Weight Loss and Disease Progression in Amyotrophic Lateral Sclerosis and Primary Lateral Sclerosis
Ikjae Lee1, Hiroshi Mitsumoto1, Pam Factor-Litvak2, Jeri Nieves2
1Neurology, Columbia University Irving Medical Center, 2Epidemiology, Mailman School of Public Health
Objective:
We studied the association of changes in body mass index (BMI) with disease progression among amyotrophic lateral sclerosis (ALS) and primary lateral sclerosis (PLS) Multicenter Cohort Study of Oxidative Stress (COSMOS) study participants, prospectively followed up to 24 months.
Background:
Weight loss is a poor prognostic factor in ALS. However, less is known about weight change in PLS.
Design/Methods:
Participants had a confirmed diagnosis of ALS or PLS and completed baseline and at least one follow-up visit. The rate of BMI change (ΔBMI) and total revised ALS functional rating scale change (ΔALSFRS-r) were calculated between baseline and the first follow-up. Correlation between ΔBMI and ΔALSFRS-r were assessed using Pearson correlation among ALS and PLS participants separately. The demographics and proportion of participants
with swallowing dysfunction at baseline and significant weight loss were compared between ALS and PLS groups using chi-square test. Cox proportional hazard models examined the association between significant weight loss (ΔBMI<-1kg/m2/year) and survival in ALS, adjusted for other prognostic factors.
Results:
279 ALS and 37 PLS participants were included. Mean age of ALS and PLS were both 60 years and 61% male. At baseline, swallowing dysfunction was more frequent in the PLS (78% vs 48%, p<0.001) while significant weight loss was more frequent in the ALS (53% vs 19%, p<0.001). ΔBMI and ΔALSFRS-r correlated significantly in ALS (r=0.3, p<0.0001) but not in PLS (r= -0.21, p=0.2). Significant weight loss was associated with increased risk of death (hazard ratio 2.08, p<0.0001) in ALS after adjusting for age, disease-duration, bulbar-onset, diagnostic-certainty, riluzole-intake, forced vital capacity, baseline BMI, baseline ALSFRS-r and ΔALSFRS-r.
Conclusions:
In ALS, significant weight loss is a strong independent prognostic factor for survival and rate of BMI change correlates with faster functional decline. In contrast, significant weight loss is infrequent in PLS despite a high prevalence of swallowing dysfunction.