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.
Original language | English |
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Pages (from-to) | 1378-1392 |
Number of pages | 15 |
Journal | American Journal of Clinical Nutrition |
Volume | 115 |
Issue number | 5 |
DOIs | |
State | Published - May 1 2022 |
Bibliographical note
Publisher Copyright:© 2022 The Author(s) 2022. Published by Oxford University Press on behalf of the American Society for Nutrition.
Funding
Funders | Funder number |
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National Center for Research Resources | M01RR000064 |
National Center for Research Resources |
Keywords
- amyotrophic lateral sclerosis
- body composition
- body mass index
- disease progression
- dual energy X-ray absorptiometry
- fat mass
- fat-free mass
- nutrition
- survival
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Nutrition and Dietetics