Female hormonal exposures and risk of rheumatoid arthritis in the French E3N-EPIC cohort study

Objective To assess the relationships between female hormonal exposures and risk of rheumatoid arthritis (RA), in a prospective cohort of French women. Methods E3N is an on-going French prospective cohort that included 98 995 women aged 40–65 years in 1990. Every 2–3 years, women completed mailed questionnaires on their lifestyles, reproductive factors, and health conditions. Cox proportional-hazards regression models were used to determine factors associated with risk of incident RA, with age as the time scale, adjusted for known risk factors of RA, and considering endogenous and exogenous hormonal factors. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated. Effect modification by smoking history was investigated. Results A total of 698 incident cases of RA were ascertained among 78 452 women. In multivariable-adjusted Cox regression models, risk of RA was increased with early age at first pregnancy (<22 vs ≥27 years; HR = 1.34; 95%CI 1.0–1.7) and menopause (≤45 vs ≥53 years; HR = 1.40; 95%CI 1.0–1.9). For early menopause, the association was of similar magnitude in ever and never smokers, although the association was statistically significant only in ever smokers (HR = 1.54; 95%CI 1.0–2.3). We found a decreased risk in nulliparous women never exposed to smoking (HR = 0.44; 95%CI 0.2–0.8). Risk of RA was inversely associated with exposure to progestogen only in perimenopause (>24 vs 0 months; multi-adjusted HR = 0.77; 95%CI 0.6–0.9). Conclusions These results suggest an effect of both endogenous and exogenous hormonal exposures on RA risk and phenotype that deserves further investigation.

Environment and Lifestyle: Their Influence on the Risk of RA

Background: Rheumatoid arthritis (RA) is a complex disease in which environmental agents are thought to interact with genetic factors that lead to triggering of autoimmunity. Methods: We reviewed environmental, hormonal, and dietary factors that have been suggested to be associated with the risk of RA. Results: Smoking is the most robust factor associated with the risk of RA, with a clear gene–environment interaction. Among other inhalants, silica may increase the risk of RA in men. There is less evidence for pesticides, pollution, and other occupational inhalants. Regarding female hormonal exposures, there is some epidemiological evidence, although not consistent in the literature, to suggest a link between hormonal factors and the risk of RA. Regarding dietary factors, available evidence is conflicting. A high consumption of coffee seems to be associated with an increased risk of RA, whereas a moderate consumption of alcohol is inversely associated with the risk of RA, and there is less evidence regarding other food groups. Dietary pattern analyses (Mediterranean diet, the inflammatory potential of the diet, or diet quality) suggested a potential benefit of dietary modifications for individuals at high risk of RA. Conclusion: To date, smoking and silica exposure have been reproducibly demonstrated to trigger the emergence of RA. However, many other environmental factors have been studied, mostly with a case-control design. Results were conflicting and studies rarely considered potential gene–environment interactions. There is a need for large scale prospective studies and studies in predisposed individuals to better understand and prevent the disease and its course.

Male origin microchimerism and ovarian cancer

Background Reduced risk of ovarian cancer is commonly ascribed to reduced exposure to endogenous hormones during pregnancy, using oral contraceptives or not using hormone replacement therapy. However, exposure to hormones alone account for less than half of all cases. Many women carry small amounts of male cells—known as male origin microchimerism—in their circulation and remarkable impacts of these cells on women’s health are being published. Here, we pursue the possibility that male origin microchimerism has a role in reducing ovarian cancer risk. Methods We conducted a prospective case-cohort study using blood samples and questionnaire data from 700 women participating in the Danish Diet, Cancer, and Health cohort. Blood samples were analysed for Y chromosome presence as a marker of male microchimerism. We evaluated the association between male microchimerism and ovarian cancer, using weighted Cox regression models reporting hazard ratios (HRs) and corresponding 95% confidence intervals (CIs). Results Male microchimerism was detected in 46% of cases and 65.9% of controls. Women testing positive for male microchimerism had a reduced hazard rate of ovarian cancer compared with women testing negative (HR = 0.44, 95% CI: 0.29-0.68). We found no evidence of interaction with measures of hormonal exposures (P = 0.50). Conclusions For the first time we report that women who test positive for male microchimerism in their circulation have reduced rates of ovarian cancer compared with women who test negative. Although the underlying mechanisms are presently unknown, we believe male microchimerism is potent in preventing ovarian cancer.

WellExplorer: an integrative resource linking hydraulic fracturing chemicals with hormonal pathways and geographic location

Exposure to hydraulic fracturing fluid in drinking water increases the risk of many adverse health outcomes. Unfortunately, most individuals and researchers are unaware of the health risks posed by a particular well due to the diversity of chemical ingredients used across sites. We constructed WellExplorer (http://WellExplorer.org), an interactive tool for researchers and community members to use for retrieving information regarding the hormonal, testosterone and estrogen modulators located at each well. We found that wells in Alabama use a disproportionately high number of ingredients targeting estrogen pathways, while Illinois, Ohio and Pennsylvania use a disproportionately high number of ingredients targeting testosterone pathways. Researchers can utilize WellExplorer to study health outcomes related to exposure to fracturing chemicals in their population-based cohorts. Community members can use this resource to search their home or work locations (e.g. town or zip code) to determine proximity between where they live or work and specific hormonal exposures.

Associations of plasma IGF1, IGFBP3 and estradiol with leucocyte telomere length, a marker of biological age, in men

Objective Effects of insulin-like growth factor 1 (IGF1) and its binding proteins (IGFBPs) on ageing, and their interaction with sex hormones, remain uncertain. We examined associations of plasma IGF1, IGFBP1, IGFBP3, estradiol and testosterone, with leucocyte telomere length (LTL), a marker of biological age, in 2999 community-dwelling men aged 70–84 years. Methods Plasma IGF1, IGFBP1 and IGFBP3 measured using immunoassay, sex hormones using mass spectrometry. LTL measured by PCR, expressed as ratio of telomeric to single-copy control gene DNA (T/S ratio). Linear regression models adjusted for age and cardio-metabolic risk factors, median splits defined low/high groups. Results Mean age was 76.7 ± 3.2 years. IGF1 and IGFBP3 showed age-adjusted correlations with LTL (coefficient 0.59, P = 0.001 and 0.45, P = 0.013 respectively), IGFBP1 did not. In multivariable-adjusted models IGF1 and IGFBP3 (but not IGFBP1) were associated with LTL (T/S ratio 0.015 higher per 1 s.d. increase in IGF1, P = 0.007, and 0.011 per 1 s.d. IGFBP3, P = 0.049). IGF1 and estradiol were independently associated with longer telomeres (T/S ratio 0.012 higher per 1 s.d. increase in estradiol, P = 0.027, when included in model with IGF1). Testosterone was not associated with LTL. Men with both high IGF1 (>133 µg/L) and high estradiol (>70 pmol/L) had longer LTL compared to men with lower values (multivariable-adjusted T/S ratio 1.20 vs 1.16, P = 0.018). Conclusions Higher IGF1 and IGFBP3 are independently associated with longer telomeres in older men. Additive associations of higher IGF1 and higher estradiol with telomere length are present. Further studies are needed to determine whether these hormonal exposures cooperate to slow biological aging.

United States Pulmonary Hypertension Scientific Registry (USPHSR): rationale, design, and clinical implications

Diagnostic World Health Organization (WHO) Group 1 pulmonary arterial hypertension (PAH) and Diagnostic Group 1' pulmonary veno-occlusive disease (PVOD) and/or pulmonary capillary hemangiomatosis (PCH) are progressive and fatal disorders. Past registries provided important insights into these disorders, but did not include hormonal exposures or genomic data. The United States Pulmonary Hypertension Scientific Registry (USPHSR) will provide demographic, physiologic, anorexigen and hormone exposure, genomic, and survival data in the current therapeutic era for 499 patients diagnosed with PAH, PVOD, or PCH. The USPHSR also will explore the relationship between pharmacologic, non-pharmacologic, and dietary hormonal exposures and the increased risk for women to develop idiopathic or heritable PAH.

A case-control study of hormonal exposures as etiologic factors for ALS in women

Objective:To investigate the role of hormonal risk factors for amyotrophic lateral sclerosis (ALS) among women from 3 European countries.Methods:ALS cases and matched controls were recruited over 4 years in Ireland, Italy, and the Netherlands. Hormonal exposures, including reproductive history, breastfeeding, contraceptive use, hormonal replacement therapy, and gynecologic surgical history, were recorded with a validated questionnaire. Logistic regression models adjusted for age, education, study site, smoking, alcohol, and physical activity were used to determine the association between female hormones and ALS risk.Results:We included 653 patients and 1,217 controls. Oral contraceptive use was higher among controls (odds ratio [OR] 0.65, 95% confidence interval [CI] 0.51–0.84), and a dose-response effect was apparent. Hormone replacement therapy (HRT) was associated with a reduced risk of ALS only in the Netherlands (OR = 0.57, 95% CI 0.37–0.85). These findings were robust to sensitivity analysis, but there was some heterogeneity across study sites.Conclusions:This large case-control study across 3 different countries has demonstrated an association between exogenous estrogens and progestogens and reduced odds of ALS in women. These results are at variance with previous findings, which may be partly explained by differential regulatory, social, and cultural attitudes toward pregnancy, birth control, and HRT across the countries included. Our results indicate that hormonal factors may be important etiologic factors in ALS; however, a full understanding requires further investigation.

Female hormonal exposures and neuromyelitis optica symptom onset in a multicenter study

Objective:To study the association between hormonal exposures and disease onset in a cohort of women with neuromyelitis optica spectrum disorder (NMOSD).Methods:Reproductive history and hormone use were assessed using a standardized reproductive survey administered to women with NMOSD (82% aquaporin-4 antibody positive) at 8 clinical centers. Using multivariable regression, we examined the association between reproductive exposures and age at first symptom onset (FS).Results:Among 217 respondents, the mean age at menarche was 12.8 years (SD 1.7). The mean number of pregnancies was 2.1 (SD 1.6), including 0.3 (SD 0.7) occurring after onset of NMOSD symptoms. In the 117 participants who were postmenopausal at the time of the questionnaire, 70% reported natural menopause (mean age: 48.9 years [SD 3.9]); fewer than 30% reported systemic hormone therapy (HT) use. Mean FS age was 40.1 years (SD 14.2). Ever-use of systemic hormonal contraceptives (HC) was marginally associated with earlier FS (39 vs 43 years, p = 0.05). Because HC use may decrease parity, when we included both variables in the model, the association between HC use and FS age became more significant (estimate = 2.7, p = 0.007). Among postmenopausal participants, 24% reported NMOSD onset within 2 years of (before or after) menopause. Among these participants, there was no association between age at menopause or HT use and age at NMOSD onset.Conclusions:Overall, age at NMOSD onset did not show a strong relationship with endogenous hormonal exposures. An earlier onset age did appear to be marginally associated with systemic HC exposure, an association that requires confirmation in future studies.

Pregnancy hormonal environment and mother’s breast cancer risk

Pregnancy can both reduce and increase lifetime breast cancer risk, and it also induces a short-term, transient increase in risk. Several biological mechanisms have been proposed to explain the protective effect, including pregnancy-induced increase in circulating estrogen levels leading to reduced estrogen receptor (ER) expression and activity. Persistent changes in ER-regulated gene expression may then alter the response of the breast to postpregnancy hormonal exposures originating, for example, from food. Understanding how pregnancy increases breast cancer risk has received less attention. Human studies indicate that those women who were exposed to an elevated pregnancy estrogenic environment, such as women who took the synthetic estrogen diethylstilbestrol or who had the highest circulating estrogen levels at the beginning or end of pregnancy, are at increased risk of developing breast cancer. There is also evidence that elevated leptin levels, for example, in pregnant women who gained excessive amount of weight, increase later breast cancer risk. This may reflect a close interaction between estradiol (E2), ER, and leptin. Our preclinical study suggests that an exposure to excess pregnancy E2 and leptin levels reverses the protective changes in genomic signaling pathways seen in the breast/mammary gland of parous women and rodents. Recent findings indicate that involution – the period after lactation when the breast regresses back to prepregnancy stage – may be related to some pregnancy-associated breast cancers. Importantly, in a preclinical model, the increase can be reversed by anti-inflammatory treatment, offering hope that the increase in lifelong breast cancer risk induced by late first pregnancy or by an exposure of pregnant women to an excessive hormonal environment may be reversible.