ABSTRACT
Human immunodeficiency virus (HIV) is associated with lower nitric oxide (NO) bioavailability and vascular dysfunction. Nitrate-rich beetroot juice (BJ) has been shown to acutely increase NO availability and vascular function in healthy and individuals at high risk for cardiovascular disease. Thus, we tested the effects of BJ ingestion on flow-mediated dilation (FMD) and pulse wave velocity (PWV) measurements in healthy and HIV-infected patients. Thirteen HIV-infected individuals (age, 36 ± 10 years) and 18 healthy (age, 27 ± 8 years) participated in the study. Individuals were submitted to vascular tests such as FMD and pulse PWV at pre (T0) and at 120 min (T120) after BJ and placebo (PLA) ingestion. The %FMD at T0 of the control group was significantly higher than the %FMD at T0 of the HIV individuals in both interventions. BJ improved the %FMD at T120 when compared with T0 in the HIV and control groups. There was no change in %FMD after PLA ingestion in the control and HIV groups. There were no differences between groups (control vs HIV), time points (T0 vs T120), and interventions (BJ vs PLA) for PWV. Our findings showed that nitrate-rich BJ ingestion acutely improved vascular function in healthy and HIV-infected patients. Clinical Trials Registry no. NCT03485248. Novelty: HIV is associated with lower NO bioavailability and vascular dysfunction. Acute supplementation with nitrate-rich BJ has been shown to acutely increases NO bioavailability. We showed for the first time that BJ acutely improves endothelial function in HIV-infected patients.
Subject(s)
Dietary Supplements , Endothelium, Vascular/physiology , Fruit and Vegetable Juices , HIV Infections/therapy , Nitrates/administration & dosage , Adult , Beta vulgaris , Blood Pressure , Case-Control Studies , Cross-Over Studies , Double-Blind Method , Female , Humans , Male , Middle Aged , Nitric Oxide , Pulse Wave Analysis , Vascular Stiffness , Young AdultABSTRACT
HIV-1 proteins and highly active antiretroviral therapy (HAART) have been associated with microvascular endothelial dysfunction. Although nitrate-rich beetroot juice (NR-BJ) consumption has been shown to improve endothelial function in clinical population, its effects in HIV-infected patients has not been addressed. We investigated the effect of a single dose of NR-BJ on muscle oxygen saturation parameters in response to a handgrip exercise in HIV-infected patients. Fifteen HIV-infected patients received NR-BJ or nitrate-depleted beetroot juice (ND-BJ) in a double-blind cross-over design. Near-IR spectroscopy was utilised to assess muscle oxygen saturation parameters during rhythmic handgrip exercise after NR-BJ or ND-BJ supplementation. A significant faster muscle oxygen desaturation rate during exercise (-7·97 (sd 5·00) v. -5·45 (3·94) %/s, P = 0·005) and muscle oxygen resaturation rate during exercise recovery (0·43 (0·24) v. 0·28 (0·24) %/s, P = 0·030) after NR-BJ ingestion was found. However, no significant difference in exercise time until fatigue was observed. Salivary nitrite and urinary nitrate concentration were analysed after NR-BJ or ND-BJ. A significant increase in salivary nitrite and urinary nitrate in NR-BJ was observed compared with ND-BJ (P < 0·05). Our findings suggest that NR-BJ consumption may acutely improve muscle oxygen saturation during exercise and exercise recovery in HIV-infected patients undergoing HAART and who are expected to present microvascular damage. Thus, future studies investigating the chronic effects of NR-BJ are warranted to delineate a better nutritional strategy based on nitrate-rich foods.
Subject(s)
Antiretroviral Therapy, Highly Active/adverse effects , Beta vulgaris , Fruit and Vegetable Juices , Nitrates/administration & dosage , Oxygen Consumption/drug effects , Adult , Cross-Over Studies , Dietary Supplements , Double-Blind Method , Endothelial Cells , Female , HIV Infections/drug therapy , HIV Infections/physiopathology , HIV Infections/virology , HIV-1 , Hand Strength , Humans , Male , Microvessels/metabolism , Middle Aged , Muscle, Skeletal/blood supply , Treatment Outcome , Young AdultABSTRACT
Highly active antiretroviral therapy has been associated with the presence of endothelial dysfunction in HIV-infected patients, which may impair oxygen delivery to muscles during exercise and exercise recovery. Near-infrared spectroscopy (NIRS) has been used to assess muscle oxygen saturation (SmO2) kinetics during exercise in different clinical populations in order to evaluate the balance between oxygen delivery and utilization by muscles. However, studies assessing SmO2 in HIV-infected patients have not been conducted. Therefore, the aim of the study was to evaluate NIRS-derived SmO2 during rhythmic handgrip exercise and flow-mediated dilation (FMD) in HIV-infected patients (HIV) compared to non-HIV-infected controls (N-HIV). Eighteen HIV and 17 N-HIV individuals underwent FMD assessment by ultrasound. The subjects then performed one set of rhythmic handgrip exercise until fatigue at 30% maximal isometric voluntary contraction. SmO2 was measured during entire exercise and 2-min exercise 3recovery. Muscle oxygen resaturation rate (upslope of the SmO2 over 10 s of recovery) was calculated. A significant lower FMD (3.5 ± 1.7 vs 5.9 ± 1.5%, P < 0.001) and slower oxygen resaturation rate (0.78 ± 0.4 vs 1.14 ± 0.4%·s-1, P = 0.020) in HIV as compared to N-HIV group were observed. In conclusion, our findings demonstrated that HIV-infected patients had reduced FMD and impaired muscle oxygenation during exercise recovery compared to non-HIV individuals.
