Genetically predicted 17β-estradiol and systemic inflammation in women: a separate-sample Mendelian randomisation analysis in the Guangzhou Biobank Cohort Study

Use of contraceptives and risk of inflammatory bowel disease: a nested case-control study

BACKGROUND

How contraceptive formulation, dose, duration of therapy and mode of delivery affects the risk of inflammatory bowel disease (IBD) is poorly described.

AIM

To examine associations between types of hormonal contraception and development of IBD.

METHODS

This was a nested case-control study using IQVIA Medical Research Data. Women aged 15-49 years with a new diagnosis of IBD were matched with up to six controls by age, practice and year. Odds ratios (OR) and 95% confidence intervals (95% CI) for incident IBD and use of contraception were calculated.

RESULTS

4932 incident cases of IBD were matched to 29 340 controls. Use of combined oral contraceptive pills (COCPs) was associated with the development of Crohn's disease and ulcerative colitis (OR 1.60 [1.41-1.82] and 1.30 [1.15-1.45], respectively). Each additional month of COCP exposure per year of follow-up increased risk of Crohn's disease by 6.4% (5.1%-7.7%) and ulcerative colitis by 3.3% (2.1%-4.4%). Progestogen-only pills had no effect on Crohn's disease risk (OR 1.09 [0.84-1.40]) but there was a modest association with ulcerative colitis (OR 1.35 [1.12-1.64]). Parenteral contraception was not associated with the development of Crohn's disease or ulcerative colitis (OR 1.15 [0.99-1.47] and 1.17 [0.98-1.39], respectively).

CONCLUSIONS

We observed an increase in the risk of IBD with increasing duration of exposure to COCPs. Progestogen-only pills were not associated with Crohn's disease but there was a modest association with ulcerative colitis. There was no association between parenteral progestogen-only contraception and IBD. These findings are broadly consistent with a hypothesis that the oestrogen component of contraception may drive IBD pathogenesis.

Central Haemodynamics Are Associated With Pulmonary Function in Postmenopausal Women

PURPOSE

Increased arterial stiffness predicts cardiovascular disease, which is associated with deteriorated pulmonary function and worsened chronic obstructive pulmonary disease. The present study examined whether arterial function was associated with pulmonary function in postmenopausal women.

METHODS

This study evaluated 41 postmenopausal women (age range: 59-85 years). Arterial function was measured as central systolic blood pressure (cSBP), central pulse pressure (cPP), brachial systolic BP (bSBP), brachial diastolic BP (bDBP), brachial PP (bPP), brachial mean arterial pressure (bMAP) and the augmentation index (AIx). AIx was adjusted for a heart rate of 75 beats per minute (bpm) (AIx@75) and served as the index of arterial stiffness determined by the reflected wave at the central artery. Pulmonary function was measured as forced vital capacity (FVC), forced expiratory volume in 1 second (FEV₁) and the FEV₁/FVC ratio.

RESULTS

Univariate regression analysis demonstrated that cPP, bDBP and bPP were correlated with FVC and FEV₁ (p<0.05, respectively), while AI@75 was correlated with FVC, FEV₁ and FEV₁/FVC ratio (p<0.01, respectively). A stepwise multivariate regression analysis revealed that bDBP was independently associated with FVC (p=0.032), while AI@75 was independently associated with FVC, FEV₁ and FEV₁/FVC ratio (p=0.001, p=0.003 and p=0.017, respectively). The FVC, FEV₁ and FEV₁/FVC ratio were lower in participants with a high AIx versus with a low AIx (p=0.0001, p=0.001 and p=0.044, respectively).

CONCLUSION

These results suggest that increased AIx is associated with lower pulmonary function in postmenopausal women.

Inflammation: Bridging Age, Menopause and APOEε4 Genotype to Alzheimer's Disease

Neuro-inflammatory processes that contribute to development of Alzheimer’s are evident early in the latent prodromal phase and worsen during the course of the disease. Despite substantial mechanistic and clinical evidence of inflammation, therapeutic approaches targeting inflammation have failed to alter the course of the disease. Disparate results from epidemiological and clinical trials targeting inflammation, highlight the complexity of the inflammatory process. Herein we review the dynamics of the inflammatory process across aging, midlife endocrine transitions, and the APOEε4 genotype and their contribution to progression of Alzheimer’s disease (AD). We discuss the chronic inflammatory processes that are activated during midlife chronological and endocrine aging, which ultimately limit the clearance capacity of microglia and lead to immune senescence. Aging, menopause, and APOEε4 combine the three hits of a compromised bioenergetic system of menopause with the chronic low grade innate inflammation of aging with the APOEε4 dyslipidemia and adaptive immune response. The inflammatory immune response is the unifying factor that bridges across each of the risk factors for AD. Immune system regulators that are specific to stage of disease and inflammatory phenotype would provide a therapeutic strategy to disconnect the bridge that drives disease. Outcomes of this analysis provide plausible mechanisms underlying failed clinical trials of anti-inflammatory agents in Alzheimer’s patients. Further, they highlight the need for stratifying AD clinical trial cohorts based on inflammatory phenotype. Combination therapies that include targeted use of anti-inflammatory agent’s specific to the immune phenotype are considered.

Menopause Is Associated with Accelerated Lung Function Decline

RATIONALE

Menopause is associated with changes in sex hormones, which affect immunity, inflammation, and osteoporosis and may impair lung function. Lung function decline has not previously been investigated in relation to menopause.

OBJECTIVES

To study whether lung function decline, assessed by FVC and FEV₁, is accelerated in women who undergo menopause.

METHODS

The population-based longitudinal European Community Respiratory Health Survey provided serum samples, spirometry, and questionnaire data about respiratory and reproductive health from three study waves (n = 1,438). We measured follicle-stimulating hormone and luteinizing hormone and added information on menstrual patterns to determine menopausal status using latent class analysis. Associations with lung function decline were investigated using linear mixed effects models, adjusting for age, height, weight, pack-years, current smoking, age at completed full-time education, spirometer, and including study center as random effect.

MEASUREMENTS AND MAIN RESULTS

Menopausal status was associated with accelerated lung function decline. The adjusted mean FVC decline was increased by -10.2 ml/yr (95% confidence interval [CI], -13.1 to -7.2) in transitional women and -12.5 ml/yr (95% CI, -16.2 to -8.9) in post-menopausal women, compared with women menstruating regularly. The adjusted mean FEV₁ decline increased by -3.8 ml/yr (95% CI, -6.3 to -2.9) in transitional women and -5.2 ml/yr (95% CI, -8.3 to -2.0) in post-menopausal women.

CONCLUSIONS

Lung function declined more rapidly among transitional and post-menopausal women, in particular for FVC, beyond the expected age change. Clinicians should be aware that respiratory health often deteriorates during reproductive aging.

Influence of estrogen therapy on immune markers in postmenopausal women

OBJECTIVE

To evaluate the impact of estrogen therapy on cellular and humoral immune markers in postmenopausal women.

METHODS

This prospective, controlled cohort study included 30 patients who used oral estradiol (1 mg) for 14-17 weeks and 28 patients who served as controls. Total leukocytes and leukocyte subtypes were counted and immunophenotyped by flow cytometry. The concentrations of immunoglobulins and pro- and anti-inflammatory cytokines were also measured in the peripheral blood before and after estrogen therapy. Immunoglobulin E level was measured by electrochemiluminescence, and levels of immunoglobulins A, G, and M were measured by nephelometry. Simultaneous quantification of multiple cytokines was performed by chemiluminescence to measure the serum concentrations of interferon gamma, interleukin (IL)-4, IL-6, IL-10, and IL-17.

RESULTS

Hematological cellular components were not significantly different before and after the use of estradiol (p = 0.332-0.984). Serum concentrations of immunoglobulins G, M, E, and A also remained stable (p = 0.248-0.845). Finally, cytokines were not modified throughout the 14-17 weeks of follow-up (p = 0.407-0.873).

CONCLUSION

Isolated estrogen therapy with 1 mg of estradiol for 14-17 weeks in postmenopausal women did not modify any of the cellular or humoral immune markers analyzed in this study.

Genetically predicted 17beta-estradiol, cognitive function and depressive symptoms in women: A Mendelian randomization in the Guangzhou Biobank Cohort Study

OBJECTIVE

The role of estrogen in cognitive function and depressive symptoms is controversial due to discrepancies between results from randomized controlled trials (RCT) and observational studies. Mendelian randomization analysis may provide further insights concerning the role of estrogen in these outcomes as it assesses the effect of lifelong endogenous exposure but is less vulnerable to confounding than observational studies.

METHOD

We used separate sample instrumental variable analysis to estimate the association of log 17β estradiol with cognitive function (Delayed 10 word recall, and Mini Mental State Examination (MMSE)) and depressive symptoms (Geriatric Depression Scale (GDS)) in older Chinese women of the Guangzhou Biobank Cohort Study (GBCS, n=3086). The estimate was derived based on the Wald estimator, the ratio of the association of genetic determinants (rs1008805 and rs2175898) of log 17β-estradiol with cognitive function and depressive symptoms in GBCS and the association of log 17β-estradiol with genetic determinants in the sample of young women in Hong Kong (n=236).

RESULTS

Genetically predicted 17β-estradiol was not associated with delayed 10-word recall (0.42 words per log increase in 17β-estradiol (pmol/L), 95% confidence interval (CI) -0.49 to 1.34) MMSE (0.39 per log increase in 17β-estradiol (pmol/L), 95% CI -0.87 to 1.65) or GDS (0.24 per log increase in 17β-estradiol (pmol/L), 95% CI -0.57 to 1.05).

CONCLUSION

These results were largely consistent with evidence from RCTs and did not show any beneficial effect of estrogen on cognitive function and depressive symptoms. However, larger Mendelian randomization analyses are needed to identify any minor effects.

Genetically predicted 17beta-estradiol and cardiovascular risk factors in women: a Mendelian randomization analysis using young women in Hong Kong and older women in the Guangzhou Biobank Cohort Study

PURPOSE

The role of estrogen in cardiovascular health remains contested with discrepancies between findings from randomized controlled trials and observational studies. Mendelian randomization, which assesses the effect of lifelong endogenous exposure, may help elucidate these discrepancies.

METHODS

We used separate sample instrumental variable analysis to estimate the association of log 17β-estradiol with factors related to cardiovascular disease risk (systolic and diastolic blood pressure, lipids, fasting glucose, body mass index, waist hip ratio, and waist circumference) and Framingham score, a predictor of 10-year risk of ischemic heart disease events, in older Chinese women from the Guangzhou Biobank Cohort Study (GBCS, n = 3092). The estimate was derived using the Wald estimator, that is, the ratio of the association of genetic determinants (rs1008805 and rs2175898) of log 17β-estradiol with cardiovascular disease risk factors and Framingham score in GBCS and the association of these genetic determinants with log 17β-estradiol in a sample of young women from Hong Kong (n = 236).

RESULTS

Genetically, higher 17β-estradiol was not associated with any cardiovascular disease-related risk factor or with Framingham score (-0.01, 95% confidence interval = -1.34 to 1.31).

CONCLUSIONS

Lifetime exposure to estrogen does not appear to be cardioprotective via the cardiovascular disease-related risk factors examined.