Key result
Healthy black African men show ~36% higher plasma ADMA and lower FMD than white European men.
Why the study?
Do healthy black African men have higher ADMA levels and lower endothelial function compared to white European men?
Cross-Sectional (n=58)
Do healthy black African men have higher ADMA levels and lower endothelial function compared to white European men?
Absolute Event Rate: 0.34% vs 0.25%
p-value: p=0.03
Healthy black African men have higher circulating ADMA levels and lower flow-mediated dilatation compared to white European men, which may contribute to their higher incidence of cardiovascular disease.
May indicate higher endothelial dysfunction risk in black African men; leaves open causal role of ADMA and need for prospective validation.
Black Africans have a higher incidence of cardiovascular disease than white Europeans. We explored potential mechanisms of this excess risk by assessing endothelium function, inflammatory status (C-reactive protein), oxidative stress (isoprostane-F2alpha), and plasma asymmetrical dimethyl arginine (ADMA; an endogenous competitive inhibitor of NO synthase) in each ethnic group. Thirty healthy black Africans and 28 well-matched white European male subjects were studied (mean age+/-SE: 32.2+/-0.9 and 29.2+/-1.2 years, respectively; P=0.07). High-resolution ultrasound was used to assess vascular function in the brachial artery by measuring flow mediated dilatation ([percentage of change]; endothelium-dependent function) and glyceryltrinitrate dilatation ([percentage of change]; endothelium-independent function). Blood pressure, fasting lipids, glucose, and estimated glomerular filtration rate levels were similar in both groups. There was no difference in C-reactive protein (black Africans: 0.8+/-0.1 mg/L; white Europeans: 0.6+/-0.1 mg/L; P=0.22), isoprostane-F2alpha (black Africans: 42.9+/-1.5 pg/mL; white Europeans: 39.2+/-1.5 pg/mL; P=0.23), and leptin (black Africans: 64.1+/-10.2 ng/mL; white Europeans: 47.8+/-9.8 ng/mL; P=0.37) levels between the 2 ethnic groups. However, compared with white Europeans, plasma ADMA levels were significantly higher in black Africans (0.34+/-0.02 micromol/L and 0.25+/-0.03 micromol/L; P=0.03). There was no difference in the percentage of glyceryltrinitrate dilatation (P=0.7), but the percentage of flow-mediated dilatation was significantly lower in black Africans (black Africans: 5.2+/-0.3; white Europeans: 6.3+/-0.4; P=0.02). In a stepwise multiple regression model, ADMA level was the only independent determinant of flow-mediated dilatation (P=0.02). In turn, race was the only independent determinant of ADMA levels (P=0.03). Our findings indicate that circulating ADMA levels are significantly higher in healthy black African males than in white European males. This may contribute to the lower NO bioavailability and higher incidence of cardiovascular disease seen in black Africans.
No takes yet. Share an insight, caveat, or question.
Melikian et al. (2007) conducted a cross-sectional in Healthy (n=58). Black African ethnicity vs. White European ethnicity was evaluated on Plasma ADMA levels (micromol/L) (p=0.03). Healthy black African men had significantly higher plasma ADMA levels (0.34 vs 0.25 micromol/L; P=0.03) and lower flow-mediated dilatation (5.2% vs 6.3%; P=0.02) compared with white European men.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: