Effects of protease inhibitors on glucose tolerance, lipid metabolism, and body composition in children and adolescents infected with human immunodeficiency virus

Age-specific abnormal glucose metabolism in HIV-positive people on antiviral therapy in China: a multicenter case-control study

BACKGROUND

Update, the link between HIV infection and abnormal glucose metabolism (AGM) is still unclear. This study aims to investigate the impact of HIV infection on AGM, including insulin resistance (IR), impaired fasting glucose (IFG), and diabetes mellitus (DM).

METHODS

A multicenter case-control study was conducted in Zhejiang province, China. After matching, the study included 1030 people living with HIV (PLWH) and 1030 people living without HIV (PLWTH). The age-specific incidence of AGM was compared between the two groups. Poisson regression models were used to calculate the relative risk (RR) and its 95% confidence interval (CI) to assess the associations.

RESULTS

Compared to PLWTH, PLWH had a higher rate of IR, IFG and DM, and a higher risk of developing IR (RR: 1.83; 95% CI: 1.60-2.10), IFG (RR: 3.87; 95% CI: 2.55-6.07), and DM (RR: 1.52; 95% CI: 1.09-2.12). In the 30-44 age group, the risk of IR, IFG, and DM was the highest, with RRs of 2.04 (95%CI: 1.69-2.48), 7.46 (95%CI: 2.91-25.27), and 1.88 (95%CI: 0.90-4.10). HIV acquisition and cART usage >5 years were associated with increased risks of DM.

CONCLUSION

HIV infection is associated with early onset and high prevalence of IR and IFG. Longer duration of HIV infection and cART usage increased the occurrence of DM. These findings contribute to a better understanding of age-specific AGM and the modified glucose monitor strategies in PLWH.

Health-Related Physical Fitness Evaluation in HIV-Diagnosed Children and Adolescents: A Scoping Review

BACKGROUND

Health-related physical fitness has been widely used to investigate the adverse effects of HIV infection/ART in children and adolescents. However, methods/protocols and cut-points applied for investigating health-related physical fitness are not clear. The aim of this scoping review was to map the literature to identify gaps in knowledge regarding the methods/protocols and cut-points.

METHODS

A scoping review, following the Joana Briggs Institute (JBI) guidelines, was conducted through ten major databases. Search followed the PCC strategy to construct block of terms related to population (children and adolescents), concept (health-related physical fitness components) and context (HIV infection).

RESULTS

The search resulted in 7545 studies. After duplicate removal, titles and abstracts reading and full text assessment, 246 studies were included in the scoping review. Body composition was the most investigated component (n = 244), followed by muscular strength/endurance (n = 23), cardiorespiratory fitness (n = 15) and flexibility (n = 4). The World Health Organization growth curves, and nationals' surveys were the most reference values applied to classify body composition (n = 149), followed by internal cut-points (n = 30) and cut-points developed through small populations (n = 16). Cardiorespiratory fitness was classified through cut-points from three different assessment batteries, as well as cut-points developed through studies with small populations, muscular strength/endurance and flexibility were classified through the same cut-points from five different assessment batteries.

CONCLUSIONS

The research on muscular strength/endurance, cardiorespiratory fitness and flexibility has been scarcely explored. The lack of studies that investigated method usability as well as reference values was evidenced.

Second generation HIV protease inhibitors against resistant virus

BACKGROUND

The AIDS epidemic has spread around the world at an alarming rate. Although the first generation of HIV protease inhibitors, including indinavir, nelfinavir, saquinavir, ritonavir and amprenavir, were initially effective against HIV infection, the fast emerging resistance to these agents has been a substantial and persistent problem in the treatment of AIDS. Attempts to address the resistance issue with 'salvage therapy' consisting of high doses of multiple protease inhibitors have only been moderately successful owing to the high level of cross-resistance and toxicities associated with the protease inhibitors.

OBJECTIVE

To study the second generation HIV protease inhibitors against resistant virus.

METHOD

This review highlights new developments achieved by various organizations to address the challenge of high level resistance of current therapies since 2000.

CONCLUSION

All second generation protease inhibitors used in patients who experienced extensive treatment require ritonavir as a pharmacological boosting agent to increase the drug level in the plasma, but there is toxicity associated with such a practice. Accordingly, there remains a need for new protease inhibitors with improved effectiveness against the resistant viral variants. A third generation protease inhibitor will require no boosting agent while maintaining high potency against resistant virus.

World Health Organization generic protocol to assess drug-resistant HIV among children <18 months of age and newly diagnosed with HIV in resource-limited countries

Increased use of nonnucleoside reverse transcriptase inhibitors (NNRTIs) in pregnant and breastfeeding women will result in fewer children infected with human immunodeficiency virus (HIV). However, among children infected despite prevention of mother-to-child transmission (PMTCT), a substantial proportion will acquire NNRTI-resistant HIV, potentially compromising response to NNRTI-based antiretroviral therapy (ART). In countries scaling up PMTCT and pediatric ART programs, it is crucial to assess the proportion of young children with drug-resistant HIV to improve health outcomes and support national and global decision making on optimal selection of pediatric first-line ART. This article summarizes a new World Health Organization surveillance protocol to assess resistance using remnant dried blood spot specimens from a representative sample of children aged <18 months being tested for early infant diagnosis.

Online electrospray ionization mass spectrometric monitoring of protease-catalyzed reactions in real time

Although there are a lot of well established methods for monitoring enzyme-catalyzed reactions, most of them are based on changes in spectroscopic properties during the conversion of substrates to products. However, reactions without optical changes are common, which are inapplicable to these spectroscopic methods. As an alternative technique for enzymologic research, mass spectrometry (MS) is favored due to its specificity, sensitivity, and the ability to obtain stoichiometric information. In this work, probe electrospray ionization (PESI) source coupled with a time of flight mass spectrometer was employed to monitor some typical protease-catalyzed reactions, including pepsinolysis and trypsinolysis of cytochrome c in real time. Due to the high electrical conductivity of each reaction system, corona discharges are likely to occur, which would decrease intensities of mass spectrometric signals. An ultra-fine sampling probe and an auxiliary vapor spray were adopted to prevent corona discharges. Experimental results from peptic and tryptic digestions of cytochrome c showed different and characteristic catalytic pathways. With the data presented in this study, PESI-MS can be considered as a potential tool for real-time monitoring of enzymatic reactions because of its simplicity in instrumental configuration, wide applicability under harsh conditions, and flexibility in combination with other techniques.

Body fat distribution in perinatally HIV-infected and HIV-exposed but uninfected children in the era of highly active antiretroviral therapy: outcomes from the Pediatric HIV/AIDS Cohort Study

BACKGROUND

Associations between abnormal body fat distribution and clinical variables are poorly understood in pediatric HIV disease.

OBJECTIVE

Our objective was to compare total body fat and its distribution in perinatally HIV-infected and HIV-exposed but uninfected (HEU) children and to evaluate associations with clinical variables.

DESIGN

In a cross-sectional analysis, children aged 7-16 y in the Pediatric HIV/AIDS Cohort Study underwent regionalized measurements of body fat via anthropometric methods and dual-energy X-ray absorptiometry. Multiple linear regression was used to evaluate body fat by HIV, with adjustment for age, Tanner stage, race, sex, and correlates of body fat in HIV-infected children. Percentage total body fat was compared with NHANES data.

RESULTS

Males accounted for 47% of the 369 HIV-infected and 51% of the 176 HEU children. Compared with HEU children, HIV-infected children were older, were more frequently non-Hispanic black, more frequently had Tanner stage ≥3, and had lower mean height (-0.32 compared with 0.29), weight (0.13 compared with 0.70), and BMI (0.33 compared with 0.63) z scores. On average, HIV-infected children had a 5% lower percentage total body fat (TotF), a 2.8% lower percentage extremity fat (EF), a 1.4% higher percentage trunk fat (TF), and a 10% higher trunk-to-extremity fat ratio (TEFR) than did the HEU children and a lower TotF compared with NHANES data. Stavudine use was associated with lower EF and higher TF and TEFR. Non-nucleotide reverse transcriptase inhibitor use was associated with higher TotF and EF and lower TEFR.

CONCLUSION

Although BMI and total body fat were significantly lower in the HIV-infected children than in the HEU children, body fat distribution in the HIV-infected children followed a pattern associated with cardiovascular disease risk and possibly related to specific antiretroviral drugs.

Factors associated with insulin resistance among children and adolescents perinatally infected with HIV-1 in the pediatric HIV/AIDS cohort study

BACKGROUND/AIMS

Because of prior inconsistent findings, we studied a large cohort of HIV-infected children to determine: (1) prevalence of insulin resistance (IR); (2) anthropometric and clinical correlates of IR, and (3) concomitant abnormalities of glucose tolerance.

METHODS

The study population consisted of 451 children from the Pediatric HIV/AIDS Cohort Study. The outcome of interest was HOMA-IR. Covariates included demographic, metabolic, growth, body composition, HIV laboratory tests, and treatment characteristics. Children meeting triggers for IR underwent oral glucose tolerance tests and hemoglobin A1c (HbA1c) measurements.

RESULTS

Among 402 children with glucose and insulin measurements, 15.2% had IR of whom 79% were pubertal. IR was associated with higher alanine aminotransferase, body mass index, and nadir CD4%, Tanner stage 5, and ever having received amprenavir. Of those with IR, three had impaired fasting glucose (IFG), three impaired glucose tolerance (IGT), one IFG and IGT, none diabetic glucose tolerance, and three HbA1c between 6.1 and 6.5%.

CONCLUSION

In our cohort of HIV-infected adolescents, we observed a 15.2% prevalence of IR more closely linked to obesity than any other variable. This finding mirrors the high prevalence of obesity-mediated IR in American youth. However, associations with CD4 count and use of protease inhibitors may indicate some effect of HIV and/or its treatment.

Lipodystrophy and metabolic complications of highly active antiretroviral therapy

OBJECTIVE

To assess the metabolic drug toxicities of first-line, World Health Organization (WHO)-recommended generic highly active antiretroviral therapy (HAART) regimens, to estimate the prevalence of body fat redistribution and to identify associated risk factors.

METHODS

Cross-sectional observational study. During 3 month period, 52 HIV infected children (25 on HAART; 27 not on HAART) were assessed. Their sociodemographic, clinical, and immunological data was recorded. Children were examined or the signs of fat redistribution (peripheral lipoatrophy and central lipohypertrophy). Liver function tests, fasting blood sugar, lipid profile, serum amylase, serum lactate, blood pH and bicarbonate levels were done in all patients.

RESULTS

Twenty-two patients were on stavudine and three on zidovudine based HAART. None of the patients ever received any protease inhibitor. There were no cases of clinical or immunological failure. Children on HAART had significantly lower weight for age and body mass index but the mean height for age was similar between study groups. Only two cases of peripheral lipoatrophy were observed. Hypercholesterolemia was observed in four children on HAART but none without therapy. Hypertriglyceridemia was observed in three children on HAART and seven without therapy. Four cases of asymptomatic mild hyperlactatemia were observed. No case of any hyperglycemia or liver impairment was observed.

CONCLUSION

Metabolic abnormalities and lipodystrophy are emerging complications of HAART in Indian children and needs very close follow up. Future studies with larger sample size and longitudinal model are recommended.

Morphologic and metabolic abnormalities in vertically HIV-infected children and youth

OBJECTIVE

To compare the distribution of lipid and glucose abnormalities and altered fat distribution among vertically HIV-infected patients and controls.

DESIGN

Cross-sectional multicenter study on HIV-infected (HIV-positive) patients, 7-24 years of age, stratified by Tanner stage and protease inhibitor use (protease inhibitor, n = 161 and non- protease inhibitor, n = 79) and seronegative controls (HIV-negative, n = 146).

METHODS

Measurements included fasting lipids, glucose, insulin, 2-h oral glucose tolerance test, dual-energy X-ray absorptiometry, anthropometry, and antiretroviral therapy and medical histories. Multiple linear regression models were used to compare distributions between HIV-positive and HIV-negative groups.

RESULTS

Both HIV-positive groups had long exposures to antiretroviral therapy. Protease inhibitor and nonprotease inhibitor groups had similar current CD4 cell count and HIV-1 RNA, but the protease inhibitor group had lower nadir CD4 cell count, higher peak HIV-1 RNA, and more advanced Centers for Disease Control disease stage. In adjusted analyses, both HIV-positive groups had significantly lower mean Z scores for height, weight, BMI, and total and limb fat than the HIV-negative group. Mean triglycerides were significantly higher and high-density lipoprotein cholesterol lower in both HIV-positive groups relative to the HIV-negative group. The protease inhibitor group also had significantly higher mean total, low-density lipoprotein, and non-high density lipoprotein cholesterol. Mean fasting insulin was higher in both HIV-positive groups, and 2-h glucose and insulin were higher in the protease inhibitor group. Ritonavir was associated with increasing dyslipidemia and altered glucose metabolism.

CONCLUSION

In a large group of vertically HIV-infected children and youth with extensive antiretroviral therapy exposure, height, weight, and total and limb fat were lower than in controls. There was a high prevalence of lipid abnormalities among those on protease inhibitors and evidence of developing insulin resistance, factors that may accelerate lifetime risk for cardiovascular disease.

Lopinavir impairs protein synthesis and induces eEF2 phosphorylation via the activation of AMP-activated protein kinase

HIV anti-retroviral drugs decrease protein synthesis, although the underlying regulatory mechanisms of this process are not fully established. Therefore, we investigated the effects of the HIV protease inhibitor lopinavir (LPV) on protein metabolism. We also characterized the mechanisms that mediate the effects of this drug on elongation factor-2 (eEF2), a key component of the translational machinery. Treatment of C2C12 myocytes with LPV produced a dose-dependent inhibitory effect on protein synthesis. This effect was observed at 15 min and was maintained for at least 4 h. Mechanistically, LPV increased the phosphorylation of eEF2 and thereby decreased the activity of this protein. Increased phosphorylation of eEF2 was associated with increased activity of its upstream regulators AMP-activated protein kinase (AMPK) and eEF2 kinase (eEF2K). Both AMPK and eEF2K directly phosphorylated eEF2 in an in vitro kinase assay suggesting two distinct paths lead to eEF2 phosphorylation. To verify this connection, myocytes were treated with the AMPK inhibitor compound C. Compound C blocked eEF2K and eEF2 phosphorylation, demonstrating that LPV affects eEF2 activity via an AMPK-eEF2K dependent pathway. In contrast, incubation of myocytes with rottlerin suppressed eEF2K, but not eEF2 phosphorylation, suggesting that eEF2 can be regulated independent of eEF2K. Finally, LPV did not affect PP2A activity when either eEF2 or peptide was used as the substrate. Collectively, these results indicate that LPV decreases protein synthesis, at least in part, via inhibition of eEF2. This appears regulated by AMPK which can act directly on eEF2 or indirectly via the action of eEF2K.

Lipid and glucose alterations in HIV-infected children beginning or changing antiretroviral therapy

OBJECTIVE

The objective of this study was to describe lipid profiles and glucose homeostasis in HIV-positive children after initiating or changing antiretroviral therapy and their associations with viral, immune, antiretroviral therapy, and growth factor parameters.

METHODS

Ninety-seven prepubertal HIV-positive children aged 1 month to <13 years were observed for 48 weeks after beginning or changing antiretroviral therapy. Fasting lipid panels, serum glucose, insulin, insulin-like growth factor-1 and binding proteins-1 and -3, plasma viral load, and CD4% were measured. Each child was matched on age, gender, and race/ethnicity to children from the National Health and Nutrition Examination Survey, used to give z scores for each child's lipid values. Multivariate regression was used to evaluate the association of changes in z scores over 48 weeks with suppression of HIV-1 RNA, change in CD4% and growth factors, and antiretroviral therapy, adjusted for entry z score, CD4%, log(10) HIV-1 RNA, Centers for Disease Control and Prevention category, and total fat and cholesterol dietary intake.

RESULTS

Lipid, apolipoprotein, and insulin levels all increased significantly by 48 weeks. Multivariate analysis of changes demonstrated that increased HDL and decreased total-HDL cholesterol ratio were associated with CD4% increase and with insulin-like growth factor-1, which increased to normal (versus remained stable or became low) over 48 weeks. Total cholesterol levels increased among children who achieved HIV-1 RNA of <400 copies per mL. Antiretroviral therapy regimens that included both a protease inhibitor and a non-nucleoside reverse transcriptase inhibitor were associated with greater increases in total-HDL cholesterol ratio than regimens that contained a protease inhibitor or a non-nucleoside reverse transcriptase inhibitor but not both.

CONCLUSIONS

In these HIV-positive children with predominantly mild-to-moderate disease, initiation or change in antiretroviral therapy was associated with significant increases in multiple lipid measures and insulin resistance. Favorable lipid changes were associated with CD4% increases, suggesting a protective effect of immune reconstitution on atherosclerosis, and with increased insulin-like growth factor-1 levels, supporting the theory that reduced growth hormone resistance may be a mechanism by which lipid profiles are improved. Finally, antiretroviral therapy regimens that contain both a non-nucleoside reverse transcriptase inhibitor and a protease inhibitor are associated with worse lipid profiles than regimens that contain 1 but not both of these drug classes.