Plasma oxytocin levels are reduced in Slovak autistic boys

Abstract

BACKGROUND: Oxytocin is a neuropeptide affecting social behaviour. Autism spectrum disorders are characterized by social defi cits, impaired communication and repetitive behaviours. Several studies have shown reduced plasma levels of oxytocin and moreover, administration of oxytocin reduced clinical symptoms of autism. AIM: The aim of this study was to reveal differences in the plasma levels of oxytocin between autistic and healthy populations in Slovakia. METHODS: After a signed consent, 108 autism spectrum disorder patients were enrolled in the study (83 males, 25 females). A control group of 131 healthy children was recruited (106 males, 25 females). Blood samples were obtained from all children and plasma oxytocin levels were measured using the ELISA method. RESULTS: Oxytocin levels were lower in the boys older than 10 years of age in comparison to controls. There were no signifi cant differences in oxytocin levels among girls. Oxytocin levels did not signifi cantly correlate with age in either of the examined groups. CONCLUSION: Decreased oxytocin levels in plasma of autism boys may be related to decreased sociability and social interactions. The addition of psychological profi ling may reveal possible correlations of hormone levels with symptom severities (Tab. 1, Fig. 2 Acknowledgements: Authors thank all the families with autism and control group children for their participation. Study was supported by the following grants: APVV-0253-10, APVV-0254-11, VEGA-1/0066/12.

Endogenous Oxytocin Levels in Autism—A Meta-Analysis

“…To further explore what underlying mechanisms might be driving the general results, more detailed subgroup analyses were performed by age, by sex and by tissue sample type. Pertaining to age, 13 studies involved comparisons of groups of children aged between 2 to 12 years [ 3 , 4 , 5 , 6 , 7 , 9 , 10 , 30 , 31 , 32 , 33 , 34 , 35 ]. Two studied adolescent groups aged between 11 to 16 years [ 8 , 36 ].…”

“…Three investigated groups of adults [ 30 , 31 , 32 ]. Pertaining to sex, eight studies reported on exclusively male populations [ 4 , 5 , 7 , 8 , 32 , 35 , 37 , 38 ] and one study adopted an exclusively female sample [ 32 ]. For the studies involving a mixed population, four studies reported separate outcomes of OT level measurement for male and female subgroups and were entered accordingly in the subgroup analyses [ 33 , 34 , 35 , 36 ].…”

“…Pertaining to sex, eight studies reported on exclusively male populations [ 4 , 5 , 7 , 8 , 32 , 35 , 37 , 38 ] and one study adopted an exclusively female sample [ 32 ]. For the studies involving a mixed population, four studies reported separate outcomes of OT level measurement for male and female subgroups and were entered accordingly in the subgroup analyses [ 33 , 34 , 35 , 36 ]. With regard to tissue sample type, twelve studies investigated blood plasma [ 3 , 4 , 5 , 7 , 9 , 10 , 30 , 32 , 34 , 35 , 36 , 37 ].…”

“…For the studies involving a mixed population, four studies reported separate outcomes of OT level measurement for male and female subgroups and were entered accordingly in the subgroup analyses [ 33 , 34 , 35 , 36 ]. With regard to tissue sample type, twelve studies investigated blood plasma [ 3 , 4 , 5 , 7 , 9 , 10 , 30 , 32 , 34 , 35 , 36 , 37 ]. Six studies took saliva samples for OT level measurement [ 6 , 8 , 31 , 33 , 38 , 39 ].…”

Oxytocin levels tend to be lower in autistic children: A meta-analysis of 31 studies

“…Husarova et al (2013); Husarova et al (2016); Lakatosova et al (2015); Ostatnikova et al (2016) and Tomova et al (2015) were all written by a largely identical research team and recruited their participants at the same institution. Because we could neither confirm nor rule out overlap of data and did not receive an answer from these researchers, we conducted the meta-analysis including all articles as well as excluding all but the one with the largest sample size (Lakatosova et al, 2015). We received additional information from Jansen et al (2006) and Zhang et al (2016), allowing us to include these studies.…”