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Bioelectrical impedance measurement of body composition in obese adolescents
ANZOS 2013 abstracts 183 Bioelectrical impedance measurement of body composition in obese adolescents Ching S. Wan 1 , Leigh C. Ward 2 , Jocelyn Halim 3 , Megan Gow 3,∗ , Mandy Ho 3 , Sarah P. Garnett 3 1 Department
of Nutrition and Dietetics, University of Sydney, Sydney, NSW, Australia 2 Chemical and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia 3 Institute of Endocrinology and Diabetes, The Children’s Hospital Westmead, Westmead, NSW, Australia Background: A stand-on bioelectrical impedance analysis (BIA) system is a safe, non-invasive, relatively inexpensive method of measuring body composition. However, little is known about how the body composition parameters measured by BIA relate to those determined by dual-energy X-ray absorptiometry (DXA) in an obese, adolescent population. Objectives: To compare body composition measures from the Tanita stand-on BIA (MC-180MA), determined by (a) in-built equations and (b) published and derived equations using raw data (resistance (R) and reactance (Xc)), with body composition parameters measured by DXA in obese adolescents. Methods: 66 obese adolescents (age: 10—18 y, BMI: 22—48 kg/m2 ) had body composition measured by both BIA (Tanita MC-180MA) and DXA (Lunar Prodigy). Raw data obtained from the BIA, R and Xc at frequencies of 5, 50, 250 and 500 kHz, were used in published bioimpedance spectroscopy [1] and BIA equations [2]. Raw data was also used to generate a new prediction equation for FFM using a double cross-validation method. Results: Compared to DXA, the BIA in-built equations overestimated fat-free mass (FFM) by 4.3 kg [95% limits of agreement −13.9 to 5.3] and underestimated % body fat (%BF) by 10.8% [−11.1 to 35.3]. There were no significant differences in the estimates of body composition parameters determined by published/derived equations using raw data and DXA; the mean differences in FFM and %BF were 0.4—0.9 kg and 0.5—0.8%, respectively. However, similar to the BIA in-built equations, all
e101 estimates had wide limits of agreement of approximately ±7 kg for FFM and ±10% for %BF. Conclusion: The Tanita BIA (MC-180MA) in-built equations cannot be recommended as a measure of body composition in obese adolescents. However, equations using the raw data can be used to measure body composition in groups, but there is the potential for significant error if used for an individual.
References [1] Ward. Nutrition 2007;23:657—64. [2] Ramírez. Eur J Clin Nutr org/10.1038/ejcn. 2012.89.
2012,
http://dx.doi.
http://dx.doi.org/10.1016/j.orcp.2013.12.682 184 Arterial elasticity in adolescents with insulin resistance and type 1 diabetes Mandy Ho 1,2,∗ , Paul Benitez-Aguirre 1,2 , Kim Donaghue 1,2 , Paul Mitchell 3 , Louise Baur 1,2 , Alicia Jenkins 4,5 , Maria Craig 1,2,6 , Chris Cowell 1,2 , Sarah Garnett 1,2 1 University
of Sydney, Sydney, NSW, Australia 2 The Children’s Hospital at Westmead, Sydney, NSW, Australia 3 Centre for Vision Research, Westmead Millennium Institute, Sydney, NSW, Australia 4 St Vincents Hospital, Melbourne, VIC, Australia 5 Faculty of Medicine, Melbourne University, Melbourne, VIC, Australia 6 School of Women and Children’s Health, University of New South Wales, Sydney, NSW, Australia Introduction: Reduced small arterial elasticity (SAE) in adults is associated with increased risk of cardiovascular events. The data relating to the association between arterial elasticity, obesity and glycaemic status in adolescents is limited and conflicting. This study aimed to determine if SAE differed between obese adolescents with clinical insulin resistance (IR), adolescents with type 1 diabetes (T1D) and healthy non-obese controls. Methods: The IR group (n = 68) were participants of a RCT, RESIST. The T1D group were recruited through the Diabetes Complications Assessment
of Nutrition and Dietetics, University of Sydney, Sydney, NSW, Australia 2 Chemical and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia 3 Institute of Endocrinology and Diabetes, The Children’s Hospital Westmead, Westmead, NSW, Australia Background: A stand-on bioelectrical impedance analysis (BIA) system is a safe, non-invasive, relatively inexpensive method of measuring body composition. However, little is known about how the body composition parameters measured by BIA relate to those determined by dual-energy X-ray absorptiometry (DXA) in an obese, adolescent population. Objectives: To compare body composition measures from the Tanita stand-on BIA (MC-180MA), determined by (a) in-built equations and (b) published and derived equations using raw data (resistance (R) and reactance (Xc)), with body composition parameters measured by DXA in obese adolescents. Methods: 66 obese adolescents (age: 10—18 y, BMI: 22—48 kg/m2 ) had body composition measured by both BIA (Tanita MC-180MA) and DXA (Lunar Prodigy). Raw data obtained from the BIA, R and Xc at frequencies of 5, 50, 250 and 500 kHz, were used in published bioimpedance spectroscopy [1] and BIA equations [2]. Raw data was also used to generate a new prediction equation for FFM using a double cross-validation method. Results: Compared to DXA, the BIA in-built equations overestimated fat-free mass (FFM) by 4.3 kg [95% limits of agreement −13.9 to 5.3] and underestimated % body fat (%BF) by 10.8% [−11.1 to 35.3]. There were no significant differences in the estimates of body composition parameters determined by published/derived equations using raw data and DXA; the mean differences in FFM and %BF were 0.4—0.9 kg and 0.5—0.8%, respectively. However, similar to the BIA in-built equations, all
e101 estimates had wide limits of agreement of approximately ±7 kg for FFM and ±10% for %BF. Conclusion: The Tanita BIA (MC-180MA) in-built equations cannot be recommended as a measure of body composition in obese adolescents. However, equations using the raw data can be used to measure body composition in groups, but there is the potential for significant error if used for an individual.
References [1] Ward. Nutrition 2007;23:657—64. [2] Ramírez. Eur J Clin Nutr org/10.1038/ejcn. 2012.89.
2012,
http://dx.doi.
http://dx.doi.org/10.1016/j.orcp.2013.12.682 184 Arterial elasticity in adolescents with insulin resistance and type 1 diabetes Mandy Ho 1,2,∗ , Paul Benitez-Aguirre 1,2 , Kim Donaghue 1,2 , Paul Mitchell 3 , Louise Baur 1,2 , Alicia Jenkins 4,5 , Maria Craig 1,2,6 , Chris Cowell 1,2 , Sarah Garnett 1,2 1 University
of Sydney, Sydney, NSW, Australia 2 The Children’s Hospital at Westmead, Sydney, NSW, Australia 3 Centre for Vision Research, Westmead Millennium Institute, Sydney, NSW, Australia 4 St Vincents Hospital, Melbourne, VIC, Australia 5 Faculty of Medicine, Melbourne University, Melbourne, VIC, Australia 6 School of Women and Children’s Health, University of New South Wales, Sydney, NSW, Australia Introduction: Reduced small arterial elasticity (SAE) in adults is associated with increased risk of cardiovascular events. The data relating to the association between arterial elasticity, obesity and glycaemic status in adolescents is limited and conflicting. This study aimed to determine if SAE differed between obese adolescents with clinical insulin resistance (IR), adolescents with type 1 diabetes (T1D) and healthy non-obese controls. Methods: The IR group (n = 68) were participants of a RCT, RESIST. The T1D group were recruited through the Diabetes Complications Assessment