Racial differences in the prevalence of hypertensive retinopathy

Few population-based data support the hypothesis that hypertensive retinopathy is more common in African Americans than in whites. We examined racial differences in the prevalence of and risk factors for hypertensive retinopathy in a population-based sample of 1860 African Americans and 7874 white persons, aged 49 to 73 years, without diabetes. Retinal photographs were taken of one randomly selected eye and evaluated for the presence of retinopathy (flame and blot-shaped retinal hemorrhages, microaneurysms, and soft exudates) according to standardized protocols by graders masked to participant characteristics. The prevalence of retinopathy was 2 times higher in African Americans than in whites (7.7% versus 4.1%, age- and gender-adjusted odds ratio [OR] 2.03, 95% confidence intervals [CI] 1.65, 2.49). After controlling for 6-year mean arterial blood pressure, use of antihypertensive medications and left ventricular hypertrophy by ECG criteria, the excess prevalence of retinopathy in African Americans was reduced by 40% (adjusted OR 1.61, 95% CI 1.26, 2.06). Further adjustment for other vascular risk factors, common carotid artery intima-media thickness, and serum creatinine levels reduced the excess prevalence in African Americans by another 13% (adjusted OR 1.48, 95% CI 1.08, 2.03). We conclude that hypertensive retinopathy is twice as frequent in African Americans compared with whites without diabetes and that the excess prevalence of retinopathy in African Americans is associated with blood pressure and severity of hypertension.     

Autoimmune hepatitis in African Americans: presenting features and response to therapy

OBJECTIVES: African Americans are at an increased risk for certain diseases and more frequently suffer complications of those diseases relative to their white counterparts. Most studies of autoimmune hepatitis consist of entirely white populations. The Emory University system of hospitals serves a large African American population, including a significant number of African Americans with autoimmune hepatitis. The goal of this study was to determine if the presentation and response to therapy in African Americans is, like other diseases, different than in whites. METHODS: This is a retrospective study from a tertiary referral center that examines the initial presenting features and response to therapy of African Americans (n = 27) and whites (n = 24) with autoimmune hepatitis. RESULTS: Eighty-five percent of African Americans had cirrhosis on the initial liver biopsy, as compared with 38% of whites. Although not statistically significant, the African Americans presented at an earlier age than white patients. The disease also appeared more advanced in African Americans, as bilibubin levels tended to be higher, but not significantly, and PTs were more prolonged. Both groups responded well to therapy, with significant falls in serum levels of AST, ALT, and bilirubin. Fifty percent of African Americans and 48% of whites entered a biochemical remission. The amount of prednisone required to maintain remission at follow-up was greater in African Americans. CONCLUSION: In contrast to whites, the majority of African Americans present with cirrhosis. Despite the high prevalence of cirrhosis, the response to therapy is good. However, more immunosuppression is required to control the disease in African Americans.     

The prevalence of peripheral arterial disease in a racially diverse population

BACKGROUND: The purpose of this study was to determine the prevalence of peripheral arterial disease (PAD) in white, African American, and English- and Spanish-speaking Hispanic patients. METHODS: We screened patients older than 50 years for PAD at 4 primary care clinics located in the Houston Veterans Affairs Medical Center and the Harris County Hospital District. The disease was diagnosed by an ankle-brachial index of less than 0.9. Patients also completed questionnaires to ascertain symptoms of intermittent claudication, walking difficulty, medical history, and quality of life. RESULTS: We enrolled 403 patients (136 whites; 136 African Americans; and 131 Hispanics, 81 of whom were Spanish speaking). The prevalence of PAD was 13.2% among whites, 22.8% among African Americans, and 13.7% among Hispanics (P =.06). African Americans had a significantly higher prevalence of PAD than whites and Hispanics combined (P =.02). Among all patients who were diagnosed as having PAD on the basis of their ankle-brachial index, only 5 (7.5%) had symptoms of intermittent claudication. CONCLUSIONS: Peripheral arterial disease is a prevalent illness in the primary care setting. Its prevalence varies by race and is higher in African Americans than in whites and Hispanics. Relative to the prevalence of PAD, the prevalence of intermittent claudication is low. Since measurement of the ankle-brachial index is not part of the routine clinic visit, many patients with PAD are not diagnosed unless they develop symptoms of intermittent claudication. Because of this, it is likely that many patients remain undiagnosed. Efforts are needed to improve PAD detection in the primary care setting.     

Epidemiology of irritable bowel syndrome among African Americans as compared with whites: a population-based study.

BACKGROUND & AIMS: We studied the prevalence as well as the sociodemographic characteristics and quality of life of African American patients with irritable bowel syndrome (IBS) among the population at large and compared them with those of whites. METHODS: A total of 990 adults from 9 different sites in the Jackson, Mississippi metropolitan area (670 African Americans and 320 whites) completed self-administered questionnaires providing sociodemographic information and details regarding bowel habits and associated symptoms for diagnosing IBS on the basis of Rome II criteria. Quality of life was assessed by the SF-12 questionnaire. RESULTS: Ninety-five of the 990 participants had IBS, giving a total sample prevalence of 9.6% (African Americans, 7.9%; whites, 13.1%). Adjusting for other risk factors in a reduced logistic regression model, we found race (P = .0004) and education (P = .0049) to be important correlates of IBS prevalence. The household income showed a trend toward statistical significance (P = .0845). With the adjusted odds ratio as an estimate of relative risk, whites were 2.5 (95% confidence interval, 1.5-4.0) more likely than African Americans to have IBS. In terms of an index for quality of life (possible score, 1-44), the adjusted mean score was lower for adults with IBS compared with non-IBS adults (IBS mean, 29.8; no IBS, 34.2; P < .0001), but the racial difference was not significant. CONCLUSIONS: IBS occurs less frequently among African Americans. Although IBS affects quality of life among both ethnicities, the degree of impairment is similar.     

Peripheral arterial disease in African Americans: clinical characteristics, leg symptoms, and lower extremity functioning

OBJECTIVES: The describe peripheral arterial disease (PAD) in African Americans, and compare findings in African Americans and whites with PAD. DESIGN: Cross-sectional. SETTING: Three academic medical centers. PARTICIPANTS: Three hundred sixty-six whites and 76 African Americans with PAD (as defined by an ankle brachial index (ABI) <0.90) aged 55 and older identified from lower extremity arterial studies performed between 1996 and the fall of 1999. MEASUREMENTS: Comprehensive medical interview, body mass index, and neuropathy score. Functional measurements included the 6-minute walk distance, 4-m walking velocity, and the summary performance score. RESULTS: Age- and sex-adjusted results showed that African Americans had a lower mean ABI than whites (0.60 vs 0.66, P=.001), were less likely to be college graduates (13.7% vs 44.4%, P<.001), and had nearly twice the prevalence of diabetes mellitus (46.8% vs 28.0%, P=.001). After adjusting for age, sex, education level, and ABI, African Americans had a higher prevalence of no exertional leg pain (28.0% vs 18.2%, P=.044) and leg pain with exertion and rest (30.0% vs 17.3%, P=.023). African Americans had a shorter 6-minute walk distance (989 vs 1,156 ft, P<.001), a slower normal-pace 4-m walking velocity (0.79 vs 0.89 m/s, P<.001), a slower fast-pace 4-m walking velocity (1.12 vs 1.20 m/s, P=.012), and a lower summary performance score (8.8 vs 9.6, P=.018) than whites. These differences in functioning were attenuated after adjusting for age, sex, ABI, education, and leg symptoms. CONCLUSION: Poorer lower extremity functioning in African Americans was largely explained by differences in leg symptoms and, to a somewhat lesser degree, lower ABI levels and poorer education in African Americans than in whites. Further study is needed to determine whether these findings affect racial treatment disparities and poorer outcomes previously reported in African Americans than in whites with PAD.     

The paradox of atrial fibrillation in African Americans

The reported lower prevalence and incidence of atrial fibrillation (AF) despite the higher prevalence of AF risk factors in African Americans compared to Caucasian whites has been referred to as the paradox of AF in African Americans. In this report we highlight this paradox and address potential explanations using data from several US populations studies. These possible explanations include limited methodology to detect AF patterns that are harder to detect (e.g. paroxysmal/intermittent AF or atrial flutter) coupled with the possibility of African Americans having more of these patterns, differential access to health care with African Americans having less access and subsequently less detected AF, survival bias with Caucasian whites living longer and subsequently having more AF, and finally differential impact of AF risk factors with Caucasian whites being more affected or African Americans less affected by AF risk factors whether this is genetically determined or via other unknown predispositions.     

Differences in prognostic factors and outcomes in African Americans and whites with acute myeloid leukemia

Whites have a more favorable prognosis than African Americans for a number of cancers. The relationship between race and outcome is less clear in acute myeloid leukemia (AML). Using data from 7 Cancer and Leukemia Group B studies initiated from 1985 to 1997, we conducted a retrospective cross-sectional analysis of 2570 patients (270 African American and 2300 white) with de novo AML who received induction chemotherapy. African Americans were younger than whites (48 versus 54 years, P <.001). African Americans also had different cytogenetic risk group distributions than whites (P <.001): they were more commonly classified in the favorable (23% versus 14%) and unfavorable (31% versus 23%) groups, and less commonly classified in the intermediate group (47% versus 63%). African American men had a lower complete remission (CR) rate (54%, compared with 64% for white men, 65% for white women, and 70% for African American women, P =.001) and a worse overall survival compared with all other patients (P =.004), when known risk factors are taken into account. African Americans and whites with AML differ with respect to important prognostic factors. African American men have worse CR rates and overall survival than whites and African American women, and should be considered a poor-risk group.     

Racial/ethnic differences in hypertension and hypertension treatment and control in the multi-ethnic study of atherosclerosis (MESA)

BACKGROUND: Most previous studies investigating the association between ethnicity and hypertension focused on differences between African Americans and whites and did not include other racial/ethnic groups such as Chinese or Hispanics. METHODS: We used data from the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based study of 6814 adults without clinical cardiovascular disease, to examine the association between ethnicity and hypertension and hypertension treatment among white, African American, Chinese, and Hispanic ethnic groups. RESULTS: The prevalence of hypertension, defined as systolic blood pressure (BP) <140 mm Hg and diastolic BP <90 mm Hg or self-reported treatment for hypertension, was significantly higher in African Americans compared to whites (60% v 38%; P < .0001), whereas prevalence in Hispanic (42%) and Chinese participants (39%) did not differ significantly from that in whites. After adjustment for age, body mass index, prevalence of diabetes mellitus, and smoking, African American (odds ratio [OR] 2.21; 95% confidence interval [95% CI] 1.91-2.56) and Chinese (OR 1.30; 95% CI 1.07-1.56) ethnicity were significantly associated with hypertension compared to whites. Among hypertensive MESA participants, the percentage of treated but uncontrolled hypertension in whites (24%) was significantly lower than in African Americans (35%, P < .0001), Chinese (33%, P = .003), and Hispanics (32%, P = .0005), but only African-American race/ethnicity remained significantly associated with treated but uncontrolled hypertension after controlling for socioeconomic factors (OR 1.35; 95% CI 1.07-1.71). Diuretic use was lowest in the Chinese (22%) and Hispanic participants (32%) and was significantly lower in these groups compared with white participants (47%; P < .0001 for both comparisons). CONCLUSIONS: Programs to improve hypertension treatment and control should focus on a better understanding of differences in the prevalence of hypertension and hypertension control among minority groups in the United States, especially African Americans, compared with whites, and on techniques to prevent hypertension and improve control in high-risk groups.     

Prevalence and ethnic differences in gallbladder disease in the United States.

BACKGROUND & AIMS: Gallbladder disease is one of the most common conditions in the United States, but its true prevalence is unknown. A national population-based survey was performed to determine the age, sex, and ethnic distribution of gallbladder disease in the United States. METHODS: The third National Health and Nutrition Examination Survey (NHANES III) conducted gallbladder ultrasonography among a representative U.S. sample of more than 14, 000 persons. The diagnosis of gallbladder disease by detection of gallstones or cholecystectomy was made with excellent reproducibility. RESULTS: An estimated 6.3 million men and 14.2 million women aged 20-74 years had gallbladder disease. Age-standardized prevalence was similar for non-Hispanic white (8. 6%) and Mexican American (8.9%) men, and both were higher than non-Hispanic black men (5.3%). These relationships persisted with multivariate adjustment. Among women, age-adjusted prevalence was highest for Mexican Americans (26.7%) followed by non-Hispanic whites (16.6%) and non-Hispanic blacks (13.9%). Among women, multivariate adjustment reduced the risk of gallbladder disease for both Mexican Americans and non-Hispanic blacks compared with non-Hispanic whites. CONCLUSIONS: More than 20 million persons have gallbladder disease in the United States. Ethnic differences in gallbladder disease prevalence differed according to sex and were only partly explained by known risk factors.     

Plasma insulin levels and incidence of hypertension in African Americans and whites

BACKGROUND: Hyperinsulinemia may play an important role in the pathogenesis of hypertension in whites but the role of hyperinsulinemia in hypertension in African Americans is controversial. SUBJECTS AND METHODS: We studied the relationship between insulin levels and subsequent incidence of hypertension in 140 African Americans and 237 whites who were initially screened for possible participation in the Trials of Hypertension Prevention, phase 1. Plasma insulin and serum glucose were measured at baseline and at a follow-up examination 7 years later. Blood pressure was measured by trained observers using a random-zero sphygmomanometer. Incident hypertension was defined as an average systolic pressure of 160 mm Hg or higher and/or diastolic pressure of 95 mm Hg or higher at a single visit and/or use of antihypertensive medication during follow-up. RESULTS: Over the 7 years of follow-up, the incidence of hypertension was 25.7% in the African Americans and 25.3% in the whites. Baseline plasma insulin and insulin-to-glucose ratio were associated with an increased risk of hypertension in both the African Americans and the whites. After adjustment for age, sex, race, body mass, heart rate, and alcohol consumption at baseline as well as intervention assignment in the Trials of Hypertension Prevention, phase 1, a 1-SD (21 pmol/mmol) difference in baseline insulin-to-glucose ratio was associated with a 2.77 (95% confidence interval, 1.48-5.19) odds ratio of hypertension in the African Americans and a 1.69 (95% confidence interval, 1.08-2.64) odds ratio in the whites. CONCLUSION: These results suggest that higher plasma insulin levels are associated with an increased risk of hypertension in both African Americans and whites.     

Outcomes in African Americans and whites after percutaneous coronary intervention

PURPOSE: We aimed to determine whether African Americans and whites have different outcomes after percutaneous coronary intervention (PCI). METHODS: We prospectively selected 8832 patients (707 African Americans) for long-term follow-up after PCI at our institution from 1992 to 2002. The primary outcome studied was death or myocardial infarction at 1 year. Propensity adjustment was performed to account for baseline differences between African Americans and whites. RESULTS: African Americans had higher rates of diabetes and less prior revascularization. Percutaneous coronary interventions in African Americans were more often urgent. Stent use was similar. Procedural success rates were similar, as were periprocedural and 30-day composite rates of death or myocardial infarction. In 1-year unadjusted outcomes, African Americans had a higher rate of death or myocardial infarction (18.0% vs 14.5%; hazard ratio (HR) = 1.25; 95% confidence interval (CI): 1.04 to 1.50; P = 0.017), but the difference was no longer significant after propensity adjustment (HR = 1.18; 95% CI: 0.98 to 1.43, P = 0.087). African Americans had a higher risk for periprocedural bleeding that persisted after propensity adjustment (adjusted odds ratio = 1.45; 95% CI: 1.14 to 1.84, P = 0.002). CONCLUSIONS: After PCI, African Americans have similar short-term rates of death or myocardial infarction when compared with whites but have a nonsignificant trend toward worse long-term outcomes. Our findings, when interpreted in the context of reportedly lower revascularization rates among African Americans, suggest that continued efforts to optimize the appropriate use of coronary revascularization among African Americans are warranted.     

Comparison of reflux esophagitis and its complications between African Americans and non-Hispanic whites

AIM： To determine the effect of ethnicity on the severity of reflux esophagitis （RE） and its complications.
METHODS： A retrospective search of the endoscopy database at the University of Florida Health Science Center/Jacksonville for all cases of reflux esophagitis and its complications from January 1 to March 31, 2001 was performed. Inclusion criteria were endoscopic evi- dence of esophagitis using the LA classification, reflux related complications and self-reported ethnicity. The data obtained included esophagitis grade, presence of a hiatal hernia, esophageal ulcer stricture and Barrett＇s esophagus, and endoscopy indication.
RESULTS： The search identified 259 patients with RE or its complications, of which 171 were non-Hispanic whites and 88 were African Americans. The mean ages and male/female ratios were similar in the two groups. RE grade, esophageal ulcer, stricture and hiatal hernia frequency were likewise similar in the groups. Barrett＇s esophagus was present more often in non-Hispanic whites than in African Americans （15.8% vs 4.5%; P 〈 0.01）. Heartburn was a more frequent indication for endoscopy in non-Hispanic whites with erosive esophagitis than in African Americans （28.1% vs 7.9%; P 〈 0.001）.
CONCLUSION： Distribution of RE grade and frequency of reflux-related esophageal ulcer, stricture and hiatal hernia are similar in non-Hispanic whites and African Americans. Heartburn was more frequently and nausea/vomiting less frequently reported as the primary endoscopic indication in non-Hispanic whites compared with African Americans with erosive esopha- gitis or its complications. African Americans have a decreased prevalence of Barrett＇s esophagus compared with non-Hispanic whites.     

Prevalence of heart disease and stroke risk factors in persons with prehypertension in the United States, 1999-2000

BACKGROUND: Recent guidelines classify persons with above-optimal blood pressure (BP) but not clinical hypertension as having prehypertension. METHODS: Data were analyzed for 3488 persons aged 20 years and older with BP measured in the 1999-2000 National Health and Nutrition Examination Survey. The prevalence of risk factors-above-normal (> or =200 mg/dL [> or =5.17 mmol/L]) and high (> or =240 mg/dL [> or =6.21 mmol/L]) total cholesterol levels, diabetes mellitus, current smoker, and overweight or obesity-and the number of risk factors present were compared among BP groups (normotension, prehypertension, and hypertension). Multivariable logistic regression included age, sex, and race/ethnicity as covariates. RESULTS: Overall, 39% of persons were normotensive,31% were prehypertensive, and 29% were hypertensive. The age-adjusted prevalence of prehypertension was greater in men (39.0%) than in women (23.1%). African Americans aged 20 to 39 years had a higher prevalence of prehypertension (37.4%) than whites (32.2%) and Mexican Americans (30.9%), but their prevalence was lower at older ages because of a higher prevalence of hypertension. The probabilities of above-normal cholesterol levels, overweight/obesity, and diabetes mellitus were greater for persons with prehypertension vs normotension, whereas the probability of currently smoking was lower. Persons with prehypertension were 1.65 times more likely to have at least 1 other adverse risk factor than were those with normotension (P<.001). Among participants with prehypertension, there were no significant race/ethnic or sex differences in the likelihood of having at least 1 other risk factor. CONCLUSIONS: The greater prevalence of risk factors in persons with prehypertension vs normotension suggests the continued need for early clinical detection and intervention of prehypertension and comprehensive preventive and public health efforts.     

Ethnic differences among patients with cutaneous melanoma

BACKGROUND: Melanoma incidence continues to increase in whites, but little is known about melanoma in minority populations. Surveillance, Epidemiology, and End Results (SEER) data were used to examine the incidence, manifestations, and survival in patients with melanoma with respect to race/ethnicity. METHODS: A SEER search (1992-2002) for primary invasive cutaneous melanoma cases identified 48 143 whites, 932 Hispanics, 394 Asian/Pacific islanders, 251 African Americans, and 52 American Indians. Multivariate analyses were performed to evaluate the relationship between race/ethnicity and clinicopathologic factors; associations between race/ethnicity and survival were examined using the Cox proportional hazards model. RESULTS: Based on our cohort of patients, the average annual age-adjusted melanoma incidence per 100 000 persons was 18.4 for whites compared with 2.3, 0.8, 1.6, and 1.0 for Hispanics, African Americans, American Indians, and Asians, respectively. Lower extremity and acral lentiginous melanomas were more common among minorities. Overall 5-year survival was 72.2% to 81.1% for minorities compared with 89.6% for whites. A 1.96- to 3.01-fold greater risk of disease-specific mortality persisted in minorities compared with whites after adjusting for age, sex, and region. In addition, Hispanics (odds ratio [OR], 3.6), African Americans (OR, 4.2), American Indians (OR, 3.4), and Asians (OR, 2.4) were more likely to present with stage IV melanoma than were whites. African Americans had a 1.48-fold higher rate of risk-adjusted, stage-specific mortality compared with whites. CONCLUSIONS: Melanoma is a public health concern for all ethnic populations. Differences in disease stage at presentation contributes to disparities in survival. Understanding melanoma in minority populations may lead to early detection and ultimately save lives.     

Increased prevalence of light chain monoclonal gammopathy of undetermined significance (LC-MGUS) in first-degree relatives of individuals with multiple myeloma

Previously, we reported increased risk of heavy-chain (HC) monoclonal gammopathy of undetermined significance (MGUS) among first-degree (1°) relatives of multiple myeloma (MM) or HC-MGUS probands. This study investigated whether there was comparable risk for light-chain (LC) MGUS among 911 relatives of the same HC-MGUS/MM probands versus a reference population of 21 463. Seventeen 1° relatives had LC-MGUS (adjusted prevalence = 1·7%, 95% CI = 0·9–2·6%). There was increased risk of LC-MGUS in relatives of MM probands (RR = 3·4, 95% CI = 2·0–5·5). We saw no increased risk in relatives of HC-MGUS probands. We conclude that the prevalence of LC-MGUS is significantly higher among 1° relatives of MM probands compared to the reference population.     

Coronary heart disease in African Americans

African Americans have the highest overall mortality rate from coronary heart disease (CHD) of any ethnic group in the United States, particularly out-of-hospital deaths, and especially at younger ages. Although all of the reasons for the excess CHD mortality among African Americans have not been elucidated, it is clear that there is a high prevalence of certain coronary risk factors, delay in the recognition and treatment of high-risk individuals, and limited access to cardiovascular care. The clinical spectrum of acute and chronic CHD in African Americans is similar to that in whites. However, African Americans have a higher risk of sudden cardiac death and present more often with unstable angina and non-Q-wave myocardial infarction than whites. African Americans have less obstructive coronary artery disease on angiography, but may have a similar or greater total burden of coronary atherosclerosis. Ethnic differences in the clinical manifestations of CHD may be explained largely by the inherent heterogeneity of the coronary syndromes, and the disproportionately high prevalence and severity of hypertension and type 2 diabetes in African Americans. Identification of high-risk individuals for vigorous risk factor modification-especially control of hypertension, regression of left ventricular hypertrophy, control of diabetes, treatment of dyslipidemia, and smoking cessation--is key for successful risk reduction.     

Patterns of compartment involvement in tibiofemoral osteoarthritis in men and women and in whites and African Americans

Objective

We conducted a cross‐sectional study to describe the prevalence of tibiofemoral joint space narrowing (JSN) in medial and lateral compartments and assess whether it differs by sex and ethnic groups, and, if it does, to what extent such a difference is accounted for by knee malalignment.

Methods

The Multicenter Osteoarthritis Study is an observational study of persons ages 50–79 years with either symptomatic knee osteoarthritis or high risk of disease. Knee radiographs were assessed for JSN in each tibiofemoral compartment. Mechanical axis angle was measured using full‐extremity films. We compared the proportion of knees with medial compartment JSN and with lateral JSN between men and women, as well as between whites and African Americans, using a logistic regression model adjusting for covariates (race or sex and body mass index, age, education, and clinic site). We used generalized estimating equations to account for correlation between 2 knees within a person.

Results

Of 5,202 knees (2,652 subjects), 1,532 (29.5%) had medial JSN and 427 (8.2%) had lateral JSN. Lateral JSN was more prevalent in the knees of women than in men (odds ratio [OR] 1.9, 95% confidence interval [95% CI] 1.5–2.4) and was also higher in the knees of African Americans than in whites (OR 2.4, 95% CI 1.7–3.3). Further adjustment for malalignment attenuated the OR for sex but not the OR for race.

Conclusion

Women and African Americans are more likely to have lateral JSN than men and whites, respectively. Valgus malalignment may contribute to the higher prevalence in women.     

Chronic hepatitis C in ethnic minority patients evaluated in Los Angeles County

OBJECTIVE: The aim of this study was to compare demographic, clinical, and histological features of hepatitis C in four ethnic groups seen at the Los Angeles County/University of Southern California Hepatitis Clinic. METHODS: We evaluated 256 patients with chronic hepatitis C, with 132 (52%) receiving a liver biopsy as part of their evaluation. We estimated fibrosis progression in 103 patients with known duration of disease. RESULTS: Asians (6%) were underrepresented in the hepatitis C cohort, whereas Latinos (51%) were overrepresented, as compared with the entire county population. A history of injection drug use was more frequent in whites (65%) than in African Americans (45%, p = 0.05), Latinos (47%, p = 0.01), or Asians (0%) and more frequent in Latinos (59%) than in Latinas (26%, p = 0.003). Such a gender difference was not found in African Americans or whites. Baseline laboratory values were comparable. The amount of alcohol consumed daily was higher in African Americans than in Asians (p = 0.0001) and whites (p = 0.10). African Americans (0.077 fibrosis stages/yr) and whites (0.084/yr) had significantly lower mean estimated progression of liver fibrosis than Latinos (0.215/yr) with hepatitis C virus infection (ps = 0.03 and 0.02, respectively): this was likely related to their longer estimated duration of disease. CONCLUSION: Minorities represent the majority of chronic hepatitis C cases in the Los Angeles County Hepatitis Clinic. Asians, Latinas, and African Americans are less likely to report injection drug use as a risk factor for hepatitis C virus. Latinos seem to have faster liver fibrosis progression rates than either African Americans or whites.     

Arterial stiffness is greater in African Americans than in whites: evidence from the Forsyth County, North Carolina, ARIC cohort

BACKGROUND: Impairment of arterial dilation is thought to occur earlier than arterial wall thickening in the atherosclerotic process. In comparison with whites, African Americans reportedly have a generalized attenuation of their vasodilation mechanisms. We set out to evaluate arterial stiffness and its correlates by ethnicity, hypothesizing that African Americans would have stiffer common carotid arteries (ie, lower arterial distension for a given systolic pressure) than their white counterparts. METHODS: The study population included 268 African Americans and 2459 whites, who were aged 45 to 64 years at baseline examination in 1986 to 1989, free of coronary heart disease and stroke/transient ischemic attack, from Forsyth County, North Carolina. The beta stiffness index and pulsatile arterial diameter change were derived from brachial blood pressure and from echo-tracked systolic and diastolic carotid arterial diameters. RESULTS: African Americans had stiffer carotid arteries than their white counterparts, with a right shift of the beta stiffness index distribution. After adjustment for selected cardiovascular risk factors, the mean beta stiffness index was 9% higher for African Americans (mean +/- SEM: 11.3 +/- 0.3) than for whites (mean +/- SEM: 10.3 +/- 0.1) among participants not taking antihypertensive medication. Socioeconomic status and comorbidities were differentially associated with arterial stiffness by ethnicity. Specifically, the association between these correlates and beta stiffness index was stronger in African Americans than in whites. CONCLUSIONS: This report on arterial mechanics in African Americans suggests that large artery stiffening either occurs earlier, or is more accelerated in African Americans than in whites in our sample, perhaps as a result of earlier exposure to multiple risk factors. This finding may have implications for hypertension prevention, as arterial stiffness is associated with the development of hypertension.