Body Composition and All-Cause Mortality in Hemodialysis Patients Cindy Huang1, Hocine Tighiouart1, Srinivasan Beddhu2, Alfred Cheung2, Johanna Dwyer1, Garabed Eknoyan3, Gerald Beck4, Andrew Levey1, Mark Sarnak1 1 Tufts Medical Center, Boston, MA; 2 Univ. of Utah, Salt Lake City, UT; 3Baylor College of Medicine, Houston, TX; 4Cleveland Clinic, Cleveland, OH Background Results Results Results Figure 1. Association between MAMC, triceps skinfold and BMI with all-cause mortality in unadjusted and adjusted models* Obesity is associated with increased mortality in the general population, but higher body mass index (BMI) is associated with decreased mortality in hemodialysis patients. The reason for the latter finding is unknown BMI does not differentiate between fat mass and muscle mass Fat mass and muscle mass may have different effects on all-cause mortality in HD patients No large study has examined the contribution of individual body composition components to all-cause mortality in HD patients Table 1. Patient characteristics by triceps quartiles Table 3. Measures of body composition and their association with all-cause mortality in continuous analyses Overall (n=1709) Triceps Q1 (n=427) triceps Q2 (n=430) triceps Q3 (n=422) triceps Q4 (n=430) p Age (yrs) 58 (14) 54 (16) 59 (14) 59 (12) <0.001 Women 56 26 45 71 80 Blacks 64 60 68 69 0.002 DM 44 22 41 53 CVD 20 17 23 0.06 PVD 16 14 18 0.36 IHD 39 33 43 0.01 CHF 40 42 37 0.44 BMI (kg/m2) 25.2 (5.1) 21.5 (3.0) 23.9 (3.5) 26.0 (4.4) 29.6 (5.1) Triceps (mm) 16.3 (7.9) 7.1 (1.8) 12.6 (1.5) 18.2 (1.8) 27.4 (4.2) MAMC (cm) 24.8 (3.8) 24.1 (3.9) 24.4 (3.6) 25.0 (3.8) 25.7 (3.9) Labs Cr (mg/dl) 10.3 (2.9) 10.9 (3.3) 10.3 (2.7) 10.1 (2.5) 9.9 (2.5) Albumin (g/dl) 3.6 (0.4) 3.7 (0.4) 3.6 (0.3) 0.86 Ca (mg/dl) 9.3 (1.0) 9.2 (0.9) 0.47 Phos (mg/dl) 5.8 (1.9) 5.8 (2.1) 5.6 (1.8) 5.9 (1.6) 0.19 HD-related Vintage (yrs) 3.7 (4.4) 4.8 (5.3) 3.8 (4.3) 3.5 (4.0) 2.8 (3.4) Unadjusted model Adjusted model* HR 95%CI BMI (per SD) 0.92 0.85- 0.99 0.89 0.82-0.96 Triceps (per SD) 0.93 0.87- 1.00 0.85 0.78-0.93 MAMC (per SD) 0.86 0.80-0.92 0.86-1.00 Demographics Comorbid Conditions *Adjusted for age, sex, race, vintage, creatinine, albumin, PVD, ischemic heart disease, CHF, other heart disease, diabetes, SBP, dialysis treatment Additional Analyses No changes in the importance of triceps skinfold and MAMC if they were included in the same model Adjusting for height did not significantly change the results Interactions were not significant (p>0.2) Triceps skinfold and MAMC Triceps skinfold and sex MAMC and sex Anthropometric measurements Methods HEMO study Prospective, randomized, multicenter clinical trial Standard dose (Kt/V 1.05) vs high dose (Kt/V 1.45) High-flux membrane vs low-flux membrane Body composition measurements BMI Fat mass: triceps skinfold Muscle mass: Mid-arm muscle circumference (MAMC) MAMC (cm)=mid-upper arm circumference-π*triceps skinfold (cm) Outcome variable All-cause mortality Functional forms of BMI, triceps skinfold and MAMC with all-cause mortality using restricted cubic splines Univariate and multivariate Cox regression Additional analyses Triceps skinfold and MAMC in the same model Triceps skinfold and MAMC adjusted for height given that BMI takes into account height Interactions Triceps skinfold and MAMC Triceps skinfold and sex MAMC and sex Table 2. Body composition quartiles and their association with for all-cause mortality Unadjusted model Adjusted model* HR 95%CI BMI P#=0.022 P#<0.001 Q1 reference Reference Q2 0.91 0.75-1.10 0.78 0.64-0.94 Q3 0.87 0.72-1.06 0.64-0.95 Q4 0.79 0.65-0.96 0.66 0.53-0.81 Triceps P#=0.13 0.97 0.81-1.18 0.72 0.59-0.88 0.95 0.78-1.15 0.73 0.59-0.91 0.64-0.96 0.58 0.46-0.74 MAMC 0.60-0.88 0.68 0.56-0.83 0.62 0.52-0.76 0.69 0.56-0.85 0.60 0.49-0.73 0.56-0.86 Conclusion Data are presented as mean (SD) or % Both high muscle and fat mass are associated with lower all-cause mortality in HD patients Individual decision making is recommended regarding weight loss in obese hemodialysis patients Nutritional interventions are required for patients with low BMI, MAMC and body fat Clinical trials to increase muscle mass and body fat in cachectic HD patients should be considered Median length of follow-up: 2.5 years Total number of deaths: n=783 Pearson correlation coefficients were: 0.62 between triceps skinfold and BMI 0.63 between MAMC and BMI 0.17 between triceps skinfold and MAMC #: p values are for trend across quartiles This project was supported by NIH T32 DK07777 and K24 DK078204 grants