Association of Body Size and Body Fat Distribution with Uterine Fibroids Among Chinese Women

Modifiable prognostic factors in uterine fibroid development: a systematic review of literature

BACKGROUND

Many risk factors in uterine fibroid development have been identified, but women and their physicians are less aware of the influence of lifestyle on uterine fibroid development. The objective of this systematic review is to investigate and summarize modifiable prognostic factors associated with uterine fibroid development.

METHODS

Pubmed and Embase were searched for relevant articles according to PRISMA guidelines. References from included articles were screened and when relevant also included. Human in vivo studies on modifiable factors in fibroid development were included. Studies on non-modifiable factors and treatment, in vitro studies and animal studies were excluded. 607 articles were screened and 33 articles were included. Two independent investigators collected data from the report.

RESULTS

The strongest risk factor for fibroid development was a high BMI, while the strongest protective factors were a high fruit and vegetable intake and high vitamin D intake.

CONCLUSION

More high-quality studies are necessary to better understand the impact of the abovementioned factors as well as the role they play in the growth of already existing fibroids.

Body Mass Index and Uterine Fibroid Development: A Prospective Study

OBJECTIVE

Fibroids are hormonally dependent uterine tumors. The literature on adiposity and fibroid prevalence is inconsistent. Previous work usually combined all those with a body mass index (BMI) ≥30 kg/m2 into a single category and relied on clinically diagnosed fibroids, which misclassifies the many women with undiagnosed fibroids. We used a prospective cohort design with periodic ultrasound screening to investigate associations between repeated measures of BMI and fibroid incidence and growth assessed at each follow-up ultrasound.

METHODS

The Study of Environment, Lifestyle & Fibroids followed 1693 Black/African American women, ages 23 to 35 years from Detroit, Michigan, with ultrasound every 20 months for 5 years. Measured height and repeated weight measures were used to calculate BMI. Fibroid incidence was modeled using Cox models among those who were fibroid free at the enrollment ultrasound. Fibroid growth was estimated for individual fibroids matched across visits as the difference in log-volume between visits and was modeled using linear mixed models. All models used time-varying BMI and adjusted for time-varying covariates.

RESULTS

Compared with BMI <25 kg/m2, those with BMI 30 to <35 kg/m2 had increased fibroid incidence (adjusted hazard ratio, 1.37; 95% CI, 0.96-1.94), those with BMI ≥40 kg/m2 had reduced incidence (adjusted hazard ratio, 0.61; 95% CI, 0.41-0.90). Fibroid growth had mostly small magnitude associations with BMI.

CONCLUSION

BMI has a nonlinear association with fibroid incidence, which could be driven by effects of BMI on inflammation and reproductive hormones. More detailed measures of visceral and subcutaneous adiposity and their effects on hormones, DNA damage, and cell death are needed.

Hypertension, Cardiovascular Risk Factors, and Uterine Fibroid Diagnosis in Midlife

Importance

Fibroids are benign neoplasms associated with severe gynecologic morbidity. There are no strategies to prevent fibroid development.

Objective

To examine associations of hypertension, antihypertensive treatment, anthropometry, and blood biomarkers with incidence of reported fibroid diagnosis in midlife.

Design, Setting, and Participants

The Study of Women's Health Across the Nation is a prospective, multisite cohort study in the US. Participants were followed-up from enrollment (1996-1997) through 13 semiannual visits (1998-2013). Participants had a menstrual period in the last 3 months, were not pregnant or lactating, were aged 42 to 52 years, were not using hormones, and had a uterus and at least 1 ovary. Participants with prior fibroid diagnoses were excluded. Data analysis was performed from November 2022 to February 2024.

Exposures

Blood pressure, anthropometry, biomarkers (cholesterol, triglycerides, and C-reactive protein), and self-reported antihypertensive treatment at baseline and follow-up visits were measured. Hypertension status (new-onset, preexisting, or never [reference]) and hypertension treatment (untreated, treated, or no hypertension [reference]) were categorized.

Main Outcomes and Measures

Participants reported fibroid diagnosis at each visit. Discrete-time survival models estimated hazard ratios (HRs) and 95% CIs for associations of time-varying hypertension status, antihypertensive treatment, anthropometry, and biomarkers with incident reported fibroid diagnoses.

Results

Among 2570 participants without a history of diagnosed fibroids (median [IQR] age at screening, 45 [43-48] years; 1079 [42.1%] college educated), 526 (20%) reported a new fibroid diagnosis during follow-up. Risk varied by category of hypertension treatment: compared with those with no hypertension, participants with untreated hypertension had a 19% greater risk of newly diagnosed fibroids (HR, 1.19; 95% CI, 0.91-1.57), whereas those with treated hypertension had a 20% lower risk (HR, 0.80; 95% CI, 0.56-1.15). Among eligible participants with hypertension, those taking antihypertensive treatment had a 37% lower risk of newly diagnosed fibroids (HR, 0.63; 95% CI, 0.38-1.05). Risk also varied by hypertension status: compared with never-hypertensive participants, participants with new-onset hypertension had 45% greater risk of newly diagnosed fibroids (HR, 1.45; 95% CI, 0.96-2.20). Anthropometric factors and blood biomarkers were not associated with fibroid risk.

Conclusions and Relevance

Participants with untreated and new-onset hypertension had increased risk of newly diagnosed fibroids, whereas those taking antihypertensive treatment had lower risk, suggesting that blood pressure control may provide new strategies for fibroid prevention.

A View on Uterine Leiomyoma Genesis through the Prism of Genetic, Epigenetic and Cellular Heterogeneity

Uterine leiomyomas (ULs), frequent benign tumours of the female reproductive tract, are associated with a range of symptoms and significant morbidity. Despite extensive research, there is no consensus on essential points of UL initiation and development. The main reason for this is a pronounced inter- and intratumoral heterogeneity resulting from diverse and complicated mechanisms underlying UL pathobiology. In this review, we comprehensively analyse risk and protective factors for UL development, UL cellular composition, hormonal and paracrine signalling, epigenetic regulation and genetic abnormalities. We conclude the need to carefully update the concept of UL genesis in light of the current data. Staying within the framework of the existing hypotheses, we introduce a possible timeline for UL development and the associated key events—from potential prerequisites to the beginning of UL formation and the onset of driver and passenger changes.

Incidence and determinants of hysterectomy among North Indian women: An 8-year follow-up study

Background

Despite indications of a rapid increase in the number of hysterectomies performed in India, very few studies have methodically investigated the rate and determinants of the incidence of hysterectomy. The present study aims to estimate the rate of incidence of hysterectomy and identify predictors/determinants of incident hysterectomy in a cohort of North Indian women.

Methods

In the present study, a cohort of 1,009 ever-married North Indian women (aged 30-75 years) was followed up after a median of 8.11 years. Those hysterectomized at the baseline (63) were excluded; and of the rest 946 participants, 702 (74.2%) could be successfully followed-up. During the baseline assessment, data about sociodemographic variables, reproductive history, menopausal status, physiological health, and selected blood biochemicals were collected. During the end-line assessment, data about sociodemographic variables, current menopausal status, and incident hysterectomy were recorded.

Results

The overall rate of incidence of hysterectomy was found to be 11.59 per 1,000 women-years, in the study population. Interestingly, the incidence rates were found to be similar among pre- and post-menopausal women. Further, while late age at menarche was found to be negatively associated with incident hysterectomy, folate repletion and high triglyceride (TG) at the baseline were found to be positively associated.

Conclusions

High rate of incident hysterectomy in the studied population points toward the huge burden of gynecological morbidity and the unavailability of non-invasive protocols. Such a situation warrants immediate policy intervention. Further, maintaining TG and folate within normal physiological ranges may be beneficial in gynecological ailments necessitating hysterectomy.

Comprehensive Review of Uterine Fibroids: Developmental Origin, Pathogenesis, and Treatment

Uterine fibroids are benign monoclonal neoplasms of the myometrium, representing the most common tumors in women worldwide. To date, no long-term or noninvasive treatment option exists for hormone-dependent uterine fibroids, due to the limited knowledge about the molecular mechanisms underlying the initiation and development of uterine fibroids. This paper comprehensively summarizes the recent research advances on uterine fibroids, focusing on risk factors, development origin, pathogenetic mechanisms, and treatment options. Additionally, we describe the current treatment interventions for uterine fibroids. Finally, future perspectives on uterine fibroids studies are summarized. Deeper mechanistic insights into tumor etiology and the complexity of uterine fibroids can contribute to the progress of newer targeted therapies.

Association between obesity and the risk of uterine fibroids: a systematic review and meta-analysis

BACKGROUND

Uterine fibroids (UFs) are the most common form of sex steroid hormone-dependent benign tumours that grow in the walls of the uterus. Several observational studies have examined the association between obesity and the risk of UFs, but findings are inconsistent. The objective of this systematic review and meta-analysis is to further examine the association of obesity with the risk/prevalence of UFs.

METHODS

A literature search was performed in three databases (PubMed, EMBASE and Web of Science) from 1 January 1992 to 30 May 2020. We used random-effect models to calculate the pooled ORs with corresponding 95% CIs. Additionally, we performed a dose-response meta-analysis to analyse the effect of body mass index (BMI), weight change since age 18, waist-to-hip ratio and waist circumference on the risk/prevalence of UFs.

RESULTS

A total of 22 articles, covering 24 studies including 325 899 participants and 19 593 cases, were selected based on our inclusion criteria. We found a positive association between obesity and the risk/prevalence of UFs (OR, 1.19; 95% CI, 1.09 to 1.29). Among participants with the highest BMI, the pooled OR was 1.19 (1.09 to 1.31) when compared to participants with normal BMI. For weight change since age 18, the pooled OR (95% CI) of UFs was 1.26 (1.12 to 1.42) among the highest change group when compared with no change. Additionally, our meta-analysis indicated the relationship of BMI with risk of UFs to be an inverse J-shaped pattern.

CONCLUSIONS

The results of this meta-analysis suggest that obesity may increase the risk/prevalence of UFs, and the association is non-linear.

Association of benign gynaecological diseases and risk of endometrial and ovarian cancers

Objective: Gynaecologic benign diseases such uterine fibroids share similar pathogeneses with endometrial and ovarian cancers. Whether a history of uterine fibroids increases the risk of developing endometrial or ovarian cancers is controversial, due to uterine fibroids was self-reported in those studies. Methods: In our current case-control study, 268 women with endometrial cancer and 108 women with ovarian cancer were included. In addition, 500 women without gynaecological cancers were randomly selected as a control group. Uterine fibroids in both groups were clinically diagnosed by pelvic examination and ultrasound. Data on age, parity, gravida, stages of cancers and history of uterine fibroids, endometriosis and adenomyosis were collected from hospital database. Results: After adjusted age and parity, the odds of women with history of uterine fibroids or endometriosis were lower in women with endometrial cancer than controls (odds ratio: 0.148, 95% CI: 0.097, 0.225, or 0.360, 95% CI: 0094, 1.381, respectively). The odds of women with a history of uterine fibroids or endometriosis were lower in women with ovarian cancer than controls (odds ratio: 0.141, 95% CI: 0.085, 0.235, or 1.057, 95% CI: 0.377, 2.963, respectively). However, the odds of women with a history of adenomyosis were higher in women with endometrial or ovarian cancers than controls (odd ratio: 3.757, 95% CI: 1.858, 7.599 or 2.341, 95% CI: 1.086, 5.045, respectively). Conclusion: Our observational data suggested that uterine fibroids or endometriosis may be not associated with the increased risk of developing endometrial or ovarian cancer. However, a history of adenomyosis may do.

Weight change and risk of uterine leiomyomas: Korea Nurses' Health Study

OBJECTIVE

This study examined the associations between anthropometric measures and uterine leiomyomas.

METHODS

This study included a total of 5,062 women (median age of 35.5 years) who had experienced pregnancy and, of these women, 210 reported a diagnosis of uterine leiomyomas within the past 2 years prior to baseline in the Korea Nurses' Health Study. Participants were asked about their anthropometric factors. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using logistic regression models.

RESULTS

Mean body mass index (BMI) was 21.8 kg/m² among non-cases. An increase in weight from the age of 18 years to the present was associated with increased risk of uterine leiomyomas (p for trend = .002); compared to women whose weight remained stable, the multivariate ORs (95% CIs) were 1.84 (1.22-2.76) for weight gain of 5-10 kg and 2.00 (1.25-3.20) for weight gain of more than 10 kg since age 18. A similar pattern was observed when the analysis was limited to women with a BMI of 18.5-25 kg/m². Current weight was associated with higher odds of uterine leiomyomas. No associations were found for body size in childhood or in adolescence, weight at age 18, current BMI, or current body size.

CONCLUSIONS

Weight gain in adulthood was associated with increased risk of uterine leiomyomas in Korean women, even in those with normal weight.

The association between ultrasound-estimated visceral fat deposition and uterine fibroids: an observational study

Uterine fibroids are the most common neoplasm of the genital tract in reproductive women. Obesity holds a role as risk factor for uterine fibroids, through hormonal and inflammatory mechanisms. Visceral fat is a hormonally active tissue, so an increase in visceral fat may be considered as a risk factor, through the increased production of inflammatory mediators. The aim of the study was, therefore, to evaluate the association between the presence of uterine fibroids and fat tissue distribution, and to assess the efficacy of both anthropometric and instrumental indicators, in particular the sonographic measurement of preperitoneal fat thickness (PFT) and subcutaneous fat thickness (SFT). Study group consisted of childbearing-age women with at least one uterine fibroid with a diameter ≥10 mm (n = 71), all the childbearing-age women who access to the outpatient service of our institution in the same period, without evidence of uterine fibroids, constituted the control group (n = 145). A significantly difference in BMI (p = 0.0034), PFT (p < 0.0001), and SFT (p = 0.0003) emerged. At the multivariate analysis, only PFT showed an independent significant association with the presence of uterine fibroids (p < 0.0001). The ROC curve analysis identified a cut-off value of 6.7 mm of PFT as discriminator for the presence of uterine fibroids.

The use of mifepristone in abortion associated with an increased risk of uterine leiomyomas

To investigate the association between widespread use of mifepristone in abortions and risk of uterine leiomyomas.We conducted a case-control study of 305 patients with uterine leiomyomas between January 2011 and July 2012; 311 women with ordinary vaginitis were selected as controls during the same period. Data were collected by questionnaires (including past history, life history, menstruation history, reproductive history, abortion history, the use of mifepristone, and uterine leiomyomas risk factors) and calculated by univariate and multivariate conditional logistic regression analyses; odds ratios and its 95% confidence interval were calculated to estimate the risk for uterine leiomyomas.Abortion with mifepristone was one of the risk factors for uterine leiomyomas, and the risk increased with increasing frequency of mifepristone use. Family history of uterine leiomyomas, body mass index, age at menarche, number of full-term delivery, and medical abortion history were also correlated with uterine leiomyomas.The use of mifepristone in abortion will increase the risk to develop uterine leiomyomas.

Preperitoneal Fat Thicknesses, Lipid Profile, and Oxidative Status in Women With Uterine Fibroids

PURPOSE

There is growing evidence supporting a possible role for metabolic syndrome and its determinants, such as dyslipidemia, in uterine fibroid (UF) pathogenesis. The present study aims to investigate the association between UFs and visceral and subcutaneous fat thickness (SFT), lipid profile, and oxidative and antioxidative status.

METHODS

In this cross-sectional study, 35 patients diagnosed with UFs and 15 women without UFs were enrolled. Clinical history and anthropometric parameters were collected for every woman. Characteristics of UFs, preperitoneal fat thickness (PFT), and SFT were assessed ultrasonically. Lipid profile, glucose, thiobarbituric acid reactive substances (TBARs), and superoxide dismutase (SOD) activity were evaluated on plasma from participants.

RESULTS

Women with UFs showed a significantly increased PFT (11.63 ± 3.39 vs 7.01 ± 3.10 mm; P < .001), lower levels of high-density lipoprotein cholesterol (HDL-C; 45.4 ± 8.3 vs 57.2 ± 13.4 mg/dL; P = .017), higher levels of low-density lipoprotein cholesterol (LDL-C; 92.3 ± 21.5 vs 72.0 ± 14.6 mg/dL; P = .007), and oxidized LDL (65.2 ± 20.7 vs 43.0 ± 11.3 U/L; P = .002). In patients, TBARs concentration was significantly higher (9.41 ± 6.49 vs 2.92 ± 1.65 nmol malondialdehyde/100 μg prot; P < .001), whereas SOD activity was lower (1.09 ± 0.19 vs 1.37 ± 0.41 U/μL; P = .005). Preperitoneal fat thickness was positively associated with body mass index, oxidized LDL, and TBARs. At multivariate analysis, PFT and HDL-C maintained a significant correlation with the diagnosis of UFs.

CONCLUSION

Chronic inflammation triggered and sustained by visceral fat could play a determinant role in cell differentiation and proliferation processes, necessary for the development of UFs. Alterations in cholesterol fractions may be explained as a consequence of the increased visceral fat deposits and can reflect an increased risk of subclinical atherosclerosis in patients with UF.

Induced and Spontaneous Abortion and Risk of Uterine Fibroids

BACKGROUND

The relationship between abortion and uterine fibroids has received little attention. The aim of the present study was to explore the association between number of induced and spontaneous abortions and the risk of uterine fibroids in middle-aged and older Chinese women.

METHODS

A total of 14,595 retired female employees from the Dongfeng-Tongji cohort study were included in our analysis. Information on induced and spontaneous abortions was collected by trained interviewers through face-to-face interviews. Diagnosis of uterine fibroids was based on ultrasound or self-reported physician diagnosis of uterine fibroids. Logistic regression models were used to explore the associations between number of induced and spontaneous abortions and the risk of uterine fibroids.

RESULTS

The prevalence of uterine fibroids was 15.1% among all participants. Higher number of induced abortions was associated with an increased risk of uterine fibroids (1 induced abortion: odds ratios [ORs] = 1.32, 95% confidence interval [CI] 1.18-1.48; 2 induced abortions: OR = 1.45, 95% CI 1.28-1.64; and ≥3 induced abortions: OR = 1.62, 95% CI 1.39-1.90). Compared with women without induced abortion, ORs for women with 1, 2, and ≥3 were 1.17 (95% CI 1.03-1.32), 1.21 (95% CI 1.06-1.39), and 1.36 (95% CI 1.15-1.61), respectively, after adjustment for potential confounders. No association was observed between the number of spontaneous abortions and the risk of uterine fibroids.

CONCLUSION

The findings of this study showed that induced abortion may be an independent risk factor for uterine fibroids in middle-aged and older Chinese women.

Body condition scoring system for greater one-horned rhino (Rhinoceros unicornis): Development and application

Preventing obesity in zoo animals is increasingly recognized as an important husbandry objective. To achieve this goal, body condition scoring (BCS) systems are available for an ever-increasing number of species. Here, we present a BCS for the greater one-horned rhinoceros (Rhinoceros unicornis) based on an evaluation (on a scale from 1 to 5) of seven different body regions, and report resulting scores for 62 animals from 27 facilities, based on digital photographs. In animals above 4 years of age, this BCS correlated with the body mass:shoulder height ratio. Although differences between the sexes for individual regions were noted (with consistently higher scores in males for the neck and shoulder and in parous females for the abdomen), the average BCS of all regions did not differ significantly between males (4.3 ± 0.4) and females (4.1 ± 0.5). Linking the BCS to results of a questionnaire survey and studbook information, there were no differences in BCS between animals with and without foot problems or between parous and non-parous females. In a very limited sample of 11 females, those eight that had been diagnosed with leiomyoma in a previous study had a higher BCS (range 3.9-4.9) than the three that had been diagnosed as leiomyoma-free (range 3.5-3.7). The BCS was correlated to the amount of food offered as estimated from the questionnaire. Adjusting the amounts and the nutritional quality of the diet components is an evident measure to maintain animals at a target BCS (suggested as 3-3.5). Zoo Biol. 35:432-443, 2016. © Wiley Periodicals, Inc.