Erratum to: A multi-stage genome-wide association study of uterine fibroids in African Americans

The article "A multi-stage genome-wide association study of uterine fibroids in African Americans", written by Jacklyn N. Hellwege, was originally published Online First without open access. After publication in volume 136, issue 10, page 1363-1373 the author decided to opt for Open Choice and to make the article an open access publication. Therefore, the copyright of the article has been changed to

A multi-stage genome-wide association study of uterine fibroids in African Americans

Uterine fibroids are benign tumors of the uterus affecting up to 77% of women by menopause. They are the leading indication for hysterectomy, and account for $34 billion annually in the United States. Race/ethnicity and age are the strongest known risk factors. African American (AA) women have higher prevalence, earlier onset, and larger and more numerous fibroids than European American women. We conducted a multi-stage genome-wide association study (GWAS) of fibroid risk among AA women followed by in silico genetically predicted gene expression profiling of top hits. In Stage 1, cases and controls were confirmed by pelvic imaging, genotyped and imputed to 1000 Genomes. Stage 2 used self-reported fibroid and GWAS data from 23andMe, Inc. and the Black Women's Health Study. Associations with fibroid risk were modeled using logistic regression adjusted for principal components, followed by meta-analysis of results. We observed a significant association among 3399 AA cases and 4764 AA controls at rs739187 (risk-allele frequency = 0.27) in CYTH4 (OR (95% confidence interval) = 1.23 (1.16-1.30), p value = 7.82 × 10-9). Evaluation of the genetic association results with MetaXcan identified lower predicted gene expression of CYTH4 in thyroid tissue as significantly associated with fibroid risk (p value = 5.86 × 10-8). In this first multi-stage GWAS for fibroids among AA women, we identified a novel risk locus for fibroids within CYTH4 that impacts gene expression in thyroid and has potential biological relevance for fibroids.

African genetic ancestry interacts with body mass index to modify risk for uterine fibroids

Race, specifically African ancestry, and obesity are important risk factors for uterine fibroids, and likely interact to provide the right conditions for fibroid growth. However, existing studies largely focus on the main-effects rather than their interaction. Here, we firstly provide evidence for interaction between categories of body mass index (BMI) and reported-race in relation to uterine fibroids. We then investigate whether the association between inferred local European ancestry and fibroid risk is modified by BMI in African American (AA) women in the Vanderbilt University Medical Center bio-repository (BioVU) (539 cases and 794 controls) and the Coronary Artery Risk Development in Young Adults study (CARDIA, 264 cases and 173 controls). We used multiple logistic regression to evaluate interactions between local European ancestry and BMI in relation to fibroid risk, then performed fixed effects meta-analysis. Statistical significance threshold for local-ancestry and BMI interactions was empirically estimated with 10,000 permutations (p-value = 1.18x10-4). Admixture mapping detected an association between European ancestry and fibroid risk which was modified by BMI (continuous-interaction p-value = 3.75x10-5) around ADTRP (chromosome 6p24); the strongest association was found in the obese category (ancestry odds ratio (AOR) = 0.51, p-value = 2.23x10-5). Evaluation of interaction between genotyped/imputed variants and BMI in this targeted region suggested race-specific interaction, present in AAs only; strongest evidence was found for insertion/deletion variant (6:11946435), again in the obese category (OR = 1.66, p-value = 1.72x10-6). We found nominal evidence for interaction between local ancestry and BMI at a previously reported region in chromosome 2q31-32, which includes COL5A2, and TFPI, an immediate downstream target of ADTRP. Interactions between BMI and SNPs (single nucleotide polymorphisms) found in this region in AA women were also detected in an independent European American population of 1,195 cases and 1,164 controls. Findings from our study provide an example of how modifiable and non-modifiable factors may interact to influence fibroid risk and suggest a biological role for BMI in fibroid etiology.

Obesity and pelvic organ prolapse: a systematic review and meta-analysis of observational studies

BACKGROUND

Studies evaluating the association between obesity and pelvic organ prolapse report estimates that range from negative to positive associations. Heterogeneous definitions for pelvic organ prolapse and variable choices for categorizing obesity measures have made it challenging to conduct meta-analysis.

OBJECTIVE

We systematically evaluated evidence to provide quantitative summaries of association between degrees of obesity and pelvic organ prolapse, and identify sources of heterogeneity.

STUDY DESIGN

We searched for all indexed publications relevant to pelvic organ prolapse up until June 18, 2015, in PubMed/MEDLINE to identify analytical observational studies published in English that reported risk ratios (relative risk, odds ratio, or hazard ratio) for body mass index categories in relation to pelvic organ prolapse. Random effects meta-analyses were conducted to report associations with pelvic organ prolapse for overweight and obese body mass index categories compared with women in the normal-weight category (referent: body mass index <25 kg/m²).

RESULTS

Of the 70 studies that reported evidence on obesity and pelvic organ prolapse, 22 eligible studies provided effect estimates for meta-analysis of the overweight and obese body mass index categories. Compared with the referent category, women in the overweight and obese categories had meta-analysis risk ratios of at least 1.36 (95% confidence interval, 1.20-1.53) and at least 1.47 (95% confidence interval, 1.35-1.59), respectively. Subgroup analyses showed effect estimates for objectively measured clinically significant pelvic organ prolapse were higher than for self-reported pelvic organ prolapse. Other potential sources of heterogeneity included proportion of postmenopausal women in study and reported study design.

CONCLUSION

Overweight and obese women are more likely to have pelvic organ prolapse compared with women with body mass index in the normal range. The finding that the associations for obesity measures were strongest for objectively measured, clinically significant pelvic organ prolapse further strengthens this evidence. However, prospective investigations evaluating obesity and pelvic organ prolapse are few.

Admixture mapping of pelvic organ prolapse in African Americans from the Women's Health Initiative Hormone Therapy trial

Evidence suggests European American (EA) women have two- to five-fold increased odds of having pelvic organ prolapse (POP) when compared with African American (AA) women. However, the role of genetic ancestry in relation to POP risk is not clear. Here we evaluate the association between genetic ancestry and POP in AA women from the Women’s Health Initiative Hormone Therapy trial. Women with grade 1 or higher classification, and grade 2 or higher classification for uterine prolapse, cystocele or rectocele at baseline or during follow-up were considered to have any POP (N = 805) and moderate/severe POP (N = 156), respectively. Women with at least two pelvic exams with no indication for POP served as controls (N = 344). We performed case-only, and case-control admixture-mapping analyses using multiple logistic regression while adjusting for age, BMI, parity and global ancestry. We evaluated the association between global ancestry and POP using multiple logistic regression. European ancestry at the individual level was not associated with POP risk. Case-only and case-control local ancestry analyses identified two ancestry-specific loci that may be associated with POP. One locus (Chromosome 15q26.2) achieved empirically-estimated statistical significance and was associated with decreased POP odds (considering grade ≥2 POP) with each unit increase in European ancestry (OR: 0.35; 95% CI: 0.30, 0.57; p-value = 1.48x10^-5). This region includes RGMA, a potent regulator of the BMP family of genes. The second locus (Chromosome 1q42.1-q42.3) was associated with increased POP odds with each unit increase in European ancestry (Odds ratio [OR]: 1.69; 95% confidence interval [CI]: 1.28, 2.22; p-value = 1.93x10^-4). Although this region did not reach statistical significance after considering multiple comparisons, it includes potentially relevant genes including TBCE, and ACTA1. Unique non-overlapping European and African ancestry-specific susceptibility loci may be associated with increased POP risk.

Evaluating the role of race and medication in protection of uterine fibroids by type 2 diabetes exposure

BACKGROUND

Uterine fibroids (UF) affect 77% of women by menopause, and account for $9.4 billion in annual healthcare costs. Type-2-diabetes (T2D) has inconsistently associated with protection from UFs in prior studies. To further evaluate the relationship between T2D and UFs we tested for association between T2D and UF risk in a large clinical population as well as the potential differences due to T2D medications and interaction with race.

METHODS

This nested case-control study is derived from a clinical cohort. Our outcome was UF case-control status and our exposure was T2D. UF outcomes and T2D exposure were classified using validated electronic medical record (EMR) algorithms. Logistic regression, adjusted for covariates, was used to model the association between T2D diagnosis and UF risk. Secondary analyses were performed evaluating the interaction between T2D exposure and race and stratifying T2D exposed subjects by T2D medication being taken.

RESULTS

We identified 3,789 subjects with UF outcomes (608 UF cases and 3,181 controls), 714 were diabetic and 3,075 were non-diabetic. We observed a nominally significant interaction between T2D exposure and race in adjusted models (interaction p = 0.083). Race stratified analyses demonstrated more protection by T2D exposure on UF risk among European Americans (adjusted odds ratio [aOR] = 0.50, 95% CI 0.35 to 0.72) than African Americans (aOR = 0.76, 95% CI 0.50 to 1.17). We also observed a protective effect by T2D regardless of type of T2D medication being taken, with slightly more protection among subjects on insulin treatments (European Americans aOR = 0.42, 95% CI 0.26 to 0.68; African Americans aOR = 0.60, 95% CI 0.36 to 1.01).

CONCLUSIONS

These data, conducted in a large population of UF cases and controls, support prior studies that have found a protective association between diabetes presence and UF risk and is further modified by race. Protection from UFs by T2D exposure was observed regardless of medication type with slightly more protection among insulin users. Further mechanistic research in larger cohorts is necessary to reconcile the potential role of T2D in UF risk.

Validation of maternal recall of early pregnancy medication exposure using prospective diary data

PURPOSE

Data about maternal recall accuracy for classifying early pregnancy medication exposure are meager. Nonetheless, studies often rely on recall to evaluate potential impact of pharmaceuticals on the developing fetus.

METHODS

Right from the Start is a community-based pregnancy cohort that enrolled women from North Carolina, Tennessee, and Texas. A subset of 318 women participated in daily medication diaries initiated before conception (2006-2012). We examined nonsteroidal anti-inflammatory drugs (NSAIDs) as an example of a drug type that is difficult to study due to its intermittent and primarily over-the-counter use as well as its incomplete documentation in medical and pharmaceutical records. Selective serotonin reuptake inhibitors (SSRI) were assessed as a prescription medication comparator. Maternal recall of NSAID and SSRI use in early pregnancy was examined by comparing diary data (gold standard) to first-trimester interview.

RESULTS

Sensitivity and specificity for recall of NSAID exposure were 78.6% and 62.3%, respectively (kappa statistic: 0.41), with 72.3% agreement for exposure classification. Sensitivity and specificity for recall of SSRI exposure were 77.8% and 99.0%, respectively (kappa statistic: 0.79), with 97.8% agreement.

CONCLUSIONS

Our findings suggest the validity of maternal recall varies with medication type and prospective data collection should be prioritized when studying early pregnancy drug exposures.

Expression Quantitative Trait Locus Mapping Studies in Mid-secretory Phase Endometrial Cells Identifies HLA-F and TAP2 as Fecundability-Associated Genes

Fertility traits in humans are heritable, however, little is known about the genes that influence reproductive outcomes or the genetic variants that contribute to differences in these traits between individuals, particularly women. To address this gap in knowledge, we performed an unbiased genome-wide expression quantitative trait locus (eQTL) mapping study to identify common regulatory (expression) single nucleotide polymorphisms (eSNPs) in mid-secretory endometrium. We identified 423 cis-eQTLs for 132 genes that were significant at a false discovery rate (FDR) of 1%. After pruning for strong LD (r² >0.95), we tested for associations between eSNPs and fecundability (the ability to get pregnant), measured as the length of the interval to pregnancy, in 117 women. Two eSNPs were associated with fecundability at a FDR of 5%; both were in the HLA region and were eQTLs for the TAP2 gene (P = 1.3x10^-4) and the HLA-F gene (P = 4.0x10^-4), respectively. The effects of these SNPs on fecundability were replicated in an independent sample. The two eSNPs reside within or near regulatory elements in decidualized human endometrial stromal cells. Our study integrating eQTL mapping in a primary tissue with association studies of a related phenotype revealed novel genes and associated alleles with independent effects on fecundability, and identified a central role for two HLA region genes in human implantation success.

Little is known about the genetics of female fertility. In this study, we addressed this gap in knowledge by first searching for genetic variants that regulate gene expression in uterine endometrial cells, and then testing those functional variants for associations with the length of time to pregnancy in fertile women. Two functional genetic variants were associated with time to pregnancy in women after correcting for multiple testing. Those variants were each associated with the expression of genes in the HLA region, HLA-F and TAP2, which are have not previously been implicated female fertility. The association between HLA-F and TAP2 genotypes on the length of time to pregnancy was replicated in an independent cohort of women. Because HLA-F and TAP2 are involved in immune processes, these results suggest their role in specific immune regulation in the endometrium during implantation. Future studies will characterize these molecules in the implantation process and their potential as drug targets for treatment of conditions related to implantation failure.

The Relationship between Total Fibroid Burden and First Trimester Bleeding and Pain

BACKGROUND

Few studies comment on the association between fibroids and symptoms among pregnant women. These studies generally are retrospective and do not to assess the influence of number of tumours or their volume on risk of symptoms.

METHODS

Right from the Start is a prospective cohort that enrolled pregnant women from the southeastern USA between 2000 and 2012. In the first trimester, all participants had standardised ultrasounds to determine the presence or absence of fibroids. Symptoms were queried in a telephone survey. We used polytomous logistic regression to model odds of bleeding, pain, or both symptoms in relation to increasing total fibroid number and volume among white and black women.

RESULTS

Among 4509 participants, the prevalence of fibroids was 11%. Among those reporting symptoms (70%), 11% reported only bleeding, 59% reported only pain, and 30% reported both symptoms. After adjusting for age, race, parity, hypertension, smoking, alcohol use, and study site, increasing number of fibroids was associated with pain [odds ratio (OR) 1.16, 95% confidence interval (CI) 1.00, 1.33] and both symptoms [OR 1.25, 95% CI 1.08, 1.45] but not with bleeding among all women. Fibroid volume was not associated with symptoms among black women, but white women with the smallest fibroid volumes were more likely to report both symptoms than those without fibroids [OR 1.79, 95% CI 1.17, 2.72].

CONCLUSIONS

Very large tumours are not requisite for experiencing symptoms, as small fibroids and increasing number of tumours are associated with pain and both symptoms.

Genetic Determinants of Pelvic Organ Prolapse among African American and Hispanic Women in the Women's Health Initiative

Current evidence suggests a multifactorial etiology to pelvic organ prolapse (POP), including genetic predisposition. We conducted a genome-wide association study of POP in African American (AA) and Hispanic (HP) women from the Women's Health Initiative Hormone Therapy study. Cases were defined as any POP (grades 1-3) or moderate/severe POP (grades 2-3), while controls had grade 0 POP. We performed race-specific multiple logistic regression analyses between SNPs imputed to 1000 genomes in relation to POP (grade 0 vs 1-3; grade 0 vs 2-3) adjusting for age at diagnosis, body mass index, parity, and genetic ancestry. There were 1274 controls and 1427 cases of any POP and 317 cases of moderate/severe POP. Although none of the analyses reached genome-wide significance (p<5x10-8), we noted variants in several loci that met p<10-6. In race-specific analysis of grade 0 vs 2-3, intronic SNPs in the CPE gene (rs28573326, OR:2.14; 95% CI 1.62-2.83; p = 1.0x10-7) were associated with POP in AAs, and SNPs in the gene AL132709.5 (rs1950626, OR:2.96; 95% CI 1.96-4.48, p = 2.6x10-7) were associated with POP in HPs. Inverse variance fixed-effect meta-analysis of the race-specific results showed suggestive signals for SNPs in the DPP6 gene (rs11243354, OR:1.36; p = 4.2x10-7) in the grade 0 vs 1-3 analyses and for SNPs around PGBD5 (rs740494, OR:2.17; p = 8.6x10-7) and SHC3 (rs2209875, OR:0.60; p = 9.3x10-7) in the grade 0 vs 2-3 analyses. While we did not identify genome-wide significant findings, we document several SNPs reaching suggestive statistical significance. Further interrogation of POP in larger minority samples is warranted.

Enhancing uterine fibroid research through utilization of biorepositories linked to electronic medical record data

BACKGROUND

Uterine leiomyomata (fibroids) affect up to 77% of women by menopause and account for $9.4 billion in yearly healthcare costs. Most studies rely on self-reported diagnosis, which may result in misclassification of controls since as many as 50% of cases are asymptomatic and thus undiagnosed. Our objective was to evaluate the performance and accuracy of a fibroid phenotyping algorithm constructed from electronic medical record (EMR) data, limiting to subjects with pelvic imaging.

METHODS

Our study population includes women from a clinical population at Vanderbilt University Medical Center (2008-2012). Analyses were restricted to women 18 years and older with at least one fibroid diagnosis confirmed by imaging for cases or at least two separate pelvic imaging procedures without a diagnosis for controls. We randomly reviewed 218 records to evaluate the accuracy of our algorithm and assess the indications for pelvic imaging. Participant characteristics and indications for imaging were compared between cases and controls in unadjusted and adjusted logistic regression analyses.

RESULTS

Our algorithm had a positive predictive value of 96% and negative predictive value of 98%. Increasing age (odds ratio=1.05, 95% confidence interval 1.03-1.08) and Black race (odds ratio=2.15, 95% confidence interval 1.18-3.94) were identified as risk factors for fibroids. The most common indications for imaging in both cases and controls were pain, bleeding, and reproductive factors, and the most common imaging modality was a pelvic ultrasound.

CONCLUSIONS

These data suggest that using biorepositories linked to EMR data is a feasible way to identify populations of imaged women that facilitate investigations of fibroid risk factors.

Prescription opioid epidemic and infant outcomes

BACKGROUND AND OBJECTIVES

Although opioid pain relievers are commonly prescribed in pregnancy, their association with neonatal outcomes is poorly described. Our objectives were to identify neonatal complications associated with antenatal opioid pain reliever exposure and to establish predictors of neonatal abstinence syndrome (NAS).

METHODS

We used prescription and administrative data linked to vital statistics for mothers and infants enrolled in the Tennessee Medicaid program between 2009 and 2011. A random sample of NAS cases was validated by medical record review. The association of antenatal exposures with NAS was evaluated by using multivariable logistic regression, controlling for maternal and infant characteristics.

RESULTS

Of 112,029 pregnant women, 31,354 (28%) filled ≥ 1 opioid prescription. Women prescribed opioid pain relievers were more likely than those not prescribed opioids (P < .001) to have depression (5.3% vs 2.7%), anxiety disorder (4.3% vs 1.6%) and to smoke tobacco (41.8% vs 25.8%). Infants with NAS and opioid-exposed infants were more likely than unexposed infants to be born at a low birth weight (21.2% vs 11.8% vs 9.9%; P < .001). In a multivariable model, higher cumulative opioid exposure for short-acting preparations (P < .001), opioid type (P < .001), number of daily cigarettes smoked (P < .001), and selective serotonin reuptake inhibitor use (odds ratio: 2.08 [95% confidence interval: 1.67-2.60]) were associated with greater risk of developing NAS.

CONCLUSIONS

Prescription opioid use in pregnancy is common and strongly associated with neonatal complications. Antenatal cumulative prescription opioid exposure, opioid type, tobacco use, and selective serotonin reuptake inhibitor use increase the risk of NAS.

Subclinical hypothyroidism and risk for incident ischemic stroke among postmenopausal women

BACKGROUND

Subclinical hypothyroidism (SCH) is postulated to increase stroke risk via atherogenic changes associated with abnormal thyroid function. However, the direct relationship of SCH with subsequent stroke is poorly studied.

METHODS

In this nested case-cohort study, we prospectively evaluated the association between any SCH and severity of SCH in relation to incident ischemic stroke risk among postmenopausal women in the Women's Health Initiative Observational Study. Trained Women's Health Initiative staff, masked to thyroid status, adjudicated stroke cases. We assessed thyroid function using baseline blood specimens. Women with normal free thyroxine levels and thyrotropin (TSH) levels ≥4.69 mU/L were considered to have SCH. Primary analysis included 639 ischemic stroke cases and 2927 randomly selected subcohort members with an average of seven years of follow-up.

RESULTS

The multivariable adjusted hazard ratios (HR) from weighted Cox models were 1.06 (95% confidence interval [CI]: 0.77, 1.46) and 0.99 (95% CI: 0.67, 1.47) for women with any SCH and with mild SCH (TSH 4.69 to 6.99 mU/L), when compared with women with normal thyroid function. The HR for moderate/severe SCH (TSH ≥7.00 mU/L) was modestly elevated (HR: 1.22; 95% CI: 0.73, 2.05).

CONCLUSIONS

We found no evidence to suggest an association between SCH and ischemic stroke among healthy postmenopausal women.

First-trimester antihistamine exposure and risk of spontaneous abortion or preterm birth

PURPOSE

We tested whether antihistamine exposure during early pregnancy is associated with spontaneous abortion (SAB) or preterm birth (PTB).

METHODS

Women were enrolled in Right from the Start (2004-2010), a prospective pregnancy cohort. Data about first-trimester antihistamine use were obtained from screening and first-trimester interviews. Self-reported outcomes included SAB and PTB and were verified by medical records. Cox proportional hazards models were used to test for an association between antihistamine use and each outcome, both performed adjusting for confounders.

RESULTS

Among the 2685 pregnancies analyzed, 14% (n = 377) reported use of antihistamines. Among antihistamine users, 12% (n = 44) experienced SABs, and 6% (n = 21) had PTBs. Antihistamine exposure was not associated with SAB (adjusted hazard ratio [aHR] = 0.88, 95% confidence interval [CI] 0.64, 1.21) or PTB, which was modified by maternal race (aHR = 1.03, 95%CI 0.61, 1.72 among White women and aHR = 0.43, 95%CI 0.14, 1.34 among Black women).

CONCLUSIONS

Despite the biologic plausibility that antihistamine use may influence pregnancy outcomes, we did not detect evidence of an association with SAB or PTB. These data demonstrate the utility of large prospective cohorts for evaluating drug safety in pregnancy when concerns are raised from animal models.

Racial differences in risk of spontaneous abortions associated with periconceptional over-the-counter nonsteroidal anti-inflammatory drug exposure

PURPOSE

Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most common medications reported in pregnancy. NSAIDs directly impact prostaglandin pathways and have been proposed as potential risk factors for spontaneous abortions (SABs, gestation <20 weeks). SAB risk and drug response across several medications differ by race; therefore, we evaluated whether associations between NSAIDs and SAB risk differ by race.

METHODS

Women were enrolled in the Right from the Start (2004-2010) prospective cohort. Data regarding over-the-counter NSAIDs up to the sixth week of pregnancy were obtained from interviews. Race was self-reported. Cox proportional hazards regression models were used to estimate the association between NSAID exposure and SAB, adjusted for confounders.

RESULTS

Among 2493 pregnancies, 12% were African American and 88% were Caucasian. NSAID exposure was reported by 40% (n = 124) of African Americans and 43% (n = 945) of Caucasians. Race-stratified analyses showed protection from SAB among African Americans (adjusted hazard ratio [aHR], 0.84; 95% confidence interval [CI], 0.73-0.96) but no effect in Caucasians (aHR, 1.01; 95% CI 0.88-1.16).

CONCLUSIONS

Our findings suggest that risk for SAB due to over-the-counter NSAIDs in early pregnancy is modified by race. Further investigation of dose, timing in gestation, and indication may help to further reconcile the relationship between race, NSAIDs, and SAB.

Uterine leiomyomata and cesarean birth risk: a prospective cohort with standardized imaging

PURPOSE

To determine if women with leiomyomata detected using uniform ultrasound methods are at increased risk of cesarean birth, without regard to indication.

METHODS

Women were enrolled in Right from the Start (2000-2010), a prospective pregnancy cohort. Leiomyomata were counted, categorized, and measured during first trimester ultrasounds. Women provided information about demographics and reproductive history during first trimester interviews. Route of delivery was extracted from medical records or vital records, if the former were unavailable. Generalized estimating equations were used to calculate risk ratios (RR) and 95% confidence intervals (CIs) for the risk of cesarean birth by leiomyoma presence and characteristics.

RESULTS

Among 2635 women, the prevalences of leiomyomata and cesarean birth were 11.2% and 29.8%, respectively. Women with leiomyomata, compared with those without, had a 27% increase in cesarean risk (RR, 1.27; CI, 1.17-1.37). The association was weaker following adjustment for maternal body mass index and age (adjusted risk ratio [ARR], 1.11; CI, 1.02-1.20). The adjusted risk was elevated for women with a single leiomyoma 3 cm or more in diameter (ARR, 1.22; CI, 1.14-1.32) and women with the largest total leiomyoma volumes (ARR, 1.59; CI, 1.44-1.76).

CONCLUSIONS

Women with leiomyomata were at increased risk for cesarean birth particularly, those with larger tumor volumes.

Association of age at menarche with increasing number of fibroids in a cohort of women who underwent standardized ultrasound assessment

Age at menarche has been associated with several reproductive conditions, and frequencies differ by race. Racial disparities also impact fibroid risk. We comprehensively examined the relationship between age at menarche, fibroid characteristics, and race. Women were enrolled in Right From the Start (2001-2010), a multistate study that systematically screened for fibroids during very early pregnancy. Endovaginal ultrasounds were conducted, and fibroid presence, number, type, volume, and diameter were recorded according to standardized definitions. Generalized estimating equations adjusted for correlations within study site were used to estimate associations between age at menarche and fibroid status and to test for interactions with race. Of 5,023 participants, 11% had a fibroid. Seven percent underwent menarche before 11 years of age and 11% at 15 years or later. We did not observe interactions between age at menarche and race. A 1-year increase in age at menarche was inversely associated with fibroids (adjusted risk ratio = 0.87, 95% confidence interval: 0.82, 0.91). Early age at menarche had a similar positive association in individual analyses with fibroid size, type, and location but was stronger for multiple fibroids (adjusted risk ratio = 0.75, 95% confidence interval: 0.68, 0.83). Our findings confirm other reports of an association between age at menarche and fibroid development (regardless of characteristics), demonstrate no effect modification by race, and suggest a stronger association for women with multiple fibroids, possibly reflecting a stronger association for early-onset disease.

BET1L and TNRC6B associate with uterine fibroid risk among European Americans

Uterine fibroid (UFs) affect 77 % of women by menopause and account for $9.4 billion in healthcare costs each year. Although UFs are heritable, genetic risk is poorly understood. The first genome-wide association study (GWAS) of UFs was recently performed in a Japanese population, with reported genome-wide significance for single nucleotide polymorphisms (SNPs) across three chromosomal regions. We tested these SNPs for association with UFs in US cohorts. Women were enrolled in the Right from the Start (RFTS) cohort and the BioVU DNA repository. UF status in both cohorts was determined by pelvic imaging. We tested 65 candidate and haplotype-tagging SNPs for association with UFs presence using logistic regression in RFTS and the top three GWAS-associated SNPs in BioVU. We also combined association results from both cohorts using meta-analysis. 1,086 European American (EA) cases and 1,549 controls were examined. Two SNP associations replicated [blocked early in transport 1 homolog (BET1L) rs2280543, RFTS-BioVU meta-odds ratio (OR) = 0.67 95 % confidence interval (CI) 0.38-0.96, Q = 0.70, I = 0, p = 6.9 × 10⁻³; trinucleotide repeat containing 6B (TNRC6B) rs12484776, RFTS-BioVU meta-OR = 1.21, 95 % CI 1.07-1.35, Q = 0.24, I = 28.37, p = 8.7 × 10⁻³). Meta-analyses combining evidence from RFTS, BioVU, and prior GWAS showed little heterogeneity in effect sizes across studies, with meta-p values between 7.45 × 10⁻⁸ and 3.89 × 10⁻⁹, which were stronger than prior GWAS and supported associations observed for all previously identified loci. These data suggest common variants increase risk for UF in both EA and Japanese populations. However, further research is needed to assess the role of these genes across other racial groups.

Variants in BET1L and TNRC6B associate with increasing fibroid volume and fibroid type among European Americans

Uterine fibroids (UFs) affect 77 % of women by menopause and account for $9.4 billion in yearly healthcare costs. We recently replicated findings from the first UF genome-wide association study (GWAS), conducted in the Japanese. Here we tested these GWAS-discovered SNPs for association with UF characteristics to further assess whether risk varies by sub-phenotypes of UFs. Women were enrolled in Right from the Start (RFTS) and the BioVU DNA repository (BioVU). UF status was determined by pelvic imaging. We tested the top GWAS-associated SNPs for association with UF characteristics (RFTS: type, number, volume; BioVU: type) using covariate adjusted logistic and linear regression. We also combined association results of UF type using meta-analysis. 456 European American (EA) cases and 1,549 controls were examined. Trinucleotide repeat containing 6B (TNRC6B) rs12484776 associated with volume in RFTS (β = 0.40, 95 % CI 0.05-0.75, p = 0.024). RFTS analyses evaluating stratified quartiles of volume showed the strongest OR at rs12484776 for the largest volume (16.6-179.1 cc, odds ratio (OR) = 2.19, 95 % confidence interval (CI) 1.07-4.46, p = 0.031). Meta-analysis showed a strong association at blocked early in transport 1 homolog (BET1L) rs2280543 for intramural UFs (meta-OR = 0.51, standard error (SE) = 0.14, Q = 0.590, I = 0, p = 2.48 × 10(-6)), which is stronger than the overall association with UF risk. This study is the first to evaluate these SNPs for association with UF characteristics and suggests these genes associate with increasing UF volume and protection from intramural UF in EAs.

Subclinical hypothyroidism and risk for incident myocardial infarction among postmenopausal women

CONTEXT

Subclinical hypothyroidism (SCH) has been associated with an increased risk for cardiovascular disease. However, few studies have specifically examined the association between SCH and myocardial infarction (MI), and the relationship is poorly understood.

OBJECTIVES

The purpose of this study was to evaluate incident MI risk in relation to SCH and severities of SCH among postmenopausal women.

METHODS

We used a population-based nested case-cohort design within the Women's Health Initiative observational study to examine the association between SCH and incident first-time MI risk among postmenopausal women in the United States. SCH was assessed using blood specimens collected at baseline. Participants presenting with normal free T4 levels and with thyrotropin levels of greater than 4.68-6.99 mU/L or 7.00 mU/L or greater were defined as having mild SCH or moderate/severe SCH, respectively. MI cases were centrally adjudicated by trained Women's Health Initiative staff. The primary analysis included 736 incident MI cases and 2927 randomly selected subcohort members. Multivariable adjusted Cox-proportional hazard models were used to assess MI risk in relation to SCH.

RESULTS

Compared with euthyroid participants, the multivariable adjusted hazard ratio (HR) for participants with any SCH was 1.05 [95% confidence interval (CI) 0.77-1.44]. HRs for participants with mild SCH, moderate/severe SCH, and moderate/severe SCH and the presence of antithyroid peroxidase antibodies (TPOAb) were 0.99 (95% CI 0.67-1.46), 1.19 (95% CI 0.72-1.96), and 0.90 (95% CI 0.47-1.74), respectively.

CONCLUSION

We did not find evidence to suggest that SCH is associated with increased MI risk among a population of predominantly older postmenopausal women with no prior history of MI.

Phenotyping clinical disorders: lessons learned from pelvic organ prolapse

Genetic epidemiology, the study of genetic contributions to risk for disease, is an innovative area in medicine. Although research in this arena has advanced in other disciplines, few genetic epidemiological studies have been conducted in obstetrics and gynecology. It is crucial that we study the genetic susceptibility for issues in women's health because this information will shape the new frontier of personalized medicine. To date, preterm birth may be one of the best examples of genetic susceptibility in obstetrics and gynecology, but many areas are being evaluated including endometriosis, fibroids, polycystic ovarian syndrome, and pelvic floor disorders. An essential component to genetic epidemiological studies is to characterize, or phenotype, the disorder to identify genetic effects. Given the growing importance of genomics and genetic epidemiology, we discuss the importance of accurate phenotyping of clinical disorders and highlight critical considerations and opportunities in phenotyping, using pelvic organ prolapse as a clinical example.

Time course of arthralgia among women initiating aromatase inhibitor therapy and a postmenopausal comparison group in a prospective cohort

BACKGROUND

More than 80,000 postmenopausal breast cancer patients in the United States each year are estimated to begin a 5-year course of aromatase inhibitors (AIs) to prevent recurrence. AI-related arthralgia (joint pain and/or stiffness) may contribute to nonadherence, but longitudinal data are needed on arthralgia risk factors, trajectories, and background in postmenopause. This study sought to describe 1-year arthralgia trajectories and baseline covariates among patients with AI and a postmenopausal comparison group.

METHODS

Patients initiating AIs (n = 91) were surveyed at the time of AI initiation and at 6 repeated assessments over 1 year. A comparison group of postmenopausal women without breast cancer (n = 177) completed concomitantly timed surveys. Numeric rating scales (0-10) were used to measure pain in 8 joint pair groups (bilateral fingers, wrists, elbows, shoulders, hips, knees, ankles, and toes). Poisson regression models were used to analyze arthralgia trajectories and risk factors.

RESULTS

By week 6, the AI-initiating group had more severe arthralgia than did the comparison group (ratio of means = 1.8, 95% confidence interval = 1.24-2.7, P = .002), adjusting for baseline characteristics. Arthralgia then worsened further over 1 year in the AI group. Menopausal symptom severity and existing joint-related comorbidity at baseline among women initiating AI were associated with more severe arthralgia over time.

CONCLUSIONS

Patients initiating AI should be told about the timing of arthralgia over the first year of therapy, and advised that it does not appear to resolve over the course of a year. Menopausal symptoms and joint-related comorbidity at AI initiation can help identify patients at risk for developing AI-related arthralgia.

Progestogens for preterm birth prevention: a systematic review and meta-analysis by drug route

PURPOSE

Progestogen has been investigated as a preventive intervention among women with increased preterm birth risk. Our objective was to systematically review the effectiveness of intramuscular (IM), vaginal, and oral progestogens for preterm birth and neonatal death prevention.

METHODS

We included articles published from January 1966 to January 2013 and found 27 randomized trials with data for Bayesian meta-analysis.

RESULTS

Across all studies, only vaginal and oral routes were effective at reducing preterm births (IM risk ratio [RR] 0.95, 95 % Bayesian credible interval [BCI]: 0.88-1.03; vaginal RR 0.87, 95 % BCI: 0.80-0.94; oral RR 0.64, 95 % BCI: 0.49-0.85). However, when analyses were limited to only single births all routes were effective at reducing preterm birth (IM RR 0.77, 95 % BCI: 0.69-0.87; vaginal RR 0.80, 95 % BCI: 0.69-0.91; oral RR 0.66, 95 % BCI: 0.47-0.84). Only IM progestogen was effective at reducing neonatal deaths (IM RR 0.78, 95 % BCI: 0.56-0.99; vaginal RR 0.75, 95 % BCI: 0.45-1.09; oral RR 0.72, 95 % BCI: 0.09-1.74). Vaginal progestogen was effective in reducing neonatal deaths when limited to singletons births.

CONCLUSIONS

All progestogen routes reduce preterm births but not neonatal deaths. Future studies are needed that directly compare progestogen delivery routes.

Changes in adjuvant endocrine therapy over one year among postmenopausal women with early-stage breast cancer initiating aromatase inhibitors

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Background: Aromatase inhibitors (AIs) are standard of care for adjuvant endocrine therapy (AET) to prevent recurrence of early stage breast cancer in postmenopausal women. Previous AET adherence research has focused on the 25-96% adherence observed with, but more information is needed about AI adherence, especially regarding the role of arthralgia (joint pain or stiffness) in AET changes. Our objective was to understand AET changes within a year of AI initiation. Methods: We examined AET switching (either to another AI or to tamoxifen), overall changes in AET (including switching and temporary or permanent discontinuation), and physician- and patient-reported arthralgia, using data abstracted from medical records and self-administered surveys among 93 patients initiating AI. We conducted Chi-square and Wilcoxon univariate analyses. Results: Anastrazole was initially prescribed to 64 patients (69%), letrozole to 28 patients (30%), and exemestane to 1 patient. A year after AI initiation, 64 patients (69%) had no change in AET. Among the 29 patients (31%) who had an AET change, 14 switched to at least one other AI, 11 switched to tamoxifen, 9 temporarily discontinued AET, and 7 entirely discontinued AET (categories not mutually exclusive). Average time to first AET switch was 182.7 days. Average number of AET switches was 1.4. Arthralgia was the most common reason for AET changes, noted in the records of 19 patients (66% of those who changed AET). Patients who changed AET reported more severe arthralgia (median pain from 0-10 among 8 joint groups =1.4, interquartile range [IQR]=0.3-2.6) at week 12 than those who did not (median=0.3, IQR=0-1.1), p=0.03. A higher proportion (46%) of the 28 patients who initiated with letrozole changed AET due to arthralgia, compared with 20% of the 64 patients who initiated with anastrazole (p=0.01). Conclusions: A substantial proportion of women initiating AI change AET over one year. Arthralgia appears to play a key role in AET changes, particularly for letrozole as compared with anastrazole. More longitudinal patient-reported arthralgia data are needed to guide clinical decision making about AI initiation and AET changes.

Consumer product exposures associated with urinary phthalate levels in pregnant women

Human phthalate exposure is ubiquitous, but little is known regarding predictors of urinary phthalate levels. To explore this, 50 pregnant women aged 18-38 years completed two questionnaires on potential phthalate exposures and provided a first morning void. Urine samples were analyzed for 12 phthalate metabolites. Associations with questionnaire items were evaluated via Wilcoxon tests and t-tests, and r-squared values were calculated in multiple linear regression models. Few measured factors were statistically significantly associated with phthalate levels. Individuals who used nail polish had higher levels of mono-butyl phthalate (P=0.048) than non-users. Mono-benzyl phthalate levels were higher among women who used eye makeup (P=0.034) or used makeup on a regular basis (P=0.004). Women who used cologne or perfume had higher levels of di-(2-ethylhexyl) phthalate metabolites. Household products, home flooring or paneling, and other personal care products were also associated with urinary phthalates. The proportion of variance in metabolite concentrations explained by questionnaire items ranged between 0.31 for mono-ethyl phthalate and 0.42 for mono-n-methyl phthalate. Although personal care product use may be an important predictor of urinary phthalate levels, most of the variability in phthalate exposure was not captured by our relatively comprehensive set of questionnaire items.