The Application Of FT, FAI And SHBG In Assessing The Clinical Features Of PCOS

Background and Objective:Judging from the development of the diagnostic criteria of polycystic ovarian syndrome(PCOS),we can conclude that hyperandrogenism being one of the criteriaes occupies an important place.Clinical features of hyperandrogenism frequently seen in PCOS include hirsutism,acne,and androgenic alopecia,while elevated circulating androgen levels in various forms can also be observed in PCOS patients.During the forms of androgen including dehydroepiandrosterone sulphate, dehydroepiandrosterone,androstenedione,testosterone,and dihydrotestosterone. Total testosterone(TT),the most common form to access the hyperandrogenemia, circulates both in its free form,and bound to protein including albumin and sex steroid hormone-binding globulin(SHBG).Only free testosterone(FT) is bioavailable. Therefore some investigators support that single measurement of serum TT is unreliably in assessing the hyperandrogenic features.However the complexity and cost of the measurement of FT are relatively high,and there are overlaps between PCOS patients and controls.There is no such problem with free androgen index(FAI), which accounts for the sex hormone-bound fraction of testosterone.It is assumed to be inherently superior estimates of hyperandrogenism.Nevertheless there is no such study about the concordance and value of these three markers in assessing the hyperandrogenic features of patients of Han Race with PCOS,which is important to determine the relative fitness of these markers for the hyperandrogenic features assessment.The obsjective of this study is to estimate the dependability between the parameters including FT,FAI and SHBG and hyperandrogenic features of PCOS patients of Han Race and the value in assessment.Material and methods:According to the diagnostic criteria endorsed by both the ESHRE and ASRM, 180 women with PCOS were included.Fasting blood samples were collected during the second to forth day of menstrual cycle for detecting serum levels of FSH,LH,E₂, TT,SHBG and FT.transvaginal sonography was taken use of and F-G score was evaluated.FAI was determined by the formula(FAI=TT^*100/SHBG).So does body mass index(BMI=weight/height²).Patients were divided into subgroups according to TT,and F-G score respectively.SHBG,FT and FAI etc.were compared among different subgroups.We also did the test about correlation between FT and FAI,TT and FAI as well as E₂ and TT.Result:(1) The average levels of T,SHBG and FT were 2.36±0.91nmol/L, 105.58±119.10nmol/L and 45.74±21.68pg/ml separately;average FAI was 3.87±3.39 and average F-G score was 2.62±3.22.(2)In 180 patients with PCOS,the pravelence of hirsutism is 57.2%(103/180),and that of ance is 24.4%(44/180).(3) The levels of FT(P＜0.001),FAI(P＜0.001),and BMI(P＜0.05) were significantly higher in high serum-T group(biological hyperandrogenemia)(T≥2.08nmol/L) compared to normal serum-T group(P＜0.001).(4) The level of T was markedly higher in hirsutism group(F-G score≥2) than that in non-hirsutism group(F-G score＜2)(P＜0.05),while no differences are seen in FT and FAI.(5) TT is correlated with FT(r=0.304) and FAI(r=0.349).FT is also correlated with FAI(r=0.211);E₂ is correlated with TT positively(r=0.256).Conclusions:1.Among the makers of accessing the hyperandrogenemia,TT,FT and FAI are better than others.And these three markers are concordant in assessing the hyperandrogenemia.2.FAI,which accounts for the sex hormone-bound fraction,is assumed to be inherently superior estimates of hyperandrogenemia.3.TT is greater relative with FAI compared with FT,and its concordance with clinical features of hyperandrogenism is better than FT and FAI.4.The serum androgen measurement can only be the auxiliary examination, which would be neither the sole marker nor the substitution of clinical assessment (Nowadays hirsutism is the only criteria to access the clinical feature of androgen excess.).However,hyperandrogenemia shoud be taken care of and treated properly in the clinical work because of the relation with obese.5.SHBG didn't directly contribute to the assessment of hyperandrogenism,but account for the calculation of FAI.