Vitamins C and E in adolescents and young adults with HIV infection

Effect of high-dose multivitamin supplements on alanine aminotransferase elevations among adults living with HIV on antiretroviral therapy in Tanzania

BACKGROUND

HIV infection can cause malabsorption and rapid utilization of nutrients. A randomized trial of multivitamin supplementation among people living with HIV/AIDS (PLWHA) initiating antiretroviral therapy (ART) in Tanzania was stopped early due to increased alanine aminotransferase (ALT) concentrations in the multiple recommended dietary allowances (RDA) multivitamin group. We conducted detailed analysis to assess the effect of multivitamins on ALT elevations and evaluate whether subgroups of PLWHA have greater hepatotoxicity risks associated with the use of high-dose multivitamins.

METHODS

We utilized data from a randomized, double-blind trial conducted in 2006-2009 that assessed the effect of high-dose multivitamins that contained vitamin B complex, vitamin C, and vitamin E at multiple RDA as compared to standard-dose multivitamins containing single RDAs among adults initiating ART in Tanzania. We evaluated the effect of high-dose multivitamins on incident mild/moderate ALT elevations > 40 IU/L, persistent ALT elevations > 40 IU/L (2 + clinic visits), and severe ALT elevations > 200IU/L using Cox proportional hazard models. We then evaluated effect modification by patient characteristics to determine if subgroups of PLWHA experienced different magnitudes of risk for ALT elevations associated with high-dose multivitamins.

RESULTS

High-dose multivitamins increased the risk of incident mild/moderate ALT elevations > 40 IU/mL as compared to standard-dose multivitamins (hazard ratio (HR): 1.41; 95%CI: 1.26,1.58) as well as incident sustained mild/moderate ALT elevations (HR: 1.19; 95%CI: 1.04,1.36), but there was no overall effect on severe ALT elevations (HR: 1.44; 95% CI: 0.91,2.28). There was no evidence that the effect of high-dose multivitamins on any or sustained mild/moderate ALT elevations was modified by any patient characteristic. However, CD4 T-cell count was found to modify the effect of high-dose multivitamins on severe ALT elevations (p-value for interaction:0.01). Among participants with a baseline CD4 T-cell count ≤ 100 cells/µL, individuals receiving high-dose multivitamins had 3.74 times (95%CI: 1.52-9.17) the risk of incident severe ALT elevations compared to standard-dose multivitamins, while participants with CD4 T-cell counts > 100 cells/µL, appeared to have no effect of high-dose multivitamins on severe ALT elevations (HR:0.92; 95% CI: 0.50,1.67).

CONCLUSIONS

High-dose RDA multivitamin supplementation increased the incidence of any mild to moderate ALT elevations among adults starting ART in Tanzania and the magnitude of the risk does not appear to differ by patient characteristics. However, immunocompromised PLWHA with CD4 T-cell counts < 100 cells/µL may experience greater risk of severe ALT elevations associated with the use of high-dose multivitamins. Although the study findings offer significant insights, it is essential to take into account limitations imposed by newer cART regimes.

Prevalence of vitamin E inadequacy, dietary intake and sources of alpha-tocopherol, and predictors of alpha- and gamma-tocopherol status in adolescent girls in Central Mozambique

An adequate alpha-tocopherol status is important for females at reproductive age. We studied the dietary intake and sources of alpha-tocopherol and alpha- and gamma-tocopherol status indicators in 14-19-year-old girls in Central Mozambique. We also explored factors associated with alpha- and gamma-tocopherol status. The participants (n 508) were from the cross-sectional ZANE Study that was conducted in 2010. We recruited two separate samples, one in January-February and the other in May-June. We collected venous blood samples and conducted 24 h dietary recall interviews. At the time of blood sampling, 11 % of participants were pregnant and 10 % were lactating. In the total sample, both seasons combined, the median intake of alpha-tocopherol was 6⋅7 mg/d, the mean plasma alpha- and gamma-tocopherol concentrations were 13⋅5 and 0⋅75 μmol/l, respectively, and the prevalence of vitamin E inadequacy (alpha-tocopherol <12 μmol/l) was 36⋅7 % (95 % CI: 31⋅9-42⋅0 %). Season and lactation status were significant predictors of alpha-tocopherol status regardless of which the three indicators (plasma concentration, alpha-tocopherol:total cholesterol ratio, gamma-tocopherol:alpha-tocopherol ratio) were used. Being a lactating mother was negatively associated and having a blood sample taken in January-February, when the main sources of alpha-tocopherol were mango and dark green leafy vegetables, was positively associated with alpha-tocopherol status. In conclusion, vitamin E inadequacy was common in Central Mozambique, and the status may fluctuate due to seasonal changes in the diet. We suggest that lactating mothers are specifically at risk of poor alpha-tocopherol status in resource-poor settings.

Vitamin C Urinary Loss and Deficiency in Human Immunodeficiency Virus (HIV): Cross-sectional Study of Vitamin C Renal Leak in Women With HIV

BACKGROUND

Reduced plasma vitamin C (vitC) concentrations in human immunodeficiency virus (HIV) may result from abnormal urinary excretion: a renal leak. VitC renal leak indicates underlying nutritional dysregulation independent of diet. We hypothesized that increased renal leak prevalence in HIV would be associated with deficient vitC concentrations.

METHODS

We conducted an outpatient cross-sectional study of 96 women (40 HIV [PWH] and 56 without HIV [PWOH]) at the National Institutes of Health and Georgetown University. Renal leak was defined as abnormal urinary vitC excretion at fasting plasma concentrations <43.2µM, 2 SDs below vitC renal threshold in healthy women. To determine the primary outcome of renal leak prevalence, matched urine and plasma samples were collected the morning after overnight fast. Secondary outcomes assessed group differences in mean plasma vitC concentrations and prevalence of vitC deficiency. Exploratory outcomes assessed clinical parameters associated with renal leak. VitC was measured by high-performance liquid chromatography with coulometric electrochemical detection.

RESULTS

PWH had significantly higher renal leak prevalence (73%vs14%; OR (odds ratio):16; P<.001), lower mean plasma vitC concentrations (14µMvs50µM; P<.001), and higher prevalence of vitC deficiency (43%vs7%; OR:10; P<.001) compared with PWOH, unchanged by adjustments for confounding factors. Significant predictors of renal leak included antiretroviral therapy (ART), Black race, older age, and metabolic comorbidities but not viral load or CD4 count. When compared with other chronic disease cohorts, PWH had the highest prevalence of renal leak and vitC deficiency (P<.001).

CONCLUSIONS

High prevalence of vitC renal leak in HIV was associated with vitC deficiency, ART use, and race/ethnicity differences.

Serum vitamin E deficiency among people living with HIV and undergoing antiretroviral therapy at Ho Teaching Hospital, Ghana

Vitamin E is a potent antioxidant that helps to counteract oxidative stress in the body. Oxidative stress is known to greatly affect people living with HIV (PLWH) through the stimulation of HIV replication and apoptosis of CD4+ T cells. There is however, a paucity of scientific data on the serum levels of vitamin E among PLWH in Ghana, and hence, there is a need to assess its level because of the pivotal role it plays in cell longevity determination and the immune system enhancement of such persons. This study aims to assess the serum levels of vitamin E among PLWH undergoing highly active antiretroviral therapy at Ho Teaching Hospital, Ghana. In a cross-sectional study, serum vitamin E levels of 103 randomly selected PLWH aged 24-88 years who attended an antiretroviral therapy clinic at the Ho Teaching Hospital, Ghana, were measured by following standard protocols. A 24-hour dietary recall and food frequency questionnaire were employed to assess dietary intake. The results show that a high level of serum vitamin E deficiency (82.5%) was observed among the participants. Majority (91.3%) of the participants had normal serum zinc status. Participants' serum vitamin E levels did not show significant correlation with their dietary intakes (correlation coefficient (ρ) = -0.094, p-value = 0.35). The prevalence of vitamin E deficiency among underweight, normal weight, overweight, and obese participants was 91.7%, 75.4%, 86.5%, and 91.7% respectively with no significant difference among these groups. There was no significant correlation between serum vitamin E levels and HIV infection duration (ρ = 0.010, p-value = 0.405) and HAART duration (ρ = 0.001, p-value = 0.313). The low serum vitamin E levels found in this study suggests that the participants could potentially be at an increased risk of developing oxidative stress and its effects.

In Vitro and In Silico Analysis of Ascorbic Acid Towards Lanosterol 14-α-Demethylase Enzyme of Fluconazole-Resistant Candida albicans

Antibiotic resistance is one of the major concerns and the biggest threats to the world population. The incidents of antibiotic resistance in Candida spp. were frequently recorded. In the present investigation, antifungal potential of ascorbic acid (AA) was evaluated. According to the in vitro analysis, the zone of inhibition of AA (24.75 ± 0.35 mm) against C. albicans was greater as compared to other vitamins tested. AA significantly modulate the growth of C. albicans at 25 mg/ml. The highest percentage (94.67%) of cell viability was observed in untreated cells, and low cell viability (29.36%) was observed in cells treated with 50 mg/ml of AA (2 × MIC). Further, AO/EB (acridine orange/ethidium bromide), propidium iodide staining, and real-time qPCR confirmed the loss of membrane integrity due to membrane lesions that caused cell death. Lanosterol 14-α-demethylase (L-14α-DM) is the product of ERG11 and acted as superior drug target of C. albicans. Molecular docking analysis confirmed that active interaction of ascorbic acid with L-14α-DM. Based on the present investigation, the efficiency of AA was effectively proved through the in vitro and in silico analysis. This finding has evidenced the effectiveness of AA as a potential candidate against C. albicans.

Infectious Agents in Atherosclerotic Cardiovascular Diseases through Oxidative Stress

Accumulating evidence demonstrates that vascular oxidative stress is a critical feature of atherosclerotic process, potentially triggered by several infectious agents that are considered as risk co-factors for the atherosclerotic cardiovascular diseases (CVDs). C. pneumoniae has been shown to upregulate multiple enzymatic systems capable of producing reactive oxygen species (ROS) such as NADPH oxidase (NOX) and cyclooxygenase in vascular endothelial cells, NOX and cytochrome c oxidase in macrophages as well as nitric oxide synthase and lipoxygenase in platelets contributing to both early and late stages of atherosclerosis. P. gingivalis seems to be markedly involved in the atherosclerotic process as compared to A. actinomycetemcomitans contributing to LDL oxidation and foam cell formation. Particularly interesting is the evidence describing the NLRP3 inflammasome activation as a new molecular mechanism underlying P. gingivalis-induced oxidative stress and inflammation. Amongst viral agents, immunodeficiency virus-1 and hepatitis C virus seem to have a major role in promoting ROS production, contributing, hence, to the early stages of atherosclerosis including endothelial dysfunction and LDL oxidation. In conclusion, oxidative mechanisms activated by several infectious agents during the atherosclerotic process underlying CVDs are very complex and not well-known, remaining, thus, an attractive target for future research.

Lipid Peroxidation and Altered Antioxidant Profiles with Pediatric HIV Infection and Antiretroviral Therapy in Addis Ababa, Ethiopia

HIV- and highly active antiretroviral therapy (HAART)-associated elevations in oxidative stress likely play a role in incomplete immune reconstitution, opportunistic infections and non-AIDS co-morbidities. We aimed to test the hypothesis that children living with HIV exhibit elevated markers of oxidative stress and reduced antioxidant profiles and that HAART-therapy will exacerbate these differences. HIV-positive HAART-naïve (n = 50) and HAART-treated (n = 50) and HIV-negative control (n = 50) participants, 3-15 years of age, were recruited from Black Lion Hospital in Ethiopia. Serum malondialdehyde (MDA) and bilirubin were higher and vitamin C and zinc were lower in HAART-naïve and HAART-treated compared with HIV-negative subjects and higher in HAART-treated compared with HAART-naïve subjects. Uric acid was higher in HAART-naïve compared with HAART-treated and HIV-negative subjects. Differences in MDA and several antioxidants were also observed across treatment regimens. Thus, children living with HIV exhibited systemic elevations in oxidative stress and reduction in antioxidants, which are exacerbated with HAART therapy.

Gut microbiota associated with HIV infection is significantly enriched in bacteria tolerant to oxygen

Objectives

Gut microbiota modifications occurring during HIV infection have recently been associated with inflammation and microbial translocation. However, discrepancies between studies justified a comprehensive analysis performed on a large sample size.

Design and methods

In a case–control study, next-generation sequencing of the 16S rRNA gene was applied to the faecal microbiota of 31 HIV-infected patients, of whom 18 were treated with antiretroviral treatment (ART), compared with 27 healthy controls. 21 sera samples from HIV-infected patients and 7 sera samples from control participants were used to test the presence of 25 markers of inflammation and/or immune activation.

Results

Diversity was significantly reduced in HIV individuals when compared with controls and was not restored in the ART group. The relative abundance of several members of Ruminococcaceae such as Faecalibacterium prausnitzii was critically less abundant in the HIV-infected group and inversely correlated with inflammation/immune activation markers. Members of Enterobacteriaceae and Enterococcaceae were found to be enriched and positively correlated with these markers. There were significantly more aerotolerant species enriched in HIV samples (42/52 species, 80.8%) when compared with the control group (14/87 species, 16.1%; χ² test, p<10⁻⁵, conditional maximum-likelihood estimate (CMLE) OR=21.9).

Conclusions

Imbalance between aerobic and anaerobic flora observed in HIV faecal microbiota could be a consequence of the gut impairment classically observed in HIV infection via the production of oxygen. Overgrowth of proinflammatory aerobic species during HIV infection raises the question of antioxidant supplementation, such as vitamin C, E or N-acetylcysteine.

Toxoplasma gondii seropositivity and cognitive functions in school-aged children

Toxoplasma gondii (T. gondii) infects one-third of the world population, but its association with cognitive functions in school-aged children is unclear. We examined the relationship between Toxoplasma seropositivity and neuropsychological tests scores (including math, reading, visuospatial reasoning and verbal memory) in 1755 school-aged children 12-16 years old who participated to the Third National Health and Nutrition Examination Survey, using multiple linear regressions adjusted for covariates. Toxoplasma seroprevalence was 7·7% and seropositivity to the parasite was associated with lower reading skills (regression coefficient [β] = -5·86, 95% confidence interval [CI]: -11·11, -0·61, P = 0·029) and memory capacities (β = -0·86, 95% CI: -1·58, -0·15, P = 0·017). The interaction between T. gondii seropositivity and vitamin E significantly correlated with memory scores. In subgroup analysis, Toxoplasma-associated memory impairment was worse in children with lower serum vitamin E concentrations (β = -1·61, 95% CI: -2·44, -0·77, P < 0·001) than in those with higher values (β = -0·12, 95% CI: -1·23, 0·99, P = 0·83). In conclusion, Toxoplasma seropositivity may be associated with reading and memory impairments in school-aged children. Serum vitamin E seems to modify the relationship between the parasitic infection and memory deficiency.

Vitamin E inadequacy in humans: causes and consequences

It is estimated that >90% of Americans do not consume sufficient dietary vitamin E, as α-tocopherol, to meet estimated average requirements. What are the adverse consequences of inadequate dietary α-tocopherol intakes? This review discusses health aspects where inadequate vitamin E status is detrimental and additional vitamin E has reversed the symptoms. In general, plasma α-tocopherol concentrations <12 μmol/L are associated with increased infection, anemia, stunting of growth, and poor outcomes during pregnancy for both the infant and the mother. When low dietary amounts of α-tocopherol are consumed, tissue α-tocopherol needs exceed amounts available, leading to increased damage to target tissues. Seemingly, adequacy of human vitamin E status cannot be assessed from circulating α-tocopherol concentrations, but inadequacy can be determined from “low” values. Circulating α-tocopherol concentrations are very difficult to interpret because, as a person ages, plasma lipid concentrations also increase and these elevations in lipids increase the plasma carriers for α-tocopherol, leading to higher circulating α-tocopherol concentrations. However, abnormal lipoprotein metabolism does not necessarily increase α-tocopherol delivery to tissues. Additional biomarkers of inadequate vitamin E status are needed. Urinary excretion of the vitamin E metabolite α-carboxy-ethyl-hydroxychromanol may fulfill this biomarker role, but it has not been widely studied with regard to vitamin E status in humans or with regard to health benefits. This review evaluated the information available on the adverse consequences of inadequate α-tocopherol status and provides suggestions for avenues for research.

Habitual nutrient intake in HIV-infected youth and associations with HIV-related factors

Few studies have evaluated habitual nutrient intake among HIV-infected youth in the United States, even though diet may influence disease progression and risk of comorbidities. This study determined habitual micronutrient and macronutrient intake in HIV-infected youth. HIV-infected subjects and healthy controls 1-25 years old were prospectively enrolled. Nutrient intake was assessed via 24-h dietary recalls performed every 3 months for 1 year and compared to recommended intake from the U.S. Dietary Reference Intakes (DRIs) and Acceptable Macronutrient Distribution Ranges (AMDRs). Subjects with two or more food recalls were analyzed (175 HIV(+) and 43 healthy controls). Groups were similar in age, race, sex, body mass index, and kilocalorie intake. In both groups, intake of several micronutrients was below the DRI. In addition, HIV(+) subjects had a lower percentage DRI than controls for vitamins A, D, E, pantothenic acid, magnesium, calcium, folate, and potassium. HIV(+) subjects' percentage caloric intake from fat was above the AMDR and was higher than controls. Caloric intake was negatively correlated with current and nadir CD4 count. Zinc, riboflavin, and magnesium percentage DRI were positively associated with current CD4 count. In HIV(+) subjects not on antiretroviral therapy, HIV-1 RNA levels were negatively correlated with protein intake. HIV(+) youth have an inadequate dietary intake of several essential nutrients and poorer dietary intake compared to controls. Intake of some nutrients was associated with important HIV-related factors. Further investigation is warranted to determine the impact of dietary intake of specific nutrients on HIV progression and chronic complication risk in this population.

Serum Micronutrient Status of Haart-Naïve, HIV Infected Children in South Western Nigeria: A Case Controlled Study

Background. Though micronutrients are vital in the pathogenesis of human immunodeficiency virus infection, most studies have been conducted in adults. Knowledge of the status of key micronutrients in HIV infected African children will indicate if supplementation may be beneficial to these children living in this resource-poor region. Objectives. We sought to determine the micronutrient status and associated factors of HAART-naïve HIV infected children and compare them with those of the HIV negative controls. Methods. We enrolled 70 apparently stable HAART naïve HIV infected children. Seventy age and sex matched HIV negative children were equally enrolled as the controls. Their social class, anthropometry, clinical stage, CD4 counts, serum zinc, selenium, and vitamin C were determined. Results. The prevalence of zinc, selenium, and vitamin C deficiency in HIV infected subjects was 77.1%, 71.4%, and 70.0%, respectively, as compared to 44.3%, 18.6%, and 15.7% in HIV negative controls. Among the HIV infected subjects, 58.6% were deficient in the three micronutrients. Micronutrient status was related to the weight, clinical, and immunological stages but not BMI or social class. Conclusion. Deficiency of these key micronutrients is widely prevalent in HAART naïve HIV infected children irrespective of social class. This suggests that supplementation trial studies may be indicated in this population.

Ascorbic acid inhibition of Candida albicans Hsp90-mediated morphogenesis occurs via the transcriptional regulator Upc2

Morphogenetic transitions of the opportunistic fungal pathogen Candida albicans are influenced by temperature changes, with induction of filamentation upon a shift from 30 to 37°C. Hsp90 was identified as a major repressor of an elongated cell morphology at low temperatures, as treatment with specific inhibitors of Hsp90 results in elongated growth forms at 30°C. Elongated growth resulting from a compromised Hsp90 is considered neither hyphal nor pseudohyphal growth. It has been reported that ascorbic acid (vitamin C) interferes with the yeast-to-hypha transition in C. albicans. In the present study, we show that ascorbic acid also antagonizes the morphogenetic change caused by hampered Hsp90 function. Further analysis revealed that Upc2, a transcriptional regulator of genes involved in ergosterol biosynthesis, and Erg11, the target of azole antifungals, whose expression is in turn regulated by Upc2, are required for this antagonism. Ergosterol levels correlate with elongated growth and are reduced in cells treated with the Hsp90 inhibitor geldanamycin (GdA) and restored by cotreatment with ascorbic acid. In addition, we show that Upc2 appears to be required for ascorbic acid-mediated inhibition of the antifungal activity of fluconazole. These results identify Upc2 as a major regulator of ascorbic acid-induced effects in C. albicans and suggest an association between ergosterol content and elongated growth upon Hsp90 compromise.

HIV-1, reactive oxygen species, and vascular complications

Over 1 million people in the United States and 33 million individuals worldwide suffer from HIV/AIDS. Since its discovery, HIV/AIDS has been associated with an increased susceptibility to opportunistic infection due to immune dysfunction. Highly active antiretroviral therapies restore immune function and, as a result, people infected with HIV-1 are living longer. This improved survival of HIV-1 patients has revealed a previously unrecognized risk of developing vascular complications, such as atherosclerosis and pulmonary hypertension. The mechanisms underlying these HIV-associated vascular disorders are poorly understood. However, HIV-induced elevations in reactive oxygen species (ROS), including superoxide and hydrogen peroxide, may contribute to vascular disease development and progression by altering cell function and redox-sensitive signaling pathways. In this review, we summarize the clinical and experimental evidence demonstrating HIV- and HIV antiretroviral therapy-induced alterations in reactive oxygen species and how these effects are likely to contribute to vascular dysfunction and disease.

An investigation of the possible interaction between the use of Vitamin C and highly active antiretroviral therapy (HAART) adherence and effectiveness in treated HIV+ women

OBJECTIVES

Our goal in this study was to examine how Vitamin C interacts with antiretroviral therapy in individuals with HIV. We specifically evaluated how Vitamin C impacts highly active antiretroviral therapy (HAART) adherence and HAART effectiveness as adjudicated by HIV viral loads and CD4 cell counts. Women served as their own controls, comparing periods of Vitamin C usage with periods of non-usage.

DESIGN

An intra-individual, cross-sectional comparative study 'nested' in the WIHS observational cohort study.

SUBJECTS

Women in the Women's Interagency HIV Study (WIHS).

OUTCOME MEASURES

Adherence, CD4 count and viral load.

RESULTS

Our study population was drawn from 2813 HIV+ participants who contributed 44,588 visits in WIHS from October, 1994 to April, 2009. Among them, there were 1122 Vitamin C users with 4954 total visits where use was reported. In the multivariate model adjusting for age, education, race, income, drug use, Vitamin C use order and depression score, there was a 44% increase in the odds of ≥ 95% HAART adherence among participants during their period of Vitamin C use compared to when they were not using Vitamin C (OR=1.44; 95% CI=1.1-1.9; P-value=0.0179). There was an association with Vitamin C usage and CD4 counts on viral loads.

CONCLUSION

Vitamin C usage appears to be associated with improved adherence. Future Vitamin C studies should target specific HAART drugs, and prospective clinical outcomes.

Tight junctions in brain barriers during central nervous system inflammation

Homeostasis within the central nervous system (CNS) is a prerequisite to elicit proper neuronal function. The CNS is tightly sealed from the changeable milieu of the blood stream by the blood-brain barrier (BBB) and the blood-cerebrospinal fluid (CSF) barrier (BCSFB). Whereas the BBB is established by specialized endothelial cells of CNS microvessels, the BCSFB is formed by the epithelial cells of the choroid plexus. Both constitute physical barriers by a complex network of tight junctions (TJs) between adjacent cells. During many CNS inflammatory disorders, such as multiple sclerosis, human immunodeficiency virus infection, or Alzheimer's disease, production of pro-inflammatory cytokines, matrix metalloproteases, and reactive oxygen species are responsible for alterations of CNS barriers. Barrier dysfunction can contribute to neurological disorders in a passive way by vascular leakage of blood-borne molecules into the CNS and in an active way by guiding the migration of inflammatory cells into the CNS. Both ways may directly be linked to alterations in molecular composition, function, and dynamics of the TJ proteins. This review summarizes current knowledge on the cellular and molecular aspects of the functional and dysfunctional TJ complexes at the BBB and the BCSFB, with a particular emphasis on CNS inflammation and the role of reactive oxygen species.

Role of Nutrition in HIV Infection: Review of Evidence for more Effective Programming in Resource-Limited Settings

Background

HIV infection and malnutrition negatively reinforce each other.

Objective

For program guidance, to review evidence on the relationship of HIV infection and malnutrition in adults in resource-limited settings.

Results and conclusions

Adequate nutritional status supports immunity and physical performance. Weight loss, caused by low dietary intake (loss of appetite, mouth ulcers, food insecurity), malabsorption, and altered metabolism, is common in HIV infection. Regaining weight, particularly muscle mass, requires antiretroviral therapy (ART), treatment of opportunistic infections, consumption of a balanced diet, physical activity, mitigation of side effects, and perhaps appetite stimulants and growth hormone. Correcting nutritional status becomes more difficult as infection progresses. Studies document widespread micronutrient deficiencies among HIV-infected people. However, supplement composition, patient characteristics, and treatments vary widely across intervention studies. Therefore, the World Health Organization (WHO) recommends ensuring intake of 1 Recommended Nutrient Intake (RNI) of each required micronutrient, which may require taking micronutrient supplements. Few studies have assessed the impact of food supplements. Because the mortality risk in patients receiving ART increases with lower body mass index (BMI), improving the BMI seems important. Whether this requires provision of food supplements depends on the patient's diet and food security. It appears that starting ART improves BMI and that ready-to-use fortified spreads and fortified-blended foods further increase BMI (the effect is somewhat less with fortified-blended foods). The studies are too small to assess effects on mortality. Once ART has been established and malnutrition treated, the nutritional quality of the diet remains important, also because of ART's long-term metabolic effects (dyslipidemia, insulin resistance, obesity). Food insecurity should also be addressed if it prevents adequate energy intake and reduces treatment initiation and adherence (due to the opportunity costs of obtaining treatment and mitigating side effects).

Nutrition and oral mucosal diseases

Oral manifestations of nutritional deficiencies can affect the mucous membranes, teeth, periodontal tissue, salivary glands, and perioral skin. This contribution reviews how the water-soluble vitamins (B(2), B(3), B(6), B(12), C, and folic acid), fat-soluble vitamins (A, D, and E), and minerals (calcium, fluoride, iron, and zinc) can affect the oral mucosa.

Reconciling conflicting clinical studies of antioxidant supplementation as HIV therapy: a mathematical approach

BACKGROUND

Small, highly reactive molecules called reactive oxygen species (ROS) play a crucial role in cell signalling and infection control. However, high levels of ROS can cause significant damage to cell structure and function. Studies have shown that infection with the human immunodeficiency virus (HIV) results in increased ROS concentrations, which can in turn lead to faster progression of HIV infection, and cause CD4+ T-cell apoptosis. To counteract these effects, clinical studies have explored the possibility of raising antioxidant levels, with mixed results.

METHODS

In this paper, a mathematical model is used to explore this potential therapy, both analytically and numerically. For the numerical work, we use clinical data from both HIV-negative and HIV-positive injection drug users (IDUs) to estimate model parameters; these groups have lower baseline concentrations of antioxidants than non-IDU controls.

RESULTS

Our model suggests that increases in CD4+ T cell concentrations can result from moderate levels of daily antioxidant supplementation, while excessive supplementation has the potential to cause periods of immunosuppression.

CONCLUSION

We discuss implications for HIV therapy in IDUs and other populations which may have low baseline concentrations of antioxidants.

The roles of HIV-1 proteins and antiretroviral drug therapy in HIV-1-associated endothelial dysfunction

Since the emergence of highly active antiretroviral therapy (HAART), human immunodeficiency virus-1 (HIV-1)-infected patients have demonstrated dramatic decreases in viral burden and opportunistic infections, and an overall increase in life expectancy. Despite these positive HAART-associated outcomes, it has become increasingly clear that HIV-1 patients have an enhanced risk of developing cardiovascular disease over time. Clinical studies are instrumental in our understanding of vascular dysfunction in the context of HIV-1 infection. However, most clinical studies often do not distinguish whether HIV-1 proteins, HAART, or a combination of these 2 factors cause cardiovascular complications. This review seeks to address the roles of both HIV-1 proteins and antiretroviral drugs in the development of endothelial dysfunction because endothelial dysfunction is the hallmark initial step of many cardiovascular diseases. We analyze recent in vitro and in vivo studies examining endothelial toxicity in response to HIV-1 proteins or in response to the various classes of antiretroviral drugs. Furthermore, we discuss the multiple mechanisms by which HIV-1 proteins and HAART injure the vascular endothelium in HIV-1 patients. By understanding the molecular mechanisms of HIV-1 protein- and antiretroviral-induced cardiovascular disease, we may ultimately improve the quality of life of HIV-1 patients through better drug design and the discovery of new pharmacological targets.

Vitamin E dietary supplementation significantly affects multiple risk factors for cardiovascular disease in baboons

BACKGROUND

Oxidative stress is a widely accepted risk factor for cardiovascular disease (CVD), but the CVD benefit of dietary antioxidants, such as vitamin E, is controversial.

OBJECTIVE

Therefore, we have investigated, in the baboon model, the effects of dietary vitamin E supplementation on risk factors for CVD.

DESIGN

Pedigreed baboons (n = 251) were fed 2 atherogenic diets, high in fat and cholesterol, that differed in vitamin E concentrations. After 7 wk on each diet, blood samples were taken, and a panel of CVD risk factor traits (ie, indicators of lipoprotein metabolism and oxidative stress) were measured.

RESULTS

Vitamin E supplementation caused significantly higher total antioxidant status (TAS) and lower oxidized LDL as expected. In addition, vitamin E caused 2 paradoxical effects on HDL metabolism: higher apolipoprotein A-I (apo A-I) concentrations and lower HDL sizes. We calculated a difference (Delta) variable for each trait as the value on the high-vitamin E diet minus that on the low-vitamin E diet and determined that several HDL concentration Delta variables were significantly correlated with Delta TAS, but only one, Delta apo A-I, was independently correlated. Genetic analyses showed that 2 Delta variables, Delta paraoxonase and Delta HDL(2), were significantly heritable, but that neither Delta TAS nor Delta apo A-I were heritable.

CONCLUSIONS

Thus, our data show that dietary vitamin E improves TAS and LDL quality. They also show 2 apparently paradoxical effects on HDL metabolism: lower HDL(2), which is mediated by genes, and higher apo A-I, which is not. These effects have contrasting associations with CVD risk and may help account for the mixed results from clinical trials of dietary vitamin E.