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The 2018 World Cancer Research Fund/American Institute for Cancer Research recommends sustained strategies of physical activity and diet for cancer prevention, but evidence for long-term prostate cancer risk is limited. Using observational data from 27,859 men in the Health Professionals Follow-up Study, we emulated a target trial of recommendation-based physical activity and dietary strategies and 26-year risks of prostate cancer, adjusting for risk factors via the parametric g-formula. Compared with no intervention, limiting sugar-sweetened beverages showed a 0.4% (0.0-0.9%) lower risk of lethal (metastatic or fatal) disease and 0.5% (0.1-0.9%) lower risk of fatal disease. Restricting consumption of processed foods showed a 0.4-0.9% higher risk of all prostate cancer outcomes. Estimated risk differences for clinically significant disease were close to null for strategies involving fruits and non-starchy vegetables, whole grains and legumes, red meat, and processed meat, as well as under a joint strategy of physical activity and diet. Compared with a "low adherence" strategy, maintaining recommended physical activity levels showed a 0.4% (0.1-0.8%) lower risk of lethal and 0.5% (0.2-0.8%) lower risk of fatal disease. Adhering to specific components of current physical activity and dietary recommendations may help to prevent lethal and fatal prostate cancer over 26 years.
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A priority of nutrition science is to identify dietary determinants of health and disease to inform effective public health policies, guidelines, and clinical interventions. Yet, conflicting findings in synthesizing evidence from randomized trials and observational data has contributed to confusion and uncertainty. Often, heterogeneity can be explained by the fact that seemingly similar bodies of evidence are asking very different questions. Improving the alignment within and between research domains begins with investigators clearly defining their diet-disease questions; however, nutritional exposures are complex and often require a greater degree of specificity. First, dietary data are compositional, meaning a change in a food may imply a compensatory change of other foods. Second, dietary data are multidimensional; that is, the primary components (i.e., foods) are comprised of sub-components (e.g., nutrients), and sub-components can be present in multiple primary components. Third, because diet is a lifelong exposure, the composition of a study population's background diet has implications on the interpretation of the exposure and the transportability of effect estimates. Collectively clarifying these key aspects of inherently complex dietary exposures when conducting research will facilitate appropriate evidence synthesis, improve certainty of evidence, and improve the ability of these efforts to inform policy and decision-making.
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OBJECTIVE: We emulated a modified randomized trial (Metformin in Women With Type 2 Diabetes in Pregnancy [MiTy]) to compare the perinatal outcomes in women continuing versus discontinuing metformin during pregnancy among those with type 2 diabetes treated with metformin plus insulin before pregnancy. RESEARCH DESIGN AND METHODS: This study used two health care claims databases (United States, 2000-2020). Pregnant women age 18-45 years with type 2 diabetes who were treated with metformin plus insulin at conception were eligible. The primary outcome was a composite of preterm birth, birth injury, neonatal respiratory distress, neonatal hypoglycemia, and neonatal intensive care unit admission. Secondary outcomes included the components of the primary composite outcome, gestational hypertension, preeclampsia, maternal hypoglycemia, cesarean delivery, infants large for gestational age, infants small for gestational age (SGA), sepsis, and hyperbilirubinemia. We adjusted for potential baseline confounders, including demographic characteristics, comorbidities, and proxies for diabetes progression. RESULTS: Of 2,983 eligible patients, 72% discontinued use of metformin during pregnancy. The average age at conception was 32 years, and the prevalence of several comorbidities was higher among continuers. The risk of the composite outcome was 46% for continuers and 48% for discontinuers. The adjusted risk ratio was 0.92 (95% CI 0.81, 1.03). Risks were similar between treatments and consistent between databases for most secondary outcomes, except for SGA, which was elevated in continuers only in the commercially insured population. CONCLUSIONS: Our findings were consistent with those reported in the MiTy randomized trial. Continuing metformin during pregnancy was not associated with increased risk of a neonatal composite adverse outcome. However, a possible metformin-associated risk of SGA warrants further consideration.
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BACKGROUND: Metformin is a first-line pharmacotherapy for type 2 diabetes, but there is limited evidence about its safety in early pregnancy. OBJECTIVE: To evaluate the teratogenicity of metformin use in the first trimester of pregnancy. DESIGN: In an observational cohort of pregnant women with pregestational type 2 diabetes receiving metformin monotherapy before the last menstrual period (LMP), a target trial with 2 treatment strategies was emulated: insulin monotherapy (discontinue metformin treatment and initiate insulin within 90 days of LMP) or insulin plus metformin (continue metformin and initiate insulin within 90 days of LMP). SETTING: U.S. Medicaid health care administration database (2000 to 2018). PARTICIPANTS: 12 489 pregnant women who met the eligibility criteria. MEASUREMENTS: The risk and risk ratio of nonlive births, live births with congenital malformations, and congenital malformations among live births were estimated using standardization to adjust for covariates. RESULTS: A total of 850 women were in the insulin monotherapy group and 1557 in the insulin plus metformin group. The estimated risk for nonlive birth was 32.7% under insulin monotherapy (reference) and 34.3% under insulin plus metformin (risk ratio, 1.02 [95% CI, 1.01 to 1.04]). The estimated risk for live birth with congenital malformations was 8.0% (CI, 5.7% to 10.2%) under insulin monotherapy and 5.7% (CI, 4.5% to 7.3%) under insulin plus metformin (risk ratio, 0.72 [CI, 0.51 to 1.09]). LIMITATION: Possible residual confounding by glycemic control and body mass index. CONCLUSION: Compared with switching to insulin monotherapy, continuing metformin and adding insulin in early pregnancy resulted in little to no increased risk for nonlive birth among women receiving metformin before pregnancy. Under conventional statistical criteria, anything between a 49% decrease and a 9% increase in risk for congenital malformations was highly compatible with our data. PRIMARY FUNDING SOURCE: National Institutes of Health.
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Anomalías Inducidas por Medicamentos , Diabetes Mellitus Tipo 2 , Hipoglucemiantes , Insulina , Metformina , Primer Trimestre del Embarazo , Embarazo en Diabéticas , Humanos , Metformina/efectos adversos , Metformina/uso terapéutico , Femenino , Embarazo , Hipoglucemiantes/efectos adversos , Hipoglucemiantes/uso terapéutico , Adulto , Anomalías Inducidas por Medicamentos/epidemiología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Insulina/efectos adversos , Insulina/uso terapéutico , Embarazo en Diabéticas/tratamiento farmacológico , Quimioterapia Combinada , Estados Unidos , Factores de RiesgoRESUMEN
Fertility procedures recorded in health-care databases can be used to estimate the start of pregnancy, which can serve as a reference standard to validate gestational age estimates based on International Classification of Diseases codes. In a cohort of 17 398 US MarketScan pregnancies (2011-2020) in which conception was achieved via fertility procedures, we estimated gestational age at the end of pregnancy using algorithms based on (1) time (days) since the fertility procedure (the reference standard); (2) International Classification of Diseases, Ninth Revision (ICD-9)/International Classification of Diseases, Tenth Revision (ICD-10) (before/after October 2015) codes indicating gestational length recorded at the end of pregnancy (method A); and (3) ICD-10 end-of-pregnancy codes enhanced with Z3A codes denoting specific gestation weeks recorded at prenatal visits (method B). We calculated the proportion of pregnancies with an estimated gestational age falling within 14 days ($\pm$14 days) of the reference standard. Method A accuracy was similar for ICD-9 and ICD-10 codes. After 2015, method B was more accurate than method A: For term births, within-14-day agreement was 90.8% for method A and 98.7% for method B. Corresponding estimates were 70.1% and 95.6% for preterm births; 35.3% and 92.6% for stillbirths; 54.3% and 64.2% for spontaneous abortions; and 16.7% and 84.6% for elective terminations. ICD-10-based algorithms that incorporate Z3A codes improve the accuracy of gestational age estimation in health-care databases, especially for preterm births and non-live births.
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Algoritmos , Bases de Datos Factuales , Edad Gestacional , Clasificación Internacional de Enfermedades , Humanos , Femenino , Embarazo , Adulto , Técnicas Reproductivas Asistidas/estadística & datos numéricos , Estados Unidos , Adulto JovenRESUMEN
We used design principles of target trial methodology to emulate the effect of sustained adherence to the Dietary Approaches to Stop Hypertension (DASH) diet on the 22-year risk of heart failure. Women and men aged 45-83 years without previous heart failure, who answered questionnaires in 1997 from the Swedish Mammography Cohort and the Cohort of Swedish Men, were eligible. Follow-up questionnaires were sent in 2008-2009. Incidence of heart failure was ascertained using the Swedish Patient Register, updated until December 31, 2019. The parametric g-formula was used to estimate the 22-year risk of heart failure under sustained adherence to a population-adapted DASH diet compared with no intervention. Intakes before 1997 for before-baseline adjustment was available only for women. In total, 31,238 women and 34,939 men were eligible. The 22-year risk of heart failure was 14.5% with long-term adherence to the DASH diet compared with 15.2% with no intervention (risk difference = -0.7%, 95% confidence interval: 1.6, 0.0%) in women and correspondingly in men 15.3% vs. 16.2% (risk difference = -0.9%, 95% confidence interval: -1.6, -0.2%). Our hypothetical intervention suggests that sustained adherence to the population-adapted DASH diet may reduce risk of heart failure in middle-aged and elderly Swedish women and men.
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Enfoques Dietéticos para Detener la Hipertensión , Insuficiencia Cardíaca , Hipertensión , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dieta , Enfoques Dietéticos para Detener la Hipertensión/métodos , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/prevención & control , Hipertensión/epidemiología , Hipertensión/prevención & control , IncidenciaRESUMEN
BACKGROUND: The association between assisted reproductive technologies (ARTs) and the body mass index (BMI) of children remains controversial. Confounding by morbidity and other factors associated with parental infertility may have biased studies comparing children born after ART with children born after no treatment. We investigated the associations between different fertility treatments and BMI in children at age 5 to 8 years, adjusting for and stratifying by causes of parental infertility. METHODS AND FINDINGS: This Danish cohort study included 327,301 children born between 2007 and 2012 (51% males, median age at follow-up 7 years). Of these, 13,675 were born after ART, 7,728 were born after ovulation induction with or without intrauterine insemination [OI/IUI], and 305,898 were born after no fertility treatments. Using the International Obesity Task Force (IOTF) standards, we defined overweight (BMI ≥ IOTF-25) and obesity (BMI ≥ IOTF-30). We compared children born after ART versus OI/IUI; intracytoplasmic sperm injection (ICSI) versus conventional in vitro fertilization (IVF); and frozen-thawed versus fresh embryo transfer and estimated crude and adjusted prevalences of children with overweight or obesity at age 5 to 8 years, prevalence odds ratios (PORs), and differences in mean BMI z-scores. Adjustment was performed using stabilized inverse probability of treatment weights, including parity, year of conception, parental causes of infertility, age, educational level, comorbidities, maternal country of origin, BMI, and smoking as covariates. The crude prevalence of obesity was 1.9% in children born after ART, 2.0% in those born after OI/IUI, and 2.7% in those born after no fertility treatment. After adjustment, children born after ART and OI/IUI had the same prevalence of being overweight (11%; POR 1.00, 95% confidence interval [CI] 0.91 to 1.11; p = 0.95) or obese (1.9%; POR 1.01, 95% CI 0.79 to 1.29; p = 0.94). Comparison of ICSI with conventional IVF yielded similar pattern (POR 0.95, 95% CI 0.83 to 1.07; p = 0.39 for overweight and POR 1.16, 95% CI 0.84 to 1.61; p = 0.36 for obesity). Obesity was more prevalent after frozen-thawed (2.7%) than fresh embryo transfer (1.8%) (POR 1.54, 95% CI 1.09 to 2.17; p = 0.01). The associations between fertility treatments and BMI were only modestly different in subgroups defined by the cause of infertility. Study limitations include potential residual confounding, restriction to live births, and lack of detailed technical information about the IVF procedures. CONCLUSIONS: We found no association with BMI at age 5 to 8 years when comparing ART versus OI/IUI or when comparing ICSI versus conventional IVF. However, use of frozen-thawed embryo transfer was associated with a 1.5-fold increased risk of obesity compared to fresh embryo transfer. Despite an elevated relative risk, the absolute risk difference was low.
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Infertilidad , Obesidad Infantil , Embarazo , Femenino , Niño , Masculino , Humanos , Preescolar , Estudios de Cohortes , Obesidad Infantil/epidemiología , Obesidad Infantil/etiología , Obesidad Infantil/terapia , Sobrepeso/epidemiología , Sobrepeso/etiología , Semen , Técnicas Reproductivas Asistidas/efectos adversos , Infertilidad/epidemiología , Infertilidad/terapia , Dinamarca/epidemiologíaRESUMEN
Background: Surgeon shortages have emerged as a prominent global issue. Although various studies have explored the factors that influence medical students in choosing surgery as a career, addressing the need for surgeons requires a multifaceted approach. However, there is currently a lack of a theoretically grounded scale to evaluate the effectiveness of surgical career development or policy promotion. Thus, this study aimed to develop a questionnaire for assessing the preference for a surgical career by adopting the Social Cognitive Career Theory (SCCT). Materials and methods: The study aimed to develop the Social Cognitive Career Theory Scale toward Surgery (SCCTSS) by adopting the framework of SCCT. The questionnaire was created through expert consensus and the content validity index (CVI) calculation. Subsequently, a pilot version of the SCCTSS was administered to 222 medical students in their clinical clerkships, and the collected data underwent item analysis. Additionally, the validation of the SCCTSS by gender was performed. Results: The SCCTSS comprised 16 items that passed expert panel evaluation, with a CVI >0.8, mean ≥ 3.00, and an interquartile range ≤1. Item analysis demonstrated that the quality of the SCCTSS met the qualifying threshold. Furthermore, the SCCTSS questionnaire effectively validated gender differences in surgical career preference. Conclusions: We developed an internally consistent and reliable scale and validated it through an expert panel method and feedback from medical students. Further research is required to evaluate the targeted interventions that may assist in recruiting medical students into the field of surgery through the application of the SCCTSS.
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The noniterative conditional expectation (NICE) parametric g-formula can be used to estimate the causal effect of sustained treatment strategies. In addition to identifiability conditions, the validity of the NICE parametric g-formula generally requires the correct specification of models for time-varying outcomes, treatments, and confounders at each follow-up time point. An informal approach for evaluating model specification is to compare the observed distributions of the outcome, treatments, and confounders with their parametric g-formula estimates under the "natural course." In the presence of loss to follow-up, however, the observed and natural-course risks can differ even if the identifiability conditions of the parametric g-formula hold and there is no model misspecification. Here, we describe 2 approaches for evaluating model specification when using the parametric g-formula in the presence of censoring: 1) comparing factual risks estimated by the g-formula with nonparametric Kaplan-Meier estimates and 2) comparing natural-course risks estimated by inverse probability weighting with those estimated by the g-formula. We also describe how to correctly compute natural-course estimates of time-varying covariate means when using a computationally efficient g-formula algorithm. We evaluate the proposed methods via simulation and implement them to estimate the effects of dietary interventions in 2 cohort studies.
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Modelos Estadísticos , Humanos , Simulación por Computador , Probabilidad , Causalidad , Estimación de Kaplan-Meier , Estudios de CohortesRESUMEN
BACKGROUND: Observational studies are often the only option to estimate effects of interventions during pregnancy. Causal inference from observational data can be conceptualized as an attempt to emulate a hypothetical pragmatic randomized trial: the target trial. OBJECTIVE: To provide a step-by-step description of how to use healthcare databases to estimate the effects of interventions initiated during pregnancy. As an example, we describe how to specify and emulate a target trial of COVID-19 vaccination during pregnancy, but the framework can be generally applied to point and sustained strategies involving both pharmacologic and non-pharmacologic interventions. METHODS: First, we specify the protocol of a target trial to evaluate the safety and effectiveness of vaccination during pregnancy. Second, we describe how to use observational data to emulate each component of the protocol of the target trial. We propose different target trials for different gestational periods because the outcomes of interest vary by gestational age at exposure. We identify challenges that affect (i) the target trial and thus its observational emulation (censoring and competing events), and (ii) mostly the observational emulation (confounding, immortal time, and measurement biases). CONCLUSION: Some biases may be unavoidable in observational emulations, but others are avoidable. For instance, immortal time bias can be avoided by aligning the start of follow-up with the gestational age at the time of the intervention, as we would do in the target trial. Explicitly emulating target trials at different gestational ages can help reduce bias and improve the interpretability of effect estimates for interventions during pregnancy.
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COVID-19 , Femenino , Humanos , Embarazo , COVID-19/prevención & control , Vacunas contra la COVID-19/uso terapéutico , Bases de Datos Factuales , Edad Gestacional , Vacunación , Ensayos Clínicos Pragmáticos como Asunto , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
OBJECTIVE: To examine the association between consumption of fruits and vegetables and pesticide residue intake from consumption of fruits and vegetables and risk of ultrasound- or hysterectomy-confirmed fibroids. Only a few studies have evaluated the association of fruit and vegetable intake with uterine fibroids, with inconsistent results. No studies have examined pesticide exposure through fruits and vegetables with fibroid risk. DESIGN: Prospective cohort study. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). SETTING: Not applicable. PATIENT(S): A total of 81,782 premenopausal participants from the Nurses' Health Study II cohort were followed from 1991 to 2009 for fruit and vegetable analysis, and 49,927 participants were followed from 1999 to 2009 for pesticide residue burden analysis. Their diet was assessed every 4 years with a food frequency questionnaire. Fruits and vegetables were classified into high- or low-pesticide residues using a validated method based on surveillance data from the US Department of Agriculture. INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Cases of ultrasound- or hysterectomy-confirmed fibroids were identified from self-reports to validated questionnaires. RESULT(S): From 1991 to 2009, 9,706 incident cases of ultrasound- or hysterectomy-confirmed fibroids were reported, and 4,195 incident cases were identified from 1999 to 2009. No association was observed between total fruit and vegetable consumption and uterine fibroid risk. Participants with the highest intake of total fruits (≥4/day) were 10% less likely to develop uterine fibroids compared with participants who consumed <1/day (95% CI = 0.80-1.01). No associations were observed with any other fruit or vegetable groups. An inverse association was observed between intake of high-pesticide-residue fruits and vegetables and fibroid risk (HR for 5th vs. 1st quintile = 0.87; 95% CI = 0.77-0.99), while no association with low-pesticide-residue fruits and vegetables was observed (HR for 5th vs. 1st quintile = 1.08; 95% CI = 0.95-1.23). CONCLUSION(S): Our findings suggest that pesticide residues on fruits and vegetables are not associated with a higher risk of uterine fibroids. Furthermore, our results suggest that intake of fruits may be associated with a lower risk of fibroids. Future research in this area should focus on dietary exposures across the life course as well as assessment of class-specific pesticides.
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Leiomioma , Residuos de Plaguicidas , Plaguicidas , Femenino , Humanos , Verduras/química , Frutas/química , Residuos de Plaguicidas/análisis , Estudios Prospectivos , Plaguicidas/efectos adversos , Plaguicidas/análisis , Leiomioma/epidemiologíaRESUMEN
Published studies report inconsistent associations of polyunsaturated fatty acid (PUFA) intake with non-Hodgkin lymphoma (NHL) risk. We conducted a nested case-control study in Nurses' Health Study and Health Professionals Follow-Up Study participants to evaluate a hypothesis of inverse association of pre-diagnosis red blood cell (RBC) membrane PUFA levels with risk of NHL endpoints. We confirmed 583 NHL cases and matched 583 controls by cohort/sex, age, race and blood draw date/time. We estimated odds ratios (OR) and 95% confidence intervals (CI) for risk of NHL endpoints using logistic regression. RBC PUFA levels were not associated with all NHL risk; cis 20:2n-6 was associated with follicular lymphoma risk (OR [95% CI] per one standard deviation increase: 1.35 [1.03-1.77]), and the omega-6/omega-3 PUFA ratio was associated with diffuse large B-cell lymphoma risk (2.33 [1.23-4.43]). Overall, PUFA did not demonstrate a role in NHL etiology; the two unexpected positive associations lack clear biologic explanations.
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Ácidos Grasos Omega-3 , Linfoma no Hodgkin , Humanos , Estudios de Seguimiento , Estudios de Casos y Controles , Linfoma no Hodgkin/etiología , Membrana Celular , Factores de RiesgoRESUMEN
OBJECTIVE: To examine the association between the intake of fruits and vegetables with high- vs. low-pesticide residue burden and diagnosis of laparoscopically confirmed endometriosis. The etiology of endometriosis is not well understood, but dietary factors may influence the risk. Pesticides may act as endocrine disruptors, and the intake of pesticide-contaminated food is a common exposure pathway. DESIGN: Prospective cohort study. Hazard ratios and 95% confidence intervals were calculated using multivariable Cox proportional hazard models to evaluate the intake of fruits and vegetables with high- and low-pesticide residues in relation to the diagnosis of laparoscopically confirmed endometriosis. SETTING: Not applicable. PATIENT(S): Premenopausal US women (N = 52,053) of the Nurses' Health Study II, aged 34-53 years at study baseline (1999), were followed until 2013. The diet was assessed every 4 years using a validated food frequency questionnaire. A previously developed and validated pesticide residue burden score (PRBS), on the basis of the US Department of Agriculture Pesticide Data Program, was used to assign fruits and vegetables to pesticide residue groups (high/low). INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Cases of laparoscopically confirmed endometriosis were identified from self-reports to validated questionnaires. RESULT(S): During 14 years of follow-up, 956 incidences of laparoscopically confirmed endometriosis were reported. No association was observed between the intake of high- or low-PRBS fruit and vegetable intake and endometriosis (hazard ratio for 5th vs. 1st quintile: high-PRBS intake = 0.94, 95% confidence interval = 0.73-1.23; low-PRBS intake = 1.07, 95% confidence interval = 0.82-1.40). No associations were observed for high- or low-PRBS fruit and vegetable intake by fertility status. CONCLUSION(S): No clear associations were observed between high- or low-PRBS fruit and vegetable intake and endometriosis risk among premenopausal women. To our knowledge, this is the first study to evaluate the association between dietary pesticide residue intake and endometriosis. Further research is needed, particularly to evaluate this association among a younger population of women (adolescence or early adulthood) and assess the dietary exposure to specific pesticides or chemical families.
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Endometriosis , Residuos de Plaguicidas , Plaguicidas , Adolescente , Femenino , Humanos , Adulto , Verduras/química , Residuos de Plaguicidas/análisis , Frutas/química , Estudios Prospectivos , Endometriosis/epidemiología , Plaguicidas/efectos adversosRESUMEN
OBJECTIVE: To compare the effectiveness and safety of 1 cycle of assisted reproductive technology (ART) vs. 3 cycles of intrauterine insemination (IUI). DESIGN: Target trial emulation using observational data. SETTING: A healthcare claims database (2011-2015). PATIENT(S): The patients were 29,021 women aged 18-45 years with an infertility diagnosis and no history of IUI or ART within the past 12 months. INTERVENTION(S): One ART cycle immediately, with no more cycles of ART or IUI within the next 4 months; or 1 IUI cycle immediately, with 2 additional consecutive cycles of IUI within the next 4 months unless pregnancy occurred. MAIN OUTCOME MEASURE(S): Live births, multiple births, congenital malformations, preterm births, small-for-gestational-age newborns, large-for-gestational-age newborns, admission to neonatal intensive care unit (NICU), gestational diabetes, preeclampsia, and gestational hypertension. RESULT(S): The probability of live birth was 27.3% for ART and 26.3% for IUI. The observational analogue of per-protocol risk difference (95% confidence interval) for ART compared with IUI was 1.0% (-0.1%, 2.2%) for live births, 4.3% (3.7%, 4.9%) for multiple births, 3.4% (2.8%, 4.0%) for preterm births, 1.5% (0.9%, 2.1%) for NICU admissions, and 0.6% (0.2%, 1.0%) for gestational diabetes. The risk differences for the other outcomes were <0.5%. The results of the 2 strategies were similar in women ≤40 years, but in women >40 years the probability of live birth was greater for ART (14.4%) than for IUI (7.4%). CONCLUSION(S): Compared with 3 cycles of IUI, 1 cycle of ART was estimated to have a similar probability of live birth but slightly higher risks of multiple gestations, preterm births, and NICU admissions.
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Diabetes Gestacional , Nacimiento Prematuro , Femenino , Fertilización In Vitro , Humanos , Recién Nacido , Inseminación , Inseminación Artificial/efectos adversos , Nacimiento Vivo , Masculino , Embarazo , Índice de Embarazo , Nacimiento Prematuro/epidemiología , Técnicas Reproductivas Asistidas/efectos adversosRESUMEN
STUDY QUESTION: What are the comparative pregnancy outcomes in women who receive up to six consecutive cycles of ovulation induction with letrozole versus clomiphene citrate? SUMMARY ANSWER: The risks of pregnancy, livebirth, multiple gestation, preterm birth, neonatal intensive care unit (NICU) admission and congenital malformations were higher for letrozole compared with clomiphene in participants with polycystic ovarian syndrome (PCOS), though no treatment differences were observed in those with unexplained infertility. WHAT IS KNOWN ALREADY: Randomized trials have reported higher pregnancy and livebirth rates for letrozole versus clomiphene among individuals with PCOS, but no differences among those with unexplained infertility. None of these trials were designed to study maternal or neonatal complications. STUDY DESIGN, SIZE, DURATION: We emulated a hypothetical trial of the comparative effectiveness of letrozole versus clomiphene citrate for ovulation induction among all women, then stratified by PCOS and unexplained infertility status. We used real-world data from a large healthcare claims database in the USA (2011-2015). PARTICIPANTS/MATERIALS, SETTING, METHODS: We analyzed data from 18â120 women who initiated letrozole and 49â647 women who initiated clomiphene during 2011-2014, and who were aged 18-45 years with no history of diabetes, thyroid disease, liver disease or breast cancer and had no fertility treatments for 3 months before trial initiation. The treatment strategies were clomiphene citrate or letrozole for six consecutive cycles. The outcomes were pregnancy, livebirth, multiple gestation, preterm birth, small for gestational age (SGA), NICU admission and major congenital malformations. We estimated the probability of each outcome under each strategy via pooled logistic regression and used standardization to adjust for confounding and selection bias due to loss to follow-up. MAIN RESULTS AND THE ROLE OF CHANCE: The estimated probabilities of pregnancy, livebirth and neonatal outcomes were similar under each strategy, both overall and among individuals with unexplained infertility. Among women with PCOS, the probability of pregnancy was 43% for letrozole vs 37% for clomiphene (risk difference [RD] = 6.0%; 95% CI: 4.4, 7.7) in the intention-to-treat analyses. The corresponding probability of livebirth was 32% vs 29% (RD = 3.1%; 95% CI: 1.5, 4.8). In per protocol analyses, the risk of multiple gestation was 19% vs 9%, the risk of preterm birth was 20% vs 15%, the risk of SGA was 5% vs 3%, the risk of NICU admission was 22% vs 16% and the risk of congenital malformation was 8% vs 2% among those with a livebirth. LIMITATIONS, REASONS FOR CAUTION: We cannot completely rule out the possibility of residual confounding by body mass index or duration of infertility. However, we adjusted for proxies identified in administrative data and results did not change. WIDER IMPLICATIONS OF THE FINDINGS: Our findings suggest that for women with unexplained infertility, the two treatments result in comparable probabilities of a livebirth. For women with PCOS, letrozole appears slightly more effective for attaining a livebirth. Neonatal outcomes were similar for the two treatments among women with unexplained infertility; we did not confirm the hypothesized higher risk of adverse neonatal outcomes for clomiphene versus letrozole. The risks of adverse neonatal outcomes were slightly greater among women with PCOS who were treated with letrozole versus clomiphene. It is likely that these effects are partially mediated through an increased risk of multiple gestation among women who received letrozole. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the National Institute of Child Health and Human Development (R01HD088393). Y.-H.C. reports grants from the American Heart Association (834106) and NIH (R01HD097778). P.R. reports grants from the National Institutes of Health. J.H. reports grants from the National Institutes of Health, the Agency for Healthcare Research and Quality, and the California Health Care Foundation during the conduct of the study; and consulting for several health care delivery organizations including Cambridge Health Alliance, Columbia University, University of Southern California, Community Servings, and the Delta Health Alliance. S.H.-D. reports grants from the National Institutes of Health and the US Food and Drug Administration during the conduct of the study; grants to her institution from Takeda outside the submitted work; consulting for UCB (biopharmaceutical company) and Roche; and being an adviser for the Antipsychotics Pregnancy Registry and epidemiologist for the North American Antiepileptics Pregnancy Registry, both at Massachusetts General Hospital. M.A.H. reports grants from the National Institutes of Health and the U.S. Veterans Administration during the conduct of the study; being a consultant for Cytel; and being an adviser for ProPublica. TRIAL REGISTRATION NUMBER: N/A.
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Infertilidad Femenina , Síndrome del Ovario Poliquístico , Nacimiento Prematuro , Adolescente , Adulto , Niño , Clomifeno/uso terapéutico , Femenino , Fármacos para la Fertilidad Femenina/uso terapéutico , Humanos , Recién Nacido , Infertilidad Femenina/etiología , Letrozol/uso terapéutico , Persona de Mediana Edad , Inducción de la Ovulación/métodos , Síndrome del Ovario Poliquístico/complicaciones , Síndrome del Ovario Poliquístico/tratamiento farmacológico , Embarazo , Índice de Embarazo , Adulto JovenRESUMEN
We aimed to determine whether intake of pesticide residues from fruits and vegetables was associated with glioma. Within 3 prospective cohorts from 1998-2016-the Nurses' Health Study (NHS), Nurses' Health Study II (NHSII), and Health Professionals Follow-up Study-we computed multivariable-adjusted hazard ratios (MVHRs) and 95% confidence intervals (CI) for glioma by quintiles of intake of low- and high-pesticide-residue fruits and vegetables using Cox proportional hazards regression. Fruits and vegetables were categorized as high or low residue using a validated method based on pesticide surveillance data. We confirmed 275 glioma cases across 2,745,862 person-years. A significant association was observed between intake of high-residue fruits and vegetables and glioma in NHS (MVHR = 2.99, 95% CI: 1.38, 6.44 comparing highest with lowest quintile, P for trend = 0.02). This was not identified in NHSII (MVHR = 0.52, 95% CI: 0.19, 1.45, P for trend = 0.20) or Health Professionals Follow-up Study (MVHR = 1.01, 95% CI: 0.42, 2.45, P for trend = 0.39). No significant associations were observed by intake of low-residue fruits and vegetables; overall intake was not significantly associated with glioma in any cohort. We found no evidence for an inverse relationship of fruit and vegetable intake with glioma. Although limited in power, this study suggests a possible association between fruit-and-vegetable pesticide residue intake and risk of glioma that merits further study.
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Glioma , Residuos de Plaguicidas , Plaguicidas , Dieta , Estudios de Seguimiento , Frutas/química , Glioma/epidemiología , Glioma/etiología , Humanos , Plaguicidas/efectos adversos , Estudios Prospectivos , Factores de Riesgo , Verduras/químicaRESUMEN
BACKGROUND: Intake of conventionally grown fruits and vegetables (FVs) is an important route of exposure to pesticide residues in the general population. However, whether health risk stemming from exposure to pesticides through diet could offset benefits of consuming FVs is unclear. OBJECTIVE: We assessed the association of FV intake, classified according to their pesticide residue status, with total and cause-specific mortality. METHODS: We followed 137,378 women (NHS, 1998-2019, and NHSII, 1999-2019) and 23,502 men (HPFS, 1998-2020) without cardiovascular disease, cancer, or diabetes at baseline. FV intake was assessed using validated food frequency questionnaires and categorized as having high- or low-pesticide-residues using data from the USDA Pesticide Data Program. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) for total and cause-specific mortality associated with high- and low-pesticide-residue FV intake. RESULTS: A total of 27,026 deaths, including 4,318 from CVD and 6,426 from cancer, were documented during 3,081,360 person-years of follow-up. In multivariable-adjusted analyses, participants who consumed ≥4 servings/day of low-pesticide-residue FVs had 36% (95% CI: 32%-41%) lower mortality risk compared to participants who consumed <1 serving/day. The corresponding estimate for high-pesticide residue FV intake was 0.93 (95% CI: 0.81-1.07). This pattern was similar across the three most frequent causes of death (cardiovascular disease, cancer and respiratory diseases). CONCLUSIONS: High-pesticide-residue FV intake was unrelated whereas low-pesticide residue FV intake was inversely related to all-cause mortality, suggesting that exposure to pesticide residues through diet may offset the beneficial effect of FV intake on mortality.
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Residuos de Plaguicidas , Dieta , Femenino , Frutas/química , Humanos , Masculino , Residuos de Plaguicidas/efectos adversos , Residuos de Plaguicidas/análisis , Estudios Prospectivos , Verduras/químicaRESUMEN
BACKGROUND: Pesticide exposure is linked to a myriad of negative health effects; however, the mechanisms underlying these associations are less clear. We utilized metabolomics to describe the alterations in the serum metabolome associated with high and low pesticide residue intake from fruits and vegetables (FVs), the most common route of exposure in humans. METHODS: This analysis included 171 women undergoing in vitro fertilization who completed a validated food frequency questionnaire and provided a serum sample during controlled ovarian stimulation (2007-2015). FVs were categorized as high or low-to-moderate pesticide residue using a validated method based on pesticide surveillance data from the USDA. We conducted untargeted metabolic profiling using liquid chromatography with high-resolution mass spectrometry and two chromatography columns. We used multivariable generalized linear models to identified metabolic features (p < 0.005) associated with high and low-to-moderate pesticide residue FV intake, followed by enriched pathway analysis. RESULTS: We identified 50 and 109 significant features associated with high pesticide residue FV intake in the C18 negative and HILIC positive columns, respectively. Additionally, we identified 90 and 62 significant features associated with low-to-moderate pesticide residue FV intake in the two columns, respectively. Four metabolomic pathways were associated with intake of high pesticide residue FVs including those involved in energy, vitamin, and enzyme metabolism. 12 pathways were associated with intake of low-to-moderate pesticide residue FVs including cellular receptor, energy, intercellular signaling, lipid, vitamin, and xenobiotic metabolism. One energy pathway was associated with both high and low-to-moderate pesticide residue FVs. CONCLUSIONS: We identified limited overlap in the pathways associated with intake of high and low-to-moderate pesticide residue FVs, which supports findings of disparate health effects associated with these two exposures. The identified pathways suggest there is a balance between the dietary antioxidant intake associated with FVs intake and heightened oxidative stress as a result of dietary pesticide exposure.
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Infertilidad , Residuos de Plaguicidas , Femenino , Frutas/química , Humanos , Metaboloma , Residuos de Plaguicidas/análisis , Verduras/químicaRESUMEN
Maternal fat intake during pregnancy affects fetal growth, but mechanisms underlying this relationship are unclear. We performed an exploratory study of the associations of fat consumption during pregnancy with cord blood DNA methylation of the insulin-like growth factor 2 (IGF2) and H19 genes. We used data from 96 uncomplicated full-term pregnancies of mothers of whom majority had normal body mass index (BMI) (66%) in Project Viva, a prospective pre-birth cohort. We assessed maternal diet with validated food frequency questionnaires during the first and second trimesters and measured DNA methylation in segments of the IGF2- and H19-differentially methylated regions (DMRs) by pyrosequencing DNA extracted from umbilical cord blood samples. Mean (SD) age was 32.8 (4.1) years and prepregnancy BMI was 24.0 (4.4) kg/m2 . Mean DNA methylation was 56.3% (3.9%) for IGF2-DMR and 44.6% (1.9%) for H19-DMR. Greater first trimester intake of omega-6 polyunsaturated fat (effect per 1% of calories at the expense of carbohydrates) was associated with lower DNA methylation of IGF2-DMR (-1.2%; 95% confidence interval [CI]: -2.2%, -0.2%) and higher DNA methylation at H19-DMR (0.8%; 95% CI: 0.3%, 1.3%). On the other hand, greater first trimester intake of omega-3 polyunsaturated fat was associated with lower DNA methylation of the H19-DMR (-4.3%; 95% CI: -7.9%, -0.8%). We did not find significant associations of IGF2 and H19 methylation with IGF2 cord blood levels. Our findings suggest that early prenatal fat intake (omega-3, omega-6, and saturated fatty acids) may influence DNA methylation at the IGF2 and H19 locus, which could impact fetal development and long-term health.