Hypermetabolism is a deleterious prognostic factor in patients with amyotrophic lateral sclerosis

Background and purposeThe aim of this study was to investigate patients with amyotrophic lateral sclerosis in order to determine their nutritional, neurological and respiratory parameters, and survival according to metabolic level. MethodsNutritional assessment included resting energy expenditure (REE) measured by indirect calorimetry [hypermetabolism if REE variation (REE) > 10%] and fat mass (FM) using impedancemetry. Neurological assessment included the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised score. Survival analysis used the Kaplan-Meier method and multivariate Cox model. ResultsA total of 315 patients were analysed. Median age at diagnosis was 65.9 years and 55.2% of patients were hypermetabolic. With regard to the metabolic level (REE: < 10%, 10-20% and >20%), patients with REE > 20% initially had a lower FM(29.7% vs. 32.1% in those with REE 10%; P = 0.0054). During follow-up, the median slope of Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised tended to worsen more in patients with REE > 20% (-1.4 vs. -1.0 points/month in those with REE 10%; P = 0.07). Overall median survival since diagnosis was 18.4 months. REE > 20% tended to increase the risk of dying compared with REE 10% (hazard ratio, 1.33; P = 0.055). In multivariate analysis, an increased REE:FM ratio was independently associated with death (hazard ratio, 1.005; P = 0.001). ConclusionsHypermetabolism is present in more than half of patients with amyotrophic lateral sclerosis. It modifies the body composition at diagnosis, and patients with hypermetabolism >20% have a worse prognosis than those without hypermetabolism. Click to view the accompanying paper in this volume.