Endophenotype properties of niacin sensitivity as marker of impaired prostaglandin signalling in Schizophrenia

BackgroundDisruption of arachidonic acid pathways and prostaglandin signalling has been implicated in the pathophysiology of schizophrenia.AimsWe intended to study prostaglandin signalling in groups of young schizophrenia patients, first-degree relatives, and healthy controls in order to assess effects of heritability on this biological marker—one important endophenotype criterion.MethodNamely, we assessed intensity of methylnicotinate skin flushing using optical reflection spectroscopy. Tests were applied to 19 adolescent first-episode schizophrenia patients, 21 first-degree relatives, and groups of age and gender matched healthy controls.ResultsCompared to healthy controls, attenuation of skin flushing at low niacin concentrations was found only in schizophrenia patients, but not in first-degree relatives.ConclusionWhile our results indicate niacin hyposensitivity as reliable biological marker in schizophrenia, they do not provide clear evidence for its heritability. Particularly, the results in adolescent schizophrenia patients are suggestive for the perception of attenuated niacin flushing as secondary to the pathophysiology at the onset of schizophrenic illness, namely increased oxidative stress, alterations of unspecific immune-response or inflammation-like processes.