Faculty Bibliography

BACKGROUND:Prehypertension (blood pressure (BP) of 120-139 mm Hg systolic and/or 80-89 mm Hg diastolic) is highly prevalent and is associated with increased cardiovascular risk. Our goal was to investigate the extent to which prehypertension is associated with end-organ alterations in cardiac structure and function in a large biracial cohort of older men and women. METHODS:We studied 4,871 participants of the Atherosclerosis Risk in Communities (ARIC) study who attended visit 5 (2011-2013) and underwent two-dimensional echocardiography while free of prevalent coronary heart disease or heart failure. We categorized participants into 3 groups: optimal BP (BP <120 mm Hg and <80 mm Hg) (n = 402), prehypertension (n = 537), and hypertension (n = 3,932). RESULTS:Individuals with prehypertension (75±5 years) had higher left ventricular (LV) mass index and wall thickness, and higher prevalence of abnormal LV geometry than those with optimal BP (74±5 years), but lower than those with frank hypertension (76±5 years). In addition, participants with prehypertension had impairment of diastolic parameters (E/A, E' and E/E'), and had higher prevalence of mild and moderate-severe diastolic dysfunction compared to those with optimal BP, but no differences in systolic parameters. These differences in cardiac structure and function remained significant after adjusting for important clinical covariates. CONCLUSION/CONCLUSIONS:In the ARIC cohort at visit 5, prehypertension was associated with increased LV remodeling and impaired diastolic function, but not systolic function, suggesting that even mildly elevated BP within the normal range is associated with cardiac end-organ damage.

BACKGROUND:Natriuretic peptides promote natriuresis, diuresis, and vasodilation. Experimental deficiency of natriuretic peptides leads to hypertension (HTN) and cardiac hypertrophy, conditions more common among African Americans. Hospital-based studies suggest that African Americans may have reduced circulating natriuretic peptides, as compared to Caucasians, but definitive data from community-based cohorts are lacking. METHODS AND RESULTS/RESULTS:We examined plasma N-terminal pro B-type natriuretic peptide (NTproBNP) levels according to race in 9137 Atherosclerosis Risk in Communities (ARIC) Study participants (22% African American) without prevalent cardiovascular disease at visit 4 (1996-1998). Multivariable linear and logistic regression analyses were performed adjusting for clinical covariates. Among African Americans, percent European ancestry was determined from genetic ancestry informative markers and then examined in relation to NTproBNP levels in multivariable linear regression analysis. NTproBNP levels were significantly lower in African Americans (median, 43 pg/mL; interquartile range [IQR], 18, 88) than Caucasians (median, 68 pg/mL; IQR, 36, 124; P<0.0001). In multivariable models, adjusted log NTproBNP levels were 40% lower (95% confidence interval [CI], -43, -36) in African Americans, compared to Caucasians, which was consistent across subgroups of age, gender, HTN, diabetes, insulin resistance, and obesity. African-American race was also significantly associated with having nondetectable NTproBNP (adjusted OR, 5.74; 95% CI, 4.22, 7.80). In multivariable analyses in African Americans, a 10% increase in genetic European ancestry was associated with a 7% (95% CI, 1, 13) increase in adjusted log NTproBNP. CONCLUSIONS:African Americans have lower levels of plasma NTproBNP than Caucasians, which may be partially owing to genetic variation. Low natriuretic peptide levels in African Americans may contribute to the greater risk for HTN and its sequalae in this population.

BACKGROUND:The extent to which the relative contributions of traditional cardiovascular risk factors to incident cardiovascular disease (CVD) may have changed over time remains unclear. METHODS AND RESULTS/RESULTS:We studied 13 541 participants (56% women, 26% black) in the Atherosclerosis Risk in Communities Study, aged 52 to 66 years and free of CVD at exams in 1987 through 1989, 1990 through 1992, 1993 through 1995, or 1996 through 1998. At each examination, we estimated the population attributable risks (PAR) of traditional risk factors (hypertension, diabetes mellitus, obesity, hypercholesterolemia, and smoking) for the 10-year incidence of CVD. Overall, the PAR of all risk factors combined appeared to decrease from the late 1980s to the late 1990s (0.58 to 0.53). The combined PAR was higher in women than men in 1987 through 1989 (0.68 versus 0.51, P<0.001) but not by the late 1990s (0.58 versus 0.48, P=0.08). The combined PAR was higher in blacks than whites in the late 1980s (0.67 versus 0.57, P=0.049), and this difference was more pronounced by the late 1990s (0.67 versus 0.48, P=0.002). By the late 1990s, the PAR of hypertension had become higher in women than men (P=0.02) and also appeared higher in blacks than whites (P=0.08). By the late 1990s, the PAR of diabetes mellitus remained higher in women than men (P<0.0001) and in blacks than whites (P<0.0001). CONCLUSIONS:The contribution to CVD of all traditional risk factors combined is greater in blacks than whites, and this difference may be increasing. The contributions of hypertension and diabetes mellitus remain especially high, in women as well as blacks. These findings underscore the continued need for individual as well as population approaches to CVD risk factor modification.