Chronic inflammation in polycystic ovary syndrome: A case-control study using multiple markers

Serum granulosa cell-derived TNF-α promotes inflammation and apoptosis of renal tubular cells and PCOS-related kidney injury through NF-κB signaling

Polycystic ovary syndrome (PCOS) is a disorder with endocrinal and metabolic problems in reproductive aged women. Evidence shows that PCOS is in a high prone trend to develop kidney diseases. In this study, we investigated the mediators responsible for PCOS-related kidney injury. We found that tumor necrosis factor (TNF-α) levels were significantly increased in serum and primary cultured granulosa cells (GCs) from PCOS patients. Serum TNF-α levels were positively correlated with serum testosterone and luteinizing hormone (LH)/follicle-stimulating hormone (FSH) ratio, suggesting its positive role in the severity of PCOS. Serum TNF-α levels were also positively correlated with the levels of urinary KapU, LamU, α1-MU and β2-MU, the markers for renal tubular cell-derived proteinuria. We established a PCOS mouse model by resection of the right kidney, followed by daily administration of dihydrotestosterone (DHT, 27.5 μg, i.p.) from D7 for 90 days. We found that TNF-α levels were significantly increased in the ovary and serum of the mice, accompanied by increased renal tubular cell apoptosis, inflammation and fibrosis in kidneys. Furthermore, the receptor of TNF-α, tumor necrosis factor receptor 1 (TNFR1), was significantly upregulated in renal tubular cells. We treated human ovarian granulosa-like tumor cells (KGN) with DHT (1 μg/ml) in vitro, the conditioned medium derived from the granulosa cell culture greatly accelerated apoptotic injury in human proximal tubular epithelial cells (HKC-8), which was blocked after knockdown of TNF-α in KGN cells. Furthermore, knockdown of TNFR1 in renal tubular epithelial cells greatly ameliorated cell injury induced by granulosa cell-derived conditioned medium. These results suggest that serum TNF-α plays a key role in mediating inflammation and apoptosis in renal tubular cells associated with PCOS-related kidney injury.

The Association Between Increment of Interleukin-1 and Interleukin-6 in Women with Polycystic Ovary Syndrome and Body Mass Index

Background

There is an association between inflammatory factors and polycystic ovary syndrome (PCOS) and most of women with PCOS experience the symptoms of hirsutism. The purpose of this study was to evaluate the role of obesity in PCOS occurrence, which is linked with inflammation and hirsutism.

Methods

This study was designed as a case-control research. It was performed on 102 women with PCOS and 102 healthy women as controls who were age-matched. Serum concentrations of testosterone, estradiol (E2), IL-1, IL-6, high-sensitivity c-reactive protein (hs-CRP), and aromatase activity were measured in blood samples. Statistical tests including unpaired t-tests, Mann-Whitney U test, Kruskal-Wallis, Spearman's correlation, and Chi-square tests were used for data analysis. Statistical significance was set at p<0.05.

Results

A significant difference was found between hs-CRP, IL-1, and IL-6 in PCOS patients and healthy individuals (p<0.001). Aromatase activity was markedly lower in PCOS cases. The serum level of IL-1 (p=0.392) and IL-6 (p=0.764) was not different between overweight and normal weight women. In both studied groups (case and control), hirsutism frequency was markedly higher in individuals with BMI ≥25 kg/m 2 (p<0.05). Inflammatory factors significantly affected the PCOS group (p<0.05). However, logistic regression showed that hs-CRP increment is more effective on increasing the risk of PCOS (OR: 6.324, p<0.001).

Conclusion

In this study, hs-CRP, IL-1, and IL-6 levels increased in all PCOS women. Although the incidence of hirsutism in PCOS is associated with obesity, in PCOS pathogenesis, only IL-1 and IL-6 were independent of BMI.

Inflammation and Insulin Resistance in a Group of Sub-Saharan African Women with Polycystic Ovary Syndrome

Background

Studies report high levels of inflammatory markers in women with polycystic ovary syndrome (PCOS), reflecting chronic low-grade inflammation. This inflammation is thought to be associated with insulin resistance. We aim to evaluate inflammatory markers [high sensitivity C reactive protein (CRP) and interleukin 6] and insulin resistance in women with PCOS in Yaoundé, Cameroon.

Methods

We conducted a comparative cross-sectional study including 32 women with PCOS aged between 18 and 44 years and 32 controls matched for age and body mass index (BMI). Homeostasis model assessment of insulin resistance (HOMA-IR) index calculated using C peptide levels was used to evaluate insulin resistance. Serum levels of high sensitivity CRP (hsCRP) and interleukin 6 (IL-6) were measured. Comparisons were made using the Student’s T-test and non-parametric tests (Mann–Whitney U-test, Kruskal–Wallis test).

Results

We found that the median [25th–75th percentile] level of hsCRP was significantly higher in women with PCOS compared to the controls (0.63 [0.32–3.81] mg/L vs. 0.47 [0.15–1.04] mg/L; p=0.01), while IL-6 levels were not different (8.61 [4.1–33.79] pg/mL for PCOS vs. 8.80 [5.28–38.85] pg/mL for controls; p=0.51). We noted that women with PCOS had a higher HOMA-IR index (1.15±0.90 vs. 0.77±0.38; p=0.03). However, there was no correlation between hsCRP level and the HOMA-IR index (Spearman correlation coefficient=0.10; p=0.62).

Conclusion

PCOS is associated with an increased level of hsCRP and insulin resistance in Cameroonian women. This exploratory study provides baseline evidence for larger-scale studies.