Objective:To investigate whether intermittent fasting alleviates insulin resistance in a polycystic ovary syndrome(PCOS) mouse model through the regulation of autophagy.Methods:Fifty 3-week-old female C57BL/6J mice were randomly assigned into the following groups using a random number table: normal control(NC) group( n=10), maintained on a standard chow diet; high-fat diet(HFD) group( n=10) fed a diet with 60% of calories derived from fat; and PCOS model group( n=30), established by combining a HFD with dehydroepiandrosterone(DHEA) administration. Successful modeling was confirmed by disrupted estrous cycles, hyperandrogenism, and polycystic ovarian morphology. The PCOS model mice were further divided into three groups: PCOS group( n=9), PCOS with intermittent fasting group(PCOS+ IF, n=9), and PCOS with intermittent fasting plus the autophagy inhibitor 3-methyladenine(3-MA) group(PCOS+ IF+ 3-MA, n=9). Autophagy levels were assessed by detecting markers LC3 and p62 and observing autophagosomes via transmission electron microscopy. Glucose tolerance test(GTT) and insulin tolerance test(ITT) were performed, and the area under the curve(AUC) was calculated to evaluate insulin resistance. Western blotting was used to detect phosphorylation levels of phosphatidylinositol 3-kinase(PI3K), protein kinase B(Akt), mammalian target of rapamycin(mTOR), and p70S6 kiase(p70S6K). Results:Compared with the NC group, the PCOS model group showed absent estrous cycles, significantly elevated serum testosterone, sex hormone binding globulin, and luteinizing hormone(LH) levels( P<0.001), and polycystic ovarian changes on hematoxylin-eosin staining, confirming successful model establishment. Immunohistochemistry, transmission electron microscopy, and Western blotting demonstrated that autophagy levels were increased in the PCOS+ IF group compared with the PCOS group, while 3-MA administration reduced the intermittent fasting - induced autophagy. The AUC values for both GTT and ITT were significantly lower in the PCOS+ IF group than those in the PCOS group( P<0.001, P=0.003), but increased in the PCOS+ IF+ 3-MA group compared to the PCOS+ IF group( P<0.001, P=0.020). Western blotting analysis showed that phosphorylation levels of PI3K, Akt, mTOR, and p70S6K were significantly decreased in the PCOS+ IF group compared with the PCOS group( P=0.002, P=0.001, P=0.001, and P<0.001, respectively), and increased in the PCOS+ IF+ 3-MA group compared with the PCOS+ IF group( P=0.021, P=0.041, P=0.047, and P=0.024, respectively). Conclusions:Intermittent fasting alleviates insulin resistance in a PCOS mouse model through inhibitiing PI3K/Akt/mTOR signaling pathway and promoting autophagy.

Objective:To investigate the changes in and correlations between melanin-concentrating hormone (MCH) and androgen levels in the serum of patients with polycystic ovary syndrome (PCOS), aiming to provide a novel research perspective for its diagnosis.Methods:A cross-sectional study. A total of 307 subjects were enrolled from the physical examination center and endocrinology clinic of the Affiliated Hospital of Zunyi Medical University from June 2023 to June 2024. The cohort comprised 114 healthy controls and 193 patients with PCOS, diagnosed according to the Rotterdam criteria. The patients were grouped into four phenotypes: Phenotype A (hyperandrogenemia [HA]+ovulatory dysfunction [OA]+polycystic ovarian morphology [PCOM], n=44), Phenotype B (HA+OA, n=50), Phenotype C (HA+PCOM, n=46), and Phenotype D (OA+PCOM, n=53). Clinical data were collected for all subjects. Serum MCH levels were determined by enzyme-linked immunosorbent assay. The relationship between MCH and androgen-related risk factors for PCOS was analyzed using Spearman partial correlation analysis and stepwise multiple linear hierarchical regression. Binary logistic regression was used to analyze factors influencing PCOS onset. The diagnostic value of MCH for PCOS was evaluated using a receiver operating characteristic (ROC) curve. Results:There were no significant differences in age and height between the healthy control group and the PCOS phenotypic groups (both P>0.05). MCH levels [17.63 (12.69, 22.00), 17.31 (11.05, 20.09), 17.82 (11.47, 19.40), 16.50 (11.14, 19.41) μg/L vs. 12.14 (9.78, 15.05) μg/L], homeostatic model assessment of insulin resistance, fasting plasma glucose, fasting serum lisulin, body mass index, and weight were significantly higher across all four PCOS phenotypes (A, B, C, and D) than in healthy controls (all P<0.05), whereas sex hormone-binding globulin (SHBG) contents were significantly lower ( P<0.05). Free androgen index (FAI), total testosterone (TES) and dehydroepiandrosterone (DHEA) levels were significantly higher in PCOS phenotypes A, B, and C than in the control group and PCOS phenotype D (all P<0.05). Spearman partial correlation analysis revealed no significant correlation between MCH and TES, DHEA, or FAI in healthy controls and patients with non-HA PCOS (all P>0.05). However, in PCOS patients with HA, MCH showed a significant positive correlation with TES and DHEA ( r=0.227 and 0.196, respectively; both P<0.05), but not FAI ( P>0.05). Stepwise multiple linear hierarchical regression analysis showed that MCH was positively correlated with TES, DHEA and luteinizing hormone and negatively correlated with SHBG (all P<0.05). Binary logistic regression indicated that an increase in MCH may be a potential risk factor for PCOS occurrence ( OR=1.113, 95% CI 1.012-1.224, P=0.028). ROC analysis showed that MCH has diagnostic value for PCOS ( P<0.05), with an area under the curve of 0.713. Conclusion:Serum MCH is closely related to FAI, TES, and DHEA levels in PCOS patients and may play an important role in the etiology and progression of the syndrome.

Objective:To investigate whether intermittent fasting alleviates insulin resistance in a polycystic ovary syndrome(PCOS) mouse model through the regulation of autophagy.Methods:Fifty 3-week-old female C57BL/6J mice were randomly assigned into the following groups using a random number table: normal control(NC) group( n=10), maintained on a standard chow diet; high-fat diet(HFD) group( n=10) fed a diet with 60% of calories derived from fat; and PCOS model group( n=30), established by combining a HFD with dehydroepiandrosterone(DHEA) administration. Successful modeling was confirmed by disrupted estrous cycles, hyperandrogenism, and polycystic ovarian morphology. The PCOS model mice were further divided into three groups: PCOS group( n=9), PCOS with intermittent fasting group(PCOS+ IF, n=9), and PCOS with intermittent fasting plus the autophagy inhibitor 3-methyladenine(3-MA) group(PCOS+ IF+ 3-MA, n=9). Autophagy levels were assessed by detecting markers LC3 and p62 and observing autophagosomes via transmission electron microscopy. Glucose tolerance test(GTT) and insulin tolerance test(ITT) were performed, and the area under the curve(AUC) was calculated to evaluate insulin resistance. Western blotting was used to detect phosphorylation levels of phosphatidylinositol 3-kinase(PI3K), protein kinase B(Akt), mammalian target of rapamycin(mTOR), and p70S6 kiase(p70S6K). Results:Compared with the NC group, the PCOS model group showed absent estrous cycles, significantly elevated serum testosterone, sex hormone binding globulin, and luteinizing hormone(LH) levels( P<0.001), and polycystic ovarian changes on hematoxylin-eosin staining, confirming successful model establishment. Immunohistochemistry, transmission electron microscopy, and Western blotting demonstrated that autophagy levels were increased in the PCOS+ IF group compared with the PCOS group, while 3-MA administration reduced the intermittent fasting - induced autophagy. The AUC values for both GTT and ITT were significantly lower in the PCOS+ IF group than those in the PCOS group( P<0.001, P=0.003), but increased in the PCOS+ IF+ 3-MA group compared to the PCOS+ IF group( P<0.001, P=0.020). Western blotting analysis showed that phosphorylation levels of PI3K, Akt, mTOR, and p70S6K were significantly decreased in the PCOS+ IF group compared with the PCOS group( P=0.002, P=0.001, P=0.001, and P<0.001, respectively), and increased in the PCOS+ IF+ 3-MA group compared with the PCOS+ IF group( P=0.021, P=0.041, P=0.047, and P=0.024, respectively). Conclusions:Intermittent fasting alleviates insulin resistance in a PCOS mouse model through inhibitiing PI3K/Akt/mTOR signaling pathway and promoting autophagy.

Objective:To investigate the changes in and correlations between melanin-concentrating hormone (MCH) and androgen levels in the serum of patients with polycystic ovary syndrome (PCOS), aiming to provide a novel research perspective for its diagnosis.Methods:A cross-sectional study. A total of 307 subjects were enrolled from the physical examination center and endocrinology clinic of the Affiliated Hospital of Zunyi Medical University from June 2023 to June 2024. The cohort comprised 114 healthy controls and 193 patients with PCOS, diagnosed according to the Rotterdam criteria. The patients were grouped into four phenotypes: Phenotype A (hyperandrogenemia [HA]+ovulatory dysfunction [OA]+polycystic ovarian morphology [PCOM], n=44), Phenotype B (HA+OA, n=50), Phenotype C (HA+PCOM, n=46), and Phenotype D (OA+PCOM, n=53). Clinical data were collected for all subjects. Serum MCH levels were determined by enzyme-linked immunosorbent assay. The relationship between MCH and androgen-related risk factors for PCOS was analyzed using Spearman partial correlation analysis and stepwise multiple linear hierarchical regression. Binary logistic regression was used to analyze factors influencing PCOS onset. The diagnostic value of MCH for PCOS was evaluated using a receiver operating characteristic (ROC) curve. Results:There were no significant differences in age and height between the healthy control group and the PCOS phenotypic groups (both P>0.05). MCH levels [17.63 (12.69, 22.00), 17.31 (11.05, 20.09), 17.82 (11.47, 19.40), 16.50 (11.14, 19.41) μg/L vs. 12.14 (9.78, 15.05) μg/L], homeostatic model assessment of insulin resistance, fasting plasma glucose, fasting serum lisulin, body mass index, and weight were significantly higher across all four PCOS phenotypes (A, B, C, and D) than in healthy controls (all P<0.05), whereas sex hormone-binding globulin (SHBG) contents were significantly lower ( P<0.05). Free androgen index (FAI), total testosterone (TES) and dehydroepiandrosterone (DHEA) levels were significantly higher in PCOS phenotypes A, B, and C than in the control group and PCOS phenotype D (all P<0.05). Spearman partial correlation analysis revealed no significant correlation between MCH and TES, DHEA, or FAI in healthy controls and patients with non-HA PCOS (all P>0.05). However, in PCOS patients with HA, MCH showed a significant positive correlation with TES and DHEA ( r=0.227 and 0.196, respectively; both P<0.05), but not FAI ( P>0.05). Stepwise multiple linear hierarchical regression analysis showed that MCH was positively correlated with TES, DHEA and luteinizing hormone and negatively correlated with SHBG (all P<0.05). Binary logistic regression indicated that an increase in MCH may be a potential risk factor for PCOS occurrence ( OR=1.113, 95% CI 1.012-1.224, P=0.028). ROC analysis showed that MCH has diagnostic value for PCOS ( P<0.05), with an area under the curve of 0.713. Conclusion:Serum MCH is closely related to FAI, TES, and DHEA levels in PCOS patients and may play an important role in the etiology and progression of the syndrome.