Potential of niacin skin flush response in adolescent depression identification and severity assessment: a case-control study

BACKGROUND

The diagnosis of adolescent Depressive Disorder (DD) lacks specific biomarkers, posing significant challenges. This study investigates the potential of Niacin Skin Flush Response (NSFR) as a biomarker for identifying and assessing the severity of adolescent Depressive Disorder, as well as distinguishing it from Behavioral and Emotional Disorders typically emerging in childhood and adolescence(BED).

METHODS

In a case-control study involving 196 adolescents, including 128 Depressive Disorder, 32 Behavioral and Emotional Disorders, and 36 healthy controls (HCs), NSFR was assessed. Depressive symptoms were measured using the Patient Health Questionnaire-9 (PHQ-9) and anxious symptoms with the Generalized Anxiety Disorder 7-item scale (GAD-7). Pearson correlation analysis determined the relationships between NSFR and the severity of depression in DD patients. Receiver Operating Characteristic (ROC) was used to identify DD from BED integrating NSFR data with clinical symptom measures.

RESULTS

The adolescent Depressive Disorder group exhibited a higher rate of severe blunted NSFR (21.4%) compared to BED (12.5%) and HC ( 8.3%). Adolescent Depressive Disorder with psychotic symptoms showed a significant increase in blunted NSFR (p = 0.016). NSFR had negative correlations with depressive (r = -0.240, p = 0.006) and anxious (r = -0.2, p = 0.023) symptoms in adolescent Depressive Disorder. Integrating NSFR with three clinical scales improved the differentiation between adolescent Depressive Disorder and BED (AUC increased from 0.694 to 0.712).

CONCLUSION

The NSFR demonstrates potential as an objective biomarker for adolescent Depressive Disorder, aiding in screening, assessing severity, and enhancing insights into its pathophysiology and diagnostic precision.

An association between niacin skin flush response and plasma triglyceride levels in patients with schizophrenia

The available data suggest that abnormalities of arachidonic acid-related signaling may be of relevance in attenuated niacin-induced flush responses and lipid and glucose metabolism disturbances, which are all common among individuals with schizophrenia. We previously demonstrated attenuated skin flush responses to niacin in patients with schizophrenia. Here we investigated whether these niacin responses might be associated with elevated plasma lipid and glucose concentrations in this patient group. We found that higher plasma triglyceride levels were associated with higher total volumetric niacin response (VNR) values and that the VNR accounted for ~14.2% of the variability in triglyceride levels. Triglyceride levels were significantly higher in patients with a positive niacin skin flush response compared to those with absent niacin skin flushing at the 5-minute interval with niacin concentrations of 0.1 and 0.01 M, and at the 10- and 15-minute intervals with a niacin concentration of 0.001 M.

Polymorphisms in PLA2G6 and PLA2G4C genes for calcium-independent phospholipase A2 do not contribute to attenuated niacin skin flush response in schizophrenia patients

We hypothesized that attenuated niacin skin flushing in schizophrenia patients might be associated with polymorphic variants in PLA2G6 and PLA2G4C genes (rs4375 and rs1549637 variations) which encode calcium-independent phospholipase A2 beta (iPLA2β) and cytosolic phospholipase A2 gamma (cPLA2γ) enzymes. The iPLA2β and cPLA2γ may play an important role in niacin-mediated signaling; in addition to their major role - mediating phospholipids remodeling, which alters membrane receptors and signal transduction, they regulate the reservoir of arachidonic acid for prostaglandins synthesis. Skin response to topical niacin of 0.1M, 0.01M, 0.001M and 0.0001M concentrations in 75 schizophrenia patients was rated using the method of volumetric niacin response (VNR). Neither PLA2G6 nor PLA2G4C gene polymorphisms were significantly associated with VNR values. Furthermore, polymorphisms׳ synergy on niacin skin flushing was also not detected.