Previous research has indicated the brain-derived neurotrophic factor (BDNF) level is lower in schizophrenia and associated with cognitive impairment. Irisin-BDNF axis may strengthen learning and memo Show more
Previous research has indicated the brain-derived neurotrophic factor (BDNF) level is lower in schizophrenia and associated with cognitive impairment. Irisin-BDNF axis may strengthen learning and memory functions. This study examined associations between BDNF, peroxisome proliferator-activated receptor-gamma (PPAR gamma) and irisin with cognitive deficits in schizophrenia. We enrolled 80 patients with schizophrenia and 80 healthy controls (HCs). The enzyme-linked immunosorbent assay (ELISA) method was used for biochemical analysis. The Stroop Test, Trail Making Test (TMT), and Verbal Fluency Test (VFT) were used for cognitive assessment. Statistical analyses included t-tests, correlations, and analysis of covariance (ANCOVA) controlling key confounders. In unadjusted analyses, patients had significantly lower BDNF and PPARγ levels than HCs (ps < 0.001). After controlling for covariates, the difference in BDNF was still significant (F = 11804.71, BDNF demonstrates the most robust association with schizophrenia and cognitive function. The association of PPARγ with schizophrenia is confounded by demographic and metabolic factors, and irisin showed a limited link only to negative symptoms. Not applicable. Show less
Postinfectious olfactory dysfunction (PIOD) is common in COVID-19 patients. This 2-arm double-blinded randomized controlled trial (RCT) aimed to establish proof-of-concept for vitamin A versus placebo Show more
Postinfectious olfactory dysfunction (PIOD) is common in COVID-19 patients. This 2-arm double-blinded randomized controlled trial (RCT) aimed to establish proof-of-concept for vitamin A versus placebo as a treatment modality for patients with PIOD. This study compared 9,000 IU daily self-administered vitamin A intranasal drops versus peanut oil drops over 12 wk in COVID-19 patients with PIOD. Outcome measures included: olfactory bulb volume (OBV), olfactory sulcus depth, cerebral functional MRI blood oxygen level dependent (BOLD) signal, Sniffin' Sticks TDI score, SSParoT, olfactory disorder questionnaire (ODQ) score, and brain-derived neurotropic factor (BDNF) levels were collected from participants at baseline and after trial intervention at 12 wk. Fifty-seven PIOD were recruited in the trial and allocated to vitamin A or placebo arm at a 2:1 ratio. After withdrawals and exclusions, 30 participants in the vitamin A arm and 15 in the placebo arm were analyzed. There was no significant difference in the change in OBV between both groups. Aside from an improvement in the quality-of-life component of ODQ questionnaire scores (P = 0.01), there were no significant differences in any of the other secondary outcome measures. This proof-of-concept trial has demonstrated no significant effect of intranasal vitamin A on olfactory function in COVID-19 PIOD patients. Further work is required to identify other therapeutic agents in the management of PIOD or evaluate a different PIOD cohort with non-COVID etiology. Show less