Body composition assessment in chronic kidney disease Jamie Macdonald

Five levels of body composition 1.Whole body 2.Tissue 3.Cellular 4.Molecular 5.Atomic

Why measure body composition in CKD? Muscle wasting is linked with morbidity (Ikizler et al., 1999) and mortality (Kato et al., 2003) Obesity is also associated with outcome (Kalantar-Zadeh et al., 2005)

Effects of body composition on functional capacity Hand grip strength Quadriceps strength 30 sec sit stand test Arm lean mass0.760*N/A Leg lean massN/A0.832*0.661* Appendicular lean mass 0.811*0.835*0.625* Data are Pearson’s r correlation coefficients. *, p < Macdonald et al., 2004

Body composition in CKD CKD patientsControlsp values Bone (kg)2.32.7< 0.05 Fat (kg) Lean mass (kg) < 0.05 Extra cellular water (L) Intra cellular water (L) < 0.01 Macdonald et al., 2004

Whole body level Something is better than nothing! –Weight –BMI Interpret results with caution! –Muscle or fat? (Beddhu et al., 2003) –Reverse epidemiology? (Kalantar- Zadeh et al., 2005) Scales must be calibrated frequently Remove shoes, wear minimal clothing I don’t believe it!!!

Traditional techniques Blood biochemistry –Serum pre/albumin –CRP SGA Anthropometry –Skin folds –Circumferences Creatinine kinetics

DXA

Bioelectrical impedance Macdonald et al., in submission

Monitoring progress: functional capacity Rikli & Jessie Jones, Human Kinetics, 2000

Future techniques Near infra-red spectroscopy (Kalantar-Zadeh et al., 1999) Bioelectrical impedance –Spectroscopy (Kaysen et al., 2005) –Segmental spectroscopy (Zhu et al., 2006) –Raw electrical data (KDOQI) Ultrasound (Mercer et al., 2005)

Thank you