Patrícia Maurer, Vanusa Manfredini, Rafael Noal Moresco, Matias Nunes Frizzo, Ivana Beatrice Mânica da Cruz, Jacqueline da Costa Escobar Piccoli
Background: The black population paradoxically has a high cardiovascular risk with decreased rates of metabolic syndrome. The objective is analyze the levels of nitric oxide metabolites (nitrite/nitrate) and their applicability as a biomarker of cardiometabolic risk in blacks.
Methods and findings: We measured several laboratory parameters in 202 Black Brazilians. The 50th percentile (50P) of the nitrite/nitrate (NOx) was 122.3 μmol/L, and was chosen as the cutoff point, then the subjects were divided into two groups (i.e., superior or lower percentile). Anthropometric assessment showed that most of the study population had an average Body Mass Index classified as grade 1 obesity, altered waist circumference and pre-hypertension. The NOx values <122.3 μmol/L were associated with higher body mass index (p=0.01), waist circumference (p=0.03) and hip circumference (p=0.04). As to biochemical criteria, the NOx was significantly correlated to blood glucose levels (p=0.04), triglycerides (p=0.04), albumin (p=0.03), uric acid (p=0.01) and urea (p=0.05). In inflammatory and oxidative stress assessment, only protein carbonylation (p<0.01) was associated with the NOx, in which the damage was greater in subjects who had NOx values lower than the 50% percentile.
Conclusion: NOx was significantly associated with obesity markers, and obese individuals have lower levels of nitric oxide. Thus, NOx is a good predictor of cardiometabolic risk in blacks.