Background
The possibility that lifestyle factors such as diet, specifically potassium intake, may modify the risk of stroke has been suggested by several observational cohort studies, including some ...recent reports. We performed a systematic review and meta‐analysis of existing studies and assessed the dose–response relation between potassium intake and stroke risk.
Methods and Results
We reviewed the observational cohort studies addressing the relation between potassium intake, and incidence or mortality of total stroke or stroke subtypes published through August 6, 2016. We carried out a meta‐analysis of 16 cohort studies based on the relative risk (RR) of stroke comparing the highest versus lowest intake categories. We also plotted a pooled dose–response curve of RR of stroke according to potassium intake. Analyses were performed with and without adjustment for blood pressure. Relative to the lowest category of potassium intake, the highest category of potassium intake was associated with a 13% reduced risk of stroke (RR=0.87, 95% CI 0.80–0.94) in the blood pressure–adjusted analysis. Summary RRs tended to decrease when original estimates were unadjusted for blood pressure. Analysis for stroke subtypes yielded comparable results. In the spline analysis, the pooled RR was lowest at 90 mmol of potassium daily intake (RRs=0.78, 95% CI 0.70–0.86) in blood pressure–adjusted analysis, and 0.67 (95% CI 0.57–0.78) in unadjusted analysis.
Conclusions
Overall, this dose–response meta‐analysis confirms the inverse association between potassium intake and stroke risk, with potassium intake of 90 mmol (≈3500 mg)/day associated with the lowest risk of stroke.
Selenium is an element present in trace amounts and different chemical forms. It may exert both beneficial and adverse effects on cellular redox status and on the generation of reactive oxygen ...species. 8-oxo-7,8-dihydro-2′deoxyguanosine (8-oxodG) is an oxidized derivative of deoxyguanosine, and a sensitive biomarker of oxidative stress and genotoxicity.
The present study assessed the extent to which selenium status was associated with urinary 8-oxodG concentrations in a Northern Italian population.
We recruited healthy, non-smoking blood donors living in the Reggio Emilia province during 2017–2019. We measured urinary 8-oxodG concentrations and used restricted cubic spline regression analyses to investigate the association between selenium status (estimated using food frequency questionnaires, urinary concentrations, and serum concentrations of selenium and selenium species) and 8-oxodG/g creatinine.
Among 137 participants aged 30–60 years, median urinary selenium and 8-oxodG concentrations were 22.02 μg/L and 3.21 μg/g creatinine, respectively. Serum samples and selenium speciation analyses were available for 104 participants. Median total serum selenium levels and dietary intake were 116.5 μg/L and 78.7 μg/day, respectively. In spline regression analysis, there was little association between dietary, serum, or urinary selenium with 8-oxodG concentrations. In sex-specific analyses, urinary selenium showed a positive association with the endpoint among males. For single selenium species, we observed positive associations with urinary 8-oxodG for serum organic selenium species, and negative associations for inorganic selenium forms. In the most adjusted analysis, urinary 8-oxodG concentrations showed a strong positive association with selenomethione-bound selenium (Se-Met) and a negative association with inorganic tetravalent selenium, selenite. In sex-specific analyses, these associations were considerably stronger in males than in females.
Overall, study findings indicate that selenium species exhibited very different patterns of associations with the biomarker of oxidative stress, and that these associations also depended on sex. Background exposure to Se-Met appears to be strongly and positively associated with oxidative stress.
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•Overall selenium was not associated with 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG).•Selected selenium species were associated with the biomarker of oxidative stress.•Effect modification by sex was encountered.•Selenomethionine-bound selenium was strongly associated with 8-oxodG.
Background Experiences of violence contribute to the occurrence of childhood asthma, but there is little information on the effect of early-life abuse on adult-onset asthma. Objective We ...prospectively assessed the relation between physical and sexual abuse during childhood and adolescence and the incidence of adult-onset asthma in the Black Women's Health Study. Methods We followed 28,456 women from 1995 through 2011 with biennial mailed questionnaires. Experiences of physical and sexual abuse that occurred during childhood and adolescence were obtained in 2005. Cox regression models were used to estimate incidence rate ratios (IRRs) and 95% CIs. Results During 417,931 person-years of follow-up, 1,160 participants reported physician-diagnosed asthma and concurrent use of asthma medication. Compared with women who experienced no abuse during childhood or adolescence, the multivariable IRR for any childhood abuse was 1.24 (95% CI, 1.06-1.45), and for any adolescent abuse, it was 1.10 (95% CI, 0.88-1.36). The IRR was higher for childhood physical abuse (IRR, 1.29; 95% CI, 1.07-1.49) than for childhood sexual abuse (IRR, 1.15; 95% CI, 0.88-1.49). IRRs for physical and sexual abuse during adolescence were compatible with 1.0. The association between childhood abuse and asthma incidence was stronger in older compared with younger women. Conclusion In this large cohort of African American women, there was a positive association between adult-onset asthma and childhood physical abuse and weaker associations for childhood sexual abuse and any abuse during adolescence. Given the high prevalence of asthma and childhood abuse, this association is of public health importance.
•Higher MIND diet adherence corresponded to lower serum selenium concentrations.•Higher MIND diet adherence corresponded to higher urinary selenium excretion.•MIND diet adherence was inversely ...associated with serum Selenoprotein P.
Selenium is a trace element found in many chemical forms. Selenium and its species have nutritional and toxicologic properties, some of which may play a role in the etiology of neurological disease. We hypothesized that adherence to the Mediterranean-Dietary Approach to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) diet could influence intake and endogenous concentrations of selenium and selenium species, thus contributing to the beneficial effects of this dietary pattern. We carried out a cross-sectional study of 137 non-smoking blood donors (75 females and 62 males) from the Reggio Emilia province, Northern Italy. We assessed MIND diet adherence using a semiquantitative food frequency questionnaire. We assessed selenium exposure through dietary intake and measurement of urinary and serum concentrations, including speciation of selenium compound in serum. We fitted non-linear spline-based regression models to investigate the association between MIND diet adherence and selenium exposure concentrations. Adherence to the MIND diet was positively associated with dietary selenium intake and urinary selenium excretion, whereas it was inversely associated with serum concentrations of overall selenium and organic selenium, including serum selenoprotein P-bound selenium, the most abundant circulating chemical form of the metalloid. MIND diet adherence also showed an inverted U-shaped relation with inorganic selenium and particularly with its hexavalent form, selenate. Our results suggest that greater adherence to the MIND diet is non-linearly associated with lower circulating concentrations of selenium and of 2 potentially neurotoxic species of this element, selenoprotein P and selenate. This may explain why adherence to the MIND dietary pattern may reduce cognitive decline.
In this cross-sectional study of 137 nonsmoking blood donors, Mediterranean-Dietary Approach to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) diet adherence was assessed using a semiquantitative food frequency questionnaire. Selenium (Se) exposure was assessed through diet, urine, and serum. The MIND diet was associated with low circulating levels of Se and specifically of selenoprotein P and selenate (Made using Biorender). Display omitted
Abstract
STUDY QUESTION
To what extent is cigarette smoking associated with reduced fecundability?
SUMMARY ANSWER
Current female smokers, particularly those who had smoked ≥10 cigarettes/day for ≥10 ...years, had lower fecundability than never smokers, but current male smoking and passive smoking in either partner showed little association with reduced fecundability.
WHAT IS KNOWN ALREADY
Female smoking has been identified as a cause of infertility, yet there has been limited characterization of the dose and duration at which an effect is observed. Results for male active smoking and passive smoking in both partners are less consistent.
STUDY DESIGN, SIZE, DURATION
We analyzed data from a North American internet-based preconception cohort study of 5473 female and 1411 male pregnancy planners, enrolled from 2013 to 2018. Participants had been attempting conception for ≤6 menstrual cycles at study entry.
PARTICIPANTS/MATERIALS, SETTING, METHODS
We collected information on active and passive smoking history on baseline questionnaires. Pregnancy was reported on female bi-monthly follow-up questionnaires. We calculated fecundability ratios (FR) and 95% CI using proportional probabilities regression models, adjusted for demographic, behavioral, medical, reproductive and dietary variables.
MAIN RESULTS AND THE ROLE OF CHANCE
Female current regular smoking (FR = 0.90, 95% CI: 0.77, 1.07), current occasional smoking (FR = 0.88, 95% CI: 0.73, 1.06), and former smoking (FR = 0.89, 95% CI: 0.81, 0.98) were associated with small reductions in fecundability. Results were stronger among women who smoked ≥10 cigarettes/day for ≥10 years (FR = 0.77, 95% CI: 0.53, 1.10). Male current regular and former smoking, and current passive smoking in either partner were not meaningfully associated with reduced fecundability. In utero exposure to ≥10 cigarettes/day among females was associated with reduced fecundability (FR = 0.75, 95% CI: 0.52, 1.06).
LIMITATIONS, REASONS FOR CAUTION
Numbers of cigarette smokers, particularly within categories of intensity and duration, were small. Under-reporting of smoking may have resulted in non-differential misclassification, and smokers were more likely to be lost to follow-up.
WIDER IMPLICATIONS OF THE FINDINGS
Given the consistency of our findings with results from previous studies and our observation of a dose–response relation in intensity of smoking, this study supports an association between female cigarette smoking and lower fecundability.
STUDY FUNDING/COMPETING INTEREST(S)
This study was funded by the National Institute of Child Health and Human Development (R01-HD086742, R21-HD072326, R03-HD090315 and T32-HD052458). The authors declare no competing interests.
Estrogen receptor (ER)-negative breast tumors and progesterone receptor (PR)-negative breast tumors occur more commonly in women of African ancestry. Recent research indicates that the effects of ...reproductive factors may differ by hormone receptor status. We assessed the relation of parity and lactation to incidence of ER(-)/PR(-) and ER(+)/PR(+) breast cancer in a cohort of African American women.
From 1995-2009, 457 incident cases of ER(+)/PR(+) and 318 cases of ER(-)/PR(-) breast cancer were confirmed by review of pathology data among 59,000 African American women followed in the Black Women's Health Study through biennial questionnaires. HRs and two-sided 95% CIs for the incidence of breast cancer subtypes were derived from proportional hazards regression models that controlled for age, reproductive variables, and breast cancer risk factors.
Higher parity was associated with an increased risk of ER(-)/PR(-) breast cancer (HR = 1.48, 95% CI: 0.98-1.84 for 3+ versus 0 births, P(trend) = 0.009), and with a reduced risk of ER(+)/PR(+) cancer (HR = 0.53, 95% CI: 0.39-0.73 for 3+ versus 0 births, P(trend) = 0.0002). Among women who had breastfed, high parity was no longer associated with increased incidence of ER(-)/PR(-) breast, but the inverse association with ER(+)/PR(+) cancer persisted.
The higher incidence of ER(-)/PR(-) breast cancer in African American women may be explained in part by their higher parity and lower prevalence of breastfeeding relative to white women.
Increased breastfeeding may lead to a reduction in the incidence of this breast cancer subtype.
Objectives. To quantify the impact of telemedicine for medication abortion (TMAB) expansion or ban removal on abortion accessibility.
Methods. We included 1091 facilities from the 2018 Advancing New ...Standards in Reproductive Health facility database and Planned Parenthood Web site, among which 241 did not offer abortion as sites for TMAB expansion. Accessibility was defined as the proportion of reproductive-aged women living within a 30-, 60-, or 90-minute drive time from an abortion-providing facility. We calculated accessibility differences between 3 scenarios: (1) facilities offering abortion in 2018 (reference), (2) the reference scenario in addition to all facilities in states without TMAB bans (TMAB expansion), and (3) all facilities (TMAB ban removal). We also stratified by state and urban–rural status.
Results. In 2018, 65%, 81%, and 89% of women lived within a 30-, 60-, or 90-minute drive time from an abortion-providing facility, respectively. Expansion and ban removal expanded abortion accessibility relative to the current accessibility scenario (range: 1.25–5.66 percentage points). Women in rural blocks experienced greater increases in accessibility than those in urban blocks.
Conclusions. TMAB program and policy changes could expand abortion accessibility to an additional 3.5 million reproductive-aged women.
Public Health Implications. Our findings can inform where to invest resources to improve abortion accessibility. (Am J Public Health. 2022;112(8):1202–1211. https://doi.org/10.2105/AJPH.2022.306876 )
To what extent are ambient concentrations of particulate matter <2.5 microns (PM2.5), nitrogen dioxide (NO2) and ozone (O3) associated with risk of self-reported physician-diagnosed uterine ...leiomyomata (UL)?
In this large prospective cohort study of Black women, ambient concentrations of O3, but not PM2.5 or NO2, were associated with increased risk of UL.
UL are benign tumors of the myometrium that are the leading cause of gynecologic inpatient care among reproductive-aged women. Black women are clinically diagnosed at two to three times the rate of white women and tend to exhibit earlier onset and more severe disease. Two epidemiologic studies have found positive associations between air pollution exposure and UL risk, but neither included large numbers of Black women.
We conducted a prospective cohort study of 21 998 premenopausal Black women residing in 56 US metropolitan areas from 1997 to 2011.
Women reported incident UL diagnosis and method of confirmation (i.e. ultrasound, surgery) on biennial follow-up questionnaires. We modeled annual residential concentrations of PM2.5, NO2 and O3 throughout the study period. We used Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for a one-interquartile range (IQR) increase in air pollutant concentrations, adjusting for confounders and co-pollutants.
During 196 685 person-years of follow-up, 6238 participants (28.4%) reported physician-diagnosed UL confirmed by ultrasound or surgery. Although concentrations of PM2.5 and NO2 were not appreciably associated with UL (HRs for a one-IQR increase: 1.01 (95% CI: 0.93, 1.10) and 1.05 (95% CI: 0.95, 1.16), respectively), O3 concentrations were associated with increased UL risk (HR for a one-IQR increase: 1.19, 95% CI: 1.07, 1.32). The association was stronger among women age <35 years (HR: 1.26, 95% CI: 0.98, 1.62) and parous women (HR: 1.28, 95% CI: 1.11, 1.48).
Our measurement of air pollution is subject to misclassification, as monitoring data are not equally spatially distributed and we did not account for time-activity patterns. Our outcome measure was based on self-report of a physician diagnosis, likely resulting in under-ascertainment of UL. Although we controlled for several individual- and neighborhood-level confounding variables, residual confounding remains a possibility.
Inequitable burden of air pollution exposure has important implications for racial health disparities, and may be related to disparities in UL. Our results emphasize the need for additional research focused on environmental causes of UL.
This research was funded by the National Cancer Institute (U01-CAA164974) and the National Institute of Environmental Health Sciences (R01-ES019573). L.A.W. is a fibroid consultant for AbbVie, Inc. and accepts in-kind donations from Swiss Precision Diagnostics, Sandstone Diagnostics, FertilityFriend.com and Kindara.com for primary data collection in Pregnancy Study Online (PRESTO). M.J. declares consultancy fees from the Health Effects Institute (as a member of the review committee). The remaining authors declare they have no actual or potential competing financial interests.
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