A Comparative Study Of Plasma Oxytocin Levels And Clinical Features In Patients With Anorexia Nervosa

Background and Objectives: Anorexia Nervosa(AN)is characterized by abnormal eating patterns,low body weight and body image distortion.There is an abnormal oxytocin(OT)secretion in patients with AN.This study will try to illustrate the role of OT in the pathological mechanism of AN,through exploring the change of plasma OT levels and clinical features between the period of baseline and follow-up in patients with AN.Methods:(1)A total of 41 low-weight female patients with AN were selected as the study group,44 matched healthy women were selected as the healthy control group(HC).AN group was divided into two groups: Restricting Type of Anorexia Nervosa(AN-R)group(n=19)and Binge Eating/Purging Type of Anorexia Nervosa(AN-BP)group(n = 22).(2)Plasma OT levels of two groups were determined with euzyme-linked immunosorbent assay,and the plasma OT levels of AN group were remeasured after treatment of 1 month and 3 months.The differences of plasma OT levels and the scores of clinical scales of Eating Disorder Examination Questionnaire(EDE-Q),Eating Attitude Test-26(EAT-26)and Eating Disorder Inventory(EDI-II)were compared between the AN group and the HC group,the different subtypes of AN in baseline and the follow-up time points.Results:(1)Comparison of the plasma OT level between AN group and HC group: Plasma OT levels of AN was significantly lower than that of healthy controls [(86.54±32.45)pg/ml,(121.19±83.05)pg/ml,t=-2.499,P=0.014].Both the plasma OT levels of the first month follow-up [(90.10±30.54)pg/ml] and the third month follow-up [(93.65±42.15)pg/ml]were significantly lower than that of healthy controls [(121.19±83.05)pg/ml](P<0.01).Compared to baseline [(86.54±32.45)pg/ml],the plasma OT levels in the first month follow-up [(90.10±30.54)pg/ml] and the third month follow-up [(93.65±42.15)pg/ml] showed no significantly difference(P>0.05),but the scale scores showed significantly decreased(P<0.01).(2)Comparison between the two subtypes: There were no significant difference of plasma OT levels and scales scores between AN-R group and AN-BP group[(90.63±335.49)pg/ml,(83.00±29.96)pg/ml,P>0.05].The OT levels of the two subtypes in the first month follow-up and the third month follow-up were higher than those in the baseline,but did not show significantly difference(P>0.05).(3)The correlation between plasma OT level and the scores of clinical scales: There is no significant correlation between the OT level and the total or sub-scale scores of EDE-Q,EAT-26,EDI-II,HAMD,HAMA and Y-BOCS in baseline,the first month follow-up and the third month follow-up,respectively(P>0.05).Conclusions:(1)There is low OT level in AN,and didn’t change significantly with the improvement of symptoms after 3-month treatment,which supports the hypotheses of low OT level in AN.(2)AN-R and AN-BP may have the same OT pathological mechanism.