Amber R Sewell-Green, Robert Capstick, Cory J Holdom, Kylie Matthews-Rensch, John Cameron, Pamela A McCombe, Robert D Henderson, Shyuan T Ngo, Frederik J Steyn
Early weight loss identifies plwALS at increased risk of subsequent weight and body-composition loss, functional decline and earlier death. Existing energy equations proposed for use in ALS show limited concordance with observed weight trajectories, particularly when applied at a single time point. These findings support serial monitoring of nutritional risk and individualized, phenotype-informed dietetic care in ALS.
BACKGROUND: Weight loss and malnutrition are associated with poorer outcomes in people living with amyotrophic lateral sclerosis (plwALS). This study investigated the prognostic relevance of early weight loss in plwALS and assessed whether existing energy equations provide useful guidance for nutritional management.
METHODS: In this prospective case-control and within-case comparison study (March 2016October 2024), 170 plwALS and 173 non-neurodegenerative disease controls completed baseline anthropometric and metabolic assessment. Participants with ALS were classified according to weight change during the first six months following study inclusion as Weight Gain, Stable Weight, or Weight Loss. Weight-change groups were compared for subsequent changes in anthropometry, functional capacity, and survival. In a nested cohort of 82 plwALS with reported energy intake and repeat assessments, we assessed whether the relationship between reported intake and equation-derived energy requirements was concordant with subsequent weight change.
RESULTS: Early weight loss was associated with continued loss of body weight, fat mass, and fat-free mass, faster functional decline, and increased risk of earlier death relative to Weight Gain (HR=4.78 [95% CI 2.68-8.53], p<0.001). Concordance between equation-derived energy requirements, reported energy intake and observed weight trajectory was low (17.3-32.1%). The IBW30(30) equation showed the greatest concordance among participants with Weight Loss, but no equation performed consistently across weight-change groups.
CONCLUSIONS: Early weight loss identifies plwALS at increased risk of subsequent weight and body-composition loss, functional decline and earlier death. Existing energy equations proposed for use in ALS show limited concordance with observed weight trajectories, particularly when applied at a single time point. These findings support serial monitoring of nutritional risk and individualized, phenotype-informed dietetic care in ALS.