Rup Tandan1,2, Evan A Levy1,2, Diantha B Howard2,3,4, John Hiser2,3,4, Nathan Kokinda2,3,4, Swatee Dey5,6, Edward J Kasarskis5,6. 1. Department of Neurological Sciences, University of Vermont Medical Center and Robert Larner, MD College of Medicine, University of Vermont, Burlington, VT, USA. 2. General Clinical Research Center, University of Vermont Medical Center and Robert Larner, MD College of Medicine, University of Vermont, Burlington, VT, USA. 3. The Northern New England Clinical and Translational Research Network, Robert Larner, MD College of Medicine, University of Vermont, Burlington, VT, USA. 4. Maine Medical Center Research Institute, Portland, ME, USA. 5. Department of Neurology, University of Kentucky, Lexington, KY, USA. 6. General Clinical Research Center, University of Kentucky, Lexington, KY, USA.
Abstract
BACKGROUND: Motor neuron degeneration and malnutrition alter body composition in amyotrophic lateral sclerosis (ALS). Resulting losses of weight, fat mass (FM), and fat-free mass (FFM) shorten survival. Nutritional management relies on body weight or BMI; neither reliably indicates malnutrition nor differentiates body compartments. OBJECTIVES: We aimed to 1) develop an equation to compute FM and FFM using clinical data, validated against DXA; and 2) examine the effect of computed FM and FFM on disease course and survival. METHODS: We studied 364 ALS patients from 3 cohorts. In Cohort #1 we used logistic regression on clinical and demographic data to create an equation (test cohort). In Cohort #2 we validated FM and FFM computed using this equation against DXA (validation cohort). In Cohort #3, we examined the effect of computed body composition on disease course and survival. RESULTS: In Cohort #1 (n = 29) the model incorporated sex, age, BMI, and bulbar-onset to create an equation to estimate body fat: % body fat = 1.73 - [19.80*gender (1 if male or 0 if female)] + [0.25*weight (kg)] + [0.95*BMI (kg/m2)] - (5.20*1 if bulbar-onset or *0 if limb-onset). In Cohort #2 (n = 104), body composition using this equation, compared to other published equations, showed the least variance from DXA values. In Cohort #3 (n = 314), loss of body composition over 6 mo was greater in males. Adjusted survival was predicted by low baseline FM (HR: 1.39; 95% CI: 1.07, 1.80), and loss of FM (HR: 1.87; 95% CI: 1.30, 2.69) and FFM (HR: 1.73; 95% CI: 1.20, 2.49) over 6 mo. CONCLUSIONS: Our equation broadens the traditional nutritional evaluation in clinics and reliably estimates body composition. Measuring body composition could target FM as a focus for nutritional management to ensure adequate energy intake and complement measures, such as the ALS functional rating scale-revised score and forced vital capacity, currently used.
BACKGROUND: Motor neuron degeneration and malnutrition alter body composition in amyotrophic lateral sclerosis (ALS). Resulting losses of weight, fat mass (FM), and fat-free mass (FFM) shorten survival. Nutritional management relies on body weight or BMI; neither reliably indicates malnutrition nor differentiates body compartments. OBJECTIVES: We aimed to 1) develop an equation to compute FM and FFM using clinical data, validated against DXA; and 2) examine the effect of computed FM and FFM on disease course and survival. METHODS: We studied 364 ALS patients from 3 cohorts. In Cohort #1 we used logistic regression on clinical and demographic data to create an equation (test cohort). In Cohort #2 we validated FM and FFM computed using this equation against DXA (validation cohort). In Cohort #3, we examined the effect of computed body composition on disease course and survival. RESULTS: In Cohort #1 (n = 29) the model incorporated sex, age, BMI, and bulbar-onset to create an equation to estimate body fat: % body fat = 1.73 - [19.80*gender (1 if male or 0 if female)] + [0.25*weight (kg)] + [0.95*BMI (kg/m2)] - (5.20*1 if bulbar-onset or *0 if limb-onset). In Cohort #2 (n = 104), body composition using this equation, compared to other published equations, showed the least variance from DXA values. In Cohort #3 (n = 314), loss of body composition over 6 mo was greater in males. Adjusted survival was predicted by low baseline FM (HR: 1.39; 95% CI: 1.07, 1.80), and loss of FM (HR: 1.87; 95% CI: 1.30, 2.69) and FFM (HR: 1.73; 95% CI: 1.20, 2.49) over 6 mo. CONCLUSIONS: Our equation broadens the traditional nutritional evaluation in clinics and reliably estimates body composition. Measuring body composition could target FM as a focus for nutritional management to ensure adequate energy intake and complement measures, such as the ALS functional rating scale-revised score and forced vital capacity, currently used.
Authors: Edward J Kasarskis; Marta S Mendiondo; Stephen Wells; Maria S Malguizo; Megan Thompson; Margaret Healey; Richard J Kryscio Journal: Amyotroph Lateral Scler Date: 2011-01
Authors: E J Kasarskis; S Berryman; T English; J Nyland; J G Vanderleest; A Schneider; R Berger; C McClain Journal: Muscle Nerve Date: 1997-03 Impact factor: 3.217