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PubMed1991

Possible contribution of pretransplant immune responder status to renal allograft survival differences of black versus white recipients.

Black end-stage renal disease patients may present as an immunologically higher-risk group for renal allograft transplantation than white ESRD patients. To test this hypothesis, we correlated graft survivals in 124 black and 241 white cyclosporine-prednisone-treated primary cadaveric renal allograft recipients with pre-Tx nonspecific immune responder status (strong vs. weak immune responders), donor-recipient-specific MLC responsiveness, HLA match, and blood transfusion (BT) history. One-, 2- and 3-year patient survival rates of 95%, 94%, and 94% were identical for both groups. However, the 1-, 2-, 3-year graft survival rates for white recipients of 82%, 79%, and 75% were significantly higher than the 70%, 62%, and 55% rates for black recipients (P less than 0.01 for each, respectively). Pre-Tx nonspecific immune response values for blacks were significantly (P less than 0.01) higher than for whites (38% vs. 28% for active T cell; 1.8 vs. 1.3 for TH:TS ratio; 28,581 c.p.m. vs. 14,870 c.p.m. for spontaneous blastogenesis; and a stimulation index (SI) of 34 vs. 20 for panel mixed lymphocyte culture). Additionally, the specific recipient-donor MLC (SI) for black recipients was significantly greater than the specific recipient-donor MLC for white recipients (MLC SI of 40 vs. 18, P less than 0.01). Blacks present as pre-Tx strong immune responders with a greater frequency than whites (90% vs. 66%, P less than 0.01). Moreover, black strong responders experience a poorer 1-year graft survival than white strong responders (67% vs. 80%, P less than 0.01). Even though the pre-Tx BT histories of white and black ESRD patients studied herein were comparable, the immunoregulatory effect of pre-Tx BT was different in white vs. black patients. A significant reduction in TH:TS ratio was observed when comparing 0 vs. 1-4 pre-Tx white patient BT groups, whereas significant changes in TH:TS ratios were not observed until after comparing 0 vs. greater than or equal to 5 pre-Tx black patient BT groups. HLA matching and pre-Tx BT had no impact on improving the graft survivals of these CsA-Pred-treated white or black recipients. These data, therefore, support the hypothesis that black recipients present as an immunologically higher-risk group than white recipients.

Black People↗
PubMed1995

Differences in joint mobility and foot pressures between black and white diabetic patients.

Limited joint mobility is common in diabetes and is related to high foot pressures and foot ulceration. We have examined the differences in joint mobility and foot pressures in four groups matched for age, sex, and duration of diabetes: 31 white diabetic, 33 white non-diabetic, 24 black diabetic, and 22 non-diabetic black subjects. Joint mobility was assessed using a goniometer at the fifth metacarpal, first metatarsal, and subtalar joints. In-shoe and without shoes foot pressures were measured using an F-Scan system. Neuropathy was evaluated using clinical symptoms (Neuropathy Symptom Score), signs (Neuropathy Disability Score), and Vibration Perception Threshold. There was no difference between white and black diabetic patients in Neuropathy Symptom Score, Neuropathy Disability Score, and Vibration Perception Threshold. Subtalar joint mobility was significantly reduced in white diabetic patients (22 +/- 7 degrees) compared to white controls (26 +/- 4 degrees, black diabetic patients (25 +/- 5 degrees), and black controls (29 +/- 7 degrees), and increased in black controls compared to white controls and black diabetic patients (level of statistical significance p < 0.05). Without shoes foot pressures were higher in white diabetic patients (8.31 +/- 400 kg cm-2) compared to white controls (6.81 +/- 2.31 kg cma2), black diabetic patients (6.2 +/- 2.53 kg cm-2) and black controls (5.00 +/- 1.24 kg cm-2) and lower in black controls compared to white and black diabetic patients (p < 0.05 in all cases). We conclude that racial differences exist in joint mobility and foot pressures between black and white subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Black-white differences in exercise blood pressure. The Lipid Research Clinics Program Prevalence Study.

After exclusion of persons on blood pressure medication or with prevalent cardiovascular disease, we studied 83 black and 2,548 white men and 113 black and 1,519 white women 20-69 years old from the Lipid Research Clinics population sample who had performed a standardized treadmill exercise test. Resting systolic and diastolic blood pressures were similar in black and white men, but the diastolic pressure was significantly higher in black than in white women (81.4 vs 77.4 mm Hg). Body weight was higher in black than in white women, and reported physical activity was higher in black than in white men. The proportion of smokers was somewhat higher in blacks than in whites. During the treadmill exercise test with a modified Bruce protocol, mean systolic blood pressure at stage 2 was 174 mm Hg in black men and 166 mm Hg in white men (p less than 0.02), but stage 2 blood pressures did not differ between black and white women (153 and 152 mm Hg, respectively). Even after adjustments were made for levels of baseline characteristics (age, weight, resting systolic blood pressure, smoking, low density lipoprotein cholesterol, physical activity, and alcohol intake), black men responded with a 7-mm Hg higher systolic blood pressure during exercise than white men (p less than 0.01). Another new finding was a highly significant positive association between stage 2 systolic blood pressure and low density lipoprotein cholesterol in men. The findings suggest a higher systemic vascular resistance during exercise in the selected sample of black men, which is consistent with the higher incidence of hypertension in black men.

Adult↗
PubMed1999

Levels of mineralocorticoids in whites and blacks.

Blacks appear, on average, to retain more Na than whites. A higher production rate of mineralocorticoids could explain the greater Na retention in blacks. Although production of aldosterone has been shown to be lower in blacks, the level of another mineralocorticoid may be increased. Plasma levels of deoxycorticosterone and cortisol were measured in young whites (n=23; age=16.4+/-3.1[SD] years) and young blacks (n=25; age=13.8+/-1.3 years). Blacks had lower plasma levels of renin activity and aldosterone and lower urinary aldosterone excretion rates; thus, they appeared to be representative of blacks that retain additional Na. Plasma deoxycorticosterone levels were lower in blacks than in whites both at baseline (247+/-161 versus 381+/-270 pmol/L, P=0.048) and after stimulation with adrenocorticotropic hormone (822+/-294 versus 1127+/-628 pmol/L at 30 minutes, P=0.047; 925+/-366 versus 1440+/-834 pmol/L at 60 minutes, P=0.013). Cortisol levels were also lower in blacks at baseline (P=0.014) but were not significantly different from levels in whites after stimulation with adrenocorticotropic hormone. In a larger cohort of 407 whites (age=12.0+/-2.9 years) and 247 blacks (age=12.9+/-3.1 years), 18-hydroxycortisol excretion rates were also lower in blacks (P=0. 021). In conclusion, increased Na retention in blacks does not appear to be secondary to increased production of either aldosterone, deoxycorticosterone, cortisol, or 18-hydroxycortisol. A primary renal mechanism may mediate the increase in Na reabsorption in blacks.

Adolescent↗
PubMed1998

Polymorphisms of the beta chain of the high-affinity immunoglobulin E receptor (Fcepsilon RI-beta) in South African black and white asthmatic and nonasthmatic individuals.

We used amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) to document the prevalence of three mutations in the beta chain of the high-affinity IgE receptor (Fcepsilon RI-beta): I181L, V183L, and E237G in a sample of black and white asthmatic and control subjects in South Africa to determine whether these variants contribute to the enhanced IgE responses in these groups and also to determine whether the discrepancy in the prevalence of atopy in these groups could be attributed to these variants, as whites tend to be more atopic than blacks. There was a significant difference in the frequency of I181L between white asthmatics (28%) and white control subjects (3%) (p = 0.00001), and between black control subjects (16%) and white control subjects (p = 0.002); no difference in the frequency of I181L was observed between black asthmatics (22%) and black control subjects (16%). V183L was found in one black asthmatic who was also positive for I181L and E237G. There was a significant difference in the frequency of E237G between black asthmatics (20%) and white asthmatics (12%) (p = 0.05), and between control subjects (20%) and white control subjects (5%) (p = 0.003). E237G was more prevalent in blacks (20%) than in whites (8.5%) (p = 0.001). I181L might predispose to atopy in the white population, but not in the black population. The significantly higher prevalence of E237G in blacks than in whites might explain why blacks tend to have more severe asthma than whites and might offer more insight into the higher asthma mortality rate in the black population as compared with the white population.

Adolescent↗
PubMed1996

Black women receive less mammography even with similar use of primary care.

BACKGROUND: Black women with breast cancer have a decreased 5-year survival rate in comparison with white women, possibly because of less frequent use of mammography. Having a regular provider or source of health care is the most important determinant of mammography use. OBJECTIVE: To examine whether the difference in mammography use between elderly black women and elderly white women is related to the number of visits made to a primary care physician. DESIGN: Retrospective review of 1990 Health Care Financing Administration billing files (Medicare part B) from 10 states. SETTING: Outpatient mammography services in 10 states. PARTICIPANTS: Black women and white women, 65 years of age and older, residing in one of the 10 states. MEASUREMENTS: Any mammogram. Predictors included race, number of visits to a primary care physician (0, 1, 2, or 3 or more), median income of ZIP code of residence (a surrogate measure of income), and state. RESULTS: The following are findings from Georgia; similar results were found in each state studied. The mean age of the 335,680 women was 75 years; 20% were black. Sixty-eight percent of the black women and 69% of the white women made at least one visit to a primary care physician. Overall, 14% of the women had had mammography; black women had mammography less often than white women (9% compared with 15%). At each primary care visit level (1, 2, or 3 or more visits), black women had mammography less often than white women (1 visit, 7% compared with 15%; 2 visits, 12% compared with 21%; and 3 or more visits, 12% compared with 20%). Even among women who had made at least one visit to a primary care physician, a deficit for blacks occurred in each income quintile (lowest quintile, 13% compared with 20%; low, 10% compared with 18%; middle, 12% compared with 18%; high, 10% compared with 19%; and highest, 12% compared with 22%) and in each state (in Georgia, for example, the percentages were 14% compared with 21%). An age-, income-, and state-adjusted logistic model predicting mammography use for 2.9 million white women in all 10 states shows the powerful effect of primary care use on mammography (odds ratios for 1, 2, and 3 or more visits were, respectively, 2.73 [95% CI, 2.70 to 2.77]; 3.98 [CI, 3.93 to 4.03]; and 4.62 [CI, 4.58 to 4.67]). The same model fit to 250 000 black women shows a lesser effect (analogous odds ratios were 1.77 [CI, 1.67 to 1.87]; 2.49 [CI, 2.36 to 2.63]; and 3.15 [CI, 3.04 to 3.25]). CONCLUSION: Among older women, mammography is used less often for blacks than for whites. More frequent use of mammography is associated with more visits to a primary care physician in both groups, but the deficit for black women persists at each income level and in each state, even after primary care use is considered. Primary care visits are less likely to "boost" mammography use for black women than for white women.

Black or African American↗
PubMedDate not supplied

Cigarette smoking and cessation behaviors among urban blacks and whites.

Smoking behaviors among blacks and whites were studied in a population-based sample of 2,626 residents of Minneapolis-St. Paul, MN. More blacks than whites were found to be smokers, before and after adjusting for age and education differences. More whites than blacks were former smokers, but the prevalence of those who had never smoked was comparable for whites and blacks. Among smokers, the mean number of cigarettes smoked per day was lower among blacks than whites, but more blacks were found to smoke cigarettes with high "tar" (dry particulate matter) and nicotine content. Men smokers were found to smoke more than women smokers, young people smoked more than older people, and those with a high school education or less smoked more than those with more than a high school education. Smoking cessation behavior consisted mostly of a variety of strategies that began with reducing cigarette consumption, followed by changing to lower tar brands, attempting to quit, and actually quitting. In general, a higher percentage of whites than blacks reported smoking cessation behaviors. A greater percentage of white than black women had tried cigarette brands lower in tar and nicotine within the previous year. Among men, a lower percentage of black than white smokers had tried quitting, and fewer black men planned to quit in the future. Blacks appeared to lag behind whites in their efforts to quit smoking. Smoking behavior continues to be problematic for both blacks and whites. Studies are needed to explain better the racial differences in smoking and smoking cessation behaviors, and to facilitate programs to encourage cessation.

Adult↗
PubMed1989

Breast lesions in black women.

A number of studies compared the clinical features and demographic characteristics of black and white patients with diseases of the breast. Only a few, however, dealt with the pathology of breast lesions. In this study, the distribution of breast lesions in blacks and whites (Caucasians) in the accessioned material of the AFIP from 1980 to 1983 was described. Additionally, the distribution of estrogen and progesterone receptors in a total of 425 black patients with breast cancer at Howard University Hospital was studied and the results compared with similar data reported in white American women. In the period January 1, 1980, to January 1, 1983, there were 380 breast lesions from black patients and 3511 comparable lesions from white patients accessioned at the AFIP. A total of 159 black women and 1819 white women were diagnosed with carcinoma of breast. Black patients had 102 (79 percent) invasive duct carcinomas, and white patients had 1112 (78 percent). Black patients with invasive duct carcinoma were generally younger than white patients, as 68 percent of black patients and 53 percent of white patients were younger than 54 years. The difference in age distribution was statistically significant. Lobular carcinoma was less common in blacks than in whites. The relative ratio frequency of mucinous, medullary, and papillary carcinoma was higher in black women than in whites. Tubular carcinoma, however, was more common in whites than in blacks. Black patients had a lower incidence of ER-positive tumors and a higher incidence of ER-negative tumors compared with published data on white patients. Postmenopausal patients were more likely to be ER positive than premenopausal patients. Stratification of the data indicated a lower incidence of ER-positive and a higher incidence of ER-negative breast cancers in both premenopausal and postmenopausal patients compared with published data from institutions with predominantly white patient populations. Microscopic examination revealed a higher frequency of poorly differentiated carcinomas and fewer well- and moderately well-differentiated carcinomas than has been reported for white women with the tumor. There was a significant correlation between tumor grade and receptor positivity. Well-differentiated carcinomas were more likely ER and PR positive than poorly differentiated ones.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1993

A comparison of peritoneal dialysis-related infections in black and white patients.

OBJECTIVE: To determine if black patients in our peritoneal dialysis (PD) program had higher rates of PD-related infections. The outcomes of black patients versus white patients were also reviewed. DESIGN: A review of prospectively collected patient demographic and PD-related infection data and outcomes, from 1979 to 1991. PATIENTS: The 68 black patients in our PD program were matched with white control patients for age, sex, insulin dependence, time on dialysis, and mode of dialysis (CAPD or CCPD). The infection, demographic, and outcome data from the two groups were compared. RESULTS: Black patients had higher peritonitis rates (1.10 vs 0.82 episodes/year, p = 0.001) and exit-site infection rates (1.13 vs 0.95 episodes/year, p = 0.02) than the white control patients. Tunnel infection rates were 0.21 episodes/year in both groups. S. epidermidis peritonitis was more common in black patients (48% of episodes vs 21% of episodes in whites, p = 0.005), and S. aureus peritonitis was more common in white patients (29% vs 11% in blacks, p = 0.005). The subset of black patients (n = 13) on a disconnect system (Y-set) had a peritonitis rate similar to their white controls on the Y-set (0.41 vs 0.74 episodes/year, p = 0.27). There were no episodes of S. epidermidis peritonitis in this subset of black patients. Black patients had fewer S. aureus exit-site infections than white patients (21% vs 41%, p = 0.005). Peritonitis was the leading cause of transfer to hemodialysis in the black patients but not in the white patients. CONCLUSION: The susceptibility to S. aureus and S. epidermidis infections differs in black and white patients on peritoneal dialysis for unclear reasons. Peritonitis rates in black patients can be reduced to that of white patients if a disconnect system is used.

Black People↗
PubMed1994

Testicular cancer in blacks. A multicenter experience.

BACKGROUND: The rarity of testis tumor in black patients has made the study of a large series difficult. Much of the epidemiologic and clinical information regarding this neoplasm in this population is in dispute, including data on incidence, prognosis, histologic distribution, age and stage at presentation, and side distribution. METHODS: A retrospective review of 66 blacks with testicular tumors from seven military medical centers was performed. RESULTS: Similar results were found for blacks with testis tumor to those of the general testis cancer population regarding prognosis, side distribution, and age of onset for nonseminoma and interstitial tumors. There is a slight increase in the expected number of interstitial tumors in blacks, but the distribution between seminoma and nonseminoma is similar to the general population. The mean age of presentation for seminoma in blacks was younger than that of the general testis cancer population. For testis tumor treated at the same institution, there was an increased delay of diagnosis in blacks compared with whites. The number of new cases of testicular cancer between 1979 and 1991 at one major center was increased for whites but not for blacks. The availability of cisplatin-based combination chemotherapy has resulted in an improved prognosis for blacks, as has already been demonstrated for white populations. CONCLUSIONS: Testis tumor in blacks behaves similarly to testis tumor in the general population except that in blacks there are more interstitial tumors and the mean age of presentation for seminoma is younger. Further, there is an increased delay in diagnosis for blacks compared with whites, but the incidence of this tumor in this population does not appear to be increasing. Cisplatin-based chemotherapy has significantly improved survival in this population.

Adult↗
PubMed1989

The association between obesity and hypertension in blacks.

The relationship between obesity (or overweight) and hypertension among blacks warrants careful consideration because of the substantial prevalence of both obesity and hypertension in the black population. Based on the relative risks of hypertension for overweight and nonoverweight persons in the 1976-1980 U.S. National Health and Nutrition Examination Survey, 21% of hypertension in black men and 18% of hypertension in black women can be attributed to overweight. In terms of numbers affected, approximately 330,000 cases of hypertension among black men and 500,000 cases of hypertension among black women in the 25- 74-year age range may be related to obesity. Thus, although several sources suggest that obesity is less strongly associated with hypertension in blacks than whites, obesity clearly plays a significant role in hypertension in blacks. The benefits of weight loss for black hypertensives may include not only reduction in blood pressure but also--as an independent effect--regression of left ventricular hypertrophy, which is also excessively prevalent in blacks compared with whites. Weight control and weight reduction warrant high priority in treatment regimens for overweight black hypertensives.

Adult↗
PubMed1999

Is peritoneal dialysis a good option for black patients?

Blacks are less likely than whites to use peritoneal dialysis (PD) as the initial renal replacement therapy. The reason for the underusage of PD by blacks is unknown. In a cross-sectional multicenter trial, we studied peritoneal transport character, small-molecular-weight solute clearances, and nutritional status in 475 patients undergoing PD (168 whites, 192 blacks, and 115 Asians). The mean age of blacks undergoing PD was significantly younger than that of whites (47.6 +/- 14.7 v 58.2 +/- 16.7 years; P < 0.0001). Target Kt/V and weekly creatinine clearance (WCC) as defined by the Dialysis Outcome Quality Initiative Work Group was achieved by 62.5% of whites, 67.2% of blacks, and 54.8% of Asians (P = 0.05). Total protein (7.25 +/- 0.88 v 6.55 +/- 0.73 g/dL), albumin (3.72 +/- 0.57 v 3.55 +/- 0.53 g/dL), and lean body mass (LBM; 41.7 +/- 15.6 v 33.0 +/- 11.8 kg) were lower in whites compared with blacks (P < 0.001). Although the normalized protein catabolic rate (nPCR) was greater (0.82 +/- 0.24 v 0.90 +/- 0.32 g/kg/d; P = 0.04), total protein (6.24 +/- 0.85 g/dL) and serum albumin levels (3.36 +/- 0.52 g/dL) and LBM (30.1 +/- 8.0 kg) were significantly lower in Asians than blacks (P < 0.0001). The favorable anabolic response in blacks may partially be explained by a higher calorie intake in this group of patients (29.6 +/- 10.7 Cal/kg/d) compared with whites (22.4 +/- 6.8 Cal/kg/d) and Asians (23.9 +/- 9.8 Cal/kg/d; P = 0.03). Multiple regression analysis identified that black race and weight were positively associated, whereas dialysate/plasma creatinine ratio (D/P(Creat)) and age had a negative effect on serum albumin level. Follow-up data indicated that the Kt/V (2.09 +/- 0.50 v 2.39 +/- 0.56; P = 0.02) and WCC (60.8 +/- 4.3 v 70.2 +/- 7.3 L/1.73 m2; P = 0.02) increased significantly from baseline only in blacks. We conclude that PD is an ideal renal replacement therapy in at least a subset of blacks with end-stage renal disease.

Adult↗
PubMed2001

Overweight and sympathetic overactivity in black Americans.

A large body of clinical investigation implicates an important role for the sympathetic nervous system in linking obesity with hypertension. However, the experimental support for this hypothesis is derived from strictly white cohorts. The goal of this study was to determine whether being overweight begets sympathetic overactivity in black Americans, the ethnic minority at highest risk for hypertension. We recorded postganglionic sympathetic nerve discharge with microelectrodes in muscle nerve fascicles of the peroneal nerve in 92 normotensive young adult black men and women within a wide range of body mass index. The same experiments were performed in a control group of 45 normotensive white men and women of similar ages and body mass indices. The major new findings are 2-fold. First, in young, normotensive, overtly healthy black women, being overweight begets sympathetic overactivity (r=0.45, P=0.0009), a putative intermediate phenotype for incident hypertension. Second, in black men, sympathetic nerve discharge is dissociated from body mass index (r=0.03, P=NS). This dissociation is explained in part by a 20% to 40% higher rate of sympathetic nerve discharge in lean black men compared with lean white men and lean black and white women (28+/-3 versus 18+/-2, 21+/-2, and 17+/-2 bursts/min, respectively; P<0.05). Sympathetic nerve discharge in lean black men is comparable to that of overweight black men and women as well as white men and women. These data provide the first microneurographic evidence for tonic central sympathetic overactivity in blacks, both adiposity-related sympathetic overactivity in black women and adiposity-independent sympathetic overactivity in black men.

Adipose Tissue↗
PubMed1995

Role of social class in excess black stroke mortality.

BACKGROUND AND PURPOSE: It has been suggested that a substantial proportion of the excess stroke mortality among black Americans may be attributable to relatively lower socioeconomic status (SES) in this group. In this report we provide the first quantitative estimates of the proportion of excess black stroke mortality attributable to SES for a large population-based cohort. METHODS: We used data from the National Longitudinal Mortality Study for persons 45 years and older (73,400 white men, 87,528 white women, 6522 black men, and 8816 black women). Sex-specific proportional hazards model were used to estimate excess black stroke mortality with and without adjustment for education and income (measures of SES). The contribution of SES to the excess black stroke risk was estimated from the difference in regression coefficients for race in these models. RESULTS: In men, low SES was associated with increased stroke mortality (P < or = .0001) and accounted for 14% to 46% of the excess black stroke risk (P < .05). However, we could find no association between SES and stroke mortality in women, and SES did not account for a significant proportion of the excess stroke mortality in black women. CONCLUSIONS: Although SES proved to account for a statistically significant proportion of excess male black stroke mortality, overall SES explained less than one quarter of the observed excess between ages 45 and 65. In women, SES did not significantly reduce the estimated excess black stroke mortality. Although SES may be playing a role in excess black stroke mortality, a substantial proportion of the excess appears attributable to other sources, including cerebrovascular risk factors that are unrelated to SES, unmeasured lifestyle influences, social resources, and genetic factors.

Black or African American↗
PubMed2004

Comparison of cross-sectional geometry of the proximal femur in white and black women from Detroit and Johannesburg.

UNLABELLED: There are known black-white differences in bone density measured by DXA but less is known about bone architecture. We compared cross-sectional geometric properties of the proximal femur in U.S. black (n = 86) and white (n = 151) and South African black (n = 60) and white (n = 48) postmenopausal women. Results are consistent with greater bone strength in the black groups in both countries. INTRODUCTION: There are well-known ethnic differences in bone density, but little is known about ethnic differences in bone architecture between U.S. and South African blacks and whites. MATERIALS AND METHODS: We compared bone density and cross-sectional geometric properties of the proximal femur in 237 U.S. black (n = 86) and white (n = 151) and 108 South African black (n = 60) and white (n = 48) postmenopausal women. The proximal femur (neck, intertrochanteric region, and proximal shaft regions of interest) was measured with DXA and further analyzed with a hip structural analysis program. For each region, BMD, cross-sectional area, outer diameter, section modulus, endosteal diameter, average cortical thickness, and the buckling ratio were estimated. RESULTS AND CONCLUSIONS: In the femoral neck, in both countries, the blacks had narrower endosteal diameters (mean difference, 2.6% and 5.1% in U.S. and South African women, respectively), thicker cortices (9.3% and 11.0%), and a lower buckling ratio (11.6% and 15.2%) despite a similar outer diameter. In the intertrochanteric region, the whites had a greater outer diameter (2.2% and 3.0% in U.S. and South African women, respectively), lower cross-sectional area (4.8% and 7.2%), and a higher buckling ratio (7.6% and 3.6%). There are fewer differences in the shaft. Compared with South African whites, U.S. whites had wider (mean difference 2.9%) femoral necks and a greater section modulus (6.4%) in the shaft. U.S. whites also had greater cross-sectional area in both the neck and shaft (5.2% and 4.6%, respectively). The U.S. blacks had significantly greater outer diameters, cross-sectional areas, endosteal diameters, and section moduli in the neck region compared with South African blacks. Our observations are consistent with greater bone strength in the black groups in both countries, and they also suggest that there are fewer differences between the same ethnic groups in the two countries than there are between different ethnic groups within a country.

Black or African American↗
PubMed1982

Evidence for genetic admixture as a determinant in the occurrence of insulin-dependent diabetes mellitus in U.S. blacks.

In recent years, it has been proposed that genetic admixture may have played a role in the increased frequency of insulin-dependent diabetes mellitus (IDDM) in young U.S. blacks relative to African blacks. In support of this proposal, the similar associations of specific markers of the major histocompatibility complex (MHC) with IDDM in U.S. blacks with respect to U.S. whites have been cited. To determine whether racial admixture was a factor in the increased prevalence, we did three analyses of admixture. In the first we used nine genetic markers (ABO, Rh, Fy, Hp, Gc, Pl, OR, Tfr, and Gm) and determined that there was significantly greater than zero genetic contribution from whites in our sample of U.S. black IDDM patients (9.6 +/- 2.3%, P less than 0.01) when a sample of U.S. blacks without IDDM was used as one "parental" population. In the next two analyses, we estimated the amounts of genetic contribution from whites in the U.S. blacks with and without IDDM using reported gene frequencies for West African blacks for four genetic markers (ABO, Rh, Fy, and Hp). The estimate of admixture (21.4 +/- 2.8%) for the black IDDM sample was greater than that for the U.S. black controls (17.9 +/- 2.3%), although the difference was not significant. Our estimate of genetic contribution from whites, 21.4% for black IDDM patients, supports the assumptions of 20% admixture which MacDonald and Rotter and Hodge used to test their respective models for the inheritance of IDDM. These results support the hypothesis that admixture with the white population is, in part, responsible for the increase in prevalence of IDDM seen in U.S. blacks.

Black People↗
PubMed1997

Barriers to black women's participation in cancer clinical trials.

This study examines attitudes that may deter black women from participating in cancer research. Subjects were recruited from women who did not respond to the initial recruitment mailing for the Women's Health Initiative. Each subject was administered a 7- to 10-minute telephone survey. One third (29) of the 80 subjects were black. Fifty-six percent of black women and 71% of white women had positive attitudes toward cancer clinical trials. More than 80% of the women surveyed agreed that clinical research benefits society and increases medical knowledge. However, almost one third of the black women agreed that scientists cannot be trusted while only 4% of whites responded similarly. Additionally, 29% of black women agreed that researchers did not care about them compared with 14% of white women. Only 28% of black women felt that clinical research in the United States was ethical, and 37% had a preference to be treated by a black scientist compared with 2% of whites. Controlling for other covariates, black women had more negative altitudes overall to clinical trials than white women. These findings support the likelihood that barriers exist for the participation of blacks and other minorities in clinical research. These barriers may impact the involvement of black women in cancer clinical trials. Improving trust and creating a perception of a caring attitude from investigators are important to overcoming these barriers. The inclusion of more black scientists as leaders of cancer clinical trials also may help improve these participation rates.

Adult↗
PubMed1992

Conservative surgery and radiation therapy in black women with early stage breast cancer. Patterns of failure and analysis of outcome.

Between 1977 and 1986, 75 black and 615 white women with American Joint Committee (AJC) Stages I and II breast cancer were treated with excisional biopsy, axillary dissection, and radiation therapy for breast conservation. Cyclophosphamide, methotrexate, and 5-fluorouracil, with and without prednisone and tamoxifen, was given to 92% of premenopausal, 83% of perimenopausal, and 63% of postmenopausal node-positive women; 20 of 106 (19%) postmenopausal node-positive women received tamoxifen only. The clinical characteristics of the similarly treated patients were compared. The 5-year actuarial local only first failure rate was 5% for black women and 6% for white women (P = 0.53). Regional only failure as the first site of failure was 9% for blacks versus 1% for whites (P = 0.002), with regional recurrence as any component of first failure being 16% for blacks and 4% for whites (P = 0.001). The supraclavicular fossa was identified as the primary site of regional recurrence in black patients with either pathologically positive or negative axillae. Distant metastases as the only site of first failure were significantly greater in the black population with a 20% 5-year actuarial failure rate versus 11% in white patients (P = 0.01). The 5-year actuarial overall survival for the black patients was 82% versus 91% for the white patients (P = 0.01), with no-evidence-of-disease (NED) survival being 64% and 83% (P = 0.0002) and relapse-free survival (RFS) being 61% and 77% (P = 0.01), respectively. Black patients younger than 40 years of age or with pathologically positive axillary nodes had significantly worse NED, RFS, and overall survival compared with similarly staged white patients. Cosmetic results were analyzed at 3 and 5 years after completion of therapy. Although significantly fewer black patients had an excellent-to-good cosmetic result at 3 years compared with white patients, the results were not significantly different at 5 years. These results show that appropriately selected black patients with early stage breast cancer have excellent local control after conservative surgery and radiation therapy and should continue to be offered breast preservation as an alternative to mastectomy. Patterns of failure, however, demonstrated higher regional and distant recurrence rates and lower NED, RFS, and overall survival rates in most subsets of black patients reviewed.

Age Factors↗