Alcohol and dietary factors associate with gut integrity and inflammation in HIV-infected adults.

OBJECTIVES: HIV-infected adults have heightened monocyte activation and inflammation, at least partially as a consequence of altered gut integrity. The role of dietary factors in microbial translocation and inflammation and their downstream effect on markers of cardiovascular disease (CVD) have not been explored. Our purpose was to describe the longitudinal dietary patterns of HIV-infected adults, and to examine the relationship between dietary intake, gut integrity, inflammation and subclinical markers of CVD in HIV-infected adults. METHODS: We conducted a secondary analysis of 147 HIV-infected participants in a 96-week randomized clinical trial of rosuvastatin as primary CVD prevention. Dietary intake was assessed using dietary recall; plasma gut integrity, monocyte activation and inflammation markers were measured using an enzyme-linked immunosorbent assay (ELISA); and CVD risk was assessed using carotid ultrasound and the coronary artery calcium score. Linear mixed models were used to analyse longitudinally measured biomarkers. RESULTS: The median age was 45 years and 78% of patients were male. At baseline, participants consumed a mean (standard deviation) of 108 (70) g of fat daily, 19 (15.6) g of fibre, 266 (186) g of carbohydrates and 15.6 (5.9) g of protein; 45% of the sample consumed alcohol. Over time, alcohol consumption was associated with several markers of gut integrity and inflammation (all P < 0.05). CONCLUSIONS: HIV-infected adults in a contemporary, high-resource setting have poor dietary patterns. Alcohol use was associated with worse gut integrity and increased inflammation, while other aspects of diet (fibre, carbohydrates and fat) were not. These data add to growing evidence illustrating the need for a better understanding of the effect of lifestyle factors on comorbidities in HIV-infected adults.

Lipoprotein-associated phospholipase A2 and cardiovascular disease risk in HIV infection.

OBJECTIVES: HIV-infected patients on antiretroviral therapy (ART) have an increased cardiovascular disease (CVD) risk as a result of heightened inflammation and immune activation, despite at times having normal lipids and few traditional risk factors. Biomarkers are needed to identify such patients before a clinical event. Lipoprotein-associated phospholipase A2 (Lp-PLA2 ) predicts CVD events in the general population. This study investigated the relationship between Lp-PLA2 and markers of CVD risk, systemic inflammation, immune activation, and coagulation in HIV infection. METHODS: One hundred subjects on stable ART with normal fasting low-density lipoprotein (LDL) cholesterol were enrolled in the study. Plasma Lp-PLA2 concentrations were measured by enzyme-linked immunosorbent assay (ELISA; > 200 ng/mL was considered high CVD risk). Subclinical atherosclerosis, endothelial function, inflammation, immune activation and fasting lipids were also evaluated. RESULTS: The median age of the patients was 47 years and 77% were male. Median (range) Lp-PLA2 was 209 (71-402) ng/mL. Fifty-seven per cent of patients had Lp-PLA2 concentrations > 200 ng/mL. Lp-PLA2 was positively correlated with soluble markers of inflammation or immune activation (tumour necrosis factor receptor-II, intercellular and vascular cellular adhesion molecules, and CD14; all R = 0.3; P < 0.01), and negatively correlated with coagulation markers (D-dimer and fibrinogen; both R = -0.2; P < 0.04). Lp-PLA2 was not correlated with lipids, coronary artery calcium score, or flow-mediated vasodilation, but trended towards a significant correlation with carotid intima-media thickness (R = 0.2; P = 0.05). CONCLUSIONS: In this population with stable ART and normal LDL cholesterol, Lp-PLA2 was in the high CVD risk category in the majority of subjects. Lp-PLA2 appears to be associated with inflammation/immune activation, but also with anti-thrombotic effects. Lp-PLA2 may represent a valuable early biomarker of CVD risk in HIV infection before subclinical atherosclerosis can be detected.

Markers of inflammation and CD8 T-cell activation, but not monocyte activation, are associated with subclinical carotid artery disease in HIV-infected individuals.

OBJECTIVES: The aim of the study was to explore the relationships between lymphocyte and monocyte activation, inflammation, and subclinical vascular disease among HIV-1-infected patients on antiretroviral therapy (ART). METHODS: Baseline mean common carotid artery (CCA) intima-media thickness (IMT) and carotid plaque (IMT > 1.5 cm) were evaluated in the first 60 subjects enrolled in the Stopping Atherosclerosis and Treating Unhealthy Bone with Rosuvastatin in HIV (SATURN-HIV) trial. All subjects were adults on stable ART with evidence of heightened T-cell activation (CD8(+)CD38(+)HLA-DR(+) ≥ 19%) or increased inflammation (high-sensitivity C-reactive protein ≥ 2 mg/L). All had fasting low-density lipoprotein (LDL) cholesterol ≤ 130 mg/dL. RESULTS: Seventy-eight per cent of patients were men and 65% were African-American. Median (interquartile range) age and CD4 count were 47 (43, 52) years and 648 (511, 857) cells/µL, respectively. All had HIV-1 RNA < 400 HIV-1 RNA copies/mL. Mean CCA-IMT was correlated with log-transformed CD8(+)CD38(+)HLA-DR(+) percentage (r = 0.326; P = 0.043), and concentrations of interleukin-6 (r = 0.283; P = 0.028), soluble vascular cell adhesion molecule (sVCAM; r = 0.434; P = 0.004), tumour necrosis factor-α receptor-I (TNFR-I; r = 0.591; P < 0.0001) and fibrinogen (r = 0.257; P = 0.047). After adjustment for traditional cardiovascular disease (CVD) risk factors, the association with TNFR-I (P = 0.007) and fibrinogen (P = 0.033) remained significant. Subjects with plaque (n = 22; 37%) were older [mean (standard deviation) 51 (7.7) vs. 43 (9.4) years, respectively; P = 0.002], and had a higher CD8(+)CD38(+)HLA-DR(+) percentage [median (interquartile range) 31% (24, 41%) vs. 23% (20, 29%), respectively; P = 0.046] and a higher sVCAM concentration [mean (standard deviation) 737 (159) vs. 592 (160) ng/mL, respectively; P = 0.008] compared with those without plaque. Pro-inflammatory monocyte subsets and serum markers of monocyte activation (soluble CD163 and soluble CD14) were not associated with CCA-IMT or plaque. CONCLUSIONS: Participants in SATURN-HIV have a high level of inflammation and immune activation that is associated with subclinical vascular disease despite low serum LDL cholesterol.

Relationship between total bilirubin and endothelial function, inflammation and oxidative stress in HIV-infected adults on stable antiretroviral therapy.

OBJECTIVES: Enhanced inflammation is evident in HIV infection, even with virological suppression. Outside HIV infection, studies show an independent association between higher total bilirubin and better endothelial function as well as a lower prevalence of coronary heart disease, possibly as a consequence of the anti-inflammatory and antioxidant effect of bilirubin. The aim of this study was to determine whether such an association exists in HIV-infected individuals. METHODS: A cross-sectional study was performed in HIV-1-infected adults on stable antiretroviral therapy (ART) to determine if a relationship exists between total bilirubin and endothelial function [flow-mediated dilation (FMD) of the brachial artery], inflammation [interleukin-6 (IL-6), soluble tumour necrosis factor receptors, C-reactive protein, and adhesion molecules], coagulation markers (fibrinogen and D-dimer) and oxidative stress (F (2) -isoprostanes). Endpoints were compared based on total bilirubin levels and atazanavir status using distributionally appropriate, two-sample tests. Correlation coefficients were determined between total bilirubin and endpoints. Linear regression was used to model the relationship between total bilirubin (and atazanavir status) and FMD. RESULTS: A total of 98 adults were included in the study. Total bilirubin was higher in the atazanavir group when compared to the non-atazanavir group [median (interquartile range) 1.8 (1.1-2.6) vs. 0.6 (0.4-1.4) mg/dL; P < 0.01] as were insulin, the homeostasis model assessment of insulin resistance (HOMA-IR) and fibrinogen. Total bilirubin was positively correlated with fibrinogen and was not correlated with other outcomes. After adjustment, neither total bilirubin nor atazanavir status was associated with FMD. CONCLUSIONS: In virologically suppressed, HIV-infected adults on stable ART, neither total bilirubin nor atazanavir use was associated with improved endothelial function as measured using FMD, inflammation or oxidative stress as measured using biomarkers.

Effects of in utero antiretroviral exposure on mitochondrial DNA levels, mitochondrial function and oxidative stress.

OBJECTIVES: HIV and antiretroviral (ART) exposure in utero may have deleterious effects on the infant, but uncertainty still exists. The objective of this study was to evaluate aspects of mitochondrial DNA (mtDNA) content, mitochondrial function and oxidative stress simultaneously in placenta, umbilical cord blood and infant blood in HIV/ART-exposed infants compared with uninfected controls. METHODS: HIV-1-infected pregnant women and HIV-1-uninfected healthy pregnant controls were enrolled in the study prospectively. Placenta and umbilical cord blood were obtained at delivery and infant blood was obtained within 48 h of delivery. mtDNA content was determined for each specimen. Nuclear [subunit IV of cytochrome c-oxidase (COX IV)]- and mitochondrial (COX II)-encoded polypeptides of the oxidative phosphorylation enzyme cytochrome c-oxidase were quantified in cord and infant blood. Placental mitochondria malondialdehyde (MDA) concentrations were measured as a marker of oxidative stress. RESULTS: Twenty HIV-positive/HIV-exposed and 26 control mother-infant pairs were enrolled in the study. All HIV-infected women and their infants received ART. Placental MDA concentration and mtDNA content in placenta and cord blood were similar between groups. The cord blood COX II:IV ratio was lower in the HIV-positive group than in the controls, whereas the infant peripheral blood mtDNA content was higher in the HIV-exposed infants, but the infant peripheral blood COX II:IV ratio was similar. No infant had clinical evidence of mitochondrial disease or acquired HIV infection. In multivariable regression analyses, the significant findings in cord and infant blood were both most associated with HIV/ART exposure. CONCLUSIONS: HIV-exposed infants showed reduced umbilical cord blood mitochondrial enzyme expression with increased infant peripheral blood mitochondrial DNA levels, the latter possibly reflecting a compensatory mechanism to overcome HIV/ART-associated mitochondrial toxicity.