Table 4.
Main information of clinical researches studying the correlation between carnitine level and schizophrenia.
| References | Study type | Samples | Age (years) | Subjects | Carnitine | Positive or negative | Main results | Schizophrenia scales or ways used |
|---|---|---|---|---|---|---|---|---|
| Tasic et al. (69) | Cross-sectional | Serum | 18–65 | Schizophrenia: n = 54; euthymic outpatients with BD type 1: n = 68; healthy: n = 60 | IsoC5:0 | + | Iso C5:0 exists only in schizophrenics, but not in bipolar disorder and normal subjects. | SCID-I PANSS GAF YMRS HDRS-17 |
| Cao et al. (70) | Cross-sectional | Plasma | Schizophrenia with MetS: 41.30 ± 9.78; Schizophrenia without MetS: 35.57 ± 10.55 |
Schizophrenia with MetS: n = 46; schizophrenia without MetS: n =1 23 | ACs (C3:0, C4:0, C5:0, C6:1, C10:1, C10:2, C14:2-OH, C16:2-OH) | + | Eight plasma ACs (C3:0, C4:0, C5:0, C6:1, C10:1, C10:2, C14:2-OH, C16:2-OH) in patients with schizophrenia and MetS were significantly higher than those in schizophrenics without MetS. | DSM-IV |
| Cao et al. (71) | Cohort study | Plasma | Schizophrenics: 37.31 ± 10.85; healthy controls: 39.44 ± 9.36 | Schizophrenia: n = 225; healthy controls: n = 175 | ACs (C2:0, C3:0, C4-OH, C8:0, C10:0, C10:1, C10:2, C12:0, C12:1, C14:1, C14:1-OH, C14:2, C14:2-OH, C16:1, C16:2, C16:2-OH, and C18:0) | + | Concentrations of ACs (C4-OH and C16:1) in schizophrenia patients were significantly higher than that in healthy controls, while C3:0, C8:0, C10:0, C10:1, C10:2, C12:0, C14:1-OH, C14:2 and C14:2-OH were lower than healthy controls. After treatment, the levels of C2:0, C8:0, C10:0, C10:1, C10:2, C12:0, C12:1, C14:1, C14:1-OH, C14:2, C14:2-OH, C16:2, C16:2-OH, and C18:0 decreased compared to the control. | PANSS CRF |
| Cao et al. (72) | Cohort study | Serum | 28.91 ± 6.21 | First-episode and drug-naïve: n = 29; recurrent or chronic schizophrenia: n = 93 | C18:0 L-C16:0 C18:2 LAC |
+ | C18:0, L-C16:0, C18:2, and LAC were decreased after treatment. | DSM-IV PANSS CRF |
The age was expressed as MEAN ± SD. Carnitine is expressed as Cm: n, “m” is the number of carbon atoms, “n” is the unsaturation. If carnitine is hydroxylated, you can could put a hydroxide in the end, like 3-hydroxy octadecenoyl carnitine (C18:1-OH).
AC, acylcarnitine; CRF, Case Report Form; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders; GAF, The Global Assessment of Functioning Scale; HDRS-17, the Hamilton Depression Rating Scale-17; LAC, acetyl-L-carnitine; MetS, metabolic syndrome; PANSS, The Positive and Negative Syndrome Scale; SCID-I, The Structured Clinical Interview for Axis I; YMRS, Young Mania Rating Scale.