Aminotransferase levels as a prospective predictor for the development of metabolic syndrome in patients with schizophrenia

Rationale Increased levels of alanine aminotransferase (ALT) are a biomarker for metabolic syndrome (MetS), but this relationship remains unproven in patients with schizophrenia. Objective We assessed the relationship between aminotransferase levels and MetS in patients with schizophrenia. Method This pooled analysis from two open-label prospective studies included 342 patients with schizophrenia who did not meet criteria for MetS at baseline. The development of MetS was assessed at weeks 12 and 24. Results MetS developed in 19.1 % of patients during the 24-week follow-up period. ALT levels were significantly associated with incident MetS: for each sex-specific standard deviation increase in log ALT, the odds ratio (OR) of MetS was 1.357 (p= .006) after adjusting for age, sex, duration of illness, smoking, and previous use of antipsychotics. This result remained significant after adjusting for interim weight changes. Compared with patients in the lowest quartile, the OR of MetS in those in the highest quartile within the normal range of ALT levels was 4.276 (p= .024). However, this association was significant only in male patients. Using a cutoff value of 23.0 U/L, sensitivity and specificity were 70.6 and 68.3 %, respectively, in male patients whose ALT levels were in the normal range. Conclusions A prospective association between ALT levels and MetS highlights the value of ALT levels, even mild ALT elevations within the normal range, as a predictor of the MetS risk in male patients. Baseline liver function tests and monitoring should be obtained during antipsychotic treatment to identify the risk for MetS.