Are serum vitamin D levels associated with the incidence of endometrial polyps (EPs) in infertile patients?
Summary Answer
Serum 25(OH)D levels were nonlinearly correlated with the incidence of EPs in infertile women.
What Is Known Already
EPs are a common condition that may affect the receptivity of the endometrium in women of reproductive age. Vitamin D regulates cell proliferation and differentiation, apoptosis, angiogenesis, anti-inflammation, and immunomodulation, in addition to its well-known functions in balancing calcium and phosphorus. Previous studies have shown that vitamin D concentrations are associated with reproductive outcomes, and that low vitamin D levels are associated with the incidence of colorectal polyps and nasal polyps. There is little evidence regarding the relationship between EPs and serum vitamin D levels.
Study Design, Size, Duration
We conducted a cross-sectional study using data from Guangdong Women and Children Hospital from January 2019 to October 2023, enrolling 3107 patients.
Participants/Materials, Setting, Methods
A total of 3107 infertile patients who underwent hysteroscopy were included in this study; 642 patients had endometrial polyps and 2465 had a normal uterine cavity. Hysteroscopy findings included risk of EPs, polyp size, percentage of multiple polyps, and incidence of chronic endometritis (CE). Serum vitamin D were assessed by measuring total 25(OH)D using chemiluminescence. According to international guideline recommendations for vitamin D deficiency, patients were divided into two groups: the <50 nmol/l group and the ≥50 nmol/l group. Univariable and multivariable logistic regression models, stratified analyses, and smooth curve fitting were used to examine the relationship between serum 25(OH)D levels and risk of EPs.
MAIN RESULTS AND THE ROLE OF CHANCE: Of all patients, 23.8% (740/3107) were vitamin D deficient (<50 nmol/l). The incidence of EPs was significantly higher in the 25(OH)D < 50 nmol/l group than in the ≥50 nmol/l group (24.9% vs 19.3%; P = 0.001). However, there were no differences in polyp size, proportion of multiple polyps, and presence of CE between the two groups. After controlling for confounders, 25(OH)D ≥ 50 nmol/l (compared with <50 nmol/l) was negatively associated with risk of EPs (adjusted OR, 0.733; 95% CI, 0.598-0.898). Other variables that had an impact on polyp incidence included BMI, type of infertility, CA125, and CD138-positive plasma cells. In addition, a linear regression model between age and serum 25(OH)D levels showed a positive linear association. Subgroup analyses were performed for different age groups, and the risk of EPs was significantly higher in the 25(OH)D < 50 nmol/l group than in the ≥50 nmol/l group, both in the younger subgroup (23.8% vs 19.1%) and in the older subgroup (28.0% vs 19.9%). The smooth curve fitting model showed a nonlinear correlation between 25(OH)D levels and risk of EPs (nonlinear P-value = 0.020), with an optimal threshold of 51.8 nmol/l for 25(OH)D levels. Moreover, subgroup smooth curve fitting models showed a nonlinear correlation between 25(OH)D levels and polyp risk in patients aged <35 years (nonlinear P-value = 0.010), whereas a linear correlation between 25(OH)D levels and polyp risk was found in patients aged ≥35 years (nonlinear P-value = 0.682).
Limitations, Reasons for Caution
Caution should be exercised in interpreting our findings as this is a correlational study and causality cannot be inferred from our results. In addition, because of strict inclusion and exclusion criteria, our results may not be generalizable to unselected populations, including premenopausal women or women of other races.
Wider Implications of the Findings
This study demonstrated for the first time that vitamin D deficiency is an independent risk factor for the incidence of EPs in infertile patients. Identifying modifiable risk factors (e.g. vitamin D deficiency) can help in the development of new strategies for treating polyps or to protect against polyp development. Further clinical intervention trials and laboratory studies are needed to evaluate the effect of vitamin D on the development of EPs and to elucidate the mechanisms. STUDY FUNDING/COMPETING INTEREST(S): The study was funded by the National Natural Science Foundation of China (82101718) and Natural Science Foundation of Guangdong Province, China (2022A1515010776). No competing interest was involved in this study.
vitamin D deficiency endometrial polyps infertile women, serum 25-hydroxyvitamin D endometrial polyp incidence, nonlinear correlation vitamin D endometrial polyps, vitamin D threshold endometrial polyp risk prevention, hysteroscopy endometrial polyps cross-sectional study, vitamin D supplementation reproductive outcomes uterine pathology, endometrial polyp risk factors infertility BMI vitamin D, chronic endometritis endometrial polyps vitamin D levels, modifiable risk factors endometrial polyps infertile patients, smooth curve fitting vitamin D polyp risk age stratification
PMID 39470411 39470411 DOI 10.1093/humrep/deae241 10.1093/humrep/deae241
Cite this article
Zhou, R., Zhu, Z., Dong, M., Wang, Z., Huang, L., Wang, S., Zhang, X., & Liu, F. (2024). Nonlinear correlation between serum vitamin D levels and the incidence of endometrial polyps in infertile women. Human reproduction (Oxford, England), 39(12), 2685-2692. https://doi.org/10.1093/humrep/deae241
Zhou R, Zhu Z, Dong M, Wang Z, Huang L, Wang S, et al. Nonlinear correlation between serum vitamin D levels and the incidence of endometrial polyps in infertile women. Hum Reprod. 2024;39(12):2685-2692. doi:10.1093/humrep/deae241
Zhou, R., et al. "Nonlinear correlation between serum vitamin D levels and the incidence of endometrial polyps in infertile women." Human reproduction (Oxford, England), vol. 39, no. 12, 2024, pp. 2685-2692.
Are dietary patterns associated with age at menarche after accounting for BMI-for-age (BMIz) and height? We observed associations between both the Alternative Healthy Eating Index (AHEI) and the Empirical Dietary Inflammatory Pattern (EDIP) and age at menarche. Dietary patterns have been sparsely examined in relation to age at menarche and no studies have examined the association between the AHEI, a healthier diet, and EDIP, a pro-inflammatory diet, and menarche. STUDY DESIGN, SIZE, The Growing Up Today Study (GUTS) is a prospective cohort of children ages 9-14 years at study enrollment. GUTS enrolled in two waves with enrollment beginning in 1996 (GUTS1) and 2004 (GUTS2). For this analysis, GUTS1 and GUTS2 participants were followed through 2001 and 2008, respectively. PARTICIPANTS/MATERIALS, SETTING, We included 7530 participants who completed food frequency questionnaire(s) (FFQ) prior to menarche who then self-reported age at menarche during study follow-up. Cox proportional hazard models were used to calculate multivariable hazard ratios (HRs) and 95% CIs for the associations between two dietary patterns, the AHEI and EDIP, and age at menarche, with and without adjustment for time-varying BMIz and height. MAIN Six thousand nine hundred ninety-two participants (93%) reported menarche during the study period. On average, participants completed the baseline FFQ 1.75 years prior to menarche. Participants in the highest quintile of AHEI diet score (indicating a healthier diet) were 8% less likely to attain menarche within the next month compared to those in the lowest quintile (95% CI = 0.85-0.99; Ptrend = 0.03). This association remained after adjustment for BMIz and height (corresponding HR = 0.93; 95% CI = 0.86-1.00; Ptrend = 0.04). Participants in the highest quintile of the EDIP score (i.e. most inflammatory diet), were 15% more likely to attain menarche in the next month relative to those in the lowest quintile (95% CI = 1.06-1.25; Ptrend = 0.0004), and the association remained following adjustment for BMIz and height (corresponding HR = 1.15; 95% CI = 1.06-1.25; Ptrend = 0.0004). LIMITATIONS, Self-reported questionnaires are subject to some error; however, given our prospective study design it is likely this error is non-differential with respect to the outcome. Our findings of an association between both the AHEI and EDIP and age at menarche indicate that diet quality may play a role in age at menarche independent of BMI or height. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Breast Cancer Research Foundation. The GUTS is supported by the National Institutes of Health U01 HL145386. C.P.D. was supported by National Institutes of Health T32 CA094880. The authors have no conflicts of interest to disclose. N/A.
EndometriosisMenopause TimingEndometriosis HistoryPooled Cohort Analysis
Open Access
What is the association between endometriosis and the type and age of menopause? Women with endometriosis had a 7-fold increased risk of undergoing surgical menopause rather than natural menopause and were more likely to experience premature or early menopause, both surgically and naturally. Endometriosis is associated with reduced ovarian reserve, but evidence on its relationship with the type of menopause (surgical vs natural) and timing (especially premature and early menopause) is limited. Women with endometriosis are more likely to undergo hysterectomy and/or oophorectomy (either unilateral or bilateral), but the average age of these surgeries remains unclear. STUDY DESIGN, SIZE, The study analysed individual-level data from 279 948 women in five cohort studies conducted in the UK, Australia, Sweden, and Japan between 1996 and 2022. PARTICIPANTS/MATERIALS, SETTING, Women whose menopause type and age could not be determined due to premenopausal hysterectomy with ovarian preservation or use of menopausal hormone therapy were excluded. Endometriosis was identified through self-reports and administrative data. Surgical menopause was defined as premenopausal bilateral oophorectomy. Fine-Gray subdistribution hazard models estimated hazard ratios (HRs) for surgical and natural menopause. Age at menopause was determined by the ages at the final menstrual period or bilateral oophorectomy. Linear regression assessed mean differences in menopause age, while multinomial logistic regression estimated odds ratios (ORs) <40 (premature), 40-44 (early), 45-49, 50-51 (reference), 52-54, and ≥55 years. Spontaneous premature ovarian insufficiency (POI) was defined as natural menopause before age 40 years. MAIN Endometriosis was identified in 3.7% of women. By the end of follow-up, 7.9% had surgical menopause and 58.2% experienced natural menopause. Using a competing risk model, women with endometriosis had a 7-fold increased risk of surgical menopause (HR: 7.54, 95% CI 6.84, 8.32) and were less likely to experience natural menopause (HR: 0.40, 95% CI 0.33, 0.49). On average, surgical menopause occurred 1.6 years (19 months) earlier (β: -1.59, 95% CI -1.77, -1.42) in women with endometriosis. Among women who experienced natural menopause, it was 0.4 years (5 months) earlier (β: -0.37, 95% CI -0.46, -0.28) for those with endometriosis. Women with endometriosis were twice as likely to experience premature surgical menopause (<40 years) (OR: 2.11, 95% CI 2.02, 2.20) or 1.4 times more likely to develop spontaneous POI (OR: 1.36, 95% CI 1.17, 1.59). They were also at increased odds of early surgical and natural menopause (40-44 years). LIMITATIONS, This study could not differentiate between subtypes and stages of endometriosis or assess treatments for ovarian endometrioma, which may impact ovarian reserve. Self-reported menopause type and age could introduce recall bias. Given the consistent findings across individual studies, our results are likely to be generalizable to different populations, highlighting the need for tailored management of endometriosis to prevent medically induced or premature menopause. Long-term monitoring of women with endometriosis is recommended, given their elevated risk of surgical menopause and premature or early menopause, which are associated with adverse health outcomes in later life. STUDY FUNDING/COMPETING INTEREST(S): The InterLACE Consortium is funded by the Australian National Health and Medical Research Council project grant (APP1027196) and Centres of Research Excellence (APP1153420). G.D.M. is funded by the Australian National Health and Medical Research Council Leadership Fellowship (APP2009577). This research is funded in part by the Japan Society for the Promotion of Science (JSPS 19KK0235, 23KK0167). The authors have no conflict of interest. Where authors are identified as personnel of the International Agency for Research on Cancer or WHO, the authors alone are responsible for the views expressed in this article, and they do not necessarily represent the decisions, policy, or views of the International Agency for Research on Cancer or WHO. N/A.
How do endometriosis diagnoses and subtypes reported in administrative health data compare with surgically confirmed disease? For endometriosis diagnosis, we observed substantial agreement and high sensitivity and specificity between administrative health data-International Classification of Diseases (ICD) 9 codes-and surgically confirmed diagnoses among participants who underwent gynecologic laparoscopy or laparotomy. Several studies have assessed the validity of self-reported endometriosis in comparison to medical record reporting, finding strong confirmation. We previously reported high interand intra-surgeon agreement for endometriosis diagnosis in the Endometriosis, Natural History, Diagnosis, and Outcomes (ENDO) Study. STUDY DESIGN, SIZE, In this validation study, participants (n = 412) of the Utah operative cohort of the ENDO Study (2007-2009) were linked to medical records from the Utah Population Database (UPDB) to compare endometriosis diagnoses from each source. The UPDB is a unique database containing linked data on over 11 million individuals, including statewide ambulatory and inpatient records, state vital records, and University of Utah Health and Intermountain Healthcare electronic healthcare records, capturing most Utah residents. PARTICIPANTS/MATERIALS, SETTING, The ENDO operative cohort consisted of individuals aged 18-44 years with no prior endometriosis diagnosis who underwent gynecologic laparoscopy or laparotomy for a variety of surgical indications. In total, 173 women were diagnosed with endometriosis based on surgical visualization of disease, 35% with superficial endometriosis, 9% with ovarian endometriomas, and 14% with deep infiltrating endometriosis. Contemporary administrative health data from the UPDB included ICD diagnostic codes from Utah Department of Health in-patient and ambulatory surgery records and University of Utah and Intermountain Health electronic health records. MAIN For endometriosis diagnosis, we found relatively high sensitivity (0.88) and specificity (0.87) and substantial agreement (Kappa [Κ] = 0.74). We found similarly high sensitivity, specificity, and agreement for superficial endometriosis (n = 143, 0.86, 0.83, Κ = 0.65) and ovarian endometriomas (n = 38, 0.82, 0.92, Κ = 0.58). However, deep infiltrating endometriosis (n = 58) had lower sensitivity (0.12) and agreement (Κ = 0.17), with high specificity (0.99). LIMITATIONS, Medication prescription data and unstructured data, such as clinical notes, were not included in the UPDB data used for this study. These additional data types could aid in detection of endometriosis. Most participants were white or Asian with Hispanic ethnicity reported 11% of the time, which may limit generalizability to some US states. Additionally, given that participants whose administrative health records we utilized were also part of the ENDO Study, the surgeons may have been more vigilant in diagnostic coding due to the operative forms they completed for the ENDO Study, which may have led to increased validity. However, the codes compared in the UPDB would have been entered by medical coders as part of standard clinical practice. We observed substantial agreement between administrative health data and surgically confirmed endometriosis diagnoses overall, and for superficial and ovarian endometrioma subtypes. These findings may provide reassurance to researchers using administrative healthcare records to assess risk factors and long-term health outcomes of endometriosis. Our findings corroborate prior research that demonstrates high specificity but low sensitivity for deep infiltrating endometriosis, indicating deep infiltrating endometriosis is not reliably annotated in administrative healthcare data. This suggests that medical record-based deep infiltrating endometriosis diagnoses may be suitable for etiologic studies but not for surveillance or detection studies. STUDY FUNDING/COMPETING INTEREST(S): The original ENDO Study was funded by the Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (contracts NO1-DK-6-3428; NO1-DK-6-3427; 10001406-02). We acknowledge partial support for the UPDB through grant P30 CA2014 from the National Cancer Institute, University of Utah and from the University of Utah's program in Personalized Health and Center for Clinical and Translational Science. This research was also supported by the NCRR grant, 'Sharing Statewide Health Data for Genetic Research' (R01 RR021746, G. Mineau, PI) with additional support from the Utah Department of Health and Human Services, University of Utah. Additionally, this research was supported by the Utah Cancer Registry, which is funded by the National Cancer Institute's SEER Program, Contract No. HHSN261201800016I, the US Centers for Disease Control and Prevention's National Program of Cancer Registries, Cooperative Agreement No. NU58DP007131, with additional support from the University of Utah and Huntsman Cancer Foundation. Research reported in this publication was also supported by the National Institutes of Health (Award Numbers R01HL164715 [to L.V.F., K.C.S., and A.Z.P.] and K01AG058781 [to K.C.S.]), by the Huntsman Cancer Institute's Breast and Gynecologic Cancers Center, and by the Doris Duke Foundation's COVID-19 Fund to Retain Clinical Scientists funded by the American Heart Association. A.C.K. was supported by Training Grant Number 5T15LM007124 from the National Library of Medicine to K.E. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or other sponsors. There are no competing interests among any of the authors. N/A.