Hair relaxer use and risk of uterine cancer in the Black Women's Health Study.

BACKGROUND: Chemical hair relaxers, use of which is highly prevalent among Black women in the US, have been inconsistently linked to risk of estrogen-dependent cancers, such as breast cancer, and other reproductive health conditions. Whether hair relaxer use increases risk of uterine cancer is unknown. METHODS: In the Black Women's Health Study, 44,798 women with an intact uterus who self-identified as Black were followed from 1997, when chemical hair relaxer use was queried, until 2019. Over follow-up, 347 incident uterine cancers were diagnosed. We used multivariable Cox proportional hazards regression models, adjusted for age and other potential confounders, to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations of hair relaxer use with risk of uterine cancer. RESULTS: Compared to women who never used hair relaxers or used them infrequently (<4 years and ≤1-2 times/year), the HR for uterine cancer associated with heavy use (≥15 years and at least 5 times/year) was 1.18 (95% CI: 0.81, 1.71). However, among postmenopausal women, compared to never/light use, the HR for moderate use was 1.60 (95% CI: 1.01, 2.53), the HR for heavy use was 1.64 (1.01, 2.64), and the HR for ≥20 years of use regardless of frequency was 1.71 (1.08, 2.72). Results among premenopausal women were null. CONCLUSIONS: In this large cohort of Black women, long-term use of chemical hair relaxers was associated with increased risk of uterine cancer among postmenopausal women, but not among premenopausal women. These findings suggest that hair relaxer use may be a potentially modifiable risk factor for uterine cancer.

Hair product use and breast cancer incidence in the Black Women's Health Study.

Hair relaxers and leave-in conditioners and oils, commonly used by Black/African American women, may contain estrogens or estrogen-disrupting compounds. Thus, their use may contribute to breast cancer risk. Results of the few previous studies on this topic are inconsistent. We assessed the relation of hair relaxer and leave-in conditioner use to breast cancer incidence in the Black Women's Health Study, a nationwide prospective study of Black women. Among 50 543 women followed from 1997 to 2017, 2311 incident breast cancers occurred. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression for breast cancer overall and by estrogen receptor (ER) status. For heavy use (≥15 years of use for ≥7 times/year) of hair relaxers relative to never/light use (<4 years, no more than 1-2 times/year), the multivariable HR for breast cancer overall was 1.13 (95%CI: 0.96-1.33). Duration, frequency, age at first use and number of scalp burns were not associated with overall breast cancer risk. For heavy use of hair relaxers containing lye, the corresponding HR for ER+ breast cancer was 1.32 (95% CI: 0.97, 1.80); there was no association for non-lye products. There was no association of conditioner use and breast cancer. Results of this study were largely null, but there was some evidence that heavy use of lye-containing hair relaxers may be associated with increased risk of ER+ breast cancer. Consistent results from several studies are needed before it can be concluded that use of certain hair relaxers impacts breast cancer development.

A prospective cohort study of ambient air pollution exposure and risk of uterine leiomyomata.

STUDY QUESTION: 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)? SUMMARY ANSWER: 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. WHAT IS KNOWN ALREADY: 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. STUDY DESIGN, SIZE, DURATION: We conducted a prospective cohort study of 21 998 premenopausal Black women residing in 56 US metropolitan areas from 1997 to 2011. PARTICIPANTS/MATERIAL, SETTING, METHODS: 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. MAIN RESULTS AND THE ROLE OF CHANCE: 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). LIMITATIONS, REASONS FOR CAUTION: 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. WIDER IMPLICATIONS OF THE FINDINGS: 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. STUDY FUNDING/COMPETING INTEREST(S): 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. TRIAL REGISTRATION NUMBER: N/A.

Air pollution and breast cancer risk in the Black Women's Health Study.

BACKGROUND: Air pollution contains numerous carcinogens and endocrine disruptors which may be relevant for breast cancer. Previous research has predominantly been conducted in White women; however, Black women may have higher air pollution exposure due to geographic and residential factors. OBJECTIVE: We evaluated the association between air pollution and breast cancer risk in a large prospective population of Black women. METHODS: We estimated annual average ambient levels of particulate matter <2.5 µm (PM2.5), nitrogen dioxide (NO2) and ozone (O3) at the 1995 residence of 41,317 participants in the Black Women's Health Study who resided in 56 metropolitan areas across the United States. Cox proportional hazards regression was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for an interquartile range (IQR) increase in each pollutant. We evaluated whether the association varied by menopausal status, estrogen receptor (ER) status of the tumor and geographic region of residence. RESULTS: With follow-up through 2015 (mean = 18.3 years), 2146 incident cases of breast cancer were confirmed. Higher exposure to NO2 or O3 was not associated with a higher risk of breast cancer. For PM2.5, although we observed no association overall, there was evidence of modification by geographic region for both ER- (p for heterogeneity = 0.01) and premenopausal breast cancer (p for heterogeneity = 0.01). Among women living in the Midwest, an IQR increase in PM2.5 (2.87 µg/m3), was associated with a higher risk of ER- (HR = 1.53, 95% CI: 1.07-2.19) and premenopausal breast cancer (HR = 1.32, 95% CI: 1.03-1.71). In contrast, among women living in the South, PM2.5 was inversely associated with both ER- (HR = 0.74, 95% CI: 0.56-0.97) and premenopausal breast cancer risk (HR = 0.75, 95% CI: 0.62-0.91). DISCUSSION: Overall, we observed no association between air pollution and increased breast cancer risk among Black women, except perhaps among women living in the Midwestern US.

Aspirin use and risk of breast cancer in African American women.

BACKGROUND: Use of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) has been hypothesized to be associated with reduced risk of breast cancer; however, results of epidemiological studies have been mixed. Few studies have investigated these associations among African American women. METHODS: To assess the relation of aspirin use to risk of breast cancer in African American women, we conducted a prospective analysis within the Black Women's Health Study, an ongoing nationwide cohort study of 59,000 African American women. On baseline and follow-up questionnaires, women reported regular use of aspirin (defined as use at least 3 days per week) and years of use. During follow-up from 1995 through 2017, 1919 invasive breast cancers occurred, including 1112 ER+, 569 ER-, and 284 triple-negative (TN) tumors. We used age-stratified Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations of aspirin use with risk of ER+, ER-, and TN breast cancer, adjusted for established breast cancer risk factors. RESULTS: Overall, the HR for current regular use of aspirin relative to non-use was 0.92 (95% CI 0.81, 1.04). For ER+, ER-, and TN breast cancer, corresponding HRs were 0.98 (0.84, 1.15), 0.81 (0.64, 1.04), and 0.70 (0.49, 0.99), respectively. CONCLUSIONS: Our findings with regard to ER- and TN breast cancer are consistent with hypothesized inflammatory mechanisms of ER- and TN breast cancer, rather than hormone-dependent pathways. Aspirin may represent a potential opportunity for chemoprevention of ER- and TN breast cancer.

PM2.5 and Diabetes and Hypertension Incidence in the Black Women's Health Study.

BACKGROUND: Clinical studies have shown that exposure to fine particulate matter (PM2.5) can increase insulin resistance and blood pressure. The epidemiologic evidence for an association of PM2.5 exposure with the incidence of type 2 diabetes or hypertension is inconsistent. Even a modest association would have great public health importance given the ubiquity of exposure and high prevalence of the conditions. METHODS: We used Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident type 2 diabetes and hypertension associated with exposure to PM2.5 in a large cohort of African American women living in 56 metropolitan areas across the US, using data from the Black Women's Health Study. Pollutant levels were estimated at all residential locations over follow-up with a hybrid model incorporating land use regression and Bayesian Maximum Entropy techniques. RESULTS: During 1995 to 2011, 4,387 cases of diabetes and 9,570 cases of hypertension occurred. In models controlling for age, questionnaire cycle, and metro area, there were positive associations with diabetes (HR = 1.13, 95% CI = 1.04, 1.24) and hypertension (HR = 1.06, 95% CI = 1.00, 1.12) per interquartile range of PM2.5 (2.9 µg/m). Multivariable HRs, however, were 0.99 (95% CI = 0.90, 1.09) for diabetes and 0.99 (95% CI = 0.93, 1.06) for hypertension. CONCLUSIONS: Our results provide little support for an association of PM2.5 with diabetes or hypertension incidence.

Neighborhood Socioeconomic Status in Relation to Serum Biomarkers in the Black Women's Health Study.

Lower neighborhood socioeconomic status (SES) is associated with higher cardiovascular disease (CVD) risk. Black women have a higher CVD risk and are more likely to live in poor neighborhoods than white women. We examined the association of neighborhood SES with several CVD biomarkers using data from the Black Women's Health Study (BWHS), a follow-up study of US black women reporting high levels of education and income. Blood specimens of 418 BWHS participants were assayed for C-reactive protein (CRP), hemoglobin A1C (hgA1C), and high-density lipoprotein (HDL) cholesterol. US Census block group data were linked to the women's addresses to reflect neighborhood SES. Multivariable-adjusted mixed linear regression models that adjusted for person-level SES and for cardiovascular risk factors were used to assess CRP, hgA1C, and HDL levels in relation to quintiles of neighborhood SES. Women living in the poorest neighborhoods had the least favorable biomarker levels. As neighborhood SES increased, CRP decreased (P for trend = 0.01), hgA1C decreased (P for trend = 0.07), and HDL increased (P for trend = 0.19). These associations were present within strata of individual educational level. The present findings suggest that neighborhood environments may affect physiological processes within residents independently of individual SES.

Long term exposure to NO2 and diabetes incidence in the Black Women's Health Study.

While laboratory studies show that air pollutants can potentiate insulin resistance, the epidemiologic evidence regarding the association of air pollution with diabetes incidence is conflicting. The purpose of the present study was to assess the association of the traffic-related nitrogen dioxide (NO2) with the incidence of diabetes in a longitudinal cohort study of African American women. We used Cox proportional hazards models to calculate hazard ratios and 95% confidence intervals (CI) for diabetes associated with exposure to NO2 among 43,003 participants in the Black Women's Health Study (BWHS). Pollutant levels at participant residential locations were estimated with 1) a land use regression model for participants living in 56 metropolitan areas, and 2) a dispersion model for participants living in 27 of the cities. From 1995 to 2011, 4387 cases of diabetes occurred. The hazard ratios per interquartile range of NO2 (9.7 ppb), adjusted for age, metropolitan area, education, vigorous exercise, body mass index, smoking, and diet, were 0.96 (95% CI 0.88-1.06) using the land use regression model estimates and 0.94 (95% CI 0.80, 1.10) using the dispersion model estimates. The present results do not support the hypothesis that exposure to NO2 contributes to diabetes incidence in African American women.

Active and passive smoking and the incidence of asthma in the Black Women's Health Study.

RATIONALE: Evidence linking active or passive smoking to the incidence of adult-onset asthma is inconsistent with both positive and inverse associations being reported. Most previous studies of active smoking have not accounted for passive smoke exposure, which may have introduced bias. OBJECTIVES: To assess the separate associations of active and passive smoking to the incidence of adult-onset asthma in the U.S. Black Women's Health Study, a prospective cohort of African American women followed since 1995 with mailed biennial questionnaires. METHODS: Active smoking status was reported at baseline and updated on all follow-up questionnaires. Passive smoke exposure during childhood, adolescence, and adulthood was ascertained in 1997. Asthma cases comprised women who reported doctor-diagnosed asthma with concurrent asthma medication use. Cox regression models were used to derive multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) for former and current smoking and for passive smoking among nonsmokers compared with a reference category of never active or passive smokers. MEASUREMENTS AND MAIN RESULTS: Among 46,182 participants followed from 1995 to 2011, 1,523 reported incident asthma. The multivariable HRs for former active smoking, current active smoking, and passive smoking only were, respectively, 1.36 (95% CI, 1.11-1.67), 1.43 (95% CI, 1.15-1.77), and 1.21 (95% CI, 1.00-1.45), compared with never active/passive smoking. CONCLUSIONS: In this large population with 16 years of follow-up, active smoking increased the incidence of adult-onset asthma, and passive smoke exposure increased the risk among nonsmokers. Continued efforts to reduce exposure to tobacco smoke may have a beneficial effect on the incidence of adult-onset asthma.

Neighborhood and Individual Socioeconomic Status and Asthma Incidence in African American Women.

OBJECTIVE: Individual socioeconomic status (SES) has been associated with asthma incidence but whether neighborhood SES has an influence is unknown. We assessed the contributions of neighborhood socioeconomic status (SES), neighborhood housing density, neighborhood racial composition, and individual SES to the development of adult-onset asthma in Black women, accounting for other known or suspected risk factors. DESIGN AND PARTICIPANTS: Prospective cohort study conducted among 47,779 African American women followed with biennial health questionnaires from 1995 to 2011. METHODS AND MAIN OUTCOME MEASURES: Incident asthma was defined as new self-report of doctor-diagnosed asthma with concurrent use of asthma medication. We assessed neighborhood SES, indicated by census variables representing income, education, and wealth, and housing density and % African American population, as well as individual SES, indicated by highest education of participant/spouse. Cox proportional hazards models were used to derive multivariable hazard ratios (HRs) and 95% CIs for the association of individual SES and neighborhood variables with asthma incidence. RESULTS: During a 16-year follow-up period, 1520 women reported incident asthma. Neighborhood factors were not associated with asthma incidence after control for individual SES, body mass index, and other factors. Compared with college graduates, the multivariable HR for asthma was 1.13 (95% CI 1.00-1.28) for women with some college education and 1.23 (95% CI 1.05-1.44) for women with no more than a high school education. CONCLUSIONS: Individual SES, but not neighborhood SES or other neighborhood factors, was associated with the incidence of adult-onset asthma in this population of African American women.

Racism, segregation, and risk of obesity in the Black Women's Health Study.

We assessed the relation of experiences of racism to the incidence of obesity and the modifying impact of residential racial segregation in the Black Women's Health Study, a follow-up study of US black women. Racism scores were created from 8 questions asked in 1997 and 2009 about the frequency of "everyday" racism (e.g., "people act as if you are dishonest") and of "lifetime" racism (e.g., unfair treatment on the job). Residential segregation was measured by linking participant addresses to 2000 and 2010 US Census block group data on the percent of black residents. We used Cox proportional hazard models to estimate incidence rate ratios and 95% confidence intervals. Based on 4,315 incident cases of obesity identified from 1997 through 2009, both everyday racism and lifetime racism were positively associated with increased incidence. The incidence rate ratios for women who were in the highest category of everyday racism or lifetime racism in both 1997 and 2009, relative to those in the lowest category, were 1.69 (95% confidence interval: 1.45, 1.96; Ptrend < 0.01) and 1.38 (95% confidence interval: 1.15, 1.66; Ptrend < 0.01), respectively. These associations were not modified by residential segregation. These results suggest that racism contributes to the higher incidence of obesity among African American women.

General and abdominal obesity and risk of death among black women.

BACKGROUND: Recent pooled analyses show an increased risk of death with increasing levels of the body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) of 25.0 or higher in populations of European ancestry, a weaker association among East Asians, and no association of an increased BMI with an increased risk of death among South Asians. The limited data available on blacks indicate that the risk of death is increased only at very high levels of BMI (≥35.0). METHODS: We prospectively assessed the relation of both BMI and waist circumference to the risk of death among 51,695 black women with no history of cancer or cardiovascular disease who were 21 to 69 years of age at study enrollment. Our analysis was based on follow-up data from 1995 through 2008 in the Black Women's Health Study. Multivariable proportional-hazards models were used to estimate hazard ratios and 95% confidence intervals. RESULTS: Of 1773 deaths identified during follow-up, 770 occurred among 33,916 women who had never smoked. Among nonsmokers, the risk of death was lowest for a BMI of 20.0 to 24.9. For a BMI above this range, the risk of death increased as the BMI increased. With a BMI of 22.5 to 24.9 as the reference category, multivariable-adjusted hazard ratios were 1.12 (95% confidence interval [CI], 0.87 to 1.44) for a BMI of 25.0 to 27.4, 1.31 (95% CI, 1.01 to 1.72) for a BMI of 27.5 to 29.9, 1.27 (95% CI, 0.99 to 1.64) for a BMI of 30.0 to 34.9, 1.51 (95% CI, 1.13 to 2.02) for a BMI of 35.0 to 39.9, and 2.19 (95% CI, 1.62 to 2.95) for a BMI of 40.0 to 49.9 (P<0.001 for trend). A large waist circumference was associated with an increased risk of death from any cause among women with a BMI of less than 30.0. CONCLUSIONS: The risk of death from any cause among black women increased with an increasing BMI of 25.0 or higher, which is similar to the pattern observed among whites. Waist circumference appeared to be associated with an increased risk of death only among nonobese women. (Funded by the National Cancer Institute.).

Depressive symptoms and the incidence of adult-onset asthma in African American women.

BACKGROUND: Some evidence suggests that depression may increase the risk of adult-onset asthma. No data are available for African American women, in whom the prevalence of depression and asthma is high. OBJECTIVE: To conduct prospective analyses of the relation of depressive symptoms to asthma incidence in the Black Women's Health Study, a prospective cohort of US black women followed since 1995 with mailed biennial questionnaires. METHODS: Of 31,848 participants followed from 1999 to 2011, 771 reported incident asthma. Depressive symptoms were ascertained on 1999 and 2005 follow-up questionnaires with the Center for Epidemiological Studies-Depression Scale (CES-D). Participants rated the frequency of 20 symptoms. A score was calculated by summing the responses to all questions. Cox regression models were used to derive incidence rate ratios and 95% confidence intervals for 4 categories of the CES-D score in relation to incident asthma, adjusted for body mass index, smoking, and other covariates. RESULTS: The multivariable incidence rate ratio in the highest category of CES-D score (≥ 33) compared with the lowest (<16) was 2.08 (95% confidence interval 1.58-2.74), with a significant trend (P < .0001). The incidence rate ratio was higher in women who took antidepressants, were current or former smokers, were not obese, and were at least 40 years old, although there were no statistically significant interactions. CONCLUSION: A positive association was observed between CES-D score and the incidence of adult-onset asthma. If the hypothesis is confirmed, depression could contribute substantially to the burden of asthma in adults.

Assessment of traffic-related noise in three cities in the United States.

BACKGROUND: Traffic-related noise is a growing public health concern in developing and developed countries due to increasing vehicle traffic. Epidemiological studies have reported associations between noise exposure and high blood pressure, increased risk of hypertension and heart disease, and stress induced by sleep disturbance and annoyance. These findings motivate the need for regular noise assessments within urban areas. This paper assesses the relationships between traffic and noise in three US cities. METHODS: Noise measurements were conducted in downtown areas in three cities in the United States: Atlanta, Los Angeles, and New York City. For each city, we measured ambient noise levels, and assessed their correlation with simultaneously measured vehicle counts, and with traffic data provided by local Metropolitan Planning Organizations (MPO). Additionally, measured noise levels were compared to noise levels predicted by the Federal Highway Administration's Traffic Noise Model using (1) simultaneously measured traffic counts or (2) MPO traffic data sources as model input. RESULTS: We found substantial variations in traffic and noise within and between cities. Total number of vehicle counts explained a substantial amount of variation in measured ambient noise in Atlanta (78%), Los Angeles (58%), and New York City (62%). Modeled noise levels were moderately correlated with measured noise levels when observed traffic counts were used as model input. Weaker correlations were found when MPO traffic data was used as model input. CONCLUSIONS: Ambient noise levels measured in all three cities were correlated with traffic data, highlighting the importance of traffic planning in mitigating noise-related health effects. Model performance was sensitive to the traffic data used as input. Future noise studies that use modeled noise estimates should evaluate traffic data quality and should ideally include other factors, such as local roadway, building, and meteorological characteristics.

Abuse during childhood and adolescence and risk of adult-onset asthma in African American women.

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.

Air pollution and incidence of hypertension and diabetes mellitus in black women living in Los Angeles.

BACKGROUND: Evidence suggests that longer-term exposure to air pollutants over years confers higher risks of cardiovascular morbidity and mortality than shorter-term exposure. One explanation is that the cumulative adverse effects that develop over longer durations lead to the genesis of chronic disease. Preliminary epidemiological and clinical evidence suggests that air pollution may contribute to the development of hypertension and type 2 diabetes mellitus. METHODS AND RESULTS: We used Cox proportional hazards models to assess incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for incident hypertension and diabetes mellitus associated with exposure to fine particulate matter (PM(2.5)) and nitrogen oxides in a cohort of black women living in Los Angeles. Pollutant levels were estimated at participants' residential addresses with land use regression models (nitrogen oxides) and interpolation from monitoring station measurements (PM(2.5)). Over follow-up from 1995 to 2005, 531 incident cases of hypertension and 183 incident cases of diabetes mellitus occurred. When pollutants were analyzed separately, the IRR for hypertension for a 10-µg/m(3) increase in PM(2.5) was 1.48 (95% CI, 0.95-2.31), and the IRR for the interquartile range (12.4 parts per billion) of nitrogen oxides was 1.14 (95% CI, 1.03-1.25). The corresponding IRRs for diabetes mellitus were 1.63 (95% CI, 0.78-3.44) and 1.25 (95% CI, 1.07-1.46). When both pollutants were included in the same model, the IRRs for PM(2.5) were attenuated and the IRRs for nitrogen oxides were essentially unchanged for both outcomes. CONCLUSION: Our results suggest that exposure to air pollutants, especially traffic-related pollutants, may increase the risk of type 2 diabetes mellitus and possibly of hypertension.

Restaurant foods, sugar-sweetened soft drinks, and obesity risk among young African American women.

BACKGROUND: The prevalence of obesity is disproportionately high in African American women, and consumption of fast foods and sugar-sweetened soft drinks is also especially high among African Americans. OBJECTIVE: We investigated the relation of intakes of sugar-sweetened soft drinks and specific types of restaurant foods to obesity in the Black Women's Health Study. DESIGN: In this prospective cohort study, 19,479 non-obese women aged 21-39 years at baseline were followed for 14 years (1995-2009). Dietary intake was assessed by validated food frequency questionnaire in 1995 and 2001. MAIN OUTCOME MEASURES: Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association of intakes of restaurant foods and sugar-sweetened soft drinks with incident obesity. RESULTS: Higher intakes of burgers from restaurants and sugar-sweetened soft drinks were associated with greater risk of becoming obese. The associations were present in models that included both factors and adjusted for overall dietary pattern. The HR of obesity in relation to restaurant burger consumption of > or = 2 times/week compared with < 5 times/year was 1.26 (95% CI: 1.14-1.40; P-trend<.001). For sugar-sweetened soft drink intake, the HR was 1.10 (95% CI: .99-1.23; P-trend = .14) for > or = 2 drinks/day compared with < 1 drink/month. The associations were stronger among women younger than age 30 with normal weight at baseline. CONCLUSIONS: Frequent consumption of burgers from restaurants and sugar-sweetened soft drinks contribute to obesity among young African American women.

A case-control study of reproductive factors, female hormone use, and risk of pancreatic cancer.

Findings from several previous studies that have assessed the relation of reproductive factors and female hormone use to the risk of pancreatic cancer are inconclusive. The authors examined the association between reproductive factors and the use of oral contraceptives and postmenopausal hormone therapy to the risk of pancreatic cancer among 284 patients with pancreatic cancer and 1,096 controls using data from the hospital-based Case-Control Surveillance Study. Older age at first pregnancy and long-duration oral contraceptive use were associated with an increased risk of pancreatic cancer: the odds ratio was 2.0 (95% CI: 1.1-3.3) for first birth at age 30 or older compared with before age 20 (p for trend = 0.042) and 2.0 (95% CI: 1.0-4.0) for ten or more years of use of oral contraceptive use relative to no-use (p for trend < 0.01). Risk of pancreatic cancer risk was not associated with postmenopausal female hormone use. The findings suggest that increased exposure to estrogen during the reproductive years may play a role in the development of pancreatic cancer in women. Further studies are needed to confirm the findings.

Statin and NSAID use and prostate cancer risk.

PURPOSE: Some studies have reported reduced risks of advanced, but not early, prostate cancer among statin users, and one study found a reduced risk only among statin users who had also used non-steroidal anti-inflammatory drugs (NSAIDs). We have previously reported no association between statin use and prostate cancer in our hospital-based Case Control Surveillance Study. The purpose of the present analyses was to update the findings by cancer stage and to evaluate the joint use of statins and NSAIDs. METHODS: Cases were 1367 men with prostate cancer and controls were 2007 men with diagnoses unrelated to statin or NSAID use. We used multivariable logistic regression analyses to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for statin use compared with no use, and joint use of statin and NSAIDs compared with use of neither. RESULTS: The odds ratio among regular statin users was 1.1 (95%CI 0.9-1.5), and odds ratios were similar among early and late stage cancers. The odds ratio among joint statin and NSAID users was 1.1 (95%CI 0.7-1.6). CONCLUSION: The present results do not support a protective effect of statin use, or statin and NSAID use, on the risk of advanced prostate cancer.

Body mass index and asthma incidence in the Black Women's Health Study.

BACKGROUND: Evidence from prospective studies consistently links obesity to asthma onset in white women, although there is controversy as to whether the association is causal. There are few data on this topic in black women, among whom the prevalence of obesity and asthma is high. OBJECTIVE: We prospectively assessed the relation of body mass index (BMI) to asthma incidence in the Black Women's Health Study. METHODS: We followed 46,435 women from 1995 through 2005 with biennial mailed questionnaires. Cox regression models were used to estimate incidence rate ratios and 95% CIs. RESULTS: During 403,394 person-years of follow-up, 1068 participants reported physician-diagnosed asthma and concurrent use of asthma medication. Compared with women with BMIs of 20 to 24, the multivariate incidence rate ratios for higher categories of BMI increased from 1.26 (95% CI, 1.05-1.51) for BMIs of 25 to 29 to 2.85 (95% CI, 2.19-3.72) for BMIs of 40 or greater, with a significant trend. The association of BMI with asthma risk was consistent across strata of smoking status, age, presence of sleep apnea, parental history of asthma, BMI at age 18 years, and energy expenditure and intake. CONCLUSION: In this large cohort of African American women, there was a positive association between BMI and asthma risk that was similar in magnitude to those observed in longitudinal studies of white women.