Metabolomics analysis of children with spastic cerebral palsy: a case-control study

Abstract

Background: Spasticity, pain, fatigue and other secondary consequences of spastic CP may lead to metabolic alterations. The aim of this study was to analyze the plasma metabolomic profiles of children with spastic CP and compare these with typically developing controls.

Methods: This case-control study (n = 50 for CP and n = 55 for control) was conducted between September 2020 and November 2020 at Mersin University Hospital. Three to ten year old patients with spastic CP and age- and sex-matched typically developing controls were included in the study. Data on anthropometric measurements and clinical profiles were collected. Plasma samples were obtained for non-targeted metabolomics. The GC-MS based metabolomics analysis was performed. Metaboanalyst software was used for multivariate analyses, principal component analysis and pathway analyses.

Results: Spastic quadriplegia, spastic diplegia and spastic hemiplegia were found in 26 (52%), 14 (28%) and 10 (20%) patients, respectively, and 31 patients (62%) were non-ambulant. Twenty-two patients (44%) had epilepsy and antiepileptic use. Mean weight-for-age, height-for- age, and body mass index z-scores were significantly lower in the CP group (p < 0.05). Total 224 metabolites were detected in all subjects. Of these metabolites, 14 were detected at higher and 37 at lower levels in the CP group compared to the control group. The most significant changes in the CP group were found in aminoacyl-tRNA biosynthesis, tyrosine metabolism, valine, leucine and isoleucine biosynthesis, alanine, aspartate and glutamate metabolism, arginine and proline metabolism, citrate cycle (TCA cycle), galactose metabolism and glutathione metabolism. Forty-five metabolites were statistically significant between control, CP with epilepsy and CP without epilepsy groups. Thirty-four metabolites were statistically significant between control, ambulant CP and non-ambulant CP groups.

Conclusion: Plasma of spastic CP children was associated with alterations in energy metabolism and protein synthesis and amino acid metabolism compared to typically developing children. Gross motor functional level and accompanying epilepsy may also alter the metabolite profiles.

Keywords: Cerebral palsy; Children; Non-targeted metabolomics; Plasma metabolomics.

Fig. 1

Principal component analysis score (left panel) and PLS-DA score (right panel) of A) the cerebral palsy group (CP) compared to the typically developing (control) group B) the cerebral palsy with epilepsy (CP-E) group compared to cerebral palsy without epilepsy (CP) group C) Gross Motor Function comparision between ambulant cerebral palsy (GII—III) and non-ambulant cerebral palsy (IV—V)

Fig. 2

Volcano plots (left panel) and variable importance in projection (VIP) plots (right panel) A) the cerebral palsy group (CP) compared to the typically developing (control) group B) the cerebral palsy with epilepsy (CP-E) group compared to cerebral palsy without epilepsy (CP) group C) Gross Motor Function comparision between ambulant cerebral palsy (GII—III) and non-ambulant cerebral palsy (IV—V)

Fig. 3

Pathway analysis and match status of serum metabolite profiles of the cerebral palsy group compared to the typically developing control group. (The metabolic pathways are represented as circles according to their scores from enrichment (Y-axis) and topology analyses (pathway impact value, X-axis). Darker circle colors indicate more significant changes in metabolites in the corresponding pathway. The size of the circle corresponds to the pathway impact score and is correlated with the centrality of the involved metabolites