Body composition in amyotrophic lateral sclerosis subjects and its effect on disease progression and survival

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.

Exercise-based oncology rehabilitation: leveraging the cardiac rehabilitation model

PURPOSE

The value of exercise and rehabilitative interventions for cancer survivors is increasingly clear, and oncology rehabilitation programs could provide these important interventions. However, a pathway to create oncology rehabilitation has not been delineated. Community-based cardiac rehabilitation (CR) programs staffed by health care professionals with experience in providing rehabilitation and secondary prevention services to individuals with coronary heart disease are widely available and provide a potential model and location for oncology rehabilitation programs. Our purpose was to outline the rehabilitative needs of cancer survivors and demonstrate how oncology rehabilitation can be created using a CR model.

METHODS

We identify the impairments associated with cancer and its therapy that respond to rehabilitative interventions. Components of the CR model that would benefit cancer survivors are described. An example of an oncology rehabilitation program using a CR model is presented.

RESULTS

Cancer survivors have impairments associated with cancer and its therapy that improve with rehabilitation. Our experience demonstrates that effective rehabilitation services can be provided utilizing an existing CR infrastructure. Few adjustments to current CR models would be needed to provide oncology rehabilitation. Preliminary evidence suggests that cancer survivors participating in an oncology rehabilitation program experience improvements in psychological and physiologic parameters.

CONCLUSIONS

Utilizing the CR model of rehabilitative services and disease management provides a much needed mechanism to bring oncology rehabilitation to larger numbers of cancer survivors.