Serum Uric Acid Levels are Associated with Cardiometabolic Risk Factors in Healthy Young and Middle-Aged Adults / Os Níveis Séricos de Ácido Úrico estão Associados a Fatores de Risco Cardiometabólico em Adultos Jovens e de Meia-Idade Saudáveis

Abstract Background: Observational studies have highlighted an association between serum uric acid (SUA) levels and cardiovascular risk factors. Despite the growing body of evidences, several studies were conducted in older individuals or in carriers of diseases susceptible to affect SUA levels and cardiometabolic risk markers. Objective: To evaluate the relationship of SUA with body adiposity, metabolic profile, oxidative stress, inflammatory biomarkers, blood pressure and endothelial function in healthy young and middle-aged adults. Methods: 149 Brazilian adults aged 20-55 years, both sexes, underwent evaluation of body adiposity, SUA, fasting glucose and insulin, lipid profile, malondialdehyde (MDA), high sensitivity C-reactive protein (hs-CRP), adiponectin, blood pressure and endothelial function. Endothelial function was assessed by the reactive hyperemia index (RHI) derived from peripheral arterial tonometry method. Participants were allocated in two groups according to SUA levels: control group (CG; n = 130; men ≤ 7 mg/dL, women ≤ 6 mg/dL) and hyperuricemia group (HG; n = 19; men > 7 mg/dL, women > 6 mg/dL). A P-value < 0.05 was considered statistically significant. Results: After adjustment for confounders, participants in HG compared with those in CG displayed higher body mass index (BMI): 34.15(33.36-37.19) vs.31.80 (26.26-34.42) kg/m2,p = 0.008, higher MDA: 4.67(4.03-5.30) vs. 3.53(3.10-4.07) ng/mL, p < 0.0001 and lower RHI: 1.68 ± 0.30 vs. 2.05 ± 0.46, p = 0.03). In correlation analysis adjusted for confounders, SUA was positively associated (p < 0.05) with BMI, waist circumference, LDL-cholesterol, triglycerides and MDA, and negatively associated (p < 0.05) with HDL-cholesterol, adiponectin and RHI. Conclusions: This study suggests that in healthy young and middle-aged adults higher SUA levels are associated with higher body adiposity, unfavorable lipid and inflammatory phenotype, higher oxidative stress and impaired endothelial function.

Resumo Fundamento: Estudos observacionais têm destacado uma associação entre níveis de ácido úrico sérico (AUS) e fatores de risco cardiovascular. Apesar do crescente conjunto de evidências, vários estudos foram realizados em indivíduos mais velhos ou em portadores de doenças passíveis de influenciar os níveis de AUS e marcadores de risco cardiometabólico. Objetivo: Avaliar a relação do AUS com adiposidade corporal, perfil metabólico, estresse oxidativo, biomarcadores de inflamação, pressão arterial e função endotelial em adultos jovens e de meia-idade saudáveis. Métodos: 149 adultos, brasileiros, com idades entre 20 e 55 anos, de ambos os sexos, foram submetidos a avaliação de adiposidade corporal, AUS, glicose e insulina de jejum, perfil lipídico, malondialdeído (MDA), proteína C-reativa ultra-sensível (PCR-us), adiponectina, pressão arterial e função endotelial. A função endotelial foi avaliada pelo índice de hiperemia reativa (RHI) derivado do método de tonometria arterial periférica. Os participantes foram divididos em dois grupos de acordo com os níveis de AUS: grupo de controle (GC; n = 130; homens ≤ 7 mg/dL, mulheres ≤ 6mg/dL) e grupo de hiperuricemia (GH; n = 19; homens > 7mg/dL, mulheres > 6mg/dL). Valor de p < 0,05 foi considerado estatisticamente significativo. Resultados: Após ajuste para fatores de confundimento, os participantes do GH comparados aos do GC apresentaram índice de massa corporal (IMC) mais alto: 34,15 (33,36-37,19) vs. 31,80 (26,26-34,42) kg/m2, p = 0,008, MDA mais alto: 4,67(4,03-5,30) vs. 3,53(3,10-4,07) ng/mL, p < 0,0001 e RHI mais baixo: 1,68 ± 0,30 vs. 2,05 ± 0,46, p = 0,03. Na análise de correlação ajustada para fatores de confundimento, o AUS se associou positivamente (p < 0,05) com IMC, circunferência da cintura, LDL colesterol, triglicérides e MDA, e se associou negativamente (p < 0,05) com HDL colesterol, adiponectina e RHI. Conclusões: Este estudo sugere que, em adultos jovens e de meia-idade saudáveis, níveis mais altos de AUS estão associados a maior adiposidade corporal, fenótipo inflamatório e de lipídios desfavorável, maior estresse oxidativo e função endotelial comprometida.

Oxidative stress is associated with the number of components of metabolic syndrome: LIPGENE study

Previous evidence supports the important role that oxidative stress (OxS) plays in metabolic syndrome (MetS)-related manifestations. We determined the relationship between the number of MetS components and the degree of OxS in MetS patients. In this comparative cross-sectional study from the LIPGENE cohort, a total of 91 MetS patients (43 men and 48 women; aged between 45 and 68 years) were divided into four groups based on the number of MetS components: subjects with 2, 3, 4 and 5 MetS components (n=20, 31, 28 and 12, respectively). We measured ischemic reactive hyperemia (IRH), plasma levels of soluble vascular cell adhesion molecule-1 (sVCAM-1), total nitrite, lipid peroxidation products (LPO), hydrogen peroxide (H2O2), superoxide dismutase (SOD) and glutathione peroxidase (GPx) plasma activities. sVCAM-1, H2O2 and LPO levels were lower in subjects with 2 or 3 MetS components than subjects with 4 or 5 MetS components. IRH and total nitrite levels were higher in subjects with 2 or 3 MetS components than subjects with 4 or 5 MetS components. SOD and GPx activities were lower in subjects with 2 MetS components than subjects with 4 or 5 MetS components. Waist circumference, weight, age, homeostatic model assessment-beta, triglycerides (TGs), high-density lipoprotein and sVCAM-1 levels were significantly correlated with SOD activity. MetS subjects with more MetS components may have a higher OxS level. Furthermore, association between SOD activity and MetS components may indicate that this variable could be the most relevant OxS biomarker in patients suffering from MetS and could be used as a predictive tool to determine the degree of the underlying OxS in MetS.

The effect of cardiopulmonary bypass in coronary artery bypass surgeries (on-pump versus off-pump) on erectile function and endothelium-derived nitric oxide levels

PURPOSE: To investigate the effects of on-pump and off-pump coronary artery bypass grafting (CABG) on the erectile function and endothelium-derived nitric oxide (eNO) levels. MATERIALS AND METHODS: Twenty-eight consecutive patients were randomized into two groups depending on use of cardiopulmonary bypass in CABG surgery. The erectile function was evaluated by using the IIEF-5 questionnaire. The plasma eNO levels were determined at baseline and after reactive hyperemia before and after surgery. Blood was collected in one minute after cuff deflation from the radial artery on the same side. RESULTS: After CABG surgery the mean IIEF-5 score increased insignificantly over baseline from 14.8 to 15.8 (p = 0.29) and 12.4 to 14.3 (p = 0.11) after on-pump and off-pump CABG surgeries, respectively. The baseline plasma NO levels before surgery were 18.16 ± 7.63 nmol/L in on-pump and 21.76 ± 11.08 nmol/L in off-pump CABG. After reactive hyperemia the plasma NO levels were 22.14 ± 10.52 nmol/L in on-pump and 21.49 ± 9.13 nmol/L in off-pump CABG before the surgery. The difference in the plasma NO levels before surgery was not significant (p = 0.51). Two hours after surgery, the difference of the plasma NO levels at baseline (24.44 ± 12.31on-pump and 20.58 ± 6.74 nmol/L off-pump CABG) and after reactive hyperemia (35.55 ± 23.54 nmol/L on-pump and 23.00 ± 15.40 nmol/L off-pump CABG) were not significantly different from each other (p = 0.11). CONCLUSIONS: Patients who had on-pump or off-pump CABG surgeries had higher IIEF-5 scores. Nevertheless, the improvement was insignificant in both groups. Meanwhile, on-pump or off-pump CABG surgeries did not have significant effect on plasma eNO levels.