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1.  Does HIV infection promote early kidney injury in women? 
Antiviral therapy  2013;19(1):79-87.
Background
In HIV-infected women, urine concentrations of novel tubulointerstitial injury markers, interleukin-18 (IL-18) and kidney injury marker-1 (KIM-1) are associated with kidney function decline and all-cause mortality. We hypothesized that HIV-infected individuals with preserved kidney filtration function would have more extensive kidney injury, as determined by urine injury markers, compared to the uninfected controls, and that risk factors for tubulointerstitial injury would differ from risk factors for albuminuria.
Methods
In this cross-sectional study, we compared urine concentrations of IL-18, KIM-1, and ACR in 908 HIV-infected and 289 HIV-uninfected women enrolled in the Women’s Interagency HIV Study, utilizing stored urine specimens from visits between 1999 and 2000.
Results
After multivariate-adjusted linear regression analysis, mean urine concentrations were higher in HIV-infected individuals by 38% for IL-18 (p<0.0001), 12% for KIM-1 (p=0.081), and 47% for ACR (p<0.0001). Higher HIV RNA level (15% per 10-fold increase, p<0.0001), lower CD4 count (8% per doubling, p=0.0025), HCV infection (30%, p=0.00018), and lower HDL (5% per 10 mg/dL, p=0.0024) were each associated with higher IL-18 concentrations. In contrast, hypertension (81%, p<0.0001) and diabetes (47%, p=0.018) were among the strongest predictors of higher ACR, though HIV RNA level (15% per 10-fold increase, p=0.0004) was also associated with higher ACR.
Conclusions
HIV-infected women had more extensive tubulointerstitial and glomerular injury than uninfected women, but the associated factors differed among the urine biomarkers. Combinations of urinary biomarkers should be investigated to further characterize early kidney injury in HIV-infected women.
doi:10.3851/IMP2677
PMCID: PMC3933452  PMID: 23970313
2.  Association of HIV clinical disease progression with profiles of early immune activation: results from a cluster analysis approach 
AIDS (London, England)  2013;27(9):1473-1481.
Objective
CD4 and CD8 T-cell activation are independent predictors of AIDS. The complete activation profile of both T-cell subtypes and their predictive value for AIDS risk is largely unknown.
Design
A total of 564 AIDS-free women in the Women's Interagency HIV Study were followed over 6.1 years (median) after T-cell activation assessment. A cluster analysis approach was used to evaluate the concurrent activation patterns of CD4 and CD8 T cells at the beginning of follow-up in relation to AIDS progression.
Methods
Percentages of CD4 and CD8 T cells with HLA-DR± and CD38± were assessed by flowcytometry. Eight immunologic variables (four on each CD4+ and CD8+: DR± and CD38±) were assessed to yield a 4-cluster solution on samples obtained before clinical endpoints. Proportional hazards survival regression estimated relative risks for AIDS progression by cluster membership.
Results
Compared with the other three clusters, outstanding activation features of each distinct cluster of women were: Cluster 1: higher CD8+CD38– DR– (average = 41% of total CD8 T-cell pool), CD4+CD38– DR– (average = 53% of total CD4 T-cell pool), and CD8+CD38– DR+ (28%); Cluster 2: higher CD8+CD38+DR– (44%) and CD4+CD38+DR– (58%); Cluster 3: higher CD8+CD38+DR+ (49%) and CD4+ CD38+DR– (48%); Cluster 4: higher CD8+CD38+DR+ (49%), CD4+CD38+DR+ (36%) and CD4+CD38– DR+ (19%). Compared with cluster 1, women in cluster 4 had two-fold increased risk of AIDS progression (Hazard ratio = 2.13; 95% confidence interval = 1.30–3.50) adjusted for CD4 cell count, HIV RNA, and other confounders.
Conclusion
A profile including CD4 and CD8 T-cell activation provided insight into HIV pathogenesis indicating concurrent hyperactivation of CD4 and CD8 T cells is associated with AIDS progression.
doi:10.1097/QAD.0b013e3283601bad
PMCID: PMC3949252  PMID: 23945505
AIDS; cluster analysis; immune activation
3.  Decreased limb muscle and increased central adiposity are associated with 5-year all-cause mortality in HIV infection 
AIDS (London, England)  2011;25(11):1405-1414.
Background
Unintentional loss of weight and muscle due to aging and disease has been associated with increased mortality. Wasting and weight loss occur in HIV infection even in the modern era of effective antiretroviral therapy.
Methods
We determined the association of MRI-measured regional and total skeletal muscle and adipose tissue with 5-year, all-cause mortality in 922 HIV-infected persons in the study of Fat Redistribution and Metabolic Change in HIV Infection (FRAM).
Results
After 5 years of follow-up, HIV-infected participants with arm skeletal muscle in the lowest tertile had a mortality rate of 23%, compared with 11 and 8% for those in the middle and highest tertiles. After multivariable adjustment for demographics, cardiovascular risk factors, HIV-related factors, inflammatory markers, and renal disease, we found that lower arm skeletal muscle, lower leg skeletal muscle and higher visceral adipose tissue (VAT) were each independently associated with increased mortality. Those in the lowest tertile of arm or leg skeletal muscle had higher odds of death [arm: odds ratio (OR)=2.0, 95% confidence interval (CI) 0.96–4.0; leg: OR=2.4, 95% CI 1.2–4.8] compared with the highest respective tertiles. Those in the highest tertile of VAT had 2.1-fold higher odds of death (95% CI 1.1–4.0) compared with the lowest VAT tertile.
Conclusion
Lower muscle mass and central adiposity appear to be important risk factors for mortality in HIV-infected individuals. A substantial proportion of this risk may be unrecognized because of the current reliance on body mass index in clinical practice.
doi:10.1097/QAD.0b013e32834884e6
PMCID: PMC3933309  PMID: 21572308
body composition; cachexia; fat redistribution; HIV infection; lipoatrophy; lipodystrophy; mortality; sarcopenia
4.  Comparisons of creatinine and cystatin C for detection of kidney disease and prediction of all-cause mortality in HIV-infected women 
AIDS (London, England)  2013;27(14):2291-2299.
Background
Cystatin C could improve chronic kidney disease (CKD) classification in HIV-infected women relative to serum creatinine.
Design
Retrospective cohort analysis.
Methods
Cystatin C and creatinine were measured from specimens taken and stored during the 1999–2000 exam among 908 HIV-infected participants in the Women’s Interagency HIV study (WIHS). Mean follow-up was 10.2 years. The associations of baseline categories (<60, 60–90, and >90 mL/min/1.73m2) of creatinine eGFR (eGFRcr), cystatin C eGFR (eGFRcys), and combined creatinine-cystatin C eGFR (eGFRcr-cys) with all-cause mortality were evaluated using multivariable Cox regression. The net reclassification index (NRI) was calculated to evaluate the effect of cystatin C on reclassification of CKD staging.
Results
The prevalence of CKD (eGFR<60) at baseline was higher with eGFRcys (10.1%) compared to eGFRcr (6.7%, p=0.0006) and eGFRcr-cys (7.5%, p=0.011). Relative to eGFR >90, the eGFR <60 category by eGFRcys (Adjusted HR: 2.56; 95% CI: 1.63, 4.02), eGFRcr-cys (3.11; 1.94–5.00), and eGFRcr (2.34; 1.44–3.79) was associated with increased mortality risk. However, the eGFR 60–90 category was associated with increased mortality risk for eGFRcys (1.80; 1.28–2.53) and eGFRcr-cys (1.91; 1.38–2.66) but not eGFRcr (1.20; 0.85–1.67). The overall NRI for mortality was 26% when reclassifying from eGFRcr to eGFRcys (p<0.001) and was 20% when reclassifying from eGFRcr to eGFRcr-cys (p<0.001).
Conclusion
Cystatin C detected a higher prevalence of CKD relative to creatinine and improves CKD staging relative to creatinine by reclassifying individuals at the highest mortality risk to lower eGFR categories.
doi:10.1097/QAD.0b013e328362e874
PMCID: PMC3919542  PMID: 23669156
Creatinine; Cystatin C; Glomerular Filtration Rate; HIV; Mortality; Kidney; Women
5.  Vitamin D insufficiency may impair CD4 recovery among Women’s Interagency HIV Study participants with advanced disease on HAART 
AIDS (London, England)  2013;27(4):573-578.
Background
Recent studies in HIV-infected men report an association between low vitamin D (25OH-D) and CD4 recovery on HAART. We sought to test this relationship in the Women’s Interagency HIV Study (WIHS).
Methods
We examined 204 HIV-infected women with advanced disease, who started HAART after enrollment in the WIHS. We measured vitamin D (25OH-D) levels about 6 months prior to HAART initiation. The relationship between CD4 recovery (defined as increases of ≥50, 100, and 200 cells at 6, 12, and 24 months) and exposure variables was examined using logistic regression models at 6, 12 and 24 months post-HAART initiation in unadjusted and adjusted analyses, and using multivariable longitudinal Generalized Estimating Equations (GEE). Vitamin D insufficiency was defined as 25OH-D levels at least 30 ng/ml.
Results
The majority were non-Hispanic black (60%) and had insufficient vitamin D levels (89%). In adjusted analyses, at 24 months after HAART, insufficient vitamin D level (OR 0.20, 95% CI 0.05–0.83) was associated with decreased odds of CD4 recovery. The undetectable viral load (OR 11.38, 95% CI 4.31–30.05) was associated with CD4 recovery. The multivariable GEE model found that average immune reconstitution attenuated significantly (P <0.01) over time among those with insufficient vitamin D levels compared with those with sufficient vitamin D levels.
Conclusion
Vitamin D insufficiency is associated with diminished late CD4 recovery after HAART initiation among US women living with advanced HIV. The mechanism of this association on late CD4 recovery may be late vitamin D-associated production of naive CD4 cells during immune reconstitution.
doi:10.1097/QAD.0b013e32835b9ba1
PMCID: PMC3902982  PMID: 23095316
antiretroviral therapy; HIV; immune reconstitution; vitamin D; women
6.  The association between diet and physical activity on insulin resistance in the Women’s Interagency HIV Study 
Objectives
To evaluate the association of diet and physical activity with insulin resistance (IR) in HIV-infected and uninfected women.
Methods
Cross sectional analyses of summary dietary measures and physical activity intensity scores obtained from women enrolled in the San Francisco (n=113) and Chicago (n=65) Women’s Interagency HIV Study (WIHS) sites. IR was estimated using the homeostasis model assessment (HOMA-IR). Stepwise regression models assessed the association of diet and physical activity with HOMA-IR after adjustment for demographic, behavioral, and clinical factors.
Results
Compared to HIV-uninfected women, HIV-infected women were older and more likely to have health insurance. In multivariable analysis including all women, being from San Francisco (p=0.005), having a higher mean body mass index (BMI, p<0.001), and a higher percent kilocalories from sweets (p=0.025) were associated with greater HOMA-IR; heavy intensity physical activity (p=0.006) and annual household income <$36,000 (p=0.002) was associated with a lower HOMA-IR. In analysis limited to HIV-infected women, having a higher BMI (p<0.001) and a history of protease inhibitor use (0.002) were significantly associated with higher HOMA-IR; heavy intensity activity (p=0.06) was marginally associated with lower HOMA-IR and being menopausal (p=0.05) was marginally associated with higher HOMA-IR.
Conclusions
Among urban women with or at risk for HIV-infection, heavy intensity physical activity was associated with lower HOMA-IR while higher percent kilocalories from sweets were associated with higher HOMA-IR. Given the overall health benefits of physical activity and a diet low on sugar, these behaviors should be encouraged whenever possible.
doi:10.1097/QAI.0b013e318275d6a4
PMCID: PMC3529765  PMID: 23075914
HIV; HOMA-IR; insulin resistance; macronutrients; physical activity; women
7.  Urinary Markers of Kidney Injury and Kidney Function Decline in HIV-Infected Women 
Objective
HIV-infected persons have substantially higher risk of kidney failure than persons without HIV, but serum creatinine levels are insensitive for detecting declining kidney function. We hypothesized that urine markers of kidney injury would be associated with declining kidney function among HIV-infected women.
Methods
In the Women's Interagency HIV Study (WIHS), we measured concentrations of albumin-to-creatinine ratio (ACR), interleukin-18 (IL-18), kidney injury marker-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) from stored urine among 908 HIV-infected and 289 uninfected participants. Primary analyses used cystatin C based estimated glomerular filtration rate (CKD-EPI eGFRcys) as the outcome, measured at baseline and two follow-up visits over eight years; secondary analyses used creatinine (CKD-EPI eGFRcr). Each urine biomarker was categorized into tertiles, and kidney decline was modeled with both continuous and dichotomized outcomes.
Results
Compared with the lowest tertiles, the highest tertiles of ACR (−0.15ml/min/1.73m2, p<0.0001), IL-18 (−0.09ml/min/1.73m2, p<0.0001) and KIM-1 (−0.06ml/min/1.73m2, p<0.001) were independently associated with faster eGFRcys decline after multivariate adjustment including all three biomarkers among HIV-infected women. Among these biomarkers, only IL-18 was associated with each dichotomized eGFRcys outcome: ≥3% (Relative Risk 1.40; 95%CI 1.04-1.89); ≥5% (1.88; 1.30-2.71); and ≥10% (2.16; 1.20-3.88) for the highest versus lowest tertile. In alternative models using eGFRcr, the high tertile of KIM-1 had independent associations with 5% (1.71; 1.25-2.33) and 10% (1.78; 1.07-2.96) decline, and the high IL-18 tertile with 10% decline (1.97; 1.00-3.87).
Conclusions
Among HIV-infected women in the WIHS cohort, novel urine markers of kidney injury detect risk for subsequent declines in kidney function.
doi:10.1097/QAI.0b013e3182737706
PMCID: PMC3509242  PMID: 23023103
HIV; KIM-1; NGAL; IL-18; albumin-to-creatinine ratio; cystatin C; kidney injury
8.  Association of subclinical atherosclerosis with lipid levels amongst antiretroviral-treated and untreated HIV-infected women in the Women’s Interagency HIV Study 
Atherosclerosis  2012;225(2):408-411.
Objective
We examined serum lipids in association with carotid artery intima-media thickness (CIMT) in HIV-infected and HIV-uninfected women.
Methods
In 2003–4, among 1827 Women’s Interagency HIV Study participants, we measured CIMT and lipids (high-density lipoprotein cholesterol [HDL-c], low-density lipoprotein cholesterol [LDL-c], total cholesterol [TC], non-HDL-c). A subset of 520 treated HIV-infected women had pre-1997 lipid measures. We used multivariable linear regression to examine associations between lipids and CIMT.
Results
In HIV-uninfected women, higher TC, LDL-c and non-HDL-c were associated with increased CIMT. Among HIV-infected women, associations of lipids with CIMT were observed in treated but not untreated women. Among the HIV-infected women treated in 2003–4, CIMT was associated both with lipids measured a decade earlier in infection, and with late lipid measurements.
Conclusion
Among HIV-infected women, hyperlipidemia is most strongly associated with subclinical atherosclerosis in treated women. Among treated women, the association appeared strongest early in the disease course.
doi:10.1016/j.atherosclerosis.2012.09.035
PMCID: PMC3696584  PMID: 23089369
cardiovascular diseases; carotid arteries; HAART; HIV; lipids
9.  Association of Regional Body Composition with Bone Mineral Density in HIV-infected and Uninfected Women: Women's Interagency HIV Study 
Objective
To understand how regional body composition affects bone mineral density (BMD) in HIV-infected and uninfected women.
Methods
Dual energy X-ray absorptiometry was used to measure regional lean and fat mass and BMD at lumbar spine (LS), total hip (TH), and femoral neck (FN) in 318 HIV-infected and 122 HIV-uninfected Women's Interagency HIV Study participants at baseline and 2 and 5 years later. Total lean and fat mass were measured using bioimpedance analysis. Multivariate marginal linear regression models assessed the association of HIV status and body composition on BMD change.
Results
Compared to HIV-uninfected women, HIV-infected women were older (44 vs. 37 yrs), more likely to be HCV-infected (32% vs. 14%), and post-menopausal (26% vs. 3%), and had lower baseline total fat mass, trunk fat and leg fat. In multivariate models, increased total lean mass was independently associated with increased BMD at LS, TH and FN and total fat mass was associated with increased BMD at TH and FN (all p<0.05). When total fat was replaced in multivariate models with trunk fat and leg fat, increased trunk fat (and not leg fat) was associated with increased TH and FN BMD (p<0.001).
Conclusions
Total fat and lean mass are strong, independent predictors of TH and FN BMD, and lean mass was associated with greater LS BMD. Regardless of HIV status, greater trunk fat (and not leg fat) was associated with increased TH and FN BMD, suggesting that weight bearing fat may be a more important predictor of BMD in the hip.
doi:10.1097/QAI.0b013e31826cba6c
PMCID: PMC3494812  PMID: 22895436
Body composition; fat redistribution; bone mineral density; HIV; women
10.  Association of HIV infection with Incident Diabetes Mellitus: Impact of using Hemoglobin A1C as a Criterion for Diabetes 
Background
Data regarding the association between HIV and DM are conflicting, with little known regarding the impact of including hemoglobin A1C (A1C) as a criterion for DM.
Methods
Pooled logistic regression was used to quantify the association between HIV and DM in 1501 HIV-infected and 550 HIV-uninfected participants from the Women’s Interagency HIV Study. Incident DM was defined using three DM definitions: (I) fasting glucose (FG) ≥126mg/dl, anti-DM medication, or reporting DM diagnosis (with confirmation by FG≥126mg/dl or anti-DM medication); (II) confirmation with a second FG≥126mg/dl; and (III) addition of A1C≥6.5% confirmed by FG≥126mg/dl or anti-DM medication.
Results
DM incidence per 100 person-years was 2.44, 1.55, and 1.70 for HIV-infected women; 1.89, 0.85, and 1.13 for HIV-uninfected women, using definition I, II, and III, respectively. After adjustment for traditional DM risk factors, HIV infection was associated with 1.23, 1.90, and 1.38-fold higher risk of incident DM, respectively; the association reached statistical significance only when confirmation with a second FG≥126mg/dl was required. Older age, obesity, and a family history of DM were each consistently and strongly associated with increased DM risk.
Conclusions
HIV infection is consistently associated with greater risk of DM. Inclusion of an elevated A1C to define DM increases the accuracy of the diagnosis and only slightly attenuates the magnitude of the association otherwise observed between HIV and DM. By contrast, a DM diagnosis made without any confirmatory criteria for FG ≥126mg/dl overestimates the incidence, while also underestimating the effects of HIV on DM risk, and should be avoided.
doi:10.1097/QAI.0b013e31826bfc32
PMCID: PMC3480977  PMID: 22878421
Diabetes mellitus; HIV; Women; Hemoglobin A1C
11.  The Parametric G-Formula to Estimate the Effect of Highly Active Antiretroviral Therapy on Incident AIDS or Death 
Statistics in medicine  2012;31(18):2000-2009.
SUMMARY
The parametric g-formula can be used to contrast the distribution of potential outcomes under arbitrary treatment regimes. Like g-estimation of structural nested models and inverse probability weighting of marginal structural models, the parametric g-formula can appropriately adjust for measured time-varying confounders that are affected by prior treatment. However, there have been few implementations of the parametric g-formula to date. Here, we apply the parametric g-formula to assess the impact of highly active antiretroviral therapy on time to AIDS or death in two US-based HIV cohorts including 1,498 participants. These participants contributed approximately 7,300 person-years of follow-up of which 49% was exposed to HAART and 382 events occurred; 259 participants were censored due to drop out. Using the parametric g-formula, we estimated that antiretroviral therapy substantially reduces the hazard of AIDS or death (HR=0.55; 95% confidence limits [CL]: 0.42, 0.71). This estimate was similar to one previously reported using a marginal structural model 0.54 (95% CL: 0.38, 0.78). The 6.5-year difference in risk of AIDS or death was 13% (95% CL: 8%, 18%). Results were robust to assumptions about temporal ordering, and extent of history modeled, for time-varying covariates. The parametric g-formula is a viable alternative to inverse probability weighting of marginal structural models and g-estimation of structural nested models for the analysis of complex longitudinal data.
doi:10.1002/sim.5316
PMCID: PMC3641816  PMID: 22495733
Cohort study; Confounding; g-formula; HIV/AIDS; Monte Carlo methods
12.  Potential cardiovascular disease risk markers among HIV-infected women initiating antiretroviral treatment 
Background
Inflammation and hemostasis perturbation may be involved in vascular complications of HIV infection. We examined atherogenic biomarkers and subclinical atherosclerosis in HIV-infected adults before and after beginning highly-active antiretroviral therapy (HAART).
Methods
In the Women's Interagency HIV Study (WIHS), 127 HIV-infected women studied pre- and post-HAART were matched to HIV-uninfected controls. Six semi-annual measurements of soluble CD14, tumor necrosis factor (TNF)-alpha, soluble interleukin (IL)-2 receptor, IL-6, IL-10, monocyte chemoattractant protein (MCP)-1, D-dimer, and fibrinogen were obtained. Carotid artery intima-media thickness (CIMT) was measured by B-mode ultrasound.
Results
Relative to HIV-uninfected controls, HAART-naïve HIV-infected women had elevated levels of soluble CD14 (1945 vs 1662 ng/mL, Wilcoxon signed rank P<0.0001), TNF-alpha (6.3 vs 3.4 pg/mL, P<0.0001), soluble IL-2 receptor (1587 vs 949 pg/mL, P<0.0001), IL-10 (3.3 vs 1.9 pg/mL, P<0.0001), MCP-1 (190 vs 163 pg/mL, P<0.0001) and D-dimer (0.43 vs 0.31 µg/mL, P<0.01). Elevated biomarker levels declined after HAART. While most biomarkers normalized to HIV-uninfected levels, in women on effective HAART, TNF-alpha levels remained elevated compared to HIV-uninfected women (+0.8 pg/mL, P=0.0002). Higher post-HAART levels of soluble IL-2 receptor (P=0.02), IL-6 (P=0.05), and D-dimer (P=0.03) were associated with increased CIMT.
Conclusions
Untreated HIV infection is associated with abnormal hemostasis (e.g., D-dimer), and pro-atherogenic (e.g., TNF-alpha) and anti-atherogenic (e.g., IL-10) inflammatory markers. HAART reduces most inflammatory mediators to HIV-uninfected levels. Increased inflammation and hemostasis are associated with subclinical atherosclerosis in recently treated women. These findings have potential implications for long-term risk of cardiovascular disease in HIV-infected patients, even with effective therapy.
doi:10.1097/QAI.0b013e31825b03be
PMCID: PMC3400505  PMID: 22592585
antiretroviral therapy; cardiovascular diseases; cytokines; hemostasis; HIV; inflammation
13.  Assessing mortality in women with hepatitis C virus and HIV using indirect markers of fibrosis 
AIDS (London, England)  2012;26(5):599-607.
Objective
Co-infection with hepatitis C virus (HCV) is a major cause of morbidity and mortality in HIV-infected individuals. However, predictors of mortality are poorly defined and most studies have focused predominantly on co-infection in men. We evaluated whether two indirect markers of hepatic fibrosis, aspartate aminotransferase-to-platelet ratio index (APRI) and FIB-4 scores, were predictive of mortality in a well defined longitudinal cohort of HCV/HIV-co-infected women on HAART.
Methods
HCV/HIV-co-infected women on antiretroviral therapy enrolled in Women’s Interagency HIV Study (WIHS), a National Institutes of Health-funded prospective, multicenter, cohort study of women with and at risk for HIV infection were included. Using Cox regression analysis, associations between APRI and FIB-4 with all-cause mortality were assessed.
Results
Four hundred and fifty HCV/HIV-co-infected women, of whom 191 women died, had a median follow-up of 6.6 years and 5739 WIHS visits. Compared with women with low APRI or FIB-4 levels, severe fibrosis was significantly associated with an increased risk of all-cause mortality {APRI: hazard ratio 2.78 [95% confidence interval (CI) 1.87, 4.12]; FIB-4: hazard ratio 2.58 (95% CI 1.68, 3.95)}. Crude death rates per 1000 patient-years increased with increasing liver fibrosis: 34.8 for mild, 51.3 for moderate and 167.9 for severe fibrosis as measured by FIB-4. Importantly, both APRI and FIB-4 increased during the 5 years prior to death for all women: the slope of increase was greater for women dying a liver-related death compared with nonliver-related death.
Conclusion
Both APRI and FIB-4 are independently associated with all-cause mortality in HCV/HIV-co-infected women and may have clinical prognostic utility among women with HIV and HCV.
doi:10.1097/QAD.0b013e32834fa121
PMCID: PMC3698040  PMID: 22156972
fibrosis markers; hepatitis C virus; HIV; longitudinal study; mortality
14.  Insulin Resistance and Cognition Among HIV-Infected and HIV-Uninfected Adult Women: The Women's Interagency HIV Study 
Abstract
Cognitive impairment remains prevalent in the era of combination antiretroviral therapy (cART) and may be partially due to comorbidities. We postulated that insulin resistance (IR) is negatively associated with cognitive performance. We completed a cross-sectional analysis among 1547 (1201 HIV+) women enrolled in the Women's Interagency HIV Study (WIHS). We evaluated the association of IR with cognitive measures among all WIHS women with concurrent fasting bloods and cognitive testing [Trails A, Trails B, and Symbol Digit Modalities Test (SDMT)] using multiple linear regression models. A smaller subgroup also completed the Stroop test (n=1036). IR was estimated using the Homeostasis Model Assessment (HOMA). Higher HOMA was associated with poorer performance on the SDMT, Stroop Color-Naming (SCN) trial, and Stroop interference trial, but remained statistically significant only for the SCN in models adjusting for important factors [β=3.78 s (95% CI: 0.48–7.08), p=0.025, for highest vs. lowest quartile of HOMA]. HIV status did not appear to substantially impact the relationship of HOMA with SCN. There was a small but statistically significant association of HOMA and reduced neuropsychological performance on the SCN test in this cohort of women.
doi:10.1089/aid.2011.0159
PMCID: PMC3332367  PMID: 21878059
15.  Marginal Structural Models for Case-Cohort Study Designs to Estimate the Association of Antiretroviral Therapy Initiation With Incident AIDS or Death 
American Journal of Epidemiology  2012;175(5):381-390.
To estimate the association of antiretroviral therapy initiation with incident acquired immunodeficiency syndrome (AIDS) or death while accounting for time-varying confounding in a cost-efficient manner, the authors combined a case-cohort study design with inverse probability-weighted estimation of a marginal structural Cox proportional hazards model. A total of 950 adults who were positive for human immunodeficiency virus type 1 were followed in 2 US cohort studies between 1995 and 2007. In the full cohort, 211 AIDS cases or deaths occurred during 4,456 person-years. In an illustrative 20% random subcohort of 190 participants, 41 AIDS cases or deaths occurred during 861 person-years. Accounting for measured confounders and determinants of dropout by inverse probability weighting, the full cohort hazard ratio was 0.41 (95% confidence interval: 0.26, 0.65) and the case-cohort hazard ratio was 0.47 (95% confidence interval: 0.26, 0.83). Standard multivariable-adjusted hazard ratios were closer to the null, regardless of study design. The precision lost with the case-cohort design was modest given the cost savings. Results from Monte Carlo simulations demonstrated that the proposed approach yields approximately unbiased estimates of the hazard ratio with appropriate confidence interval coverage. Marginal structural model analysis of case-cohort study designs provides a cost-efficient design coupled with an accurate analytic method for research settings in which there is time-varying confounding.
doi:10.1093/aje/kwr346
PMCID: PMC3282878  PMID: 22302074
acquired immunodeficiency syndrome; case-cohort studies; cohort studies; confounding bias; HIV; pharmacoepidemiology; selection bias
16.  Liver diffusivity in healthy volunteers and patients with chronic liver disease: Comparison of breath-hold and free-breathing techniques 
Purpose
To compare liver ADC obtained with breath-hold and free-breathing diffusion weighted imaging (DWI) in healthy volunteers and patients with liver disease.
Materials and Methods
Twenty-eight subjects, 12 healthy volunteers and 16 patients (9 NAFLD, 7 chronic active HCV), underwent breath-hold (BH) and free-breathing (FB) DWI MRI at 1.5T. Pearson’s correlation coefficient was used to determine correlation while paired t-tests assessed differences between BH and FB ADC. Estimated bias was calculated using the Bland-Altman method.
Results
Liver ADC (×10−3 mm2/sec) was lower on BH for all groups (mean difference 0.36±0.20; p<0.01). ADC was higher in healthy volunteers (BH 1.80±0.18; FB 2.24±0.20) compared to NAFLD patients (BH 1.43±0.27; FB 1.78±0.28) (p<0.001) and HCV patients (BH 1.63±0.191; FB 1.88±0.12). Overall correlation between BH and FB ADC was (r =0.75), greatest in NAFLD (r =0.90) compared to the correlation in HCV (r =0.24) and healthy subjects (r =0.34). Bland-Altman plots did not show agreement in mean absolute difference and estimated bias between subjects.
Conclusion
Correlation between BH and FB liver ADC is moderate indicating that BH and FB should not be used interchangeably. Additionally, the lower ADC values in BH versus FB should be accounted for when comparing different liver DWI studies.
doi:10.1002/jmri.22748
PMCID: PMC3241899  PMID: 22034200
Diffusion-weighted Imaging (DWI); Breath-hold (BH); Free-breathing (FB); Non-Alcoholic Fatty Liver Disease (NAFLD); Hepatitis C (HCV)
17.  Factors associated with hepatitis C viremia in a large cohort of HIV-infected and - uninfected women 
Background
Coinfection with hepatitis C virus (HCV) is common among HIV-infected women.
Objective
To further our understanding of the risk factors for HCV viremia and the predictors of HCV viral load among women.
Study design
We investigated sociodemographic, immunologic, and virologic factors associated with presence and level of HCV viremia among 882 HIV-infected and 167 HIV-uninfected HCV-seropositive women at entry into the Women's Interagency HIV Study.
Results
Plasma HCV RNA was detected in 852 (81%) of these 1,049 women (range: 1.2–7.8 log10 copies/ml). HCV-viremic women were more likely to have an HIV RNA level >100,000 copies/ml (P =0.0004), have reported smoking (P =0.01), or to be Black (P =0.005). They were less likely to have current or resolved hepatitis B infection. HCV RNA levels were higher in women who were >35 years old, or HIV-infected. Current smoking and history of drug use (crack/freebase cocaine, marijuana, amphetamines, or heroin) were each associated with both presence and level of viremia.
Conclusions
Substance abuse counseling aimed at eliminating ongoing use of illicit drugs and tobacco may reduce clinical progression, improve response to treatment, and decrease HCV transmission by lowering levels of HCV viremia in women.
doi:10.1016/j.jcv.2007.08.021
PMCID: PMC3493623  PMID: 18243785
Hepatitis C; Hepatitis C RNA levels; Hepatitis C viremia; HIV/hepatitis C virus coinfection
19.  Age-Related Skeletal Muscle Decline Is Similar in HIV-Infected and Uninfected Individuals 
Background.
Skeletal muscle (SM) mass decreases with advanced age and with disease in HIV infection. It is unknown whether age-related muscle loss is accelerated in the current era of antiretroviral therapy and which factors might contribute to muscle loss among HIV-infected adults. We hypothesized that muscle mass would be lower and decline faster in HIV-infected adults than in similar-aged controls.
Methods.
Whole-body 1H-magnetic resonance imaging was used to quantify regional and total SM in 399 HIV-infected and 204 control men and women at baseline and 5 years later. Multivariable regression identified associated factors.
Results.
At baseline and Year 5, total SM was lower in HIV-infected than control men. HIV-infected women were similar to control women at both time points. After adjusting for demographics, lifestyle factors, and total adipose tissue, HIV infection was associated with lower Year 5 SM in men and higher SM in women compared with controls. Average overall 5-year change in total SM was small and age related, but rate of change was similar in HIV-infected and control men and women. CD4 count and efavirenz use in HIV-infected participants were associated with increasing SM, whereas age and stavudine use were associated with decreasing SM.
Conclusions.
Muscle mass was lower in HIV-infected men compared with controls, whereas HIV-infected women had slightly higher SM than control women after multivariable adjustment. We found evidence against substantially faster SM decline in HIV infected versus similar-aged controls. SM gain was associated with increasing CD4 count, whereas stavudine use may contribute to SM loss.
doi:10.1093/gerona/glq228
PMCID: PMC3041474  PMID: 21310810
Sarcopenia; Lipoatrophy; Fat redistribution; Body composition
20.  PRE-EXISTING ALBUMINURIA PREDICTS AIDS AND NON-AIDS MORTALITY IN WOMEN INITIATING ANTIRETROVIRAL THERAPY 
Antiviral therapy  2011;16(4):591-596.
Background
We previously reported an increased risk of all-cause and AIDS mortality among HIV-infected women with albuminuria (proteinuria or microalbuminuria) enrolled in the Women’s Interagency HIV Study (WIHS) prior to the introduction of highly active antiretroviral therapy (HAART).
Methods
The current analysis includes 1,073 WIHS participants who subsequently initiated HAART. Urinalysis for proteinuria and semi-quantitative testing for microalbuminuria from two consecutive study visits prior to HAART initiation were categorized as follows: confirmed proteinuria (both specimens positive for protein), confirmed microalbuminuria (both specimens positive with at least one microalbuminuria), unconfirmed albuminuria (one specimen positive for proteinuria or microalbuminuria), or negative (both specimens negative). Time from HAART initiation to death was modeled using proportional hazards analysis.
Results
Compared to the reference group of women with two negative specimens, the hazard ratio (HR) for all-cause mortality was significantly elevated for women with confirmed microalbuminuria (HR 1.9; 95% CI 1.2–2.9). Confirmed microalbuminuria was also independently associated with AIDS death (HR 2.3; 95% CI 1.3–4.3), while women with confirmed proteinuria were at increased risk for non-AIDS death (HR 2.4; 95% CI 1.2–4.6).
Conclusions
In women initiating HAART, pre-existing microalbuminuria independently predicted increased AIDS mortality, while pre-existing proteinuria predicted increased risk of non-AIDS death. Urine testing may identify HIV-infected individuals at increased risk for mortality even after the initiation of HAART. Future studies should consider whether these widely available tests can identify individuals who would benefit from more aggressive management of HIV infection and comorbid conditions associated with mortality in this population.
doi:10.3851/IMP1766
PMCID: PMC3119869  PMID: 21685547
HIV; microalbuminuria; proteinuria; mortality; non-AIDS death
22.  Associations of antiretroviral drug use and HIV-specific risk factors with carotid intima–media thickness 
AIDS (London, England)  2010;24(14):2201-2209.
Background
Previous research has demonstrated an increase in carotid intima–media thickness (cIMT) in HIV-infected individuals compared to controls. However, the reason for this increased level of subclinical vascular disease is unknown.
Objective
To identify HIV-related risk factors for increased cIMT.
Methods
We evaluated the relationship between HIV-related characteristics (including markers of HIV disease severity and use of antiretroviral therapy) and cIMT measurements in the internal/bulb and common carotid regions among 538 HIV-infected participants from the Study of Fat Redistribution and Metabolic Change in HIV Infection (FRAM). We used Bayesian model averaging to estimate the posterior probability of candidate HIV and non-HIV-related risk factors being true predictors of increased cIMT. Variables with a posterior probability of more than 50% were used to develop a selected regression model for each of the anatomic regions.
Results
For common cIMT, the Bayesian model selection process identified age, African-American race, and systolic and diastolic blood pressure with probability more than 95%, HDL cholesterol with probability 85% and Hispanic ethnicity with probability 51%. Among the HIV-related factors included in the analysis, only tenofovir use was selected (51% probability). In the selected model, duration of tenofovir use was associated with lower common cIMT (−0.0094 mm/year of use; 95% confidence interval: −0.0177 to −0.0010). For internal cIMT, no HIV-related risk factors were above the 50% posterior probability threshold.
Conclusion
We observed an inverse association between duration of tenofovir use and common carotid cIMT. Whether this association is causal or due to confounding by indication needs further investigation.
doi:10.1097/QAD.0b013e32833d2132
PMCID: PMC3224487  PMID: 20671544
atherosclerosis; carotid intima–media thickness; HIV; tenofovir
23.  Fracture incidence in HIV-infected women: results from the Women’s Interagency HIV Study 
AIDS (London, England)  2010;24(17):2679-2686.
Background
The clinical importance of the association of HIV infection and antiretroviral therapy (ART) with low bone mineral density (BMD) in premenopausal women is uncertain because BMD stabilizes on established ART and fracture data are limited.
Methods
We measured time to first new fracture at any site with median follow-up of 5.4 years in 2391 (1728 HIV-infected, 663 HIV-uninfected) participants in the Women’s Interagency HIV Study (WIHS). Self-report of fracture was recorded at semiannual visits. Proportional hazard models assessed predictors of incident fracture.
Results
At baseline, HIV-infected women were older (40 ± 9 vs. 36 ± 10 years, P <0.0001), more likely to report postmenopausal status and be hepatitis C virus-infected, and weighed less than HIV-uninfected women. Among HIV-infected women, mean CD4+ cell count was 482 cells/μl; 66% were taking ART. Unadjusted incidence of fracture did not differ between HIV-infected and uninfected women (1.8 vs. 1.4/100 person-years, respectively, P = 0.18). In multivariate models, white (vs. African-American) race, hepatitis C virus infection, and higher serum creatinine, but not HIV serostatus, were statistically significant predictors of incident fracture. Among HIV-infected women, older age, white race, current cigarette use, and history of AIDS-defining illness were associated with incidence of new fracture.
Conclusion
Among predominantly premenopausal women, there was little difference in fracture incidence rates by HIV status, rather traditional risk factors were important predictors. Further research is necessary to characterize fracture risk in HIV-infected women during and after the menopausal transition.
doi:10.1097/QAD.0b013e32833f6294
PMCID: PMC3108019  PMID: 20859192
fracture; fragility fracture; HIV-infected women; premenopausal
24.  Inflammation and Mortality in HIV-infected Adults: Analysis of the FRAM Study Cohort 
Objective
To determine the association of inflammatory markers, fibrinogen and C-reactive protein (CRP), with 5-year mortality risk.
Methods
Vital status was ascertained in 922 HIV-infected participants from the Study of Fat Redistribution and Metabolic Change in HIV infection. Multivariable logistic regression estimated odds ratios (OR) after adjustment for demographic, cardiovascular and HIV-related factors.
Results
Over a 5-year period, HIV-infected participants with fibrinogen levels in the highest tertile(>406mg/dL) had 2.6-fold higher adjusted odds of death than those with fibrinogen in the lowest tertile(<319mg/dL). Those with high CRP(>3mg/L) had 2.7-fold higher adjusted odds of death than those with CRP<1mg/L. When stratified by CD4 count category, fibrinogen (as a linear variable) remained independently associated [OR(95% confidence intervals) per 100mg/dL increase in fibrinogen: 1.93(1.57,2.37);1.43(1.14,1.79);1.43(1.14,1.81);and 1.30(1.04,1.63) for CD4 <200,200–350,>350–500, and >500cells/μL, respectively. Higher CRP also remained associated with higher odds of death overall and within each CD4 subgroup.
Conclusion
Fibrinogen and CRP are strong and independent predictors of mortality in HIV-infected adults. Our findings suggest that even in those with relatively preserved CD4 counts >500cells/μL, inflammation remains an important risk factor for mortality. Further investigation should determine whether interventions to reduce inflammation might decrease mortality risk in HIV-infected individuals.
doi:10.1097/QAI.0b013e3181e66216
PMCID: PMC2955817  PMID: 20581689
HIV; inflammation; C-reactive protein; fibrinogen; mortality
25.  Cystatin C, Albuminuria, and 5-Year All-Cause Mortality in HIV-Infected Persons 
Background
Compared with controls, HIV-infected persons have a greater prevalence of kidney disease as assessed by high levels of cystatin C and albuminuria, but not as assessed by creatinine level. However, the clinical importance of elevated cystatin C and albuminuria in the HIV-infected population has not been studied.
Study Design
We conducted an observational cohort study to determine the association of kidney disease (measured by albuminuria, cystatin C, and serum creatinine) with mortality.
Setting & Participants
922 HIV-infected persons enrolled in the FRAM (Fat Redistribution and Metabolic Change in HIV infection) study.
Predictor
Serum cystatin C and serum creatinine were used to estimate glomerular filtration rate (eGFR). Albuminuria was defined as a positive urine dipstick (≥1+) or a urine albumin-creatinine ratio > 30 mg/g.
Outcome
5-year mortality
Results
At baseline, reduced kidney function (eGFRSCysC <60 mL/min/1.73m2) or albuminuria was present in 28% of participants. After five years of follow-up, mortality was 48% among those with both eGFRSCysC <60 mL/min/1.73m2 and albuminuria, 23% in those with eGFRSCysC <60 mL/min/1.73m2 alone, 20% in those with albuminuria alone, and 9% in those with neither condition. After multivariable adjustment for demographics, cardiovascular risk factors, HIV-related factors, and inflammatory markers, eGFRSCysC <60 mL/min/1.73m2 and albuminuria were associated with nearly a twofold increase in mortality, whereas eGFRSCr <60 mL/min/1.73m2 did not appear to have any substantial association with mortality. Together, eGFRSCysC <60 mL/min/1.73m2 and albuminuria accounted for 17% of the population-level attributable risk for mortality.
Limitations
Vital status was unknown in 261 participants from the original cohort.
Conclusions
Kidney disease marked by albuminuria or increased cystatin C levels appears to be an important risk factor for mortality in HIV-infected individuals. A substantial proportion of this risk may be unrecognized because of the current reliance on serum creatinine to estimate kidney function in clinical practice.
doi:10.1053/j.ajkd.2010.05.019
PMCID: PMC3164880  PMID: 20709438
kidney disease; mortality; HIV infection

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