Prevalence of polycystic ovary syndrome in Chinese obese women of reproductive age with or without metabolic syndrome

Alterations in nonesterified free fatty acid trafficking rather than hyperandrogenism contribute to metabolic health in obese women with polycystic ovary syndrome

OBJECTIVE

To determine whether alterations in nonesterified fatty acid (NEFA) dynamics or degree of hyperandrogenism (HA) contribute to the difference in insulin sensitivity between women with metabolically healthy obese polycystic ovary syndrome (PCOS) (MHO-PCOS) and women with metabolically unhealthy obese PCOS (MUO-PCOS).

DESIGN

Prospective cross-sectional study.

SETTING

Tertiary-care academic center.

PATIENTS

One hundred twenty-five obese women with PCOS.

INTERVENTION

Consecutive obese (body mass index [BMI] ≥ 30 kg/m2) oligo-ovulatory women (n = 125) with PCOS underwent an oral glucose tolerance test and a subgroup of 16 participants underwent a modified frequently sampled intravenous glucose tolerance test to determine insulin-glucose and -NEFA dynamics.

MAIN OUTCOME MEASURES

Degree of insulin resistance (IR) in adipose tissue (AT) basally (Adipo-IR) and dynamically (the nadir in NEFA levels observed [NEFAnadir], the time it took for NEFA levels to reach nadir [TIMEnadir], and the percent suppression in plasma NEFA levels from baseline to nadir [%NEFAsupp]); peak lipolysis rate (SNEFA) and peak rate of NEFA disposal from plasma pool (KNEFA); whole-body insulin-glucose interaction (acute response of insulin to glucose [AIRg], insulin sensitivity index [Si], glucose effectiveness [Sg], and disposition index [Di]); and HA (hirsutism score, total and free testosterone levels, and dehydroepiandrosterone sulfate levels).

RESULTS

A total of 85 (68%) women were MUO-PCOS and 40 (32%) were MHO-PCOS using the homeostasis model of assessment of IR. Subjects with MUO-PCOS and MHO-PCOS did not differ in mean age, BMI, waist-to-hip ratio, HA, and lipoprotein levels. By a modified frequently sampled intravenous glucose tolerance test, eight women with MUO-PCOS had lesser Si, KNEFA, and the percent suppression in plasma NEFA levels from baseline to nadir (%NEFAsupp) and greater TIMEnadir, NEFAnadir, and baseline adipose tissue IR index (Adipo-IR) than eight subjects with MHO-PCOS, but similar fasting NEFA levels and SNEFA. Women with MUO-PCOS had a higher homeostasis model of assessment-β% and fasting insulin levels than women with MHO-PCOS. In bivalent analysis, Si correlated strongly and negatively with Adipo-IR and NEFAnadir, weakly and negatively with TIMEnadir, and positively with KNEFA and %NEFAsupp, in women with MUO-PCOS only.

CONCLUSION

Independent of age and BMI, women with MUO-PCOS have reduced NEFA uptake and altered insulin-mediated NEFA suppression, but no difference in HA, compared with women with MHO-PCOS. Altered insulin-mediated NEFA suppression, rather than HA or lipolysis rate, contributes to variations in insulin sensitivity among obese women with PCOS.

Metabolically Healthy Obesity (MHO) vs. Metabolically Unhealthy Obesity (MUO) Phenotypes in PCOS: Association with Endocrine-Metabolic Profile, Adherence to the Mediterranean Diet, and Body Composition

Obesity and obesity-related low-grade inflammation are common findings in polycystic ovary syndrome (PCOS), the most common endocrine-metabolic disorder-affecting women in reproductive age. The terms metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO) have been introduced to define individuals with obesity in whom cardio-metabolic risk factors are absent or present, respectively. To date, evidence investigating differences in body composition and adherence to the Mediterranean diet (MD) between MHO and MUO-PCOS women are lacking. Aim of this study was to better characterize the determinants of the metabolic health status in PCOS patients with obesity according to MHO and MUO phenotypes by evaluating endocrine-metabolic profile, inflammatory status, adherence to the MD, and body composition. The study population consisted of 94 treatment-naïve women with PCOS and obesity (BMI = 38.23 ± 6.62 kg/m² and age = 24.12 ± 3.68 years). Compared PCOS MHO with PCOS MUO patients, the latter had higher levels of high-sensitivity C-reactive protein (hs-CRP) (p < 0.001), testosterone (p < 0.001), and insulin (p < 0.001), worse metabolic parameters, and higher Homeostatic Model Assessment of Insulin Resistance (HoMA-IR), Visceral Adiposity Index (VAI), and Fatty liver Index (FLI) (p < 0.001). Furthermore, PCOS MUO patients had lower adherence to the MD (p < 0.001) in spite of the same total energy intake (p = 0.102) as compared to PCOS MHO. The presence of MUO was associated with highest hs-CRP levels (OR = 1.49, p < 0.001), more severe hyperandrogenism and cardio-metabolic indices (p < 0.001). On the contrary, being PCOS MUO was associated with lower adherence to the MD (OR = 0.28, p < 0.001), and smaller PhAs (OR = 0.04, p < 0.001). Using a regression linear analysis model PREDIMED score entered at the first step (p < 0.001), followed by VAI (p < 0.001), and FLI (p = 0.032) in this analysis. At ROC analysis, a PREDIMED score of ≤4 (p < 0.001, AUC 0.926) could serve as a threshold for a significantly increased risk of presence the MUO-PCOS phenotype. To the best of our knowledge, this is the first study that characterized MHO and MUO-PCOS women on the basis of their adherence to the MD, body composition, and cardio-metabolic indices, providing evidence of the usefulness of adjunctive diagnostic parameters to better differentiate the MHO/MHO phenotypes in this cohort of PCOS patients with obesity.

The risk factors of gestational hypertension in patients with polycystic ovary syndrome: a retrospective analysis

BACKGROUND

The hypertensive disorders complicating pregnancy (HDCP) is common in patients with polycystic ovary syndrome (PCOS), yet the potential influencing factors remained unclear. We aimed to assess the independent risk factors of HDCP in patients with PCOS, to provide clinical evidences for the management of PCOS.

METHODS

Pregnant PCOS patients treated in our hospital from June 1, 2018 to November 30, 2020 were approached. The personal and clinical characteristics of patients with and without gestational hypertension were evaluated. Logistic regressions were conducted to identify the independent risk factors of HDCP, Receiver operating characteristics (ROC)curve analysis was conducted to evaluate the predicting value.

RESULTS

A total of 188 PCOS patients were included, the incidence of HDCP in patients with PCOS was 27.66 %. There were significant differences in the age, BMI, family history of hypertension, the history of adverse pregnancy, history of contraceptive pills use and family history of HDCP between HDCP group and no-HDCP group (all p < 0.05), and there were no significant differences in the family history of diabetes, multiple pregnancy and long-term smoking history between HDCP group and no-HDCP group (all p > 0.05). Age ≥ 27y(OR2.048, 95 %CI1.121 ~ 3.208), BMI ≥ 24 kg/m2(OR1.463, 95 %CI1.069 ~ 2.011), family history of hypertension(OR2.129, 95 %CI1.093 ~ 3.042), the history of adverse pregnancy(OR2.435, 95 %CI1.264 ~ 4.085), history of contraceptive pills use(OR3.806, 95 %CI1.184 ~ 6.102), family history of HDCP(OR1.934, 95 %CI1.016 ~ 2.774) were the independent risk factors of HDCP in patients with PCOS (all p < 0.05). ROC curve analyses indicated that those factors had good predictive value on HDCP in PCOS patients.

CONCLUSIONS

The incidence of HDCP in PCOS patients is relatively high. In clinical practice, medical workers should carry out early prevention and intervention measures for these risk factors to reduce the incidence of HDCP.

Association of Metabolic Syndrome With Prevalence of Obstructive Sleep Apnea and Remission After Sleeve Gastrectomy

Obesity is an important risk factor for metabolic syndrome and obstructive sleep apnea (OSA). Bariatric surgery has been shown to effectively reduce weight and obesity-related comorbidities. However, the prevalence and severity of OSA in obese patients with different baseline metabolic states and the improvements of OSA after bariatric surgery remain unknown. The main aims of this study were to ascertain the prevalence of OSA in young Chinese obese patients with different metabolic states and to evaluate their respective OSA remission after laparoscopic sleeve gastrectomy. We first performed a cross-sectional study involving 123 metabolically healthy obese patients and 200 metabolically unhealthy obese patients (who had the same age and BMI ranges) to estimate the prevalence of OSA at baseline. Then we performed a retrospective study, which was registered at ClinicalTrials.gov (ref. NCT02653430) of 67 patients who underwent laparoscopic sleeve gastrectomy to evaluate the remission of OSA. Metabolically healthy and unhealthy obese patients had similar apnea-hypopnea index levels (16.6 ± 22.0 vs. 16.7 ± 18.7 events/h, P = 0.512) and prevalence of OSA (66.7% vs. 69.0%, P = 0.662). Male sex, age, waist circumference and lower liver-to-spleen ratio were independent risk factors for OSA. After laparoscopic sleeve gastrectomy, no difference was found in the decrease in body mass index (BMI) change (10.8 ± 4.8 vs. 10.8 ± 3.0 kg/m², P = 0.996) or the decrease in the apnea-hypopnea index (18.9 ± 24.6 vs. 17.0 ± 24.0 events/h, P = 0.800). The remission of moderate-to-severe OSA was observed in the MHO (36.3%; 54.5-18.2%, P = 0.125) and MUO (32.2%; 66.1-33.9%, P = 0.001) patients. These results suggest that, in patients with obesity, metabolic syndrome does not add extra risk for the prevalence or severity of OSA. Both metabolically healthy and unhealthy obese patients could benefit equally from laparoscopic sleeve gastrectomy in terms of weight loss and obstructive sleep apnea remission.

Metabolomic Signature Between Metabolically Healthy Overweight/Obese and Metabolically Unhealthy Overweight/Obese: A Systematic Review

The clinical manifestations of overweight/obesity are heterogeneous and complex. In contrast to metabolically unhealthy overweight/obese (MUO), a particular sub-group of obese patients who are considered as metabolically healthy overweight/obese (MHO), display favorable metabolic profiles characterized by high levels of insulin sensitivity, normal blood pressure, as well as favorable lipid, inflammation, hormone, liver enzyme, and immune profiles. While only a few available studies focused on the metabolic files underlying the obese phenotypes, the current review aimed to perform a systematic review of available studies focusing on describing the metabolomic signature between MUO and MHO. We did the systematic search for literature on MEDLINE (PubMed), the Cochrane Library, EMBASE, and searched for the references of relevant manuscripts from inception to 29 May 2020. After critical selection, 20 studies were eligible for this systematic review and evaluated by using QUADOMICS for quality assessment. Eventually, 12 of 20 studies were classified as "high quality". Branched-chain amino acids (isoleucine, leucine, and valine), aromatic amino acids (phenylalanine and tyrosine), lipids (palmitic acid, palmitoleic acid, oleic acid, eicosapentaenoic acid, and docosahexaenoic acid), and acylcarnitines (propionyl carnitine) levels might be elevated in MUO. The current results suggested that MHO showed a favorable trend in the overall metabolic signature. More longitudinal studies are needed to elaborate deeply on the metabolic pathway and the relationship between metabolic patterns and the occurrence of the disease.

AMH Is a Good Predictor of Metabolic Risk in Women with PCOS: A Cross-Sectional Study

OBJECTIVE

The relationship between metabolic risk and ovarian function is ambiguous. This retrospective study analyzed the medical records of 461 PCOS patients collected between January 2019 and June 2020 to investigate the relationship between serum anti-Müllerian hormone (AMH) and parameters of metabolic risk in the population with polycystic ovary syndrome (PCOS).

METHODS

A total of 461 PCOS patients aged 20-40 years were included and stratified into four groups according to the AMH level. The association between AMH and the parameters related to metabolic risk in these groups was compared, and the discrepancies were further explored. Binary logistic regression was performed to examine the risk factors of HOMA-IR. The values of AMH that best predicted the risk of HOMA-IR were also analyzed by ROC curves.

RESULTS

AMH was negatively associated with HOMA-IR (odds ratio (OR) -0.279, 95% confidence interval (CI) -0.36 to -0.20), fasting insulin (OR -0.282, 95% CI -0.36 to -0.20), 1-hour postprandial insulin (OR -0.184, 95% CI -0.28 to -0.11), 2-hour postprandial insulin (-0.180, 95%CI -0.28 to -0.11), 3-hour postprandial insulin (OR -0.198, 95% CI -0.30 to -0.13), waist-hip ratio (OR -0.235, 95% CI -0.31 to -0.14), and body mass index (OR -0.350, 95% CI -0.43 to -0.27). There was no statistically significant relationship between blood pressure, serum glucose profile, or lipid levels and AMH. Binary logistic regression showed that AMH protected against the occurrence of PCOS patients (OR: 0.835, 0.776, and 0.898). For the prediction of HOMA-IR, AMH had an AUC-ROC of 0.704 (95% CI 0.652-0.755) with a cutoff value of 7.81 mmol/L, a sensitivity of 70.3%, and a specificity of 70.1%.

CONCLUSIONS

Higher AMH levels were significantly associated with a lower insulin profile and might be a useful predictor for HOMA-IR in PCOS patients.

Go Girls!-Dance-Based Fitness to Increase Enjoyment of Exercise in Girls at Risk for PCOS

Weight loss can reduce the hyperandrogenemia associated with polycystic ovary syndrome (PCOS) in peripubertal girls. Yet, adolescent girls have the lowest rates of physical activity and enjoyment of exercise. We created a dance-based support group (Go Girls!) to entice physical activity and improve enjoyment. Girls ages 7-21 over the 85th BMI percentile were recruited and attended once-weekly sessions for 3-6 months. We assessed changes in Physical Activity Enjoyment Scale (PACES), anthropometrics, laboratory data, and amounts of home exercise at 0, 3, and 6 months. Sixteen girls completed either 3 or 6 months. PACES scores were surprisingly high at baseline and remained high. Systolic blood pressure percentile decreased post-intervention. Although no group differences were observed, the majority of individual girls had decreased waist circumference, triglycerides, and metabolic syndrome severity score. Forty percent had decreased free testosterone levels. More girls enjoyed physical education class, got exercise outside of school, and made other lifestyle changes. This dance-based support group was enjoyed by girls and demonstrated health benefits. Continued efforts to engage girls in physical activity are necessary to protect girls from the consequences of obesity, including PCOS and metabolic syndrome. Dance exercise remains a promising tool to encourage physical activity in girls.

Prevalence of polycystic ovary syndrome in a metabolically healthy obese population

OBJECTIVE

To determine whether polycystic ovary syndrome (PCOS) prevalence is increased among metabolically healthy obese (MHO) women.

METHODS

A national epidemiologic survey in 10 provinces and municipalities of China between October 2007 and September 2011. Women were stratified into four groups according to metabolic health (assessment by Adult Treatment Panel III) and obesity (body mass index [BMI] ≥28): metabolically healthy nonobese (MHNO), metabolically unhealthy nonobese (MUNO), MHO, and metabolically unhealthy obese (MUO). PCOS was diagnosed via Rotterdam Criteria. Participants completed a questionnaire and underwent physical and transvaginal ultrasound examination. BMI, blood pressure, glucose, and lipid profile were measured.

RESULTS

The survey included 3551 women. The MHO group had a higher prevalence of PCOS and chronic anovulation versus nonobese groups (all P<0.05). Obesity was a risk factor for PCOS (odds ratio [OR], 2.30; 95% confidence interval [CI], 1.68-3.14, P<0.05). Being metabolically unhealthy was a risk factor for PCOS (OR, 1.32; 95% CI, 1.09-1.60; P<0.05). The MHO group had an increased risk of PCOS relative to the MHNO group (OR, 2.39; 95% CI, 1.42-4.02; P<0.05).

CONCLUSION

MHO women had an increased risk of PCOS and chronic anovulation. Obesity might be an independent risk factor for these two disorders.

Salvianolic acid B plays an anti-obesity role in high fat diet-induced obese mice by regulating the expression of mRNA, circRNA, and lncRNA

Background

Adipose tissue plays a central role in obesity-related metabolic diseases such as type 2 diabetes. Salvianolic acid B (Sal B), a water-soluble ingredient derived from Salvia miltiorrhiza, has been shown to reduce obesity and obesity-related metabolic diseases by suppressing adipogenesis. However, the role of Sal B in white adipose tissue (WAT) is not yet clear.

Methods

Illumina Hiseq 4000 was used to study the effects of Sal B on the expression of long non-coding RNA (lncRNA) and circular RNA (circRNA) in epididymal white adipose tissue induced by a high fat diet in obese mice.

Results

RNA-Seq data showed that 234 lncRNAs, 19 circRNAs, and 132 mRNAs were differentially expressed in WAT under Sal B treatment. The up-regulated protein-coding genes in WAT of the Sal B-treated group were involved in the insulin resistance pathway, while the down-regulated genes mainly participated in the IL-17 signaling pathway. Other pathways may play an important role in the formation and differentiation of adipose tissue, such as B cell receptor signaling. Analysis of the lncRNA–mRNA network provides potential targets for lncRNAs in energy metabolism. We speculate that Sal B may serve as a potential therapeutic approach for obesity.

Prevalence and degree of insulin resistance in Chinese Han women with PCOS: Results from euglycemic-hyperinsulinemic clamps

OBJECTIVE

The euglycemic-hyperinsulinemic clamp is the gold standard to evaluate insulin resistance (IR), but there are only a few studies on the prevalence of IR in Chinese Han women with polycystic ovary syndrome (PCOS). This study investigated: (a) the prevalence of IR in Chinese Han women with PCOS by clamp, (b) the degree of reduction in insulin sensitivity (IS) and the contribution of body mass index (BMI).

DESIGN

Retrospective cross-sectional analysis.

PATIENTS

Chinese Han women with PCOS (n = 448) visiting the Department of Endocrinology or the Department of Obstetrics and Gynaecology of the First Affiliated Hospital of Chongqing Medical University. Chinese Han women without PCOS (controls) from the same area (n = 40).

MEASUREMENTS

Clamp-measured IS, age, BMI, and total testosterone.

RESULTS

The prevalence of IR and reduction in IS were 56.3% and 30.3%, respectively, in Chinese Han women with PCOS (both P < 0.001). The inherent reduction in IS was 18.8% in lean women with PCOS and BMI independently reduced IS by 37.9% in obese women with PCOS. The prevalence of IR estimated by homeostatic model assessment (HOMA) was lower than that determined by clamp. The multivariable analysis showed that IR by clamp (R²  = 0.48, P < 0.001) was independently associated with BMI (β = -0.52, P < 0.001), waist-hip ratio (β = -0.23, P < 0.001), total testosterone (β = -0.07, P = 0.045) and age (β = 0.17, P < 0.001), while IR by HOMA was only associated with BMI (R²  = 0.25, β = 0.50, P < 0.001). There were no differences in BMI groups distribution, HOMA-IR and M values among the four PCOS subtypes (all P > 0.05).

CONCLUSIONS

56.3% of Chinese Han women with PCOS had IR and their reduction in IS was 30.3%. Obesity exacerbated the reduction in IS. When being evaluated by HOMA, the prevalence and the risk factors of IR in Chinese women with PCOS were underestimated.

Subclinical hypothyroidism is not a risk factor for polycystic ovary syndrome in obese women of reproductive age

Obese women are at high risk for polycystic ovary syndrome (PCOS). Subclinical hypothyroidism (SCH) has been associated with weight gain, insulin resistance and impaired fertility, which are also factors involved in PCOS. However, there is limited information regarding the influence of SCH on the presence of PCOS. In order to determine whether SCH increases the prevalence of PCOS, we performed a cross-sectional study in a cohort of reproductive-aged obese women. All subjects underwent anthropometric evaluation, laboratory tests and ultrasound examination. Diagnosis of PCOS was based on the Rotterdam criteria. A total of 534 obese women were included and 108 (20.2%) of them were diagnosed with SCH. Patients with SCH showed similar insulin resistance, comparable androgen levels, and higher triglycerides levels (1.7 vs. 1.5 mmol/L, p = .002) compared to those with normal thyroid status. The frequency of PCOS did not differ between the two groups (56.1% for normal thyroid function vs. 60.2% for subclinical hypothyroidism, p = .514). In logistic regression analysis, SCH was not an independent risk factor for PCOS after adjusting for confounding factors (OR = 0.984, 95% CI 0.581-1.667). For the first time, our results suggest that SCH does not increase the risk of PCOS in obese women of reproductive age.

Identification of Potential Biomarkers for Urine Metabolomics of Polycystic Ovary Syndrome Based on Gas Chromatography-Mass Spectrometry

Background:

Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder, and it's diagnosis is difficult. The aim of this study was to investigate the metabolic profiles of PCOS patients by analyzing urine samples and identify useful biomarkers for diagnosis of PCOS.

Methods:

This study was carried out in the Department of Obstetrics and Gynecology of the Maternal and Child Health Hospital of Hunan Province from December 2014 to July 2016. In this study, the urine samples of 21 women with PCOS and 16 healthy controls were assessed through gas chromatography-mass spectrometry to investigate the urine metabolite characteristics of PCOS and identify useful biomarkers for the diagnosis of this disorder. The Student's t-test and rank sum test were applied to validate the statistical significance of the between the two groups.

Results:

In total, 35 urine metabolites were found to be significantly different between the PCOS patients and the controls. In particular, a significant increase in the levels of lactose (10.01 [0,13.99] mmol/mol creatinine vs. 2.35 [0.16, 3.26] mmol/mol creatinine, P = 0.042), stearic acid (2.35 [1.47, 3.14] mmol/mol creatinine vs. 0.05 [0, 0.14] mmol/mol creatinine, P < 0.001), and palmitic acid (2.13 [1.07, 2.79] mmol/mol creatinine vs. 0 [0, 0] mmol/mol creatinine, P < 0.001) and a decrease in the levels of succinic acid (0 [0, 0] mmol/mol creatinine vs. 38.94 [4.16, 51.30] mmol/mol creatinine, P < 0.001) were found in the PCOS patients compared with the controls. It was possible to cluster the PCOS patients and the healthy controls into two distinct regions based on a principal component analysis model. Of the differentially expressed metabolites, four compounds, including stearic acid, palmitic acid, benzoylglycine, and threonine, were selected as potential biomarkers.

Conclusions:

This study offers new insight into the pathogenesis of PCOS, and the discriminating urine metabolites may provide a prospect for the diagnosis of PCOS.

Metabolic characteristics of normal weight central obesity phenotype polycystic ovary syndrome women: a large-scale national epidemiological survey

RESEARCH QUESTION

The aim was to investigate the metabolic profiles of women with normal weight but central obesity in polycystic ovary syndrome (PCOS).

DESIGN

In total, 727 women with PCOS from a large-scale epidemiological survey were included. Diagnosis of PCOS was based on Rotterdam criteria. Subjects were categorized into four subgroups: (i) normal weight non-central obesity (NWNCO): body mass index (BMI) ≤18.5 kg/m² to <25 kg/m² and waist-to-hip ratio (WHR) <0.85; (ii) normal weight central obesity (NWCO): BMI ≤18.5 kg/m² to <25 kg/m² and WHR ≥0.85; (iii) obese non-central obesity (ONCO): BMI ≥25 kg/m² and WHR <0.85; and (iv) obese central obesity (OCO): BMI ≥25 kg/m² and WHR ≥0.85. BMI, WHR, blood pressure, glucose and lipid profiles were measured.

RESULTS

NWCO subjects had significantly higher percentages of insulin resistance, high triglycerides and low high-density lipoprotein cholesterol (HDL-C) than NWNCO subjects (all P < 0.05), and similar percentages compared with ONCO subjects. Compared with the NWNCO group, the NWCO group had higher age-adjusted risks of insulin resistance, high triglycerides and low HDL-C (odds ratio [OR] = 3.83, 95% confidence interval [CI] = 2.23-6.58; OR = 1.66, 95% CI = 1.00-2.77, OR = 1.60, 95% CI = 1.11-2.30, respectively).

CONCLUSIONS

PCOS women with normal weight but central obesity had increased risks of insulin resistance and dyslipidaemia compared with normal weight PCOS women without central obesity, suggesting that combining BMI with measurement of central obesity may provide better adiposity-related metabolic risk factor stratification in clinical practice than either method alone.

Steroid hormone profiling in obese and nonobese women with polycystic ovary syndrome

The study explored differences in the steroidogenic pathway between obese and nonobese women with polycystic ovary syndrome (PCOS) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). 1044 women with PCOS (including 350 lean, 312 overweight and 382 obese) and 366 control women without PCOS (including 203 lean, 32 overweight and 131 obese) were enrolled. The differences in steroid hormones were amplified in lean PCOS versus lean controls compared with obese PCOS versus obese controls. Compared with obese PCOS, lean PCOS demonstrated increased dehydroepiandrosterone sulfate (P = 0.015), 17-hydropregnenolone (P = 0.003), 17-hydroprogesterone (17-OHP) (P < 0.001), progesterone (P < 0.001) and estrone (P < 0.001) levels. Enzyme activity evaluation showed that lean PCOS had increased activity of P450c17 (17-hydropregnenolone/pregnenolone, P < 0.001), P450aro (P < 0.001), 3βHSD2 (progesterone/ pregnenolone and 17-OHP/17-hydropregnenolone, both P < 0.001) and decreased activity of P450c21(11-deoxycorticorsterone/progesterone and 11-deoxycortisol/17-OHP, P < 0.001). Moreover, we found higher frequencies of CYP21A2- (encoding P450c21) c.552 C > G (p. D184E) in lean PCOS compared with obese PCOS patients (P = 0.006). In conclusion, this study demonstrated for the first time that the adrenal-specific enzyme P450c21 showed decreased activity in lean PCOS patients, and that the adrenal androgen excess may play different roles in lean and obese PCOS patients, which represents as different enzyme activity in the steroidogenic pathway.