A multi-centre prospective evaluation of post-gastrostomy outcomes in patients with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) often causes significant nutritional decline and weight loss, which negatively impacting prognosis. Gastrostomy is a standard intervention to provide long-term nutritional support, yet its efficacy in stabilising nutritional status and preventing post-procedure weight loss is uncertain. This study explored factors influencing weight change post-gastrostomy.

This multicentre, prospective observational cohort study was conducted across 17 UK sites and involved longitudinal assessments at placement (M0) and at three (M3), six (M6), and nine (M9) months. Data collection included nutritional, clinical and functional parameters. The primary outcome was the percentage weight change between M0 and M3. Secondary outcomes included nutritional intake, functional decline, and survival. Statistical analysis employed hierarchical logistic regression to identify independent predictors of weight change post-gastrostomy.

Successful gastrostomy was performed in 155 included participants, of which 64 had complete M0 and M3 weight data. Mean percentage weight change from M0 to M3 was -3.3% (SD 7.4%), with 51.6% losing >1 kg in the first three months (p < 0.01). Amongst those with available dietary data weight loss (n = 21/43) was associated with lower mean daily energy (1620 kcal vs 2022 kcal, p = 0.017) and protein intake (64 g vs 77 g, p = 0.048) compared to those who maintained stable or gained weight (n = 22/43). At M3, 50% (n = 29/58) used a combination of oral and gastrostomy intake, 27.6% (n = 16/58) used gastrostomy only, and 22.4% (13/58) were not using the gastrostomy. Based on available data for total daily expenditure energy expenditure (TDEE) calculation (n = 39), 61.5% did not meet predicted total daily energy expenditure. Participants who lost weight (>1 kg) post-gastrostomy had shorter median survival (270 days) compared to the weight stable/gain group (p = 0.018). Hierarchical logistic regression suggested that mean daily water intake may potentially be an independent predictor of weight maintenance or gain, though this finding should be considered exploratory due to the limitations of our study (OR = 1.003, p = 0.040).

Despite gastrostomy placement, over half of participants in our final analytical cohort continued to lose weight. For a smaller subset of participants, for whom nutritional intake were available, this was potentially due to insufficient energy, macronutrient, and fluid intake, alongside disease-specific catabolism. As post-gastrostomy weight loss negatively impacts survival, these findings highlight a need for proactive, tailored, and ongoing nutritional support and monitoring, to optimise post-gastrostomy outcomes and survival in ALS.