Prehypertensive African-American Women Have Preserved Nitric Oxide and Renal Function but High Cardiovascular Risk

Abstract

Aims: African-Americans, in particular women, exhibit disproportionate levels of hypertension, inflammation, and oxidative stress compared to other ethnic groups. The relationship between prehypertension, renal function, inflammation, and oxidative stress was examined. Methods: Twenty-eight African-American women (53.5 ± 1.1 years) followed an AHA diet and then underwent 24-hour ambulatory BP (ABP) monitoring. Urinary albumin (uAlb), serum and urinary creatinine, glomerular filtration rate (GFR), 24-hour urinary Na⁺ excretion, plasma superoxide dismutase, total antioxidant capacity (TAC), urinary (uNOx) and plasma (pNOx) nitric oxide levels, and high-sensitivity C-reactive protein (hsCRP) were measured. Results: When the group was divided by average 24-hour ABP into optimal and nonoptimal groups, a significant difference existed between the groups for uNOx (p = 0.001; nonoptimal: 933.5 ± 140.4, optimal: 425.0 ± 52.6 µmol/gCr), and for hsCRP (p = 0.018, nonoptimal: 3.9 ± 0.7, optimal: 1.9 ± 0.6 mg/l). Significant inverse relationships existed between hsCRP and uNOx and between uAlb and pNOx in the non-optimal group, between GFR and pNOx in the entire group, and positive association existed between TAC and uNOx in the optimal group. Conclusions: These results suggest that in African-American women as BP levels rise toward hypertension, the NO/NOS balance may be associated with renal function, and may have implications for CV risk based on their hsCRP levels.

Racial Differences in Oxidative Stress and Inflammation: In Vitro and In Vivo

“…Human plasma samples and HUVEC supernatant were ultrafiltered through a 10,000 MWCO Amicon Ultra Filter (Millipore, Billerica, MA, USA) by microcentrifuge (14,000 g , 30 minutes, 4°C). Levels of NO end products were measured using a modified Griess assay (Assay Designs, Ann Arbor, MI, USA), while both SOD activity and TAC were measured by assay kit (Cayman Chemical, Ann Arbor, MI, USA), as previously reported 7 . Interassay and intraassay coefficients of variation were 7.6% and 10.6% (NO); 5.9% and 12.4% (SOD); and 6.7% and 9.2% (TAC), respectively.…”

Racial differences in tumor necrosis factor-α-induced endothelial microparticles and interleukin-6 production

“…Total SOD activity in cell lysate samples by assay (Cayman Chemical, Ann Arbor, MI), as previously reported. 42 Concentrations were normalized to protein content (μg/μL). Inter-assay and intra-assay CVs were 5.9% and 12.4%, respectively.…”

Racial differences in the responses to shear stress in human umbilical vein endothelial cells

“…Cell lysate was collected by fractionation using methods previously described 6. NO end-products, SOD, and total antioxidant capacity (TAC) activity were measured as described 9. Culture samples were not diluted for any oxidative stress measurement.…”