Marc van der Valk

Nevirapine-containing antiretroviral therapy in HIV-1 infected patients results in an anti-atherogenic lipid profile.

BackgroundProtease inhibitor-containing antiretroviral therapy for the treatment of HIV-1 infection is associated with elevated triglyceride and low-density lipoprotein (LDL)-cholesterol levels which may expose patients to an increased risk of coronary artery disease (CAD). We report the lipid and lipoprotein profiles of a representative subset of treatment-naive patients included in the Atlantic Study. This study compares patients treated with stavudine and didanosine plus the random addition of either the non-nucleoside reverse transcriptase inhibitor nevirapine (NVP), the protease inhibitor indinavir or the nucleoside reverse transcriptase inhibitor lamivudine. MethodsLipids and lipoproteins were quantified from prospectively collected and cryopreserved plasma samples obtained at weeks 0, 6 and 24. ResultsWe observed a striking increase in high-density lipoprotein (HDL)-cholesterol (49%), apolipoprotein AI (19%), lipoprotein AI (38%) and HDL particle size (3%) in the NVP-treated patients (n = 34) at week 24. Much less pronounced changes in these parameters were seen to a similar extent both in patients receiving lamivudine (n = 39) and indinavir (n = 41). LDL-cholesterol also increased significantly both in the NVP and indinavir arms, but only in the NVP arm was this offset by a significant reduction (14%) in total over HDL-cholesterol ratio. Using a multivariate linear regression model, adjusting for CD4 cell count and plasma HIV RNA both at baseline and during treatment, randomization to the NVP-containing arm remained significant in explaining the observed changes in HDL-cholesterol and other HDL-related parameters. ConclusionsIn HIV-1 infected patients treated with a regimen of stavudine, didanosine and NVP we found changes in lipids and lipoproteins which are associated with a sharp decrease in risk for CAD in other settings. If confirmed in larger studies, these findings both may influence the initial choice of therapy for HIV-1 infection, and might lead to novel approaches targeted at raising HDL-cholesterol for CAD prevention.

Cross-sectional comparison of the prevalence of age-associated comorbidities and their risk factors between HIV-infected and uninfected individuals: the AGEhIV Cohort Study

BACKGROUND Human immunodeficiency virus (HIV)-infected individuals may be at increased risk of age-associated noncommunicable comorbidities (AANCCs). METHODS Cross-sectional analyses of AANCC prevalence (including cardiovascular, metabolic, pulmonary, renal, bone, and malignant disease) and risk factors in a prospective cohort study of HIV type 1-infected individuals and HIV-uninfected controls, who were aged ≥45 years and comparable regarding most lifestyle and demographic factors. RESULTS HIV-infected participants (n = 540) had a significantly higher mean number of AANCCs than controls (n = 524) (1.3 [SD, 1.14] vs 1.0 [SD, 0.95]; P < .001), with significantly more HIV-infected participants having ≥1 AANCC (69.4% vs 61.8%; P = .009). Hypertension, myocardial infarction, peripheral arterial disease, and impaired renal function were significantly more prevalent among HIV-infected participants. Risk of AANCC by ordinal logistic regression was independently associated with age, smoking, positive family history for cardiovascular/metabolic disease, and higher waist-to-hip ratio, but also with HIV infection (odds ratio, 1.58 [95% confidence interval, 1.23-2.03]; P < .001). In those with HIV, longer exposure to CD4 counts <200 cells/µL, and, to a lesser extent, higher levels of high-sensitivity C-reactive protein and soluble CD14, and longer prior use of high-dose ritonavir (≥400 mg/24 hours) were each also associated with a higher risk of AANCCs. CONCLUSIONS All AANCCs were numerically more prevalent, with peripheral arterial, cardiovascular disease, and impaired renal function significantly so, among HIV-infected participants compared with HIV-uninfected controls. Besides recognized cardiovascular risk factors, HIV infection and longer time spent with severe immunodeficiency increased the risk of a higher composite AANCC burden. There was a less pronounced contribution from residual inflammation, immune activation, and prior high-dose ritonavir use.

A randomized trial to study first-line combination therapy with or without a protease inhibitor in HIV-1-infected patients

Objective: To compare one protease inhibitor (PI)-based and two PI-sparing antiretroviral therapy regimens. Methods: International, open label, randomized study of antiretroviral drug-naive patients, with CD4 lymphocyte counts ⩾ 200 × 106 cells/l and plasma HIV-1 RNA levels > 500 copies/ml. Treatment assignment to stavudine and didanosine plus indinavir or nevirapine or lamivudine. Primary study endpoint was the percentage of patients with plasma HIV-1 RNA levels < 500 copies/ml after 48 weeks in the intention-to-treat analysis (ITT). Results: In total, 298 patients were enrolled. After 48 weeks, the percentage of patients in the indinavir, nevirapine and lamivudine arms with HIV-1 RNA < 500 copies/ml was 57.0%, 58.4% and 58.7%, respectively, in an ITT analysis. After 96 weeks of follow-up, these percentages were 50.0%, 59.6% and 45.0%, respectively. The percentage of patients with HIV-1 RNA < 50 copies/ml was significantly less for those allocated to lamivudine in an on-treatment analysis after 48 and 96 weeks of follow-up. Patients in the nevirapine arm experienced a smaller increase in the absolute number of CD4 T lymphocytes. There were no significant differences in the incidence of serious adverse events. Conclusions: A comparable virological response can be achieved with first-line PI-base and PI-sparing regimens. The triple nucleoside regimen utilized may be less likely to result in viral suppression to < 50 copies/ml, while the nevirapine-based regimen is associated with a lower increase in CD4 T lymphocytes.

Lipodystrophy in Hiv-1-positive patients is associated with insulin resistance in multiple metabolic pathways

BackgroundTreatment for HIV-1 infection is complicated by fat redistribution (lipodystrophy). This is associated with insulin resistance concerning glucose uptake. Our aim was to characterize glucose metabolism more comprehensively in HIV-1-infected patients with lipodystrophy. We assessed glucose disposal and its pathways, glucose production, plasma free fatty acid (FFA) levels, and the degree to which these parameters could be suppressed by insulin. MethodsSix HIV-1-infected men on protease inhibitor-based HAART with lipodystrophy (HIV+LD) were studied. The results were compared with those in six matched healthy male volunteers. Insulin sensitivity was quantified by hyperinsulinemic euglycaemic clamp. Glucose production and uptake were assessed by tracer dilution employing 6,6d2-glucose. ResultsAt post-absorptive insulin concentrations, glucose production was 47% higher in HIV+LD than controls (P = 0.025). During clamp, glucose production was suppressed by 53% in HIV+LD, but by 85% in controls (P = 0.004). Glucose disposal increased in both groups, but by only 27% in HIV+LD versus 201% in controls (P = 0.004). Consequently, insulin-stimulated total glucose disposal was lower in HIV+LD patients (P = 0.006). Non-oxidative glucose disposal as percentage of total disposal did not differ significantly between groups (63% in HIV+LD and 62% in controls). Baseline plasma FFA concentrations were higher (0.60 versus 0.35 mmol/l;P = 0.024), whereas FFA decline during hyperinsulinemia was less (65 versus 85%;P = 0.01) in HIV+LD versus controls . ConclusionsPost-absorptive glucose production is increased in HIV-1-infected patients with lipodystrophy. Moreover, both the ability of insulin to suppress endogenous glucose production and lipolysis, and to stimulate peripheral glucose uptake and its metabolic pathways is reduced, indicating severe resistance concerning multiple effects of insulin.

Ritonavir Impairs Lipoprotein Lipase–Mediated Lipolysis and Decreases Uptake of Fatty Acids in Adipose Tissue

Objective—The use of the HIV protease inhibitor ritonavir (RTV) is frequently associated with hypertriglyceridemia and lipodystrophy. The aim of our study was to determine the mechanism underlying the observed hypertriglyceridemia. Methods and Results—Feeding female APOE*3-Leiden transgenic mice a Western-type diet supplemented with RTV (35 mg/kg per day) for 2 weeks resulted in a 2-fold increase in fasting plasma triglyceride (TG) levels, which was specific for very low–density lipoprotein (VLDL). RTV did not change the hepatic VLDL-TG production. Instead, RTV did increase the postprandial TG response to an oral fat load (area under the curve, 25.5±12.1 versus 13.8±6.8 mmol/L per hour in controls; P<0.05). Likewise, RTV hampered the plasma clearance of intravenously injected glycerol tri[3H]oleate-labeled VLDL–like emulsion particles (half time, 19.3±10.5 versus 5.0±1.3 minutes in controls; P<0.05) associated with a decrease of 44% in plasma lipoprotein lipase activity. Accordingly, RTV decreased the uptake of TG-derived fatty acids (FAs) into adipose tissue, as well as the uptake of albumin-bound FA. Conclusions—We conclude that RTV causes hypertriglyceridemia via decreased lipoprotein lipase–mediated clearance of VLDL-TG. In addition, RTV specifically impairs the uptake of FA in adipose tissue, which may contribute to the lipodystrophy that is frequently observed in HIV-infected subjects on antiretroviral therapy.

Low Bone Mineral Density in Patients With Well-Suppressed HIV Infection: Association With Body Weight, Smoking, and Prior Advanced HIV Disease

BACKGROUND Human immunodeficiency virus (HIV) and combination antiretroviral therapy (cART) may both contribute to the higher prevalence of osteoporosis and osteopenia in HIV-infected individuals. METHODS Using dual-energy X-ray absorptiometry, we compared lumbar spine, total hip, and femoral neck bone mineral density (BMD) in 581 HIV-positive (94.7% receiving cART) and 520 HIV-negative participants of the AGEhIV Cohort Study, aged ≥45 years. We used multivariable linear regression to investigate independent associations between HIV, HIV disease characteristics, ART, and BMD. RESULTS The study population largely consisted of men who have sex with men (MSM). Osteoporosis was significantly more prevalent in those with HIV infection (13.3% vs 6.7%; P<.001). After adjustment for body weight and smoking, being HIV-positive was no longer independently associated with BMD. Low body weight was more strongly negatively associated with BMD in HIV-positive persons with a history of a Centers for Disease Control and Prevention class B or C event. Interestingly, regardless of HIV status, younger MSM had significantly lower BMD than older MSM, heterosexual men, and women. CONCLUSIONS The observed lower BMD in treated HIV-positive individuals was largely explained by both lower body weight and more smoking. Having experienced symptomatic HIV disease, often associated with weight loss, was another risk factor. The low BMD observed in younger MSM remains unexplained and needs further study.

Cost-effectiveness analysis of pre-exposure prophylaxis for HIV-1 prevention in the Netherlands: a mathematical modelling study

BACKGROUND Pre-exposure prophylaxis (PrEP) with tenofovir and emtricitabine prevents HIV infections among men who have sex with men (MSM). PrEP can be given on a daily or intermittent basis. Unfortunately, PrEP is not reimbursed in most European countries. Cost-effectiveness analyses of PrEP among MSM in Europe are absent but are key for decision makers to decide upon PrEP implementation. METHODS We developed a deterministic mathematical model, calibrated to the well defined Dutch HIV epidemic among MSM, to predict the effect and cost-effectiveness of PrEP. PrEP was targeted to 10% of highly sexually active Dutch MSM over the coming 40 years. Cost-effectiveness ratios were calculated to predict the cost-effectiveness of daily and on-demand PrEP. Cost-effectiveness ratios below €20 000 were considered to be cost-effective in this analysis. FINDINGS Within the context of a stable HIV epidemic, at 80% effectiveness and current PrEP pricing, PrEP can cost as much as €11 000 (IQR 9400-14 100) per quality-adjusted life-year (QALY) gained when used daily, or as little as €2000 (IQR 1300-3000) per QALY gained when used on demand. At 80% effectiveness, daily PrEP can be considered cost-saving if the price of PrEP is reduced by 70%, and on-demand PrEP can be considered cost-saving if the price is reduced by 30-40%. INTERPRETATION PrEP for HIV prevention among MSM in the Netherlands is cost-effective. The use of PrEP is most cost-effective when the price of PrEP is reduced through on-demand use or through availability of generic PrEP, and can quickly be considered cost-saving. FUNDING None.

Sympathetic nervous system function in HIV-associated adipose redistribution syndrome.

It was recently suggested that HIV-associated adipose redistribution syndrome (HARS) results from an autonomic dysbalance. We investigated the local and global sympathetic nervous system function of patients with HIV-1 infection and HARS. Interstitial noradrenaline concentrations in skeletal muscle and subcutaneous adipose tissue were increased in the absence of changes in global sympathetic nerve activity, consistent with locally increased sympathetic activity. This could promote localized lipolysis in subcutaneous adipose tissue and contribute to the development of HARS.

Higher Prevalence of Hypertension in HIV-1-Infected Patients on Combination Antiretroviral Therapy Is Associated With Changes in Body Composition and Prior Stavudine Exposure

BACKGROUND Individuals infected with human immunodeficiency virus (HIV) have a higher risk of cardiovascular disease, potentially partly mediated by a higher prevalence of hypertension. We therefore examined the prevalence and determinants of hypertension in HIV-1-infected patients compared with appropriate HIV-negative controls. METHODS Data from 527 HIV-1-infected and 517 HIV-uninfected participants at the time of enrollment into the ongoing AGEhIV Cohort Study were analyzed. Hypertension was defined as systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, and/or self-reported use of antihypertensive drugs. RESULTS Hypertension prevalence was higher among HIV-1-infected individuals compared with controls (48.2% vs 36.4%; odds ratio [OR], 1.63; 95% confidence interval [CI], 1.27-2.09). In logistic regression models adjusted for age, sex, ethnicity, family history of hypertension, smoking, alcohol use, physical activity, and body mass index, the association between HIV and hypertension remained statistically significant (ORHIV, 1.65; 95% CI, 1.25-2.19), but was attenuated after additional adjustment for waist-to-hip ratio (ORHIV, 1.29; 95% CI, .95-1.76). Among HIV-1-infected individuals, particularly among those with mono/dual nucleoside reverse transcriptase inhibitor therapy prior to combination antiretroviral therapy, stavudine exposure was independently associated with hypertension (ORstavudine, 1.54; 95% CI, 1.04-2.30). This association was attenuated after additional adjustment for either waist-to-hip ratio (ORstavudine, 1.30; 95% CI, .85-1.96) or hip circumference (ORstavudine, 1.40; 95% CI, .93-2.11). CONCLUSIONS Our findings suggest that changes in body composition, involving both abdominal obesity and stavudine-induced peripheral lipoatrophy, might contribute to the higher prevalence of hypertension in HIV-1-infected patients. CLINICAL TRIALS REGISTRATION NCT01466582.

Liver fibrosis in HIV-infected individuals on long-term antiretroviral therapy: associated with immune activation, immunodeficiency and prior use of didanosine.

Background:It is unclear whether HIV infection is associated with liver fibrosis in the absence of chronic hepatitis B or C virus (HBV/HCV) coinfection. We compared prevalence of liver fibrosis, noninvasively assessed by the Fibrosis-4 (FIB-4) index, between HIV-infected patients and uninfected controls, and explored determinants of a higher FIB-4 score, indicative of more liver fibrosis. Methods:FIB-4 was assessed in HIV-uninfected and HIV-1-infected, predominantly virologically suppressed participants of the AGEhIV Cohort Study without HBV and/or HCV coinfection, and aged at least 45. Using multivariable regression, we investigated associations between FIB-4 and HIV-status, HIV-disease characteristics, antiretroviral drugs and markers of microbial translocation and immune activation. Results:Prevalence of advanced liver fibrosis (FIB-4 ≥ 3.25) was low: 1.4% in HIV-infected and 1.0% in HIV-uninfected participants. After adjustment for age, sex, ethnicity, detectable anti-hepatitis B core/anti-HCV antibodies and excessive alcohol intake, HIV remained significantly associated with higher FIB-4 (+4.2%, P = 0.05). Prior exposure to didanosine, longer duration of a CD4+ cell count below 500 cells/&mgr;l and a lower CD4+ cell count at enrollment were each associated with a higher FIB-4. Markers of immune activation (soluble CD163, activated CD8+ T-lymphocytes and regulatory T-lymphocytes) were associated with a higher FIB-4 in HIV-infected but not HIV-uninfected study participants. Conclusion:HIV infection was independently associated with higher FIB-4 scores, indicating more advanced liver fibrosis, though the difference in FIB-4 scores between HIV-infected and HIV-uninfected was small. Higher levels of immune activation were associated with liver fibrosis in HIV-infected, even in the absence of HBV or HCV infection, but not in HIV-uninfected individuals.