Subjects with schizophrenia have high risks of metabolic abnormalities and bioenergetic dysfunction. Acyl-carnitines involved in bioenergetic pathways provide potential biomarker targets for identifying early changes and onset characteristics in subjects with schizophrenia. We measured 29 acyl-carnitine levels within well-characterized plasma samples of adults with schizophrenia and healthy controls using liquid chromatography-mass spectrometry (LC-MS). Subjects with schizophrenia were measured at baseline and after 8 weeks of treatment. A total of 225 subjects with schizophrenia and 175 age- and gender-matched healthy controls were enrolled and 156 subjects completed the 8-week follow-up. With respect to plasma acyl-carnitines, the individuals with schizophrenia at baseline showed significantly higher levels of C4-OH (C3-DC) and C16:1, but lower concentrations of C3, C8, C10, C10:1, C10:2, C12, C14:1-OH, C14:2, and C14:2-OH when compared with healthy controls after controlling for age, sex, body mass index (BMI), smoking, and drinking. For the comparison between pretreatment and posttreatment subjects, all detected acyl-carnitines were significantly different between the two groups. Only the concentration of C3 and C4 were increased after selection by variable importance in projection (VIP) value >1.0 and false discovery rate (FDR) q value <0.05. A panel of acyl-carnitines were selected for the ability to differentiate subjects of schizophrenia at baseline from controls, pre- from post-treatment, and posttreatment from controls. Our data implicated acyl-carnitines with abnormalities in cellular bioenergetics of schizophrenia. Therefore, acyl-carnitines can be potential targets for future investigations into their roles in the pathoetiology of schizophrenia.

The etiology and pathophysiology of schizophrenia remain obscure. This study explored the associations between schizophrenia risk and serum levels of 10 trace elements. A 1:1 matched case-control study was conducted and matched by age and sex. Blood samples were collected to determine the concentrations of nickel, molybdenum, arsenic, aluminum, chromium, manganese, selenium, copper, iron and zinc by an inductively coupled plasma-mass spectrometry. The conditional logistic regression model was used to analyze the associations between trace elements and schizophrenia risk. Totally 114 schizophrenia patients and 114 healthy controls were recruited in the study. The multivariate analysis demonstrated that copper≤0.97 μg/mL, selenium≤72 ng/mL and manganese>3.95 ng/mL were associated with an increased risk of schizophrenia. The study showed that lower levels of selenium, copper and higher levels of manganese were found in schizophrenia patients compared with healthy controls.