ABSTRACT
PURPOSE: Intimate care products may contain substances associated with increased risk of hormone-related cancers. The relationship between genital talc use and ovarian cancer, in particular, has been well studied, but concerns about recall bias and exposure misclassification have precluded conclusions. We examined the association between intimate care products and female hormone-related cancers, accounting for potential biases, using data from a US-based cohort study. METHODS: The Sister Study enrolled 50,884 women who had a sister with breast cancer. Data on genital talc use and douching were collected at enrollment (2003-2009) and follow-up (2017-2019). We used Cox proportional hazards models to estimate hazard ratios (HRs) for associations between intimate care product use and breast, ovarian, and uterine cancers. To account for potential exposure misclassification and recall bias, we conducted quantitative bias analyses under various exposure reassignment assumptions. RESULTS: Across considered scenarios, 41%-64% of participants douched and 35%-56% used genital talc. In models adjusted for exposure misclassification, genital talc use was positively associated with ovarian cancer (HR range, 1.17-3.34) Frequent douching and douching during young adulthood were positively associated with ovarian cancer, but neither douching nor talc was associated with breast or uterine cancer. Differential reporting of talc use by cases and noncases likely produces positive biases, but correcting for error still resulted in HRs above 1.0. For example, HR, 1.40 (95% CI, 1.04 to 1.89) when 25% of exposed cases and 10% of unexposed noncases had talc status reassigned. CONCLUSION: Although results show how differential recall would upwardly bias estimates, corrected results support a positive association between use of intimate care products, including genital talc, and ovarian cancer.
Subject(s)
Breast Neoplasms , Ovarian Neoplasms , Talc , Humans , Female , Talc/adverse effects , Incidence , Breast Neoplasms/epidemiology , Middle Aged , Ovarian Neoplasms/epidemiology , Bias , Adult , Aged , Uterine Neoplasms/epidemiology , Cohort Studies , United States/epidemiologyABSTRACT
BACKGROUND: A high body mass index (BMI, kg/m2) is associated with decreased risk of breast cancer before menopause, but increased risk after menopause. Exactly when this reversal occurs in relation to menopause is unclear. Locating that change point could provide insight into the role of adiposity in breast cancer etiology. METHODS: We examined the association between BMI and breast cancer risk in the Premenopausal Breast Cancer Collaborative Group, from age 45 up to breast cancer diagnosis, loss to follow-up, death, or age 55, whichever came first. Analyses included 609,880 women in 16 prospective studies, including 9956 who developed breast cancer before age 55. We fitted three BMI hazard ratio (HR) models over age-time: constant, linear, or nonlinear (via splines), applying piecewise exponential additive mixed models, with age as the primary time scale. We divided person-time into four strata: premenopause; postmenopause due to natural menopause; postmenopause because of interventional loss of ovarian function (bilateral oophorectomy (BO) or chemotherapy); postmenopause due to hysterectomy without BO. Sensitivity analyses included stratifying by BMI in young adulthood, or excluding women using menopausal hormone therapy. RESULTS: The constant BMI HR model provided the best fit for all four menopausal status groups. Under this model, the estimated association between a five-unit increment in BMI and breast cancer risk was HR=0.87 (95% CI: 0.85, 0.89) before menopause, HR=1.00 (95% CI: 0.96, 1.04) after natural menopause, HR=0.99 (95% CI: 0.93, 1.05) after interventional loss of ovarian function, and HR=0.88 (95% CI: 0.76, 1.02) after hysterectomy without BO. CONCLUSION: The BMI breast cancer HRs remained less than or near one during the 45-55 year age range indicating that the transition to a positive association between BMI and risk occurs after age 55.
Subject(s)
Breast Neoplasms , Menopause , Adult , Female , Humans , Middle Aged , Young Adult , Body Mass Index , Breast Neoplasms/epidemiology , Breast Neoplasms/etiology , Breast Neoplasms/diagnosis , Premenopause , Prospective Studies , Risk FactorsABSTRACT
Importance: Changes in leukocyte composition often precede chronic disease onset. Patients with a history of breast cancer (hereinafter referred to as breast cancer survivors) are at increased risk for subsequent chronic diseases, but the long-term changes in peripheral leukocyte composition following a breast cancer diagnosis and treatment remain unknown. Objective: To examine longitudinal changes in peripheral leukocyte composition in women who did and did not develop breast cancer and identify whether differences in breast cancer survivors were associated with specific treatments. Design, Setting, and Participants: In this prospective cohort study, paired blood samples were collected from 2315 women enrolled in The Sister Study, a US-nationwide prospective cohort study of 50â¯884 women, at baseline (July 2003 to March 2009) and follow-up (October 2013 to March 2015) home visits, with a mean (SD) follow-up interval of 7.6 (1.4) years. By design, approximately half of the included women had been diagnosed and treated for breast cancer after enrollment and before the second blood draw. A total of 410 women were included in the present study, including 185 breast cancer survivors and 225 who remained free of breast cancer over a comparable follow-up period. Data were analyzed from April 21 to September 9, 2022. Exposures: Breast cancer status and, among breast cancer survivors, cancer treatment type (chemotherapy, radiotherapy, endocrine therapy, or surgery). Main Outcomes and Measures: Blood DNA methylation data were generated in 2019 using a genome-wide methylation screening tool and deconvolved to estimate percentages of 12 circulating leukocyte subsets. Results: Of the 410 women included in the analysis, the mean (SD) age at enrollment was 56 (9) years. Compared with breast cancer-free women, breast cancer survivors had decreased percentages of circulating eosinophils (-0.45% [95% CI, -0.87% to -0.03%]; P = .03), total CD4+ helper T cells (-1.50% [95% CI, -2.56% to -0.44%]; P = .01), and memory B cells (-0.22% [95% CI, -0.34% to -0.09%]; P = .001) and increased percentages of circulating naive B cells (0.46% [95% CI, 0.17%-0.75%]; P = .002). In breast cancer survivor-only analyses, radiotherapy was associated with decreases in total CD4+ T cell levels, whereas chemotherapy was associated with increases in naive B cell levels. Surgery and endocrine therapy were not meaningfully associated with leukocyte changes. Conclusions and Relevance: In this cohort study of 410 women, breast cancer survivors experienced lasting changes in peripheral leukocyte composition compared with women who remained free of breast cancer. These changes may be related to treatment with chemotherapy or radiotherapy and could influence future chronic disease risk.
Subject(s)
Breast Neoplasms , Humans , Female , Middle Aged , Breast Neoplasms/diagnosis , Breast Neoplasms/therapy , Cohort Studies , Prospective Studies , Leukocytes , Chronic DiseaseABSTRACT
BACKGROUND: Seasonal patterns in measured exposure biomarkers can cause measurement error in epidemiological studies. There is little research about the seasonality of metals and trace elements when assessed in toenail samples. Adjusting for such patterns in models for estimating associations between long-term exposures and health outcomes can potentially improve precision and reduce bias. OBJECTIVES: Assess and describe seasonal patterns in toenail measurements of trace elements. METHODS: The Sister Study enrolled women residing in the US, including Puerto Rico, whose sister had been diagnosed with breast cancer. At the time of enrollment, participants removed nail polish and collected their toenail clippings, which were cleaned before analysis. We considered the following elements: iron, vanadium, aluminum, chromium, manganese, cobalt, nickel, copper, zinc, arsenic, selenium, molybdenum, cadmium, tin, antimony, mercury, and lead. For two subsamples of the cohort, we fit trigonometric regression models with toenail element measures as the outcome, using sine and cosine functions of the collection day (transformed to an angle) to capture seasonal patterns. These models can estimate the amplitude and timing of the peaks in measures. We evaluated the evidence for a seasonal effect by comparing for each measured element the trigonometric model to a model that was constant across time. RESULTS: There was a seasonal trend in toenail element concentration for iron, aluminum, vanadium, chromium, manganese, cobalt, arsenic, molybdenum, cadmium, tin, and lead, all of which peaked near mid-August. Seasonal patterns were concordant across two non-overlapping samples of women, analyzed in different labs. DISCUSSION: Given the evidence supporting seasonal patterns for 11 of the 17 elements measured in toenails, correcting for seasonality of toenail levels of those trace elements in models estimating the association between those exposures and health outcomes is important. The basis for higher concentrations in toenails collected during the summer remains unknown.
ABSTRACT
Iron status is often assessed in epidemiologic studies, and toenails offer a convenient alternative to serum because of ease of collection, transport, and storage, and the potential to reflect a longer exposure window. Very few studies have examined the correlation between serum and toenail levels for trace metals. Our aim was to compare iron measures using serum and toenails on both a cross-sectional and longitudinal basis. Using a subset of the US-wide prospective Sister Study cohort, we compared toenail iron measures to serum concentrations for iron, ferritin and percent transferrin saturation. Among 146 women who donated both blood and toenails at baseline, a subsample (59%, n = 86) provided specimens about 8 years later. Cross-sectional analyses included nonparametric Spearman's rank correlations between toenail and serum biomarker levels. We assessed within-woman maintenance of rank across time for the toenail and serum measures and fit mixed effects models to measure change across time in relation to change in menopause status. Spearman correlations at baseline (follow-up) were 0.08 (0.09) for serum iron, 0.08 (0.07) for transferrin saturation, and - 0.09 (- 0.17) for ferritin. The within-woman Spearman correlation for toenail iron between the two time points was higher (0.47, 95% CI 0.30, 0.64) than for serum iron (0.30, 95% CI 0.09, 0.51) and transferrin saturation (0.34, 95% CI 0.15, 0.54), but lower than that for ferritin (0.58, 95% CI 0.43, 0.73). Serum ferritin increased over time while nail iron decreased over time for women who experienced menopause during the 8-years interval. Based on cross-sectional and repeated assessments, our evidence does not support an association between serum biomarkers and toenail iron levels. Toenail iron concentrations did appear to be moderately stable over time but cannot be taken as a proxy for serum iron biomarkers and they may reflect physiologically distinct fates for iron.
Subject(s)
Iron , Nails , Humans , Female , Iron/metabolism , Nails/metabolism , Follow-Up Studies , Prospective Studies , Postmenopause , Cross-Sectional Studies , Ferritins , Biomarkers , Transferrins , TransferrinABSTRACT
Vitamin D status has been inconsistently associated with ovarian reserve and menopause. We used data from the Sister Study cohort to examine the associations of vitamin D supplement use, total 25-hydroxyvitamin D (25OHD) level, and calcium supplement use with the timing of natural menopause. Vitamin D and calcium supplement use were assessed on a questionnaire at baseline (mean age: 46) and two follow-up time points, and characterized in multiple ways based on type, dose, and duration of use. Serum samples from a random subset of participants were analyzed for total 25OHD (25OHD3 + 25OHD2 + epi-25OHD3) using liquid chromatography-mass spectrometry. Menopause was assessed at each yearly follow-up with the question "Have you had a menstrual period in the past 12 months?"; if the response was "no", age at last menstrual period was recorded. We censored women at time of hysterectomy or medically induced menopause, death, loss to follow-up or October 2020. We used multivariable Cox proportional hazard models with age as the time scale to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs), adjusting for race/ethnicity, education, body mass index, alcohol use, smoking status, and physical activity. Among the 13,102 eligible premenopausal participants, 8897 experienced natural menopause during follow-up. Concomitant use of a multivitamin and a vitamin D supplement was associated with slightly earlier menopause (HR(CI): 1.10 (0.98, 1.24)). None of the remaining vitamin D or calcium supplement variables (alone or in combination) were meaningfully associated with timing of natural menopause. In a subsample with 25OHD measurements (n = 906), neither total 25OHD nor 25OHD3 was associated with timing of menopause. Our study includes, on average, 6 years of follow-up from an average age of 46 years and did not find associations between vitamin D or calcium supplement use and timing of menopause. Future studies should focus on a life course approach to this question and include 25OHD measures from early mid-life when examining menopause timing.
Subject(s)
Calcium , Vitamin D , Female , Humans , Vitamins , Menopause , Dietary SupplementsABSTRACT
BACKGROUND: Expansion of genome-wide association studies across population groups is needed to improve our understanding of shared and unique genetic contributions to breast cancer. We performed association and replication studies guided by a priori linkage findings from African ancestry (AA) relative pairs. METHODS: We performed fixed-effect inverse-variance weighted meta-analysis under three significant AA breast cancer linkage peaks (3q26-27, 12q22-23, and 16q21-22) in 9241 AA cases and 10 193 AA controls. We examined associations with overall breast cancer as well as estrogen receptor (ER)-positive and negative subtypes (193,132 SNPs). We replicated associations in the African-ancestry Breast Cancer Genetic Consortium (AABCG). RESULTS: In AA women, we identified two associations on chr12q for overall breast cancer (rs1420647, OR = 1.15, p = 2.50×10-6; rs12322371, OR = 1.14, p = 3.15×10-6), and one for ER-negative breast cancer (rs77006600, OR = 1.67, p = 3.51×10-6). On chr3, we identified two associations with ER-negative disease (rs184090918, OR = 3.70, p = 1.23×10-5; rs76959804, OR = 3.57, p = 1.77×10-5) and on chr16q we identified an association with ER-negative disease (rs34147411, OR = 1.62, p = 8.82×10-6). In the replication study, the chr3 associations were significant and effect sizes were larger (rs184090918, OR: 6.66, 95% CI: 1.43, 31.01; rs76959804, OR: 5.24, 95% CI: 1.70, 16.16). CONCLUSION: The two chr3 SNPs are upstream to open chromatin ENSR00000710716, a regulatory feature that is actively regulated in mammary tissues, providing evidence that variants in this chr3 region may have a regulatory role in our target organ. Our study provides support for breast cancer variant discovery using prioritization based on linkage evidence.
Subject(s)
Black People , Breast Neoplasms , Genetic Predisposition to Disease , Female , Humans , Black People/genetics , Breast Neoplasms/genetics , Genome-Wide Association Study , Polymorphism, Single NucleotideABSTRACT
Excess iron has been shown to promote tumor growth in animals whereas iron deficiency has been associated with reduced or slowed tumor growth. The objective of this analysis was to estimate the associations between serum iron biomarkers and tumor size at diagnosis and metastatic status in a sample of breast cancer cases from the Sister Study.The analytic sample included 2,494 incident breast cancer cases with information on tumor size and iron biomarkers, including serum iron (mcg/dL), ferritin (mcg/dL), and percent transferrin saturation, measured in serum collected at baseline. We used Spearman rank correlation and linear regression models to assess the associations between one SD changes in serum iron biomarker levels and natural log of tumor size (cm) adjusting for body mass index and age at study entry.We did not find strong associations between any of the three serum iron biomarkers and tumor size. Adjusted regression slopes (95% confidence interval) were -0.016 (-0.048 to 0.016) for serum iron, -0.032 (-0.064 to <0.001) for ferritin, and -0.010 (-0.043 to 0.023) for transferrin saturation.This study did not provide evidence supporting the hypothesis of a positive association between breast cancer tumor size at diagnosis and prediagnostic serum iron levels. Conflicting evidence between this study and previous research in animal models suggests that iron in the human tumor microenvironment may operate independently of circulating iron or body iron stores.Iron has shown protumorigenic activity in animal models, but our data do not support a positive relationship between breast tumor growth and iron status. SIGNIFICANCE: Using a large sample of women from a U.S. prospective cohort, we assessed associations between several serum iron measures at baseline and breast cancer tumor size and metastatic status. All estimated associations were close to zero with no evidence to support our hypothesis of higher body iron levels associated with larger tumor size. These results suggest the human tumor microenvironment operates independently of circulating serum iron levels.
Subject(s)
Breast Neoplasms , Iron , Humans , Female , Prospective Studies , Transferrin/analysis , Ferritins , Biomarkers , Tumor MicroenvironmentABSTRACT
BACKGROUND: Phthalate exposures are ubiquitous during pregnancy and may contribute to racial and ethnic disparities in preterm birth. OBJECTIVES: We investigated race and ethnicity in the relationship between biomarkers of phthalate exposure and preterm birth by examining: a) how hypothetical reductions in racial and ethnic disparities in phthalate metabolites might reduce the probability of preterm birth; and b) exposure-response models stratified by race and ethnicity. METHODS: We pooled individual-level data on 6,045 pregnancies from 16 U.S. cohorts. We investigated covariate-adjusted differences in nine urinary phthalate metabolite concentrations by race and ethnicity [non-Hispanic White (White, 43%), non-Hispanic Black (Black, 13%), Hispanic/Latina (38%), and Asian/Pacific Islander (3%)]. Using g-computation, we estimated changes in the probability of preterm birth under hypothetical interventions to eliminate disparities in levels of urinary phthalate metabolites by proportionally lowering average concentrations in Black and Hispanic/Latina participants to be approximately equal to the averages in White participants. We also used race and ethnicity-stratified logistic regression to characterize associations between phthalate metabolites and preterm birth. RESULTS: In comparison with concentrations among White participants, adjusted mean phthalate metabolite concentrations were consistently higher among Black and Hispanic/Latina participants by 23%-148% and 4%-94%, respectively. Asian/Pacific Islander participants had metabolite levels that were similar to those of White participants. Hypothetical interventions to reduce disparities in metabolite mixtures were associated with lower probabilities of preterm birth for Black [13% relative reduction; 95% confidence interval (CI): -34%, 8.6%] and Hispanic/Latina (9% relative reduction; 95% CI: -19%, 0.8%) participants. Odds ratios for preterm birth in association with phthalate metabolites demonstrated heterogeneity by race and ethnicity for two individual metabolites (mono-n-butyl and monoisobutyl phthalate), with positive associations that were larger in magnitude observed among Black or Hispanic/Latina participants. CONCLUSIONS: Phthalate metabolite concentrations differed substantially by race and ethnicity. Our results show hypothetical interventions to reduce population-level racial and ethnic disparities in biomarkers of phthalate exposure could potentially reduce the probability of preterm birth. https://doi.org/10.1289/EHP12831.
Subject(s)
Maternal Exposure , Phthalic Acids , Premature Birth , Female , Humans , Infant, Newborn , Pregnancy , Biomarkers , Ethnicity , Premature Birth/epidemiology , Maternal Exposure/adverse effects , Phthalic Acids/adverse effects , Racial GroupsABSTRACT
Serum iron levels can be important contributors to health outcomes, but it is not often feasible to rely on blood-based measures for a large epidemiologic study. Predictive models that use questionnaire-based factors such as diet, supplement use, recency of blood donation, and medical conditions could potentially provide a noninvasive alternative for studying health effects associated with iron status. We hypothesized that a model based on questionnaire data could predict blood-based measures of iron status biomarkers. Using iron (mcg/dL), ferritin (mcg/dL), and transferrin saturation (%) based on blood collected at study entry, in a subsample from the U.S.-wide Sister Study (n = 3171), we developed and validated a prediction model for iron with multivariable linear regression models. Model performance based on these cross-sectional data was weak, with R2 less than 0.10 for serum iron and transferrin saturation, but better for ferritin, with an R2 of 0.13 in premenopausal women and 0.19 in postmenopausal women. When menopause was included in the predictive model for the sample, the R2 was 0.31 for ferritin. Internal validation of the estimates indicated some optimism present in the observed prediction model, implying there would be worse performance when applied to new samples from the same population. Serum iron status is hard to assess based only on questionnaire data. Reducing measurement error in both the exposure and outcome may improve the prediction model performance, but environmental heterogeneity, temporal variation, and genetic heterogeneity in absorption and storage may contribute substantially to iron status.
Subject(s)
Hemoglobins , Iron , Humans , Female , Iron/metabolism , Cross-Sectional Studies , Hemoglobins/metabolism , Ferritins , Transferrins , TransferrinABSTRACT
Objective: Recent studies report high-titer anti-dense fine speckled 70 (DFS70) autoantibodies in persons with inflammatory conditions, but the clinical significance remains unclear. Our goals were to estimate anti-DFS70 autoantibody prevalence, identify correlates, and assess time trends. Methods: Serum antinuclear antibodies (ANA) were measured by indirect immunofluorescence assay on HEp-2 cells in 13,519 participants ≥12 years old from three time periods (1988-1991, 1999-2004, 2011-2012) of the National Health and Nutrition Examination Survey. ANA-positive participants with dense fine speckled staining were evaluated for anti-DFS70 antibodies by enzyme-linked immunosorbent assay. We used logistic models adjusted for survey-design variables to estimate period-specific anti-DFS70 antibody prevalence in the US, and we further adjusted for sex, age, and race/ethnicity to identify correlates and assess time trends. Results: Women were more likely than men (odds ratio (OR)=2.97), black persons were less likely than white persons (OR=0.60), and active smokers were less likely than nonsmokers (OR=0.28) to have anti-DFS70 antibodies. The prevalence of anti-DFS70 antibodies increased from 1.6% in 1988-1991 to 2.5% in 1999-2004 to 4.0% in 2011-2012, which corresponds to 3.2 million, 5.8 million, and 10.4 million seropositive individuals, respectively. This increasing time trend in the US population (P<0.0001) was modified in some subgroups and was not explained by concurrent changes in tobacco smoke exposure. Some, but not all, anti-DFS70 antibody correlates and time trends resembled those reported for total ANA. Conclusion: More research is needed to elucidate anti-DFS70 antibody triggers, their pathologic or potentially protective influences on disease, and their possible clinical implications.
Subject(s)
Antibodies, Antinuclear , Autoantibodies , Female , Humans , Male , Adaptor Proteins, Signal Transducing , Nutrition Surveys , Prevalence , United States/epidemiologyABSTRACT
BACKGROUND: Breast cancer survivors have increased incidence of age-related diseases, suggesting that some survivors may experience faster biological aging. METHODS: Among 417 women enrolled in the prospective Sister Study cohort, DNA methylation data were generated on paired blood samples collected an average of 7.7 years apart and used to calculate 3 epigenetic metrics of biological aging (PhenoAgeAccel, GrimAgeAccel, and Dunedin Pace of Aging Calculated from the Epigenome [DunedinPACE]). Approximately half (n = 190) the women sampled were diagnosed and treated for breast cancer between blood draws, whereas the other half (n = 227) remained breast cancer-free. Breast tumor characteristics and treatment information were abstracted from medical records. RESULTS: Among women who developed breast cancer, diagnoses occurred an average of 3.5 years after the initial blood draw and 4 years before the second draw. After accounting for covariates and biological aging metrics measured at baseline, women diagnosed and treated for breast cancer had higher biological aging at the second blood draw than women who remained cancer-free as measured by PhenoAgeAccel (standardized mean difference [ß] = 0.13, 95% confidence interval [CI) = 0.00 to 0.26), GrimAgeAccel (ß = 0.14, 95% CI = 0.03 to 0.25), and DunedinPACE (ß = 0.37, 95% CI = 0.24 to 0.50). In case-only analyses assessing associations with different breast cancer therapies, radiation had strong positive associations with biological aging (PhenoAgeAccel: ß = 0.39, 95% CI = 0.19 to 0.59; GrimAgeAccel: ß = 0.29, 95% CI = 0.10 to 0.47; DunedinPACE: ß = 0.25, 95% CI = 0.02 to 0.48). CONCLUSIONS: Biological aging is accelerated following a breast cancer diagnosis and treatment. Breast cancer treatment modalities appear to differentially contribute to biological aging.
Subject(s)
Breast Neoplasms , Cancer Survivors , Female , Humans , Breast Neoplasms/epidemiology , Breast Neoplasms/genetics , Breast Neoplasms/therapy , Prospective Studies , Aging/genetics , DNA Methylation , Epigenesis, GeneticABSTRACT
Seasonal patterns in measured exposure biomarkers can cause measurement error in epidemiological studies. There is little known about the seasonality of trace elements when measured in toenails. Adjusting for such patterns when estimating associations between long-term exposures and health outcomes could be needed to improve precision and reduce bias. Our goal was to assess seasonal patterns in toenail measurements of trace elements. At enrollment, Sister Study participants, who were US residents, removed polish and collected toenail clippings, which were cleaned before analysis. We measured: iron, vanadium, aluminum, chromium, manganese, cobalt, nickel, copper, zinc, arsenic, selenium, molybdenum, cadmium, tin, antimony, mercury, and lead. For a sample of the cohort we fit trigonometric regression models with toenail element measures as the outcome, using sine and cosine functions of the collection day of the year (transformed to an angle) to assess seasonality. Results were replicated in a second sample of women, with measurements done in a separate lab. There was a seasonal association between day of collection and toenail measures for iron, aluminum, vanadium, chromium, manganese, cobalt, arsenic, molybdenum, cadmium, tin, and lead, all of which peaked near mid-August. Seasonal patterns were concordant across the two samples of women. Given the evidence supporting seasonal patterns for 11 of the 17 elements measured in toenails, correcting for seasonality of toenail levels of those trace elements in models estimating the association between those exposures and health outcomes is important. The basis for higher concentrations in toenails collected during the summer remains unknown.
ABSTRACT
BACKGROUND: Fecundability (conception rate per menstrual cycle) varies among non-contracepting couples. Time-to-pregnancy studies can identify exposures contributing to that variability, using three designs: incident cohort, prevalent cohort, and retrospective. Typically, researchers then apply semi-parametric, generalized linear time-to-pregnancy models to data, with either a log or a logit "link," to estimate either a fecundability ratio (FR) or a fecundability odds ratio (FOR). The ongoing-attempt study design can also be informative. METHODS: We consider a different generalized linear model, based on an inverse link. It models the heterogeneity as beta distributed and enables estimation of both the FR and FOR, defined based on population mean fecundabilities, without requiring constancy across attempt time. Under an ongoing-attempt design, the parameter associated with a dichotomous exposure has no clear meaning with a log or a logit link, but under the proposed approach estimates the ratio of the two average times to pregnancy. Basing simulations on conception rates from a large study, we compare the three analytic approaches for confidence interval coverage and power. We also assess the performance of a commonly used method for verifying the constancy of FOR or FR across time. RESULTS: The inverse-link approach had slightly less power than the others, but its estimates maintained nominal confidence interval coverage under nonconstancy. A popular method for testing constancy across time for the FR and FOR had poor power. CONCLUSIONS: The inverse-link analysis offers a useful alternative to the usual methods, with estimation performance that generalizes to the ongoing-attempt design and does not require hard-to-verify constancy assumptions.
Subject(s)
Menstrual Cycle , Time-to-Pregnancy , Female , Pregnancy , Humans , Retrospective Studies , Linear Models , Odds RatioABSTRACT
Coronavirus disease 2019 (COVID-19) vaccines have been reported to have a short-term effect on the menstrual cycle, delaying the onset of the next menses. However, the analytical methods that have been used to study this are subject to a statistical phenomenon called "length-biased sampling" that calls the results into question. Those data are important and should be reanalyzed in an unbiased way.
Subject(s)
COVID-19 Vaccines , COVID-19 , Female , Humans , COVID-19/epidemiology , COVID-19/prevention & control , Menstrual Cycle , Time Factors , VaccinationABSTRACT
PURPOSE: To estimate the risk of contralateral breast cancer (CBC) among women with germline pathogenic variants (PVs) in ATM, BRCA1, BRCA2, CHEK2, and PALB2. METHODS: The study population included 15,104 prospectively followed women within the CARRIERS study treated with ipsilateral surgery for invasive breast cancer. The risk of CBC was estimated for PV carriers in each gene compared with women without PVs in a multivariate proportional hazard regression analysis accounting for the competing risk of death and adjusting for patient and tumor characteristics. The primary analyses focused on the overall cohort and on women from the general population. Secondary analyses examined associations by race/ethnicity, age at primary breast cancer diagnosis, menopausal status, and tumor estrogen receptor (ER) status. RESULTS: Germline BRCA1, BRCA2, and CHEK2 PV carriers with breast cancer were at significantly elevated risk (hazard ratio > 1.9) of CBC, whereas only the PALB2 PV carriers with ER-negative breast cancer had elevated risks (hazard ratio, 2.9). By contrast, ATM PV carriers did not have significantly increased CBC risks. African American PV carriers had similarly elevated risks of CBC as non-Hispanic White PV carriers. Among premenopausal women, the 10-year cumulative incidence of CBC was estimated to be 33% for BRCA1, 27% for BRCA2, and 13% for CHEK2 PV carriers with breast cancer and 35% for PALB2 PV carriers with ER-negative breast cancer. The 10-year cumulative incidence of CBC among postmenopausal PV carriers was 12% for BRCA1, 9% for BRCA2, and 4% for CHEK2. CONCLUSION: Women diagnosed with breast cancer and known to carry germline PVs in BRCA1, BRCA2, CHEK2, or PALB2 are at substantially increased risk of CBC and may benefit from enhanced surveillance and risk reduction strategies.
Subject(s)
Breast Neoplasms , Genetic Predisposition to Disease , Female , Humans , Ataxia Telangiectasia Mutated Proteins/genetics , Black or African American/genetics , Black or African American/statistics & numerical data , BRCA1 Protein/genetics , BRCA2 Protein/genetics , Breast Neoplasms/epidemiology , Breast Neoplasms/ethnology , Breast Neoplasms/genetics , Breast Neoplasms/surgery , Checkpoint Kinase 2/genetics , Fanconi Anemia Complementation Group N Protein/genetics , Genes, BRCA2 , Genetic Predisposition to Disease/genetics , Germ-Line Mutation , Heterozygote , White/genetics , White/statistics & numerical dataABSTRACT
BACKGROUND: The development and consequences of hypertension involve multiple biological systems that may include changes in immune profiles. Whether hypertension is related to peripheral immune cell composition has not been examined in large human cohorts. METHODS: We estimated circulating proportions of 12 leukocyte subsets from the lymphoid and myeloid lineages by deconvolving cell-type-specific DNA methylation data from 4124 women. Hypertension status at baseline was defined by current use of antihypertensive medication and blood pressure measurements while new incident cases were identified during follow-up via annual health questionnaires. RESULTS: Among hypertension-free women at baseline, higher B cell and lower naïve CD4+ helper T cell proportions were associated with subsequent increased hazard of hypertension incidence (B cells; adjusted HR: 1.17 [95% CI: 1.02-1.35]; P=0.03; naïve CD4+ T cell, adjusted HR: 0.88 [95% CI: 0.78-0.99]; P=0.04). Blood pressure measurements at baseline were similarly positively associated with B cells and inversely associated with naïve CD4+ helper T cells. Compared to normotensive women, women with hypertension had higher circulating proportions of neutrophils (adjusted odds ratio: 1.18 [95% CI: 1.07-1.31]; P=0.001) and lower proportions of CD4+ helper T cells (adjusted odds ratio: 0.90 [95% CI: 0.81-1.00] P=0.05), natural killers (adjusted odds ratio: 0.82 [95% CI: 0.74-0.91]; P<0.001), and B cells (adjusted odds ratio: 0.84 [95% CI: 0.74-0.96]; P=0.01). CONCLUSIONS: These observations suggest that shifts in lymphocyte subsets occur before hypertension development, followed by later changes to neutrophils and additional lymphocytes.
Subject(s)
Humans , FemaleABSTRACT
STUDY QUESTION: Are urinary phenol concentrations of methylparaben, propylparaben, butylparaben, triclosan, benzophenone-3, 2,4-dichlorophenol or 2,5-dichlorophenol associated with fecundability and early pregnancy loss? SUMMARY ANSWER: 2,5-dichlorophenol concentrations were associated with an increased odds of early pregnancy loss, and higher concentrations of butylparaben and triclosan were associated with an increase in fecundability. WHAT IS KNOWN ALREADY: Phenols are chemicals with endocrine-disrupting potential found in everyday products. Despite plausible mechanisms of phenol reproductive toxicity, there are inconsistent results across few epidemiologic studies examining phenol exposure and reproductive function in non-fertility treatment populations. STUDY DESIGN, SIZE, DURATION: Specimens and data were from the North Carolina Early Pregnancy Study prospective cohort of 221 women attempting to conceive naturally from 1982 to 1986. This analysis includes data from 221 participants across 706 menstrual cycles, with 135 live births, 15 clinical miscarriages and 48 early pregnancy losses (before 42 days after the last menstrual period). PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants collected daily first-morning urine specimens. For each menstrual cycle, aliquots from three daily specimens across the cycle were pooled within individuals and analyzed for phenol concentrations. To assess sample repeatability, we calculated intraclass correlation coefficients (ICCs) for each phenol. We evaluated associations between phenol concentrations from pooled samples and time to pregnancy using discrete-time logistic regression and generalized estimating equations (GEE), and early pregnancy loss using multivariable logistic regression and GEE. MAIN RESULTS AND THE ROLE OF CHANCE: ICCs for within-person variability across menstrual cycles in pooled phenol concentrations ranged from 0.42 to 0.75. There was an increased odds of early pregnancy loss with 2,5-dichlorophenol concentrations although the CIs were wide (5th vs 1st quintile odds ratio (OR): 4.79; 95% CI: 1.06, 21.59). There was an increased per-cycle odds of conception at higher concentrations of butylparaben (OR: 1.62; 95% CI: 1.08, 2.44) and triclosan (OR: 1.49; 95% CI: 0.99, 2.26) compared to non-detectable concentrations. No associations were observed between these endpoints and concentrations of other phenols examined. LIMITATIONS, REASONS FOR CAUTION: Limitations include the absence of phenol measurements for male partners and a limited sample size, especially for the outcome of early pregnancy loss, which reduced our power to detect associations. WIDER IMPLICATIONS OF THE FINDINGS: This study is the first to use repeated pooled measures to summarize phenol exposure and the first to investigate associations with fecundability and early pregnancy loss. Within-person phenol concentration variability underscores the importance of collecting repeated samples for future studies. Exposure misclassification could contribute to differences between the findings of this study and those of other studies, all of which used one urine sample to assess phenol exposure. This study also contributes to the limited literature probing potential associations between environmental exposures and early pregnancy loss, which is a challenging outcome to study as it typically occurs before a pregnancy is clinically recognized. STUDY FUNDING/COMPETING INTEREST(S): This research was supported by the National Institute of Environmental Health Sciences of the National Institutes of Health (award number F31ES030594), the Intramural Research Program of the National Institutes of Health, the National Institute of Environmental Health Sciences (project numbers ES103333 and ES103086) and a doctoral fellowship at the Yale School of Public Health. The authors declare they have no competing interests to disclose. TRIAL REGISTRATION NUMBER: N/A.
Subject(s)
Abortion, Spontaneous , Triclosan , Pregnancy , Male , Humans , Female , Abortion, Spontaneous/chemically induced , Abortion, Spontaneous/epidemiology , Phenol , Prospective Studies , Triclosan/adverse effects , Fertility , Phenols/adverse effects , Phenols/urineABSTRACT
OBJECTIVE: Growing evidence suggests increasing frequencies of autoimmunity and autoimmune diseases, but findings are limited by the lack of systematic data and evolving approaches and definitions. This study was undertaken to investigate whether the prevalence of antinuclear antibodies (ANA), the most common biomarker of autoimmunity, changed over a recent 25-year span in the US. METHODS: Serum ANA were measured by standard indirect immunofluorescence assays on HEp-2 cells in 13,519 participants age ≥12 years from the National Health and Nutrition Examination Survey, with approximately one-third from each of 3 time periods: 1988-1991, 1999-2004, and 2011-2012. We used logistic regression adjusted for sex, age, race/ethnicity, and survey design variables to estimate changes in ANA prevalence across the time periods. RESULTS: The prevalence of ANA was 11.0% (95% confidence interval [95% CI] 9.7-12.6%) in 1988-1991, 11.4% (95% CI 10.2-12.8%) in 1999-2004, and 16.1% (95% CI 14.4-18.0%) in 2011-2012 (P for trend <0.0001), corresponding to ~22.3 million, ~26.6 million, and ~41.5 million affected individuals, respectively. Among adolescents age 12-19 years, ANA prevalence increased substantially, with odds ratios of 2.07 (95% CI 1.18-3.64) and 2.77 (95% CI 1.56-4.91) in the second and third time periods relative to the first (P for trend = 0.0004). ANA prevalence increased in both sexes (especially in men), older adults (age ≥50 years), and non-Hispanic white individuals. These increases in ANA prevalence were not explained by concurrent trends in weight (obesity/overweight), smoking exposure, or alcohol consumption. CONCLUSION: The prevalence of ANA in the US has increased considerably in recent years. Additional studies to determine factors underlying these increases in ANA prevalence could elucidate causes of autoimmunity and enable the development of preventative measures.