Hair cortisol levels in schizophrenia and metabolic syndrome.

Aim: Individuals with schizophrenia demonstrate higher rates of metabolic syndrome (MetS) than the general population. Hair cortisol concentrations (HCC) reflect longer‐term cortisol secretion and can provide additional insights into the role of the hypothalamic pituitary adrenal (HPA) axis in schizophrenia and co‐occurring MetS. Methods: In a case–control study of 16 patients with schizophrenia (11 first episode psychosis [FEP] and 5 chronic) and 21 controls hair samples, representing a 3‐month retrospective window of cortisol, were collected and analysed utilizing liquid chromatography tandem mass spectrometry. We investigated whether schizophrenia and MetS co‐occurrence were associated with HCC utilizing multivariate regression models. We also explored the longitudinal trajectory of HCC in FEP patients by conducting a mixed models analysis. Results: At baseline HCC were significantly lower (Cohen's d = 0.88) in patients with schizophrenia than in controls (p =.014). HCC increased from baseline to month‐12 in FEP patients compared to controls, demonstrating a trend towards significance (p =.097). MetS was not associated with HCC at baseline, but HCC increased significantly from baseline to month‐12 in relation to MetS (p =.037). Conclusions: In a subgroup of schizophrenia patients, psychosis may be associated with a blunted HPA axis with lower long‐term cortisol output. MetS was associated with an increase in HCC and elevated cortisol levels observed in schizophrenia may be related to increased rates of MetS in schizophrenia patients. [ABSTRACT FROM AUTHOR]