Clinical, Social, and Healthcare Factors Associated with Nutritional Status in Amyotrophic Lateral Sclerosis: A Multidimensional Approach

Background: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease where malnutrition significantly worsens clinical outcomes. We performed a multidimensional analysis to identify clinical, social, and healthcare factors associated with nutritional vulnerability in a real-world setting. Methods: This cross-sectional study included 97 adults with ALS recruited through a national association (APELA) and a hospital-based outpatient consultation (ANOC). Nutritional status was assessed using the Mini Nutritional Assessment (MNA®), Body Mass Index (BMI), and Global Leadership Initiative on Malnutrition (GLIM) criteria. Associations with total MNA® scores were evaluated using a prespecified multivariable linear model with HC3 robust standard errors and bootstrap validation to assess inferential stability. Results: Malnutrition prevalence was high, with 42.3% of participants classified as moderately malnourished and 43.3% as severely malnourished under GLIM criteria. Mean MNA® score was 19.69 (SD 4.53). In the adjusted model, ANOC recruitment was associated, after adjustment, with a 4.477-point lower MNA® score compared with APELA (HC3 95% CI −7.071 to −1.884; p<0.001). Other sociodemographic and clinical factors yielded imprecise estimates. Although explanatory power was modest (Adjusted R2=0.067; optimism-corrected R2=−0.005), the recruitment setting remained a robust correlate across sensitivity analyses. Conclusions: Recruitment setting emerged as the most consistent adjusted correlate of MNA® scores, likely reflecting differences in clinical case mix and referral pathways in the Portuguese healthcare context. These findings highlight nutritional vulnerability in ALS as a multifaceted construct that should be interpreted in relation to both clinical and healthcare-contextual factors. This study supports considering systemic factors and the need for longitudinal research that incorporates comprehensive functional and social metrics to optimize multidisciplinary nutritional interventions.