Nutritional Status and Nutrient Intake Challenges in Children With Spinal Muscular Atrophy

Nutrition is recognized as a core component of multidisciplinary care for patients with spinal muscular atrophy, but specific nutritional challenges in this population are not well described. We aimed to describe the nutritional status and nutrient intake in children with spinal muscular atrophy.

We performed a retrospective medical record review of prospectively collected data from children with spinal muscular atrophy followed at a multidisciplinary clinic at a tertiary referral center. We collected data including clinical parameters; anthropometrics, including weight, height, and body mass index (BMI); and 24-hour dietary intake records in all children followed in the clinic. Available data were found in records from the dietitian as part of a standard evaluation process, and additional clinical data were acquired from patient medical records. Subjects were classified based on spinal muscular atrophy type, and nutritional intake data were compared with dietary reference intakes for gender and age. Z-scores were calculated for weight for age (WAZ), height for age, and BMI (BMIZ) using the World Health Organization AnthroPlus software with appropriate World Health Organization reference growth standards. Subjects were classified as malnourished if their WAZ was <-2 or >+2. Anthropometric measurements were obtained at first visit and at a follow-up visit at an average of a 3-year interval between the clinic visits. A decline of more than 0.5 WAZ over this period was defined a priori as significant nutritional deterioration.

We analyzed data from 60 subjects, 26 (43%) female, with median age 5.5 years (interquartile range 2 years to 12 years). The cohort consisted of children with spinal muscular atrophy type 1 (28 %), type 2 (45 %), and type 3 (27 %). At the first clinic visit, nine (15%) patients were malnourished. Thirteen (23%) subjects had a significant decline in WAZ from -0.35 (-1.31 to 0.58) to -1.04 (-2.15 to 0.02) at follow-up after approximately 3 years. A third of these subjects were already malnourished at first visit. A significant decline in BMIZ was noted in 47% of the cohort, and the prevalence of severe malnutrition (BMIZ < -3) increased from 2% to 17% after 3 years. In children receiving specialized enteral nutrition via a feeding tube, overfeeding was recorded in 29% and underfeeding was recorded in 35%. Suboptimal vitamin D intake was recorded in 35% of patients with enteral feeding device.

Malnutrition was prevalent in children with spinal muscular atrophy, and nearly half the cohort demonstrated nutritional deterioration over time. Energy, protein, and vitamin D intakes were inadequate in a majority of the cohort. Underfeeding was highly prevalent, but overfeeding was also present in a third of the enterally fed cohort. Future studies describing optimal nutrient requirements and body composition variables in this group are required.