Blunted Niacin Skin Flushing Response in Schizophrenia: A Meta-analysis.

Abstract

Background and hypothesis: The multifactorial pathogenesis of schizophrenia (SZ) hinders the diagnosis and treatment of this disorder. Niacin skin flushing response (NSFR) has been identified as an endophenotype for SZ, but the proportion of blunted NSFR (BNR) varied between studies. This study aims to clarify the relationship between NSFR and SZ through a meta-analysis.

Study design: PubMed, Embase, Web of Science, Cochrane, and Scopus databases were searched for articles published until May 2024, and 32 studies were eligible. Using random-effects models, we examined the characteristics of NSFR in SZ, including the reaction degree, speed, sensitivity, and risk and prevalence of BNR. Subgroup analyses and regression analyses were performed to investigate the relevant effect factors of NSFR.

Study results: The reaction degree (SMD = -0.90; CI, -1.08 to -0.72), speed (SMD = 0.64; CI, 0.02-1.25), and sensitivity (SMD = 0.89; CI, 0.49-1.29) of NSFR was significantly reduced in SZ compared to healthy controls (HC). Moreover, we observed a positive association between BNR and SZ (OR = 8.50; CI, 5.93-12.19). The overall prevalence of BNR was 58.5% in SZ (CI, 49.3%-67.8%) compared to 11.8% in HC (CI, 7.7%-15.9%). In addition, NSFR detection method, geographical regions, and age were found to have effects on reaction degree and prevalence of BNR.

Conclusions: This study confirmed a significantly abnormal NSFR and higher prevalence of BNR in SZ, which highlights the potential facilitation of the diagnosis and personalized intervention of SZ subgroups. In addition, the study points to a need to establish a standardized method for NSFR assessment.