The potential impact of antipsychotics on lipids in schizophrenia: is there enough evidence to confirm a link?

Lipid abnormalities are common in the general population and early data suggests that they may be more common in people with schizophrenia. Little data exist from treatment-naive patients making it difficult to differentiate any genetic contribution associated with a diagnosis of schizophrenia from the lifestyle risks associated with this diagnosis. Additional potential risks associated with antipsychotic drug treatment have been noted in the literature since 1971. The majority of the existing data on lipids derive from retrospective and cross-sectional analyses of datasets that have been designed for other purposes. Specifically screening bias for lipid testing and treatment selection bias are important potential confounders. Prospective clinical trials are difficult to interpret, as many are short-term, report on non-fasting data and were never designed to evaluate the differential effects of antipsychotic drugs on lipids as a primary endpoint. There is little reported data on lipid fractions such as LDL and HDL. Nevertheless there is some evidence from placebo-controlled studies that antipsychotics may be differentially associated with a small, clinically insignificant increase in cholesterol and a larger, potentially clinically significant increase in triglycerides. Further prospective randomized trials, using fasting data and controlling for established risk factors such as diet and exercise are essential to determine if there are clinically meaningful differential effects on lipids associated with individual antipsychotic drugs.