ESPE Abstracts

Background: Myo-inositol(MI)is a polyol involved in intracellular signaling pathways of insulin and MI has been used orally for therapeutic purposes in girls and adult women with polycystic ovary syndrome(PCOS)with variable success. As yet, serum MI levels have not been assessed in girls with PCOS.

Aim: Our primary goal was to compare serum MI levels in girls with PCOS with those in healthy peers. Secondary goal was to investigate the associations of serum MI with several gluco-insulinaemic variables, biochemical indices of hyperandrogenism, thyroid function tests and some metabolic variables.

Setting: Tertiary care centre.

Patients and Methods: Thirty-nine consecutive, treatment-naїve girls with PCOS(15.9±1.1 yr) and39healthy peers(16.0±1.1yr)were enrolled. Clinical examinations were performed using standard methods. Fasting blood samples were drawn from girls with PCOS for hormonal assessments to rule out other causes of oligomenorrhea and/or hirsutism and oral glucose tolerance test was performed to calculate insulin sensitivity index(ISI) (Matsuda index). Serum MI levels were measured using high performance liquid chromatography. Fasting blood samples were also drawn from healthy controls to measure serum MI and anti-mullerian hormone(AMH)levels. The girls with PCOS were stratified into subgroups according to a-abdominal obesity status,b- metabolic syndrome(MetS) status based on International Diabetes Federation criteria,c- having reduced ISI;i.e.Matsuda index less than2.5,d-having increased free androjen index(FAI); i.e.FAI>6.1.Serum MI levels were compared within the subgroups. Multivariable regression analysis was performed to investigate putatively influential variables associated with serum MI in the girls with PCOS. Signicance was granted for P≤0.05.

Results: Twenty-two(56.4%)girls with PCOS had abdominal obesity and nine(23%)had normal weight. Ten(25.6%)girls with PCOS had MetS.Reduced ISI was found in16(41%) and FAI was increased in31(80%) girls with PCOS. Serum MI levels were significantly higher in girls with PCOS than in controls(2.46ng/mL[25%-75%IQR 0.89-4.86]and0.88 ng/mL[25%-75%IQR 0.29-2.70];respectively, P<0.001). Serum AMH was also higher in the PCOS group (P<0.001). Serum MI levels were not different within the subgroups in girls with PCOS (P>0.05 for all). In girls with PCOS, serum MI was associated with serum total testosterone(T) (β=+0.499), Matsuda index(β=-0.582) and serumTSH levels (β=-0.582) (Adjusted R2=0.319, P<0.001).

Conclusions: We found significantly increased serum MI levels in girls with PCOS and serum MI levels were associated positively with T and negatively with ISI. Our results might suggest the need for further studies to rectify the use of oral MI in PCOS.