Association of central serotonin transporter availability and body mass index in healthy Europeans

Serotonin-mediated mechanisms,inparticularviatheserotonintransporter(SERT),arethought to haveaneffectonfoodintakeandplayanimportantroleinthepathophysiologyofobesity. However,imagingstudiesthatexaminedthecorrelationbetweenbodymassindex(BMI)and SERTaresparseandprovidedcontradictoryresults.Theaimofthisstudywastofurthertestthe association betweenSERTandBMIinalargecohortofhealthysubjects. Methods: 127subjects of theENCDATdatabase(58females,age52718 years,range20-83, BMI25.273.8 kg/m2, range 18.2-41.1) wereanalysedusingregion-of-interest(ROI)andvoxel-basedapproachesto calculate [123I]FP-CIT specific-to-nonspecific bindingratios(SBR)inthehypothalamus/thalamus and midbrain/brainstemasSERT-specific targetregions. Results: Inthevoxel-basedanalysis, SERTavailabilityandBMIwerepositivelyassociatedinthethalamus,butnotinthemidbrain. In theROI-analysis,theinteractionbetweengenderandBMIshowedatrendwithhigher correlation coefficient formeninthemidbrainalbeitnotsignificant (0.033SBRm2/kg, p=0.1). Conclusions: ThedataareinagreementwithpreviousPET findings ofanalteredcentral serotonergic tonedependingonBMI,asaprobablepathophysiologicmechanisminobesity,and should encouragefurtherclinicalstudiesinobesitytargetingtheserotonergicsystem.