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.
Vitamin D and risk of hypertension among Black women Sheehy, Shanshan; Palmer, Julie R.; Cozier, Yvette ...
The journal of clinical hypertension (Greenwich, Conn.),
February 2023, Letnik:
25, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Evidence of an association between plasma 25‐hydroxyvitamin D 25(OH)D levels and risk of hypertension, predominantly from studies of White individuals, suggests an inverse relationship. Limited data ...are available on Black individuals, who are more likely to have vitamin D deficiency. In the Black Women's Health Study (BWHS), a prospective study of 59 000 self‐identified Black women from across the US, we assessed levels of a validated predicted vitamin D score in relation to incident hypertension. We followed 42 239 participants who were free of cardiovascular disease and cancer from 1995 to 2019, during which time 19 505 incident cases of hypertension were identified. Cox proportional hazards model were used to calculate multivariable‐adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of predicted vitamin D with the risk of incident hypertension. In age‐adjusted analyses, there was a strong inverse dose‐response association between predicted vitamin D score and hypertension risk, with an HR of .66 (95% CI: .63‐.68, p trend < .0001) for the highest quartile of predicted vitamin D relative to the lowest. After control for potential confounders including body mass index, physical activity, and cigarette smoking, the HR was attenuated to .91 (95% CI: .87–.95, p trend = .002). In this prospective cohort study of Black women, predicted vitamin D score was weakly inversely associated with the incidence of hypertension. This observed association may reflect an inability to fully control for confounding factors.
Prevalence of obesity, type 2 diabetes (T2D), and being born with low birth weight are much higher in African American women compared to U.S. white women. Genetic factors may contribute to the excess ...risk of these conditions. We conducted admixture mapping of body mass index (BMI) at age 18, adult BMI, and adult waist circumference and waist-to-hip ratio adjusted for BMI using 2918 ancestral informative markers in 2596 participants of the Black Women's Health Study. We also searched for evidence of shared African genetic ancestry components among the four examined anthropometric traits and among birth weight and T2D. We found that global percent African ancestry was associated with higher adult BMI. We also found that African ancestry at 9q34 was associated with lower BMI at age 18. Our shared ancestry analysis identified ten genomic regions with local African ancestry associated with multiple traits. Seven out of these ten genomic loci were related to T2D risk. Of special interest is the 12q14-21 region where local African ancestry was associated with low birth weight, low BMI, high BMI-adjusted waist-to-hip ratio, and high T2D risk. Findings in the 12q14-21 genomic locus are consistent with the fetal insulin hypothesis that postulates that low birth weight and T2D have a common genetic basis, and they support the hypothesis of a shared African genetic ancestry component linking low birth weight and T2D in African Americans. Future studies should identify the actual genetic variants responsible for the clustering of these conditions in African Americans.
Aims/hypothesis
The aim of this study was to assess shift work in relation to incident type 2 diabetes in African-American women.
Methods
In the Black Women’s Health Study (BWHS), an ongoing ...prospective cohort study, we followed 28,041 participants for incident diabetes during 2005–2013. They answered questions in 2005 about having worked a night shift. We estimated HR and 95% CIs for incident diabetes using Cox proportional hazards models. The basic multivariable model included age, time period, family history of diabetes, education and neighbourhood socioeconomic status. In further models, we controlled for lifestyle factors and BMI.
Results
Over the 8 years of follow-up, there were 1,786 incident diabetes cases. Relative to never having worked the night shift, HRs (95% CI) for diabetes were 1.17 (1.04, 1.31) for 1–2 years of night-shift work, 1.23 (1.06, 1.41) for 3–9 years and 1.42 (1.19, 1.70) for ≥10 years (
p
-trend < 0.0001). The monotonic positive association between night-shift work and type 2 diabetes remained after multivariable adjustment (
p
-trend = 0.02). The association did not vary by obesity status, but was stronger in women aged <50 years.
Conclusions/interpretation
Long duration of shift work was associated with an increased risk of type 2 diabetes. The association was only partially explained by lifestyle factors and BMI. A better understanding of the mechanisms by which shift work may affect the risk of diabetes is needed in view of the high prevalence of shift work among workers in the USA.
Background Obesity occurs more commonly among African-American women than among other racial/ethnic groups, and most weight gain occurs before middle age. Purpose The study prospectively investigated ...the relationship of vigorous exercise and brisk walking to the incidence of obesity (BMI ≥30) among African-American women aged <40 years. Methods During 1995–2009 in the Black Women’s Health Study, the current authors followed 20,259 African-American women who were aged <40 years and not obese at baseline. BMI, exercise, and walking were assessed at baseline and on biennial follow-up questionnaires. Data for BMI were collected through 2009. Data for exercise and walking were collected through 2007. Validation and reproducibility data indicated that reporting was more accurate for vigorous exercise than for brisk walking. Cox proportional hazards models estimated incidence rate ratios (IRRs) and 95% CIs of incident obesity for hours/week of vigorous exercise and walking relative to “little or no exercise” (<1 hour/week of vigorous exercise and <1 hour/week of brisk walking). The analyses were conducted in 2012. Results The incidence of obesity decreased with increasing vigorous exercise; the IRR was 0.77 (95% CI=0.69, 0.85) for ≥7 hours/week relative to little or no exercise; the IRRs were reduced both among women with a healthy weight (BMI <25) at baseline and among women who were overweight (BMI 25–<30) at baseline. The IRRs for brisk walking for exercise and walking for transport were <1.0 for most levels of walking, but without clear trends of decreasing risk with increasing time spent walking. Conclusions The results suggest that vigorous exercise may reduce the incidence of obesity among young African-American women. Results for brisk walking were inconclusive.
Background: There is a paucity of data on the validity of self‐report of periodontal disease in African Americans. The Black Women’s Health Study (BWHS), a United States national cohort study of ...59,000 black women followed via mailed questionnaires since 1995, offered the opportunity to clinically validate self‐reported periodontitis among a sample of participants.
Methods: Oral health questionnaires were sent to study participants residing in Massachusetts. Respondents living in the Boston metro area were invited for clinical examination. Self‐reports were compared with clinical data obtained from the 77 women (mean age: 59 years) who were examined. The authors examined the predictive ability of individual and combined questionnaire items with respect to clinical periodontal disease severity. Validation parameters were calculated for each question, and receiver operating characteristic statistics were generated to compare questionnaire items.
Results: Periodontitis prevalence in the validation sample was 24% for severe periodontitis and 61% for moderate disease. Performance of individual questionnaire items with respect to predicting periodontitis was better for severe compared with moderate disease. Combinations of questionnaire items improved the predictive ability with respect to severe disease beyond that of individual questionnaire items.
Conclusions: Prevalence of severe periodontitis was similar to other age‐comparable populations, without regard for race or sex, whereas prevalence of total periodontitis (moderate and severe) among women of similar age and/or race was much higher. Predictive ability of questionnaire items assessed in the BWHS was similar to that in other studies.
This study assessed the relation of BMI and waist circumference to the risk of death among black women participating in the Black Women's Health Study. The risk of death from any cause increased with ...increasing BMI above 25.0, a pattern similar to that observed in whites.
The prevalence of overall and abdominal obesity has increased rapidly in the United States, with the greatest increases reported among black women.
1
By 2020, overall obesity (body-mass index BMI, the weight in kilograms divided by the square of the height in meters ≥30.0) and abdominal obesity (waist circumference >35 in. >88.0 cm) are projected to affect up to 70% and 90% of black women, respectively, in the United States.
1
Although overall obesity has been clearly associated with an increased risk of death,
2
–
4
the association of overweight (BMI, 25.0 to 29.9) with risk of death has been inconsistent.
5
,
6
A . . .
Hypertension affects nearly 1 of 3 women and contributes to cardiovascular disease, the leading cause of death in the United States. Breastfeeding leads to metabolic changes that could reduce risks ...of hypertension. Hypertension disproportionately affects black women, but rates of breastfeeding among black women lag behind those in the general population. In the Black Women's Health Study (n = 59,001), we conducted a nested case-control analysis using unconditional logistic regression to estimate the association between breastfeeding and incident hypertension at ages 40-65 years using data collected from 1995 to 2011. Controls were frequency-matched 2:1 to 12,513 hypertensive women by age and questionnaire cycle. Overall, there was little evidence of association between ever breastfeeding and incident hypertension (odds ratio = 0.97, 95% confidence interval: 0.92, 1.02). However, age modified the relationship (P = 0.02): Breastfeeding was associated with reduced risk of hypertension at ages 40-49 years (odds ratio = 0.92, 95% confidence interval: 0.85, 0.99) but not at older ages. In addition, risk of hypertension at ages 40-49 years decreased with increasing duration of breastfeeding (P for trend = 0.08). Our results suggest that long-duration breastfeeding may reduce the risk of incident hypertension in middle age. Addressing breastfeeding as a potential preventative health behavior is particularly compelling because it is required for only a discrete period of time.
Although endometrial cancer risk differs among white and black women, few data on its associations with exogenous hormone use in the latter group are available. Studies have reported lower ...endometrial cancer risk among users of oral contraceptives (OCs), but higher risk among users of estrogen-only female menopausal hormones (FMHs). Evidence for the risk among estrogen plus progestin FMHs users is equivocal.
We followed 47,555 Black Women's Health Study participants with an intact uterus from 1995 through 2013. Data on exogenous hormone use, covariates, and endometrial cancer were obtained biennially. Self-reported incident cases of endometrial cancer were confirmed by medical records or cancer registries whenever possible. We estimated incidence rate ratios (IRRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression.
We observed 300 endometrial cancer cases during 689,546 person-years of follow-up. Compared with never use, ≥10 years' duration of OC use was associated with lower risk (multivariable IRR = 0.45, 95% CI, 0.27-0.74), but risk was higher among current users of estrogen-only (IRR = 3.78, 95% CI, 1.69-8.43) and estrogen plus progestin FMH (IRR = 1.55, 95% CI, 0.78-3.11). Risk was not increased among former users of estrogen-only (IRR = 0.87, 95% CI, 0.44-1.72) or estrogen plus progestin FMH (IRR = 0.63, 95% CI, 0.36-1.09).
Current use of estrogen-only and estrogen plus progestin FMH was associated with increased risk of endometrial cancer. Risk appeared lower among former users of estrogen plus progestin FMH. Long-term OC use was associated with reduced risk.
Our results are generally consistent with those among white women.
.
African American (AA) women have higher incidence of aggressive, young-onset (<40 years) breast cancers. Young- and older-onset disease may have distinct tumor biologies and etiologies; however, ...studies investigating age differences among AA women have been rare and generally underpowered.
We examined tumor characteristics and breast cancer risk factors associated with premenopausal young (<40) vs. older (≥40) AA women's breast cancer in the African American Breast Cancer Epidemiology and Risk Consortium (2,008 cases and 5,144 controls). Unconditional logistic regression models assessed heterogeneity of tumor biology and risk factor associations by age, overall, and by estrogen receptor status.
Premenopausal AA women <40 years had higher frequency of poorer-prognosis tumor characteristics compared with older women, including negative estrogen and progesterone receptor status, triple-negative subtype, higher grade, higher stage, and larger tumors. Adiposity (i.e., waist-to-hip ratio) and family history of breast cancer were more strongly associated with young-onset disease case-control OR = 1.46, 95% confidence interval (CI) = 1.04-2.05; OR = 3.10, 95% CI = 2.08-4.63, respectively compared with older-onset disease (OR = 1.11, 95% CI = 0.91-1.35; OR = 1.57, 95% CI = 1.26-1.94). Breastfeeding showed a slight inverse risk association among young women (OR = 0.70, 95% CI = 0.43-1.16). Oral contraceptive use was associated with increased risk regardless of age. Considering various cutoff points for young age (<40, <45, <50), age-related heterogeneity was greatest when <40 was used.
Among premenopausal AA women, diagnosis before age 40 is associated with more aggressive breast tumor biology and some etiologic differences.
Modifiable risk factors including breastfeeding, adiposity, and oral contraceptive use may be important targets for mitigating harms of young-onset breast cancer.
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