.188 Â weight þ 0.128 Â age þ 0.500 Â sexÀ0.316 Â ThaisÀ4.574 (R 2 ¼ 88.0%, root mean square error (RMSE) ¼ 1.3 kg), and for the estimation of FFM was as follows: FFM ¼ 0.299 Â height 2 /resistance þ 0.086 Â height þ 0.245 Â weight þ 0.260 Â age þ 0.901 Â sexÀ0.415 Â ethnicity (Thai ethnicity =1, others = 0)À6.952 (R 2 ¼ 88.3%, RMSE ¼ 1.7 kg). No significant difference between measured and predicted values for the whole cross-validation sample was found. However, the prediction equation for estimation of TBW/FFM tended to overestimate TBW/FFM at lower levels whereas underestimate at higher levels of TBW/FFM. Accuracy of the general equation for TBW and FFM was also valid at each body mass index category. Conclusions: Ethnicity influences the relationship between BIA and body composition in Asian pre-pubertal children. The newly developed BIA prediction equations are valid for use in Asian pre-pubertal children.

“…Body build tends to vary among different ethnic groups (Duncan et al, 2004). Generally, relative sitting height tends to be higher in Asian ethnic groups, which may result in a relatively low BMI Gurrici et al, 1999). Furthermore, when adjusting for body build, most of the ethnic-specific differences were eliminated associated with %TBF prediction equations for bioelectrical impedance analysis (BIA) in Chinese, Malay, and Indian Singaporeans (Deurenberg et al, 2002).…”

Section: Relationship Of Total Body Fatness and Anthropometric Indicementioning

confidence: 99%

Relationship of total body fatness and five anthropometric indices in Chinese aged 20–40 years: different effects of age and gender

Liu

et al. 2005

Objectives: We aim to evaluate the ethnic-specific relationship of total fat mass and anthropometric indices in Chinese. Design: Cross-section study. Setting: This study was performed at the College of Life Sciences, Hunan Normal University, P.R. China. Subjects and method: To increase our understanding of the relationship of total fat mass and anthropometric indices in Chinese, 793 females and 1091 males aged 20-40 years were randomly recruited from Changsha city of P. R. China. Hip circumference (HC) and waist circumference (WC) were measured using standardized equipments, and other three anthropometric indices of body mass index (BMI), waist-to-hip ratio (WHR), and conicity index (CI) were calculated using weight, height, HC and WC. Total body fatness (TBF) in kg was measured using a Hologic QDR 4500 W dual-energy X-ray absorptiometry (DEXA) scanner. Results: There was an increasing trend of TBF, %TBF (percent total body fatness) and the five anthropometric indices in successively older age groups. Compared with females, males generally had high average BMI, WC, HC, WHR and CI, but had low average TBF and %TBF. Except for some correlations in 25-29 years age groups, TBF and %TBF were significantly correlated with five anthropometric indices with the Pearson's correlation coefficients ranging from 0.07 to 0.87. Principal component analysis (PCA) was performed to form four principal components (PCs) that interpreted over 99% of the total variation of the five related anthropometric indices in all age groups, with over 53% of the total variation accounted for by the PC1. Multiple regression analyses showed that four PCs combined explained a greater variance (R 2 ¼ 55.2-80.8%) in TBF than did BMI alone (R 2 ¼ 40-74.9%). Conclusion: Our results suggest that there is an increasing trend of total fat mass and five anthropometric indices with aging; that age and sex have the important effects on influencing the correlations of TBF and the studied anthropometric indices; and that the accuracy of predicting the TBF using five anthropometric indices is higher than using BMI alone.