The prevalence of cardiovascular disease is increased with human immunodeficiency virus (HIV) infection, but the mechanism is unclear. We hypothesized that HIV increases microvascular reactive oxygen species, thereby impairing endothelial function and enhancing contractility.
Subcutaneous microarterioles were isolated from gluteal skin biopsies in premenopausal, African American, HIV positive women receiving effective anti-retroviral therapy, but without cardiovascular risk factors except for increased body mass index (n=10) and healthy matched controls (n=10). The arterioles were mounted on myographs, preconstricted and relaxed with acetylcholine for: endothelium-dependent relaxation, endothelium-dependent relaxation factor (nitric oxide synthase-dependent relaxation), endothelium-dependent hyperpolarizing factor (potassium-channel dependent relaxation) and endothelium-independent relaxation (nitroprusside). Contractions were tested to endothelium-dependent contracting factor (acetylcholine contraction with blocked relaxation); phenylephrine, U-46,619 and endothelin-1. Plasma L-arginine and asymmetric dimethylarginine were measured by high performance capillary electrophoresis.
The micro-arterioles from HIV positive women had significantly (% change in tension; P<0.05) reduced acetylcholine relaxation (-51 ± 6 vs. -78 ± 3%), endothelium-dependent relaxation factor (-28 ± 4 vs. -39 ± 3%), endothelium-dependent hyperpolarizing factor (-17 ± 4 vs. -37 ± 4%) and decreased nitric oxide activity (0.16 ± 0.03 vs. 0.70 ± 0.16 Δ unit) but unchanged nitroprusside relaxation. They had significantly enhanced endothelium-dependent contracting factor (+21 ± 6 vs. +7 ± 2%) and contractions to U-46,619 (+164 ± 10 vs. +117 ± 11%) and endothelin-1(+151 ± 12 vs. +97 ± 9%), but not to phenylephrine. There was enhanced reactive oxygen species with acetylcholine (0.11 ± 0.02 vs. 0.05 ± 0.01 Δ unit; P<0.05) and endothelin-1 (0.31 ± 0.06 vs. 0.10 ± 0.02 Δ unit; P<0.05). Plasma L-arginine: assymetric dimethyl arginine rates was reduced (173 ± 12 vs. 231 ± 6 μmol·μmol-1, P<0.05).
Premenopausal HIV positive womenhad microvascular oxidative stress with severe endothelial dysfunction and reduced nitric oxide and arginine: assymetric dimethylarginine ratio but enhanced endothelial, thromboxane and endothelin contractions. These microvascular changes may herald later cardiovascular disease.
Cardiovascuar disease (CVD); Endothelial dysfunction; Nitric oxide (NO); Endothelium-dependent relaxing factor (EDRF); Reactive oxygen species (ROS); Asymmetric dimethylarginine (ADMA); Thromboxane-prostanoid receptors (TP-Rs); Endothelin-1 (ET-1)
Iron-sulfur cluster biosynthesis involving the nitrogen fixation (Nif) proteins has been proposed as a general mechanism acting in various organisms. NifU-like protein may play an important role in protecting plants against abiotic and biotic stresses. An iron-sulfur cluster scaffold protein gene, IbNFU1, was isolated from a salt-tolerant sweetpotato (Ipomoea batatas (L.) Lam.) line LM79 in our previous study, but its role in sweetpotato stress tolerance was not investigated. In the present study, the IbNFU1 gene was introduced into a salt-sensitive sweetpotato cv. Lizixiang to characterize its function in salt tolerance. The IbNFU1-overexpressing sweetpotato plants exhibited significantly higher salt tolerance compared with the wild-type. Proline and reduced ascorbate content were significantly increased, whereas malonaldehyde (MDA) content was significantly decreased in the transgenic plants. The activities of superoxide dismutase (SOD) and photosynthesis were significantly enhanced in the transgenic plants. H2O2 was also found to be significantly less accumulated in the transgenic plants than in the wild-type. Overexpression of IbNFU1 up-regulated pyrroline-5-carboxylate synthase (P5CS) and pyrroline-5-carboxylate reductase (P5CR) genes under salt stress. The systemic up-regulation of reactive oxygen species (ROS) scavenging genes was found in the transgenic plants under salt stress. These findings suggest that IbNFU1gene is involved in sweetpotato salt tolerance and enhances salt tolerance of the transgenic sweetpotato plants by regulating osmotic balance, protecting membrane integrity and photosynthesis and activating ROS scavenging system.
CYP2B6 variation predicts pharmacokinetic characteristics of its substrates. Consideration for underlying genetic structure is critical to protect against spurious associations with the highly polymorphic CYP2B6 gene.
The effect of CYP2B6 variation on response to its substrates, nonnucleoside reverse transcriptase inhibitors (NNRTIs), was explored in the Women's Interagency HIV Study.
Five putative functional polymorphisms were tested for associations with virologic suppression within one year after NNRTI initiation in women naïve to antiretroviral agents (n=91). Principal components (PCs) were generated to control for population substructure. Logistic regression was used to test the joint effect of rs3745274 and rs28399499, which together indicate slow, intermediate, and extensive metabolizers.
Rs3745274 was significantly associated with virologic suppression (OR=3.61, 95% CI 1.16-11.22, p trend=0.03); the remaining polymorphisms tested were not significantly associated with response. Women classified as intermediate and slow metabolizers were 2.90 (95% CI 0.79-12.28) and 13.44 (95% CI 1.66-infinity) times as likely to achieve virologic suppression compared to extensive metabolizers after adjustment for PCs (p trend=0.005). Failure to control for genetic ancestry resulted in substantial confounding of the relationship between the metabolizer phenotype and treatment response.
The CYP2B6 metabolizer phenotype was significantly associated with virologic response to NNRTIs; this relationship would have been masked by simple adjustment for self-reported ethnicity. Given the appreciable genetic heterogeneity that exists within self-reported ethnicity, these results exemplify the importance of characterizing underlying genetic structure in pharmacogenetic studies. Further follow-up of the CYP2B6 metabolizer phenotype is warranted given the potential clinical importance of this finding.
CYP2B6; population substructure; women; NNRTIs; confounding
Coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) is common. HIV infection and treatment are associated with hypercoaguability; thrombosis in HCV is under-investigated. Proposed markers of hemostasis in HIV include higher D-dimer, Factor VIII% and Plasminogen Activator Inhibitor-1 (PAI-1Ag), and lower total Protein S% (TPS), but have not been examined in HCV. We assessed the independent association of HCV with these four measures of hemostasis in a multicenter, prospective study of HIV: the Women’s Interagency HIV Study (WIHS).
We randomly selected 450 HCV-infected (anti-HCV+ with detectable plasma HCV RNA) and 450 HCV-uninfected (anti-HCV−) women. HCV was the main exposure of interest in regression models.
443 HCV+ and 425 HCV− women were included. HCV+ women had higher Factor VIII% (124.4% ±3.9 vs. 101.8% ±3.7, p <0.001) and lower TPS (75.7% ±1.1 vs. 84.3% ±1.1, <0.001) than HCV−, independent of HIV infection and viral load; there was little difference in PAI-1Ag or log10 D-dimer. After adjustment for confounders, these inferences remained. HIV infection was independently associated with higher Factor VIII% and log10 D-dimer, and lower TPS.
HCV was independently associated with higher Factor VIII% and lower TPS consistent with hypercoaguability. Higher Factor VIII % and D-dimer and lower total Protein S % were also strongly associated with HIV infection and levels of HIV viremia, independent of HCV infection. Further investigation is needed to determine if there is increased thrombotic risk from HCV. Studies examining hemostasis markers in HIV infection must also assess the contribution of HCV infection.
The Met allele of the catechol-o-methyltransferase (COMT) Val158Met polymorphism is associated with increased cortical dopamine and risk behaviors including illicit drug use and unprotected sex. Therefore, we examined whether or not the distribution of the Val158Met genotype differed between HIV-infected and HIV-uninfected women. We conducted an Armitage-Cochran Test and logistic regression to compare genotype frequencies between 1,848 HIV-infected and 612 HIV-uninfected women from the Women’s Interagency HIV Study (WIHS). The likelihood of carrying one or two Met alleles was greater in HIV-infected women (61%) compared to HIV-uninfected women (54%), Z = −3.60, p < 0.001. We report the novel finding of an association between the Val158Met genotype and HIV serostatus that may be mediated through the impact of dopamine function on propensity for risk-taking.
Herpes zoster (HZ) is common among HIV-infected individuals, but the impacts of highly active antiretroviral therapy (HAART) and HAART adherence on HZ risk have not been well studied.
The effects of HAART and HAART adherence on HZ incidence were evaluated by comparing HIV-infected women on HAART (HAART use group) with the HIV-infected women remaining HAART naïve (HAART naïve group) in the Women’s Interagency HIV Study (WIHS). A 1:1 matching with propensity score for predicting HAART initiation was conducted to balance background covariates at index visit, including HIV disease stage. Kaplan-Meier method was used to compare the risk of HZ development between the matched pairs. Cox proportional hazard models were used to assess the effects of HAART and HAART adherence on HZ incidence.
Through propensity score matching, 389 pairs of participants were identified and they contributed 3,909 person years after matching. The background covariates were similar between the matched pairs at the index visit. The participants had a mean age around 39 years old, and about 61% of them were Black and 22% were Latina. No significant difference in HZ risk was observed between the HAART use group and the HAART naïve group during the first year of follow-up in any analyses. In the univariate analysis, the HAART use group had marginally lower HZ risk (Hazard Ratio (HR): 0.72; 95% Confidence Interval (CI): 0.48-1.1) over the entire follow-up period. However, women with a HAART adherence level of ≥95% had significantly lower HZ risk (HR: 0.54; 95% CI: 0.31, 0.94) compared to the HAART naïve women. The association remained significant after adjusting for quality of life score and acyclovir use, but it attenuated and was no longer statistically significant after adjusting for an intermediate variable, either CD4+ T cell counts or HIV viral load.
Among adult women, we observed a significant preventive effect of long-term HAART use on HZ incidence when a HAART adherence level of ≥95% was attained, and this effect was mediated through reduction of HIV viral load and improvement of CD4+ T cell counts.
HAART; Adherence; Herpes zoster; Incidence; Propensity score
Background. Efavirenz exhibits marked interindividual variability in plasma levels and toxicities. Prior pharmacogenetic studies usually measure exposure via single plasma levels, examine limited numbers of polymorphisms, and rarely model multiple contributors. We analyzed numerous genetic and nongenetic factors impacting short-term and long-term exposure in a large heterogeneous population of human immunodeficiency virus (HIV)–infected women.
Methods. We performed 24-hour intensive pharmacokinetic studies in 111 women receiving efavirenz under actual-use conditions and calculated the area-under-the-concentration-time curve (AUC) to assess short-term exposure; the efavirenz concentration in hair was measured to estimate long-term exposure. A total of 182 single-nucleotide polymorphisms (SNPs) and 45 haplotypes in 9 genes were analyzed in relationship to exposure by use of multivariate models that included a number of nongenetic factors.
Results. Efavirenz AUCs increased 1.26-fold per doubling of the alanine aminotransferase level and 1.23-fold with orange and/or orange juice consumption. Individuals with the CYP2B6 516TT genotype displayed 3.5-fold increases in AUCs and 3.2-fold increases in hair concentrations, compared with individuals with the TG/GG genotype. Another SNP in CYP2B6 (983TT) and a p-glycoprotein haplotype affected AUCs without substantially altering long-term exposure.
Conclusions. This comprehensive pharmacogenomics study showed that individuals with the CYP2B6 516TT genotype displayed >3-fold increases in both short-term and long-term efavirenz exposure, signifying durable effects. Pharmacogenetic testing combined with monitoring of hair levels may improve efavirenz outcomes and reduce toxicities.
Background.Inflammation persists in treated human immunodeficiency virus (HIV) infection and may contribute to an increased risk for non–AIDS-related pathologies. We investigated the correlation of cytokine responses with changes in CD4 T-cell levels and coinfection with hepatitis C virus (HCV) during highly active antiretroviral treatment (HAART).
Methods.A total of 383 participants in the Women's Interagency HIV Study (212 with HIV monoinfection, 56 with HCV monoinfection, and 115 with HIV/HCV coinfection) were studied. HIV-infected women had <1000 HIV RNA copies/mL, 99.7% had >200 CD4 T cells/μL; 98% were receiving HAART at baseline. Changes in CD4 T-cell count between baseline and 2–4 years later were calculated. Peripheral blood mononuclear cells (PBMCs) obtained at baseline were used to measure interleukin 1β (IL-1β), interleukin 6 (IL-6), interleukin 10 (IL-10), interleukin 12 (IL-12), and tumor necrosis factor α (TNF-α) responses to Toll-like receptor (TLR) 3 and TLR4 stimulation.
Results.Undetectable HIV RNA (<80 copies/mL) at baseline and secretion of IL-10 by PBMCs were positively associated with gains in CD4 T-cell counts at follow-up. Inflammatory cytokines (IL-1β, IL-6, IL-12, and TNF-α) were also produced in TLR-stimulated cultures, but only IL-10 was significantly associated with sustained increases in CD4 T-cell levels. This association was significant only in women with HIV monoinfection, indicating that HCV coinfection is an important factor limiting gains in CD4 T-cell counts, possibly by contributing to unbalanced persistent inflammation.
Conclusions.Secreted IL-10 from PBMCs may balance the inflammatory environment of HIV, resulting in CD4 T-cell stability.
Neurotrophins control cell survival. Therefore, we examined whether HIV-1 reduces neurotrophin levels. Serum of HIV-positive individuals exhibited lower concentrations of brain-derived neurotrophic factor (BDNF), but not of other neurotrophins, than HIV negative subjects. In addition, R5 and X4 strains of HIV-1 decreased BDNF expression in T cells. Our results support the hypothesis that reduced levels of BDNF may be a risk factor for T cell apoptosis and for neurological complications associated with HIV-1 infection.
BDNF; NGF; NT-3; HIV-1; drug abuse; Women’s Interagency HIV Study
Highly active antiretroviral therapy (HAART) rapidly suppresses human immunodeficiency virus (HIV) viral replication and reduces circulating viral load, but the long-term effects of HAART on viral load remain unclear.
We evaluated HIV viral load trajectories over 8 years following HAART initiation in the Multicenter AIDS Cohort Study and the Women’s Interagency HIV Study. The study included 157 HIV-infected men and 199 HIV-infected women who were antiretroviral naïve and contributed 1311 and 1837 semiannual person-visits post-HAART, respectively. To account for within-subject correlation and the high proportion of left-censored viral loads, we used a segmental Bernoulli/lognormal random effects model.
Approximately 3 months (0.30 years for men and 0.22 years for women) after HAART initiation, HIV viral loads were optimally suppressed (ie, with very low HIV RNA) for 44% (95% confidence interval = 39%–49%) of men and 43% (38%–47%) of women, whereas the other 56% of men and 57% of women had on average 2.1 (1.5–2.6) and 3.0 (2.7–3.2) log10 copies/mL, respectively.
After 8 years on HAART, 75% of men and 80% of women had optimal suppression, whereas the rest of the men and women had suboptimal suppression with a median HIV RNA of 3.1 and 3.7 log10 copies/mL, respectively.
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.
An intra-individual, cross-sectional comparative study ‘nested’ in the WIHS observational cohort study
Women in the Women’s Interagency HIV Study (WIHS).
Adherence, CD4 count and Viral load.
Our study population was drawn from 2,813 HIV+ participants who contributed 44,588 visits in WIHS from October, 1994 to April, 2009. Among them, there were 1,122 Vitamin C users with 4,954 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.
Vitamin C usage appears to be associated with improved adherence. Future Vitamin C studies should target specific HAART drugs, and prospective clinical outcomes.
To compare neuropsychological scores in women infected with HIV, women infected with both HIV and hepatitis C, and uninfected subjects.
Some, but not all, studies have demonstrated that dual infection with HCV and HIV has worse effects on cognition than infection with HIV alone.
The Women’s Interagency HIV Study (WIHS) is an ongoing prospective study of the natural history of HIV in women where participants are reevaluated every 6 months. In a cross-sectional analysis, we evaluated the effects of active HIV and HCV-infections on scores on symbol-digit test (SDMT), the Stroop interference test, and trails A and B after controlling for age, ethnicity, education, depression, liver disease, and current or past substance abuse.
Data were available for 1338 women – 17.8 % had detectable hepatitis C virus and 67% were HIV-seropositive. In fully adjusted general linear models, HCV viremia was not associated with scores on any of the cognitive tests.
In this large sample of women, active HCV infection was not associated with scores on a small battery of neuropsychological tests.
Hepatitis C; HIV; neurocognition; women
Previous studies of the association of the C17T polymorphism of the mu opiate receptor gene with substance dependence compared cases with substance dependence to controls and usually found no significant association. However, the studies were limited by small sample size - no study had more than 12 subjects with the TT genotype, a genotype that is rare in white and Asian subjects. Moreover, drug use is not dichotomous but follows a spectrum from non-use to modest, intermittent use, to use several times daily. We asked whether the Kreek-McHugh-Schluger-Kellogg (KMSK) scales for alcohol, cocaine, opiates, and tobacco that quantify substance use during the time of a subject's maximal use might be more sensitive measures than dichotomous outcomes. We administered the KMSK scales and completed C17T genotyping on 1009 HIV-infected and 469 HIV-uninfected women in The Women's Interagency HIV Study (WIHS), an ongoing study of HIV in women. Forty-two of 697 African-American, 1 of 182 Hispanic, and none of 161 white women had the TT genotype. KMSK cocaine, alcohol, and tobacco scores were significantly higher in African-American women with the TT genotype (p =0.008, 0.0001, and 0.006 respectively) but opiate scores were not. Ordinal regression models controlling for HIV-serostatus, age, education, and income had odds ratios for the TT genotype for predicting alcohol, tobacco, cocaine, and opiates scores of 2.1 (p = 0.02), 2.4 (p = 0.0004), 2.0 (p = 0.03), and 1.9 (p = 0.07). We conclude that the TT genotype of OPRM1 may increase the risk of substance use and abuse.
C17T polymorphism; HIV; mu opioid receptor gene; quantitative measures; substance abuse; substance dependence
Despite use of HAART, cognitive impairment remains prevalent in HIV. Indeed, a recent study suggested that in certain instances, stopping HAART was associated with improved cognitive function (Robertson et al. 2010). HAART is occasionally associated with cardiovascular pathology and such pathology may be associated with cognitive impairment. To explore these associations, we assessed the relative contributions of cardiovascular variables such as hypertension and atherosclerosis, of HIV and HAART to cognition. Participants were members of the Women’s Interagency HIV Study (WIHS). In analysis of cross-sectional data using general linear models we assessed the relationship between each cardiovascular variable and Stroop interference time and symbol digit modalities test while adjusting for age, HIV, education, depression, and race/ethnicity. We also analyzed the association of summary measures of HAART use with cognition. In multivariate models significance was limited to carotid lesions and carotid intima-medial thickness quintile (CIMT) with Stroop interference time (for carotid lesions, coefficient = 10.5, CI: 3.5 to 17.5, p = 0.003, N = 1130; for CIMT quintile, coefficient = 8.6, CI = 1.7 to 15.4, p = 0.025, N = 1130). Summary measures of protease inhibitor use and other HAART measures were in most cases not associated with cognitive score in multivariate models. We conclude that in the HAART era among middle-aged women with HIV, carotid disease may be significantly associated with some measures of cognitive impairment. In this cross-sectional study, we could detect neither positive nor negative effects of HAART on cognition.
Cognition; HIV; Women; Hypertension; Atherosclerosis; Middle-Aged
Transient HIV infections have been invoked to account for the cellular immune responses detected in highly virus-exposed individuals who have remained HIV seronegative. We tested for very low levels of HIV RNA in 524 seronegative plasma samples from 311 highly exposed women and men from 3 longitudinal HIV cohorts.
2073 transcription mediated amplification (TMA) HIV RNA tests were performed for an average of 3.95 TMA assays per plasma sample. Quadruplicate TMA assays, analyzing a total of 2 ml of plasma, provided an estimated sensitivity of 3.5 HIV RNA copies/ml.
Four samples from subjects who did not sero-convert within the following six months were positive for HIV RNA. For one sample, human polymorphism DNA analysis indicated a sample mix up. Borderline HIV RNA detection signals were detected for the other three positive samples and further replicate TMA testing yielded no positive results. Nested PCR assays (n=254) for HIV proviral DNA on PBMC from these 3 subjects were negative.
Transient viremia was not reproducibly detected in highly HIV exposed seronegative men and women. If transient infections do occur, plasma HIV RNA levels may remain below the detection limits of the sensitive assay used here, be of very short duration, or viral replication may be restricted to mucosal surfaces or their draining lymphoid tissues.
Microglia might play an important role in nociceptive processing and hyperalgesia by neuroinflammatory process. Mineralocorticoid receptor (MR) expressed on microglia might play a central role in the modulation of microglia activity. However the roles of microglia and MR in radicular pain were not well understood. This study sought to investigate whether selective MR antagonist spironolactone develop antinociceptive effects on radicular pain by inhibition neuroinflammation induced by spinal microglia activation.
Radicular pain was produced by chronic compression of the dorsal root ganglia with SURGIFLO™. The expression of microglia, interleukin beta (IL-1β), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), NR1 subunit of the NMDA receptor (t-NR1), and NR1 subunit phosphorylated at Ser896 (p-NR1) were also markedly up-regulated. Intrathecal injection of spironolactone significantly attenuated pain behaviors as well as the expression of microglia, IL-1β, TNF-α, t-NR1, and p-NR1, whereas the production of IL-6 wasn’t affected.
These results suggest that intrathecal delivery spironolactone has therapeutic effects on radicular pain in rats. Decreasing the activation of glial cells, the production of proinflammatory cytokines and down-regulating the expression and phosphorylation of NMDA receptors in the spinal dorsal horn and dorsal root ganglia are the main mechanisms contributing to its beneficial effects.
Human immunodeficiency virus (HIV)–infected individuals frequently have consumed garlic, a popular complementary supplement. Researchers rarely have studied garlic’s association with antiretroviral therapies, however, even though that association is very relevant clinically.
To examine associations of supplemental use of garlic with highly active antiretroviral treatment (HAART) adherence level and HAART effectiveness (HIV viral load and CD4+ cell counts) in HIV-infected women.
The research team carried out a self-controlled, longitudinal study nested within the Women’s Interagency HIV Study (WIHS). The team used a paired study design that allowed participants to serve as their own controls. The team first identified all of the study’s visits in which the participant self-reported the use of a garlic supplement since her last visit (index visit). Then for each index visit, the team identified a matching visit (a control visit) using the following criteria: (a) the visit must be one for the same participant in which that participant reported no garlic supplementation; (b) the visit must immediately precede the index visit (less than 1 year apart); and (c) at the time of the control visit, the participant must have been using antiretroviral therapy identical to that used at the time of the index visit.
Participants were persons using garlic supplementation who already were participants in the WIHS.
The research team used a logistic regression model to examine the association between garlic supplementation and HAART adherence level. The team used a mixed linear model to examine the association of garlic supplementation with HIV viral load and CD4+ cell counts.
From October 1994 to April 2009, 390 HIV-infected women in the WIHS made 1112 visits at which they reported using garlic supplements. Seventy-seven HIV-infected women using HAART met the research team’s selection criteria and contributed 99 pairs of visits for the study. Among the women who used garlic supplements, 22% were 50 years and older; 58% were black and non-Hispanic; and 23% had less than a high-school education. Neither use of garlic supplementation nor reasons for using garlic supplements were significantly associated with the HAART adherence level, HIV viral load, or CD4+ cell counts; however, “use garlic as needed,” a potential marker of a disease state, was significantly associated with higher viral load (P = .0003).
Short-term garlic supplementation did not impact HAART adherence level, HIV viral load, and CD4+ cell counts.
Linear regression with a left-censored independent variable X due to limit of detection (LOD) was recently considered by 2 groups of researchers: Richardson and Ciampi, and Schisterman and colleagues.
Both groups obtained consistent estimators for the regression slopes by replacing left-censored X with a constant, that is, the expectation of X given X below LOD E(X|X
Schisterman and colleagues argued that their approach would be a better choice because the sample mean of X given X above LOD is available, whereas E(X|X
Recommendations are given based on theoretical and simulation results. These recommendations are illustrated with 1 case study.
Serosorting, the practice of selectively engaging in unprotected sex with partners of the same HIV serostatus, has been proposed as a strategy for reducing HIV transmission risk among men who have sex with men (MSM). However, there is a paucity of scientific evidence regarding whether women engage in serosorting. We analyzed longitudinal data on women’s sexual behavior with male partners collected in the Women’s Interagency HIV Study from 2001 to 2005. Serosorting was defined as an increasing trend of unprotected anal or vaginal sex (UAVI) within seroconcordant partnerships over time, more frequent UAVI within seroconcordant partnerships compared to non-concordant partnerships, or having UAVI only with seroconcordant partners. Repeated measures Poisson regression models were used to examine the associations between serostatus partnerships and UAVI among HIV-infected and HIV-uninfected women. The study sample consisted of 1,602 HIV-infected and 664 HIV-uninfected women. Over the follow-up period, the frequency of seroconcordant partnerships increased for HIV-uninfected women but the prevalence of UAVI within seroconcordant partnerships remained stable. UAVI was reported more frequently within HIV seroconcordant partnerships than among serodiscordant or unknown serostatus partnerships, regardless of the participant’s HIV status or types of partners. Among women with both HIV-infected and HIV-uninfected partners, 41% (63 HIV-infected and 9 HIV-uninfected) were having UAVI only with seroconcordant partners. Our analyses suggest that serosorting is occurring among both HIV-infected and HIV-uninfected women in this cohort.
HIV; Unprotected sex; Serosorting; Risk reduction; Condom use
Two of the most pressing public health challenges in the United States are treating human immunodeficiency virus (HIV) infection and illegal substance use. High rates of complementary and alternative medicine (CAM) use have been reported by individuals who suffer from both of these diseases. The goal of this study was to examine the relationship between CAM use and illegal substance use in a cohort of women with HIV or at risk for HIV disease. Based on previous research, it was hypothesized that CAM use may decrease substance use.
This was a longitudinal cohort study.
The subjects comprised Women in the Women's Interagency HIV Study.
The role of CAM use in illegal substance use was examined. Due to the hierarchical structure of the dataset, logistic regression analysis adjusting for repeated measurements (generalized estimating equation model) was carried out to assess associations of CAM use and illicit drug use.
There were 2176 women included in the analysis. After excluding for marijuana use, CAM use was associated with less drug use (odds ratio 0.82; 95% confidence interval: 0.73, 0.90).
The results supported our hypothesis that CAM users are more health conscious and thus less likely to use illicit drugs. Future studies should target both specific drugs and CAM modalities to help finalize this association.
To determine prevalence and predictors of complementary and alternative medicine (CAM) use disclosure to health care providers and whether CAM use disclosure is associated with highly active antiretroviral therapy (HAART) adherence among HIV-infected women, we analyzed longitudinal data collected between October 1994 and March 2002 from HIV-infected CAM-using women enrolled in the Women's Interagency HIV Study. Repeated measures Poisson regression models were constructed to evaluate associations of selected predictors with CAM use disclosure and association between CAM use disclosure and HAART adherence. A total of 1377 HIV-infected women reported CAM use during study follow-up and contributed a total of 4689 CAM-using person visits. The overall prevalence of CAM use disclosure to health care providers was 36% across study visits. Women over 45 years old, with a college education, or with health insurance coverage were more likely to disclose their CAM use to health care providers, whereas women identified as non-Hispanic Black or other ethnicities were less likely to communicate their CAM usage. More health care provider visits, more CAM domains used, and higher health care satisfaction scores had significant relationships with increased levels of CAM use disclosure. Restricting analysis to use of herbal or nonherbal medications only, similar results were obtained. Compared to other CAM domains, mind–body practice had the lowest prevalence of CAM use disclosure. Additionally, CAM use disclosure was significantly associated with higher HAART adherence. From this study, we showed that a high percentage of HIV-infected women did not discuss their CAM use with health care providers. Interventions targeted towards both physicians and patients may enhance communication of CAM use, avoid potential adverse events and drug interactions, and enhance HAART adherence.
The search for disease biomarkers within human peripheral fluids has become a favorable approach to preventative therapeutics throughout the past few years. The comparison of normal versus disease states can identify an overexpression or a suppression of critical proteins where illness has directly altered a patient's cellular homeostasis. In particular, the analysis of HIV-1 infected serum is an attractive medium with which to identify altered protein expression due to the ease and non-invasive methods of collecting samples as well as the corresponding insight into the in vivo interaction of the virus with infected cells/tissue. The utilization of proteomic techniques to globally identify differentially expressed serum proteins in response to HIV-1 infection is a significant undertaking that is complicated due to the innate protein profile of human serum.
Here, the depletion of 12 of the most abundant serum proteins, followed by two-dimensional gel electrophoresis coupled with identification of these proteins using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, has allowed for the identification of differentially expressed, low abundant serum proteins. We have analyzed and compared serum samples from HIV-1 infected subjects who are being treated using highly active antiretroviral therapy (HAART) to those who are latently infected but have not progressed to AIDS despite the absence of treatment, i.e. long term non-progressors (LTNPs). Here we have identified unique serum proteins that are differentially expressed in LTNP HIV-1 patients and may contribute to the ability of these patients to combat HIV-1 infection in the absence of HAART. We focused on the cdk4/6 cell cycle inhibitor p16INK4A and found that the treatment of HIV-1 latently infected cell lines with p16INK4A decreases viral production despite it not being expressed endogenously in these cells.
Identification of these unique proteins may serve as an indication of altered viral states in response to infection as well as a natural phenotypic variability in response to HIV-1 infection in a given population.
To determine prevalence and predictors of complementary and alternative medicine (CAM) use disclosure to health care providers and whether CAM use disclosure is associated with highly active antiretroviral therapy (HAART) adherence among HIV-infected women, we analyzed longitudinal data collected between October 1994 and March 2002 from HIV-infected CAM-using women enrolled in the Women’s Interagency HIV Study. Repeated measures Poisson regression models were constructed to evaluate associations of selected predictors with CAM use disclosure and association between CAM use disclosure and HAART adherence. A total of 1377 HIV-infected women reported CAM use during study follow-up and contributed a total of 4689 CAM-using person visits. The overall prevalence of CAM use disclosure to health care providers was 36% across study visits. Women over 45 years old, with a college education, or with health insurance coverage were more likely to disclose their CAM use to health care providers, whereas women identified as non-Hispanic Black or other ethnicities were less likely to communicate their CAM usage. More health care provider visits, more CAM domains used, and higher health care satisfaction scores had significant relationships with increased levels of CAM use disclosure. Restricting analysis to use of herbal or nonherbal medications only, similar results were obtained. Compared to other CAM domains, mind–body practice had the lowest prevalence of CAM use disclosure. Additionally, CAM use disclosure was significantly associated with higher HAART adherence. From this study, we showed that a high percentage of HIV-infected women did not discuss their CAM use with health care providers. Interventions targeted towards both physicians and patients may enhance communication of CAM use, avoid potential adverse events and drug interactions, and enhance HAART adherence.
Cigarette smoking is an important risk factor for adverse health events in HIV-infected populations. While recent US population-wide surveys report annual sustained smoking cessation rates of 3.4–8.5%, prospective data are lacking on cessation rates for HIV-infected smokers.
To determine the sustained tobacco cessation rate and predictors of cessation among women with or at risk for HIV infection.
Prospective cohort study.
A total of 747 women (537 HIV-infected and 210 HIV-uninfected) who reported smoking at enrollment (1994–1995) in the Women’s Interagency HIV Study (WIHS) and remained in follow-up after 10 years. The participants were mostly minority (61% non-Hispanic Blacks and 22% Hispanics) and low income (68% with reported annual incomes of less than or equal to $12,000).
MEASUREMENTS AND MAIN RESULTS
The primary outcome was defined as greater than 12 months continuous cessation at year 10. Multivariate logistic regression was used to identify independent baseline predictors of subsequent tobacco cessation. A total of 121 (16%) women reported tobacco cessation at year 10 (annual sustained cessation rate of 1.8%, 95% CI 1.6–2.1%). Annual sustained cessation rates were 1.8% among both HIV-positive and HIV-negative women (p = 0.82). In multivariate analysis, the odds of tobacco cessation were significantly higher in women with more years of education (p trend = 0.02) and of Hispanic origin (OR = 1.87, 95% CI = 1.4–2.9) compared to Black women. Cessation was significantly lower in current or former illicit drug users (OR = 0.42 95% CI = 0.24–0.74 and OR = 0.65, 95% CI = 0.49–0.86, respectively, p trend = 0.03) and women reporting a higher number of cigarettes per day at baseline (p trend < 0.001).
HIV-infected and at-risk women in this cohort have lower smoking cessation rates than the general population. Given the high prevalence of smoking, the high risk of adverse health events from smoking, and low rates of cessation, it is imperative that we increase efforts and overcome barriers to help these women quit smoking.
smoking cessation; HIV/AIDS; clinical epidemiology; vulnerable populations
To assess whether complementary and alternative medicine (CAM) use is associated with the timing of highly active antiretroviral therapy (HAART) initiation among human immunodeficiency virus (HIV)–infected participants of the Women’s Interagency HIV Study.
Prospective cohort study between January 1996 and March 2002. Differences in the cumulative incidence of HAART initiation were compared between CAM users and non–CAM users using a logrank test. Cox regression model was used to assess associations of CAM exposures with time to HAART initiation.
Main Outcome and Exposures
Study outcome was time from January 1996 to initiation of HAART. Primary exposure was use of any CAM modality before January 1996, and secondary exposures included the number and type of CAM modalities used (ingestible CAM medication, body practice, or spiritual healing) during the same period.
One thousand thirty-four HIV-infected women contributed a total of 4987 person-visits during follow-up. At any time point, the cumulative incidence of HAART initiation among CAM users was higher than that among non–CAM users. After adjustment for potential confounders, those reporting CAM use were 1.34 times (95% confidence interval: 1.09, 1.64) more likely to initiate HAART than non–CAM users.
Female CAM users initiated HAART regimens earlier than non–CAM users. Initiation of HAART is an important clinical marker, but more research is needed to elucidate the role specific CAM modalities play in HIV disease progression.
Results 1-25 (26)
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