L-Carnitine and Acetyl-L-Carnitine: Potential Novel Biomarkers for Major Depressive Disorder.
Level 4 - case-series / case-control
Case-control diagnostic biomarker study with short-term longitudinal follow-up.
PubMed 34658942 · doi:10.3389/fpsyt.2021.671151
What was done
Serum concentrations of L-carnitine (LC) and acetyl-L-carnitine (ALC) were measured via ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) in patients with major depressive disorder (MDD) and healthy controls. Diagnostic performance was evaluated using receiver operating characteristic (ROC) curves and correlation with 24-item Hamilton Depression Rating Scale (HDRS-24) scores. In MDD patients, LC and ALC concentrations were also compared after 2 weeks of treatment between treatment-responsive (effective group) and non-responsive (ineffective group) patients.
What was found
Serum LC and ALC levels were significantly reduced in MDD patients compared with healthy controls (P < 0.001). HDRS-24 score was negatively associated with serum ALC (r = -0.325, P = 0.007). For distinguishing MDD patients from healthy controls, ROC analysis showed an AUC of 0.801 (83.1% sensitivity, 66.3% specificity) for LC and an AUC of 0.898 (88.8% sensitivity, 76.4% specificity) for ALC. Following 2 weeks of treatment, LC and ALC concentrations significantly increased in the effective treatment group, with no significant change in the ineffective treatment group.
Why it matters
Circulating LC and ALC may serve as accessible peripheral biomarkers to assist in MDD diagnosis and provide early objective monitoring of treatment response.
Limits
The abstract does not report the sample size (n), patient demographics, or specific antidepressant treatments used. Testing diagnostic accuracy against healthy controls rather than symptomatic psychiatric controls limits clinical relevance, and a 2-week follow-up is insufficient to establish durable response.
Cited by
- supports Acetyl-L-carnitine is low in patients with depression and increases or resolves in association with antidepressant treatment response.