Cardiovascular, endothelial function, and immune markers in response to treatment with a polysaccharide in HIV(+) adults in a randomized, double-blind placebo-controlled trial

BACKGROUND AND AIM: Given the ongoing problems of hypertension and endothelial dysfunction in the HIV population, the primary objective of the study was to assess the cardiovascular, endothelial function, and immune markers in response to rice bran arabinoxylan compound (RBAC) treatment in a sample of HIV(+) adults on antiretroviral therapy (ART). STUDY DESIGN: A randomized, double-blind placebo-controlled trial of 6 months was used to execute the study. MATERIALS AND METHODS: Forty-seven subjects were enrolled and randomly assigned to one of two study conditions (n=22 RBAC and n=25 placebo) for 6 months with assessments at baseline and 3 and 6 months. A multivariate repeated measures analysis of variance model was used to assess the differences between RBAC and placebo groups in cardiovascular (systolic blood pressure), endothelial function (skin blood flow in response to nitric oxide), and immune (CD4(+) cell count) markers from baseline to 6 months. RESULTS: The effect of treatment (RBAC versus placebo) was significant (Wilks’ λ=0.92, F[3, 102]=3.07, P=0.03). The effect of time was significant (Wilks’ λ=0.10, F[2, 103]=474.6, P<0.001). The overall interaction between treatment and time was significant (Wilks’ λ=0.92, F[2, 103]=4.58, P=0.01). Time contrasts showed that a difference in the overall dependent variable did not occur from baseline to 3 months (F[1, 104]=2.7, P=0.10), marginally occurred from baseline to 6 months (F[1, 104]=3.2, P=0.08), and was significant from 3 to 6 months (F[1, 104]=6.43, P=0.01). CONCLUSIONS: The overall significant interaction suggests varying responses in the dependent variables between RBAC and placebo over time, which is being driven by systolic blood pressure, as it decreased in the RBAC group, but increased in the placebo group. In addition, CD4(+) manifested a non-significant increase from baseline to 3 months then decreased from 3 to 6 months in the RBAC group, whereas it decreased at 3 months followed by a slight increase at 6 months in the placebo group. Skin blood flow in response to nitric oxide improved non-significantly overall in both groups, but worsened from 3 to 6 months in the placebo group. Thus, RBAC treatment may contribute to modest short-term improvements in systolic blood pressure, endothelial function, and CD4(+) cell count, which could help improve the overall health profile of HIV(+) adults. RELEVANCE FOR PATIENTS: Persons with HIV on ART suffer disproportionately from hypertension and endothelial dysfunction compared to the non-infected population, and conventional medical therapy does not alleviate these issues. RBAC is a safe, low-risk alternative that may help to improve the overall quality of life of these patients through modest improvements in these biomarkers plus CD4(+) cell count.