Healthy African American Women Research Articles

Strategies for Recruitment of Healthy Premenopausal Women into the African American Nutrition for Life (A NULIFE) Study.

Although African American women have an overall lower incidence of breast cancer, African American women <40 years of age are more likely than Caucasian women of all ages and postmenopausal African American women to be diagnosed with breast cancer and exhibit tumor characteristics associated with poorer survival. To begin to address this disparity, studies must be conducted to examine breast cancer preventive factors in this subpopulation of women. However, the strategies needed to recruit younger African American women have not been well defined. In this study, we assessed methods used for recruiting and retaining healthy premenopausal African American women into the African American Nutrition for Life (A NULIFE) Study. The number of women contacted, enrolled, and retained by each recruitment strategy and the efficiency of individual strategies were calculated. Overall, recruitment through social networking was most effective in contacting large numbers of healthy premenopausal African American women. The worksite recruitment method was the most efficient recruitment strategy employed, with a ratio of 40%. The study participants (n = 164) were more likely to be >or=35 years of age and have completed some college. Additionally, the interpersonal relationships recruitment approach proved most efficient (33%) in retaining participants who completed the yearlong study. The findings from this study add to the evolving research literature on minority recruitment strategies for research studies but specifically address effective recruitment of healthy young premenopausal African American women. The results demonstrate the need to use multiple recruitment strategies when recruiting this subgroup of African American women.

Neonatal physiological regulation is associated with perinatal factors: A study of neonates born to healthy African American women living in poverty

Maternal mental health and prenatal stress are linked with neurobehavioral differences in the offspring. The majority of studies documenting this effect have been conducted using either predominantly European American infants or minority infants exposed to teratogens in utero. In this study, we focus on healthy African American women from low-income environments to investigate the earliest individual differences in biobehavioral regulation, including resting heart rate and variability (HRV). In 87 neonates, HRV was significantly lower in those born to mothers reporting past major depressive disorder (p = .01). The number of maternal life stressors also was associated with lower neonatal HRV (p = .03). Obstetrical complications were not associated with significant differences, but breast- versus bottle-feeding in the first few days of life was related to higher HRV (p = .04). Early variation in physiological regulation may be linked to subsequent individual differences in response to stress. Thus, identifying the earliest point in development when such differences can be reliably measured may result in opportunities for prevention of later deficits in regulating response to stress.

Re: “Aerobic Exercise Alters Postprandial Lipemia in African American versus White Women”

Purpose: To determine whether ethnicity influences postprandial lipemia after a bout of aerobic exercise. Methods: Randomized crossover design. Healthy White (W; n = 6) and African American (AA; n = 6) women (age, W 27.0 ± 3.3 yr, AA 21.6 ± 1.4 yr; body-mass index, W 25.0 ± 0.93 kg/m2, AA 25.8 ± 0.79 kg/m2) participated in 2 treatments (control and exercise), each conducted over 2 d. On d 1, participants rested (control) or walked at 60% of maximal oxygen uptake for 90 min (exercise) and then consumed a meal. On d 2, after a 12-hr overnight fast, participants consumed an oral fat-tolerance test (OFTT) meal of 1.7 g fat, 1.65 g carbohydrate, and 0.25 g protein per kg fat-free mass. Blood was collected premeal and at 0.5, 1, 2, 3, 4, 5, and 6 hr post-OFTT and analyzed for triacylglycerol (TAG), glucose, and insulin. Areas under the curve (AUCs) were calculated for each blood variable. Results: A significantly lower TAG AUC was observed for AA (0.86 ± 0.24 mmol · L−1 · 6 hr−1) after exercise than for W (2.25...

Macular Thickness Assessment in Healthy Eyes Based on Ethnicity Using Stratus OCT Optical Coherence Tomography

To assess the variation in macular thickness measurements in healthy Caucasian and African American men and women through Stratus OCT optical coherence tomography (OCT-3). One hundred sixty-six eyes of 83 healthy patients underwent complete ophthalmologic examination in this prospective study. Exclusion criteria included a diagnosis of diabetes mellitus, hypertension, intraocular pressure (IOP) greater than 21 mm Hg, history of eye surgery or trauma, or evidence of eye disease. For analysis purposes, the authors excluded those participants in whom OCT signal strength was <7 in each eye. A fast macular thickness protocol consisting of a 6-mm radial scan centered on the fovea was used for the analysis, and the data were analyzed using the t-test for independence and linear regression. Both eyes of each patient were analyzed using the OCT-3, and analysis showed a statistically significant correlation between right and left eyes. Therefore, only one eye from each patient was randomly selected for final correlation and analysis. Mean foveal thickness (MFT) for Caucasians was 32 microm greater than for African Americans (217 vs. 185 microm, respectively; P < 0.001). The MFT was significantly thicker in males than in females (220 vs. 197 microm, respectively; P < 0.001). The fovea is significantly less thick in African Americans and females than in Caucasians and males. Racial and sexual differences should be considered when interpreting an OCT scan.

Do Sex or Race Differences Influence Strength Training Effects on Muscle or Fat?

To examine the influence of sex and race on the effects of strength training (ST) on thigh muscle volume (MV), midthigh subcutaneous fat (SCF), and intermuscular fat (IMF). One hundred eighty-one previously inactive healthy Caucasian (N = 117) and African American (N = 54) men (N = 82) and women (N = 99), aged 50-85 yr, underwent about 10 wk of unilateral knee extension ST. Ten subjects were neither Caucasian nor African American and were, therefore, not included in the race analysis. Quadriceps MV and midthigh SCF and IMF cross-sectional area were measured with computed tomography before and after ST. Sex and race comparisons were made with a 2 x 2 (sex by race) analysis of covariance. Training-induced increases in absolute MV were significantly greater (P < 0.001) in men than in women, though both sex groups increased MV significantly with ST (P < 0.001), and the relative (%) increases were similar. There were significant increases in MV within race groups (P < 0.001), but no significant differences between races. There were no significant changes in SCF or IMF, whether sex and racial groups were separated or combined. In addition, there was no sex by race interaction for changes in MV, SCF, or IMF with ST. Strength training does not alter subcutaneous or intermuscular fat, regardless of sex or racial differences. Although men exhibit a greater muscle hypertrophic response to strength training than do women, the difference is small. Race does not influence this response.

Aerobic Exercise Alters Postprandial Lipemia in African American versus White Women

To determine whether ethnicity influences postprandial lipemia after a bout of aerobic exercise. Randomized crossover design. Healthy White (W; n=6) and African American (AA; n=6) women (age, W 27.0+/-3.3 yr, AA 21.6+/-1.4 yr; body-mass index, W 25.0+/-0.93 kg/m2, AA 25.8+/-0.79 kg/m2) participated in 2 treatments (control and exercise), each conducted over 2 d. On d 1, participants rested (control) or walked at 60% of maximal oxygen uptake for 90 min (exercise) and then consumed a meal. On d 2, after a 12-hr overnight fast, participants consumed an oral fat-tolerance test (OFTT) meal of 1.7 g fat, 1.65 g carbohydrate, and 0.25 g protein per kg fat-free mass. Blood was collected pre-meal and at 0.5, 1, 2, 3, 4, 5, and 6 hr post-OFTT and analyzed for triacylglycerol (TAG), glucose, and insulin. Areas under the curve (AUCs) were calculated for each blood variable. A significantly lower TAG AUC was observed for AA (0.86+/-0.24 mmol x L(-1) x 6 hr(-1)) after exercise than for W (2.25+/- .50 mmol x L(-1) x 6 hr(-1)). Insulin AUC was significantly higher for AA after exercise (366.2+/-19.9 mmol x L(-1) x 6 hr(-1)) than for the control (248.1+/-29.2 mmol x L(-1) x 6 hr(-1)). The data indicate that exercise performed approximately 13 hr before an OFTT significantly reduces postprandial lipemia in AA compared with W. It appears that AA women have an increased ability to dispose of TAG after exercise and a high-fat meal.

Intermuscular adipose tissue rivals visceral adipose tissue in independent associations with cardiovascular risk

The metabolic implications of intermuscular adipose tissue (IMAT) are poorly understood compared to those of visceral adipose tissue (VAT) even though the absolute quantities of both depots are similar in many individuals. The aim was to determine the independent relationship between whole-body IMAT and cardiovascular risk factor parameters. Whole body magnetic resonance imaging (MRI) was used to quantify total skeletal muscle (SM), total adipose tissue (TAT) of which IMAT, defined as the AT visible by MRI within the boundary of the muscle fascia, is a sub-component. Fasting serum measures (n=262) of glucose, total cholesterol (T-Chol), high-density lipoprotein cholesterol (HDL-Chol), triglycerides (TG), protein bound glucose (PBG, n=206) and insulin (n=119) were acquired in healthy African-American (AA, n=78) and Caucasian (Ca, n=109) women (body mass index (BMI) 26.5+/-5.7 kg/m(2); 44.4+/-16.4 years) and men (39 AA, 62 Ca; BMI 25.6+/-3.5 kg/m(2); 45.6+/-17.4 years). General linear models identified the independent effects of IMAT after covarying for SM, VAT, TAT, race, sex and two-way interactions. Significant independent associations were observed for IMAT with glucose (P<0.001), PBG (P<0.001) and T-Chol (P<0.05). The association of IMAT with cholesterol differed by race in such a manner that for a unit increase in IMAT, T-Chol increased more rapidly in Ca compared to AA (P<0.05). TG, HDL-Chol and insulin had no independent association with IMAT. The strong independent associations of IMAT with fasting glucose and PBG suggest that IMAT may be related to glucose metabolism; however, IMAT is also associated with T-Chol in Ca.

Fighting cancer with fitness: Dietary outcomes of a randomized, controlled lifestyle change intervention in healthy African–American women

Objectives. This study tested the efficacy of an 8-week, culturally targeted community-based nutrition and physical activity promotion intervention, Fight Cancer with Fitness! (FCF). Methods. A randomized, controlled trial was conducted in a black-owned commercial gym in a sample of 366 predominantly overweight or obese, healthy African–American women. Results. Dietary quality as indexed by fruit and vegetable intake improved significantly in the intervention group compared to the control group at 12-month follow-up, and proportion of calories consumed as fat decreased in both groups. Conclusions. This individually targeted cancer prevention intervention produced beneficial effects on dietary quality that were sustained for at least 12 months.

Independent association of intermuscular adipose tissue with CVD risk factors

The metabolic implications of intermuscular adipose tissue (IMAT, adipose tissue visible by MRI within the boundary of the muscle fascia) have been little studied compared to total body adipose tissue (TAT) and visceral adipose tissue (VAT). Whole body magnetic resonance imaging was used to quantify TAT and its components: subcutaneous adipose tissue (SAT), VAT, and IMAT. Fasting serum measures (n=262) of glucose, cholesterol (Chol), high density lipoprotein (HDL), triglycerides (Trig) protein bound glucose (PBG, n=206), and insulin (n=119), were acquired in healthy adult African American (AA, n=78) and Caucasian (Ca, n=109) women (BMI 26.5±5.7 kg/m2; 44.4±16.4 years) and men (39 AA, 62 Ca; BMI 25.6±3.5 kg/m2; 45.6±17.4 years). General linear models were used to identify independent effects of IMAT after covarying for VAT, SAT, race, sex and 2-way interactions. Correlations of IMAT with VAT and SAT ranged between 0.38 and 0.78. Statistically significant independent associations were observed for IMAT with glucose (p<0.001), PBG (p<0.001), and Chol (p=0.005). The association of IMAT to Chol differed by race (p=0.011). TG, HDL and insulin had no independent association with IMAT. The strong independent associations of IMAT with fasting glucose and PBG suggest that IMAT may be related to glucose metabolism, however, IMAT also shows some association to Chol. This study was supported by NIH AG14715, DK42618; RR00645, DK40414; and a contract from the NIA.

Reference Range for Serum Parathyroid Hormone

To determine whether the reference range for parathyroid hormone (PTH) should be lowered (from 65 pg/mL to a proposed value of 46 pg/mL) with use of the Allegro radioimmunometric assay. We examined the reference range for PTH, adjusted for serum 25-hydroxyvitamin D (25-OHD), in 503 healthy African American and white women, who were 20 to 80 years old. We also analyzed other factors that are thought to influence PTH levels. Univariate predictors of PTH were identified, and a multivariate model was developed with use of the variables and PTH. Serum PTH was significantly higher in black study subjects than in white study subjects (P<0.02). Increasing PTH was also significantly correlated with increasing body mass index, age, and serum creatinine and with decreasing dietary calcium intake and serum 25-OHD levels. A stepwise multiple linear regression analysis yielded the following predictors of PTH: body mass index (R2=9.4%), age (R2=1.0%), and serum 25-OHD (R2=0.8%). In our study population, many PTH values were above the proposed new upper limit of 46 pg/mL. The upper limit of the reference range for serum PTH should not be changed. Factors to be considered in analysis of serum PTH values in the upper reference range in patients with normocalcemia include obesity, race, 25-OHD levels, advanced age, serum creatinine, and dietary calcium intake.

Metacarpal index and bone mineral density in healthy African-American women

Bone mineral density (BMD) reference data of non-Caucasian women is scarce but greatly needed for African-American women. The objective of this study was to establish a metacarpal normative reference database for African-American women using digital X-ray radiogrammetry (DXR) and hand radiographs and compare these values to existing Caucasian data. Two hundred and fifty healthy African-American women between the ages of 20 and 79 years old, 14 of whom were excluded, were recruited to participate from four different clinical sites. The study population was recruited in approximately equal number into the following groups: 20-29, 30-39, 40-49, 50-59, 60-69 and 70-79 years of age. A radiograph was acquired of each subject's non-dominant hand. The radiographs were scanned and analyzed using radiogrammetric techniques, and the BMD, MCI (Metacarpal Index), bone width and cortical thickness were calculated. The regression curve that best fit the data was a second order polynomial. The BMD and MCI of young adult women (20-40 years of age) were used to calculate T-score parameters. The young reference BMD and MCI with their associated standard deviations were found to be 0.6045 g/cm2+/-0.0529 g/cm2 and 0.5096 and 0.0792, respectively. However, the MCI was found to be approximately 2.5% lower (-0.0118) compared to Caucasian women. The African-American metacarpal BMD was found to be 3.5% (0.0207 g/cm2) higher across all ages when compared to existing Caucasian reference data acquired in a similar way. The differences were found to be entirely due to larger bone size, cortical diameter and bone width in the African-American women.

Brief report: etiological attributions for breast cancer among healthy African American and European American women

Anecdotal evidence suggests that African American women's attributions about breast cancer may differ from European American women, but empirical studies are lacking. The present study examined attributions about breast cancer made by a sample of healthy African American and European American women. The sample included 197 women (75 African American, 122 European American), with a mean age of 39.2. Overall, women were most likely to attribute the development of breast cancer to genetics, "no one", environmental poisons, diet, personal behavior and stress. European American women were more likely to attribute breast cancer to broadly external causes such as the environment, heredity and chance, while African American women were more likely to list immediate, interpersonal-level causes such as a blow to the breast, and personal behavior. Results highlight the need for attention to cultural processes in cancer prevention and control.

Lipoprotein Compositional Changes With Combination Hormone Therapy (Conjugated Estrogen And Medroxyprogesterone) in African American Women

To determine whether combination hormone therapy (HT) significantly alters lipoprotein composition in healthy African American women. Postmenopausal African American women, 45 to 65 years old, were randomly assigned to receive daily HT (conjugated equine estrogen, 0.625 mg, and medroxyprogesterone, 2.5 mg) or placebo (treated, 44; placebo, 16) for 12 weeks. Lipoproteins were separated by gradient ultracentrifugation into very-low-density, intermediate-density, and low-density lipoproteins (VLDL, IDL, and LDL) and 3 high-density lipoprotein (HDL) subfractions (light, medium, and dense--L, M, and D). Apolipoprotein (apo) A-I, A-II, C-III, C-II, and C-I were measured by high-performance liquid chromatography. Apo B, phospholipids, triglycerides, cholesterol, and free cholesterol were measured by standard assays. Total plasma cholesterol, triglycerides, LDL apo B, and total apo B did not change during HT. A small, transient reduction occurred in LDL cholesterol, and a persistent reduction was noted in VLDL apo B, apo C-II, and apo C-III. Total HDL phospholipids, cholesterol, apo A-I, and apo A-II increased, whereas the LDL/HDL ratio and the apo B/apo A-I ratio decreased. Cholesterol ester increased in both HDL-L and HDL-M, but only a transient increase occurred in HDL-L phospholipids. Apo A-I increased in HDL-L, HDL-M, and HDL-D; however, a similar increase occurred in HDL-D apo A-I in the control subjects. Moreover, an increase occurred in apo A-II in HDL-M. A reduction in the apo A-II:A-I ratio in HDL-L but not in HDL-M indicated an increase in HDL-L LpA-I particles. The increase in HDL particles in HDL-M was entirely due to an increase in LpA-I:A-II particles. Apo C-III increased in both HDL-L and HDL-M. The absence of changes in the HDL lipid ratios indicated an unaltered lipid composition of these particles. No changes were found in IDL compositional measurements. In 12 treated patients and 4 control subjects, Lp(a) was detected by ultracentrifugation; no changes were noted in Lp(a) composition or quantity with HT. Total Lp(a) measured by enzyme immunosorbent assay showed a trend toward an increase in treated patients after 12 weeks of HT. African American women had a beneficial response to HT by increasing the number of LpA-I particles in HDL-L and LpA-I:A-II particles in HDL-M as well as cholesterol esters in both. There was a small reduction in VLDL apo B (and thus particle number) but only a transient reduction in LDL cholesterol. A shift of apo C-III from VLDL to HDL was noted. No detrimental changes occurred in any lipoprotein subfraction (specifically, no increase in triglycerides).

Sex Hormone Levels in Premenopausal African-American Women With Upper and Lower Body Fat Phenotypes

Body fat distribution may be a better marker of a hormonal pattern associated with increased breast cancer risk than obesity. This cross-sectional study of 106 healthy premenopausal African-American (AA) women compared the midfollicular phase sex hormone and sex hormone-binding globulin levels in upper body fat (UBF) and lower body fat (LBF) phenotype and obese and nonobese women. Multivariate regression analyses were used to control for various confounders, including dietary factors. UBF phenotype women had 37% (P = 0.02), 50% (P = 0.01), 52% (P = 0.007), and 50% (P = 0.009) higher levels of estradiol (E2), free E2, testosterone (T), and free T, respectively, than LBF phenotype women. Only %free T was higher in obese than in nonobese women (P = 0.02). The levels of E2, free E2, %free E2, T, and free T were higher [by 42% (P = 0.01), 68% (P = 0.001), 18% (P = 0.04), 36% (P = 0.04), and 61% (P = 0.01), respectively] and the level of sex hormone-binding globulin was lower [by 28% (P = 0.04)] in obese UBF than in nonobese LBF phenotype women. These findings support the hypothesis that body fat distribution may be a better marker of a hormonal pattern associated with increased breast cancer risk than obesity. Obese UBF phenotype AA women, in particular, have a high-risk hormonal profile. Future breast cancer studies might consider controlling for measures of obesity and body fat distribution to minimize confounding.

Measures of Body Size Based on Height, Weight, and Reported Ideal Weight: Conceptual Distinctions and Empirical Demonstrations

Using height, weight, and self-reported weight, eight additional measures of body size were computed. The purpose of this paper was to specify conceptual distinctions and test hypothesized relationships among those newly constructed measures. Using a sample of healthy African American and European American women, correlations among the measures and race differences were assessed. High correlations suggested only two independent constructs, but theoretical considerations would suggest retaining, in addition to the traditional measure of body mass index, three new constructs: ideal body mass, a discrepancy measure, and a desirability measure. The only significant race difference was on ideal body mass. African American women reported a larger ideal body mass index than European American women. The use of actual versus self-report measures of height and weight, different conceptualizations of ideal weight, and clinical implications also were discussed.

Leptin is related to epinephrine levels but not reproductive hormone levels in cycling African-American and Caucasian women

This study examined the effects of the menstrual cycle and race on plasma leptin levels. Sixty-one healthy African-American and Caucasian women and men (mean age 32 years) were studied twice, approximately six weeks apart, women once during the follicular phase (days 7–10 following menses) and once during the luteal phase (days 7–10 following LH surge) of the menstrual cycle. Consistent with the literature, women showed approximately 4-fold higher leptin levels as compared to men (p < 0.001). There were no effects of the menstrual cycle nor race on leptin levels. Leptin levels were correlated with BMI in both women and men respectively, r = 0.602, p < 0.001 and r = 0.338, p < 0.05. Leptin levels showed a high degree of test-retest reliability across the 6-week testing interval (r = 0.62, p < 0.001 for women and r = 0.91, p < 0.001 for men). In addition, in women, and independent of BMI, leptin was negatively correlated with plasma epinephrine levels (r = −0.38, p = 0.01). No such relationship was observed in men. The findings indicate that in women leptin levels are not associated with cyclic changes in estrogen or progesterone but may be associated with catecholamine levels.

Comparison of cardiac versus vascular reactors and ethnic groups in plasma epinephrine and norepinephrine responses to stress

This study examined differences in plasma epinephrine (EPI) and norepinephrine (NOREPI) responses to stressors in 67 healthy African-American and Caucasian American men and women of the ages 18 to 49. Subjects were divided into three groups: (a) those who showed high blood pressure (BPI responses to stress associated with consistently high cardiac output (CO) increases with no substantial increases in total peripheral resistance (TPR), labeled cardiac reactors: (b) those with equally high BP increases associated with consistently higher TPR increases and lesser CO increases. labeled vascular reactors; (c) those who showed mixed hemodynamic responses or were low BP reactors. Ethnic and gender group differences in EPI and NOREPI responses were also examined. Cardiac reactors, vascular reactors and mixed + low reactors did not differ in EPI or NOREPI levels at baseline. During stressors, cardiac reactors showed greater increases in plasma EPI than vascular reactors or others during math, reaction time, and passive and active speech tasks: they also showed a weak trend toward greater NOREPI increases during these challenges as well. No differences were seen during the cold pressor: this stressor evoked the least change in EPI of all tasks, whereas the active speech elicited the greatest increases in both EPI and NOREPI of all tasks. Vascular reactors did not differ from mixed + low reactors in EPI or NOREPI reactivity, and men and women did not differ in EPI or NOREPI reactivity to any task. In contrast, Black subjects showed greater increases in NOREPI levels across all stressors compared to White subjects. These findings have implications for investigations of the role of sympathetic nervous system activity in the pathogenesis of hypertension in both African-American and Caucasian American populations.

Recruitment of Older African American and White Women for a Longitudinal Study of Skeletal Health

ABSTRACT We report our experience with successfully recruiting 377 skeletally healthy African American and white (and other) women into a longitudinal study of bone loss. The objective of this 2-year observational study was to prospectively measure changes in bone mineral density and determinants of that change in women who were at least 10 years postmenopause. We recruited from a random sample of women who were members of our health maintenance organization, including the urban and five suburban regions of Detroit. Of those contacted by telephone, 91% completed a 15–20 survey containing demographic and eligibility variables. We recruited 1 in 17 potential subjects who were contacted by telephone. Of the eligible women, 33% participated in the study. The eligibility rate was higher among the African American than among the white women, but there was no ethnic difference in the participation rate. We also describe eligibility and participation rates with regard to demographic and sociologie variables, such...