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

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.http://deepblue.lib.umich.edu/bitstream/2027.42/57748/1/Racial Ethnic Differences in Hypertension and Hypertension Treatment and Control in the Multi Ethnic of Atherosclerosis.pd

Genome-wide linkage of plasma adiponectin reveals a major locus on chromosome 3q distinct from the adiponectin structural gene - The IRAS family study

Adiponectin (APM1) is an adipocyte-derived peptide that contributes to glucose, lipid, and energy homeostasis. We assessed the genetic basis of plasma adiponectin in Hispanic-American and African-American families enrolled through the Insulin Resistance Atherosclerosis Study Family Study. A 10-cM genome scan was performed in two batches: an original set (set 1) consisting of 66 families (45 Hispanic American and 21 African American) and a replication set (set 2) consisting of 66 families (45 Hispanic American and 21 African American). Adiponectin levels were measured by radioimmunoassay in 1,727 individuals from 131 of 132 families. Linkage analysis was carried out in Hispanic Americans and African Americans separately in set 1, set 2, and the pooled set (set I plus set 2), with and without diabetic subjects. A major gene was mapped to 3q27 with a logarithm of odds (LOD) score of 8.21 in the Hispanic-American sample. Ninety-six unrelated individuals were screened for polymorphisms in the APMI gene, and 18 single nucleotide polyporphisms (SNPs) were genotyped in the Hispanic-American sample. Plasma adiponeetin level was modestly associated with two SNPs and their accompaning haplotypes. Incorporating each or both SNPs in the linkage analysis, however, did not significantly re- duce the LOD score. Therefore, a quantitative trait locus at 3q27, likely distinct from the APM1 gene, contributes to the variation of plasma adiponectin levels in the Hispanic-American population