Study population

Table 1 presents the demographic information of the 421 women in the study, aged 20–37 years. The cohort comprised 168 individuals in the PCOS group and 253 in the control group. Comparative analysis showed no significant differences in age or infertility duration between the two groups. However, the PCOS group demonstrated significant higher BMI and AFC level than the control group. Additionally, the PCOS group display higher insulin levels, indicative of possible insulin resistance. Furthermore, the PCOS group exhibited significantly higher levels of LDL, TC and TG in their blood lipids compared to the control group (Table 1). A comparison of hormone indicators revealed that LH, TSTO and AMH levels were significantly higher in the PCOS group (Table 1).

Table 1 Baseline data of the 421 assessed womenCorrelation analysis between hormone and metabolism indicators and PCOS

PCOS was positively correlated with several parameters, including FPG (r = 0.113, P = 0.020), insulin (r = 0.189, P < 0.001), BMI (r = 0.230, P < 0.001), AMH (r = 0.628, P < 0.001), LH (r = 0.474, P < 0.001), TSTO (r = 0.381, P < 0.001) and AFC (r = 0.656, P < 0.001). Additionally, PCOS displayed positive correlations with LDL (r = 0.195, P < 0.001), TC (r = 0.126, P = 0.010), and TG (r = 0.283, P < 0.001) but showed a negative correlation with HDL (r = − 0.127, P < 0.001). Furthermore, AMH exhibited positive correlation with LH (r = 0.460, P < 0.001), TSTO (r = 0.323, P < 0.001), AFC (r = 0.737, P < 0.001), LDL (r = 0.159, P = 0.001), TC (r = 0.125, P = 0.010) and TG (r = 0.167, P = 0.001) but demonstrated a negative correlation with FSH (r = − 0.131, P < 0.001).

Independent factors predicting PCOS with hormone and metabolism indicators

After adjusting for age, the independent risk factors for PCOS were predicted using a logistic regression model, which revealed BMI, LH, TSTO, AMH, AFC and TG as independent risk factors for PCOS (Table 2).

Table 2 Comparison of markers of independent risk factors for PCOSPredictive value of AMH and other indicators for PCOS

Parameters with significant differences between the PCOS and control groups were screened, and ROC curve analysis was performed to determine their efficiency in predicting PCOS. ROC analysis results revealed that AMH exhibited the most robust predictive value, with an area under the curve (AUC) of 0.888, sensitivity of 83.93% and specificity of 80.63% (Table 3, Fig. 1). The predictive value was higher than TSTO (AUC = 0.725), LH (AUC = 0.779), and AFC (AUC = 0.887). Interestingly, the combined diagnostic value of AMH and AFC (AUC = 0.913) is higher than that of AMH and LH (AUC = 0.901) (Table 3, Fig. 1).

Table 3 Comparison of predictive values of AMH and other indicators of PCOSFig. 1

ROC curves of the predictors of PCOS of hormone indicators and AFC. LH, luteinizing hormone; TSTO, testosterone; AMH, anti-Müllerian Hormone; AFC, antral follicle count

Comparison of basic and hormone indexes in individual with obesity

To assess the differences in hormone and metabolic parameters among individuals with obesity (BMI ≥ 24), we conducted subgroup analyses between obese PCOS and obese control groups. We observed that levels of LH and AMH in the obese PCOS group were significantly higher (P < 0.05, Table 4). And the number of AFC in obese PCOS group was higher than that in obese control group (P < 0.05, Table 4). However, there were no significant differences in BMI, FPG, blood lipid, E2, FSH, P, PRL and TSTO between the two groups (P > 0.05, Table 4).

Table 4 Comparison of general data in the obese populationPredictive value of hormone-related indicators for PCOS with obesity

ROC curve analysis was conducted to investigate the predictive efficacy of PCOS in obese individuals. Among the individuals with obesity, AMH was found to be the most effective diagnostic parameter for PCOS (AUC = 0.879), with a sensitivity of 73.13%, specificity of 89.58%, and cut off value of 5.63 (Table 5, Fig. 2). In contrast, TSTO demonstrated a lower diagnostic capacity for PCOS (AUC = 0.587), whereas LH exhibited a certain diagnostic value for PCOS (AUC = 0.771). Remarkably, the combined diagnostic use of AMH, LH and AFC increased PCOS diagnostic accuracy. The diagnostic capacity of AMH and LH was 0.893 and that of AMH and AFC was 0.897 (Table 5, Fig. 2).

Table 5 Comparison of predictive value of hormones and AFC to PCOS in individuals with obesityFig. 2

ROC curves of the predictors of hormone indicators and AFC for PCOS in the population with obesity. LH, luteinizing hormone; TSTO, testosterone; AMH, anti-Müllerian Hormone; AFC, antral follicle count

Comparison of basic and hormone indicators in individuals with no obesity

We observed no significant differences in age, years of infertility, BMI, FPG or TC levels in patients between the nonobese PCOS and nonobese control groups (P > 0.05, Table 6). However, nonobese PCOS group exhibited significantly elevated insulin, LDL and TG levels compared with those with the control group, and the HDL level was significantly decreased (P < 0.05, Table 6). The hormone levels of LH, TSTO and AMH in the PCOS subgroup were significantly higher than those in the control group. Concurrently, the number of AFCs in nonobese PCOS group was significantly higher than that in the nonobese control group (P < 0.05, Table 6).

Table 6 Comparison of general data in individuals with no obesityPredictive value of hormone indicators for PCOS in individuals with no obesity

In contrast to the results in obese individuals, it appears that AMH and hormone indicators had better predictive value nonobese individuals (BMI < 24). AMH exhibited the highest diagnostic value (AUC = 0.903) among LH, TSTO and AMH, (Table 7, Fig. 3). Both LH (AUC = 0.804) and TSTO (AUC = 0.796) demonstrated diagnostic utility for PCOS in individuals with no obesity. The diagnosis of PCOS frequently requires a comprehensive evaluation that includes AMH, LH and AFC in clinical practice. Accordingly, a combined diagnosis involving AMH and LH demonstrated an improved predictive value (AUC = 0.916) and AMH and AFC showed the highest predictive value (AUC = 0.927) (Table 7, Fig. 3).

Table 7 Comparison of the predictive value of hormones and AFC for PCOS in individuals with no obesityFig. 3

ROC curves of the predictive value of hormone indicators and AFC for PCOS with individuals with no obesity. LH, luteinizing hormone; TSTO, testosterone; AMH, anti-Müllerian Hormone; AFC, antral follicle count

Comparison of hormone indicators in obese and non-obese patients with PCOS

Patients with PCOS were stratified into subgroups based on their BMI. The PCOS subgroup with obesity demonstrated notable increases in FBG levels and metabolism indicators, insulin and TG (P < 0.05, Table 8). In contrast, the LH, TSTO, AMH and AFC levels in the obese PCOS group were significantly decreased compared with those in the nonobese PCOS group (P < 0.05, Table 8).

Table 8 Comparison of general data for PCOS according to BMI