According to the literature, weight loss is associated with shorter survival. In our ALS population it was accordingly connected with a significantly worse mean ALSFRS_R score and a significantly higher death rate after two years. Weight loss had a significant impact on QOL regarding the SF36 subitem “vitality”, meaning that it made patients feel more exhausted, tired and spiritless, regardless of the respective disease stage. Nevertheless, high calorie nutritional supplements were only consumed by one third of patients with weight loss, mainly due to the fact that the costs are often not covered by the respective health insurances. According to our survey, substantial benefit can be obtained from high calorie supplements and they should therefore be given more frequently. Only one quarter of patients with dysphagia had undergone PEG placement. Most of these patients reported weight stabilization and improvement of QOL. The decision about PEG insertion is mostly based on nutritional status and presence of dysphagia
[16, 17]. From clinical practise it is known, that patients are often cautious accepting a PEG, even when food intake becomes time consuming and laborious. Neurologists also tend to postpone the discussion of PEG
. As a result, PEG placement is often initiated too late and therefore associated with higher complication rates as it is known that FVC >50% at the time of PEG insertion is an important prognostic factor
[16, 18–20]. Our data confirm that PEG placement can stabilize body weight
[10, 21, 22] and suggest additionally an impact on the QOL. The impact of PEG on QOL has been studied very little so far. Beside anecdotal impressions, only one study collected quantitative data: here, the majority of the patients mentioned stabilized nutritional and hydrational status as most positive effect of PEG. Fewer patients listed less fatigue or less time spent on meals and improved psychological wellbeing as positive effects of PEG
[21, 23]. Interestingly, in our cohort, even patients who had undergone further weight loss after PEG insertion, unanimously stated improvement of QOL. This suggests that other factors such as reduction of time consuming and tiring food and fluid intake with frequent choking are equally important for patients.
A further important result of our study is that weight loss without dysphagia is frequent in ALS. We aimed to define what distinguishes these patients from patients without weight loss. As the groups did not differ regarding site of onset and gender, these factors could not be relevant. While thorough neuropsychological testing had not been routinely performed, clinical signs of dementia were only detectable in one of the patients without weight loss, so that weight loss in the patients without dysphagia in our cohort could not be attributed to major cognitive or behavioural abnormalities. Patients with weight loss without dysphagia did not show differences in disease severity, grade of depression or presence of muscle fasciculations, but they did report higher respiratory efforts. It remains unclear how far this contributes to the weight loss. Two studies in ALS patients did not detect a relation between forced vital capacity (FVC) and energy expenditure (REE)
[2, 24] while two others suggest that increased respiratory efforts cause elevated REE
[25, 26]. Based on the existing literature, this increased energy consumption in ALS can probably not only be explained by respiratory insufficiency but rather by general hypermetabolism which occurs in about 50% of ALS patients and whose origin has not yet been fully elucidated
The proportion of patients taking other, not high calorie dietary supplements such as vitamins was lower in our cohort (with 54.5%) than in the literature, were the percentage of supplement intake among ALS-patients is estimated as approximately 80%
The observed differences in disease severity, depression and QOL are most probably not a direct effect of these diverse dietary supplements. While one must take into account a certain placebo-effect, the most likely explanation is that patients self-medicating with dietary supplements presumably represent a more hopeful and optimistic subgroup. This assumption is supported by the fact that they had higher SF36 “social functioning” scores, i.e. felt less affected in their interactions with family members, friends and neighbours. A more active social life may also have provided increased stimulations to try alternative treatment approaches. Discontinuation of dietary supplements over time (as revealed by our two-year follow-up interview) presumably is the result of loss of hope generally associated with further disease progression.
Although there is a lack of evidence for any relevant benefit of dietary supplements, as long as there is no clear contraindication and as long as efficient neuroprotective drugs beyond riluzole have not been discovered, self-medication with dietary supplements may represent hope and confidence for some patients and thereby have a positive impact on the disease course and quality of life.