The association between endometrial polyps and metabolic syndrome: a case-control study

The association between endometrial polyps and insulin resistance from the expression of PI3K and AKT proteins perspective

BACKGROUND

Insulin resistance (IR) induces hyperinsulinemia, which activates downstream signaling pathways such as the phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) pathway, ultimately leading to abnormal proliferation and apoptosis of endometrial cells. This is thought to be a key pathogenic mechanism underlying the development of endometrial polyps (EP). This study aims to investigate the relationship between IR and the development of EP, the expression levels of downstream signaling molecules, including PI3K and AKT, and related laboratory parameters were examined.

METHODS

A total of 100 patients who visited the gynecology outpatient clinic of Zhongda Hospital affiliated with Southeast University from May 2021 to March 2023 and were diagnosed with abnormal endometrial echoes by vaginal ultrasound and underwent hysteroscopic diagnostic curettage were enrolled in this study. General data and relevant hematological indicators were compared, and intraoperative specimens were obtained for pathological examination. Possible factors influencing the development of endometrial polyps were analyzed using Pearson correlation analysis and logistic regression analysis.

RESULTS

In terms of body mass index, waist circumference, fasting insulin, insulin resistance index, serum total testosterone, and free testosterone index, women of childbearing age in the endometrial polyp group had higher values than those in the non-polyp group, while sex hormone-binding globulin in the endometrial polyp group was lower than that in the non-polyp group, and the differences were statistically significant (P < 0.05). The expression scores and mRNA expression levels of PI3K and AKT proteins were higher in the EP group than in the non-EP group (p < 0.05). Pearson correlation analysis showed a positive correlation between HOMA-IR and the expression scores of PI3K and AKT proteins (p < 0.01).

CONCLUSIONS

Insulin resistance and abnormal activation of the phosphatidylinositol 3-kinase/protein kinase B signaling pathway may be potential pathogenic mechanisms for the development of endometrial polyps.

Mutations of RAS genes in endometrial polyps

Endometrial polyps are common, yet the molecular mechanisms underlying their formation and progression remain unclear. We examined gene mutations possibly related to the pathogenesis of endometrial polyps, as well as to their clinical features. Four premenopausal patients with endometrial polyps, who were not under drug treatment, were recruited. Whole exomes of endometrial polyps and peripheral blood lymphocytes were analyzed by next‑generation sequencing, and somatic mutations were derived by subtraction. Then, 35 samples of endometrial polyps and 12 samples of atypical polypoid adenomyoma were newly recruited to validate the identified mutations by polymerase chain reaction‑reverse sequence specific oligonucleotide method. The mutations were also analyzed in separate stromal and glandular components of the polyps after laser‑capture microdissection. Whole exome sequencing revealed that KRAS mutations were the only type of mutation detectable in multiple cases (2/4). Targeted mutation analysis revealed that 16 of 35 samples (45.7%) of endometrial polyps harbored RAS mutations. Mutation‑positive cases exhibited a significantly higher number of endometrial polyps (3.25±2.70 vs. 1.74±0.87, P=0.045). Laser‑capture microdissection in NRAS‑mutated endometrial polyps revealed that both stromal and glandular components harbored RAS mutations. There was no RAS mutation in 12 samples of atypical polypoid adenomyoma. This is the first report demonstrating that pathogenic RAS mutations are frequent in non‑treated endometrial polyps. RAS mutations may have an important role in tumorigenesis and in the formation of multiple endometrial polyps.

Is there any relationship between benign endometrial pathologies and metabolic status?

The aim of this study was to assess the relation between benign endometrial pathologies (polyp and/or hyperplasia without atypia) and the metabolic status (insulin resistance and metabolic syndrome) of the patients. A total of 168 cases were enrolled in the study. The patients were classified according to the presence of benign endometrial pathologies and their menopausal status. Then, the subjects were evaluated according to the metabolic syndrome criteria and the presence of an insulin resistance. The insulin resistance levels of the cases were analysed by four different methods. Obesity and a waist circumference of greater than 88 cm were observed significantly more in the study group with endometrial pathologies (p = .005 and p < .001, respectively). It was also observed that a fasting blood glucose level of higher than 110 mg/dL increased the risk of developing endometrial polyps and/or hyperplasia without atypia by almost five folds (OR: 5.26, 95% CI: 1.25-22.12). Furthermore, an insulin resistance was found to be significantly high in the study group (p = .002). Based on the observed significant relationship between an insulin resistance and benign endometrial pathologies, it can be concluded that insulin resistance plays an important role in the development of benign endometrial pathologies. Impact Statement What is already known on this subject? Metabolic anomalies such as obesity, type 2 diabetes, hypertension and dyslipidaemia play an important role in abnormal endometrial proliferation. Also, these metabolic anomalies have been known as risk factors for type I endometrial cancer. What the results of this study add? A significant relationship between an insulin resistance and benign endometrial pathologies was observed. What the implications are of these findings for clinical practice and/or further research? Based on this finding, we concluded that an insulin resistance may play an important role in the development of benign endometrial pathologies. The prevention and the treatment of obesity as a key factor of developing an insulin resistance, may reduce not only the incidence of malignant endometrial pathologies, but also the incidence of benign pathologies and of a malignant transformation.

Metabolic syndrome as a predictor of endometrial polyps in postmenopausal women

OBJECTIVE

The aim of the study was to evaluate clinical predictive factors for endometrial polyps in postmenopausal women compared with postmenopausal women without polyps.

METHODS

In this cross-sectional study, 132 Brazilian women with a histopathological diagnosis of endometrial polyps were compared with 264 women without endometrial alterations (control). The study group included women aged at least 45 years with amenorrhea for at least 12 months, who underwent hysteroscopic polypectomy. The control group consisted of women aged at least 45 years with amenorrhea for at least 12 months, without postmenopausal bleeding and endometrial thickness less than 5 mm by transvaginal ultrasonography. Clinical, anthropometric (body mass index and waist circumference), laboratory, and ultrasonographic data were collected to evaluate predictive factors for endometrial polyps. The Student's t test, χ test, and logistic regression (odds ratio [OR]) were used for statistical analysis.

RESULTS

A higher percentage of women with polyps were obese (72%) when compared with control (39%) (P < 0.0001). Waist circumference was greater among women with polyps (P = 0.0001). The incidence of diabetes, hypertension, and dyslipidemia was higher among women with endometrial polyps (P < 0.0001). According to the diagnostic criteria of the US National Cholesterol Education Program/Adult Treatment Panel III (NCEP/ATP III), 48.5% of the women with polyps and 33.3% of the controls were classified as having metabolic syndrome (MetS) (P = 0.004). The risk of endometrial polyps was higher in women with body mass index at least 25 kg/m (OR = 4.66; 95% CI 2.16-10.05); glucose at least 100 mg/dL (OR = 2.83; 95% CI 1.36-5.90); dyslipidemia (OR = 7.02; 95% CI 3.70-13.32); diabetes (OR = 2.58; 95% CI 1.05-6.32); and MetS (OR = 2.76; 95% CI 1.18-6.46) when compared with control, adjusted for age, and time since menopause.

CONCLUSIONS

In postmenopausal women, obesity, dyslipidemia, hyperglycemia, and the presence of MetS were predictive factors for endometrial polyps.