Targeted Metabolomic Profiling of Carnitines Reveals Diagnostic Candidates in Postpartum Cardiomyopathy

Key findings from this study

• The study found that PPCM patients display significantly reduced free carnitine and long-chain acylcarnitines (C14:1, C18:1) alongside elevated short-chain species (C2, C3) and C6DC compared to healthy controls.
• The researchers demonstrate that acetylcarnitine (C2), C6DC, and C16 function as the strongest metabolic discriminators between PPCM patients and controls in multivariate analysis.
• The authors report that individual metabolite biomarkers exhibit limited diagnostic performance when used alone, with area under curve values ranging from 0.623 to 0.635.

Overview

Postpartum cardiomyopathy (PPCM) involves left ventricular dysfunction in the peripartum period. Carnitine metabolism dysfunction may contribute to myocardial energy dysregulation in PPCM. This targeted metabolomics study profiled serum carnitine and acylcarnitine species in PPCM patients versus healthy controls to identify metabolic signatures and diagnostic biomarker candidates.

Methods and approach

The researchers compared serum carnitine profiles between 40 PPCM patients and 40 age-matched controls using liquid chromatography-tandem mass spectrometry (LC–MS/MS). Multivariate analyses included principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). Univariate statistical tests comprised t-tests, analysis of variance (ANOVA), and Tukey's honest significant difference (HSD) post-hoc testing. Receiver operating characteristic (ROC) curve analysis assessed diagnostic utility of candidate metabolites.

Results

PPCM patients exhibited significantly decreased free carnitine (C0, p < 0.001) and elevated short-chain acylcarnitines including acetylcarnitine (C2, p < 0.001) and propionylcarnitine (C3, p < 0.001) relative to controls. Long-chain acylcarnitines C14:1 and C18:1 were substantially reduced in PPCM. The dicarboxylate C6DC elevated significantly in PPCM patients (p < 0.001). PLS-DA and variable importance in projection (VIP) analyses identified C2, C6DC, and C16 as primary discriminators between groups. ROC curve analysis demonstrated modest but notable diagnostic performance: acetylcarnitine C2 (area under curve = 0.633), C6DC (area under curve = 0.635), and C16 (area under curve = 0.623).

Implications

The metabolomic findings establish that PPCM involves profound dysregulation of carnitine metabolism characterized by a shift toward short-chain and away from long-chain acylcarnitine profiles. This metabolic signature likely reflects compromised mitochondrial fatty acid oxidation capacity, which underpins cardiac energy homeostasis. The identified dysregulation patterns suggest impaired β-oxidation flux and accumulation of incompletely metabolized acyl intermediates. These alterations may serve as mechanistic biomarkers reflecting the metabolic stress underlying PPCM pathophysiology.

Scope and limitations

This summary is based on the study abstract and available metadata. It does not include a full analysis of the complete paper, supplementary materials, or underlying datasets unless explicitly stated. Findings should be interpreted in the context of the original publication.