Insulin Resistance in HIV-Patients: Causes and Consequences

Here we review how immune activation and insulin resistance contribute to the metabolic alterations observed in HIV-infected patients, and how these alterations increase the risk of developing CVD. The introduction and evolution of antiretroviral drugs over the past 25 years has completely changed the clinical prognosis of HIV-infected patients. The deaths of these individuals are now related to atherosclerotic CVDs, rather than from the viral infection itself. However, HIV infection, cART, and intestinal microbiota are associated with immune activation and insulin resistance, which can lead to the development of a variety of diseases and disorders, especially with regards to CVDs. The increase in LPS and proinflammatory cytokines circulating levels and intracellular mechanisms activate serine kinases, resulting in insulin receptor substrate-1 (IRS-1) serine phosphorylation and consequently a down regulation in insulin signaling. While lifestyle modifications and pharmaceutical interventions can be employed to treat these altered metabolic functions, the mechanisms involved in the development of these chronic complications remain largely unresolved. The elucidation and understanding of these mechanisms will give rise to new classes of drugs that will further improve the quality of life of HIV-infected patients, over the age of 50.

Plasma levels of lipopolysaccharide correlate with insulin resistance in HIV patients

BACKGROUND

In HIV patients using HAART insulin resistance is a central pathophysiological condition that can contribute to the development of diabetes and cardiovascular complications. To examine the role of adipocyte hormones and LPS in insulin resistance in HIV patients, we investigated the role of adiponectin, leptin, visfatin and LPS levels in the insulin resistance of HIV-infected patients treated with HAART.

METHODS

This study included 67 HIV positive individuals on HAART and ten healthy controls. All participants performed plasma or serum levels of glucose; insulin; lipids, visfatin, leptin, adiponectin, and LPS. The homeostasis model assessment (HOMA-IR), was used to estimate insulin resistance.

RESULTS

The levels of visfatin, leptin and adiponectin were similar between controls and HIV patients. However, circulating levels of LPS were higher in HIV patients on HAART than in controls. There was a positive correlation between LPS and TG (r = 0.49, p = 0.0001), between LPS and TG/HDL (r = 0.50, p = 0.0001), between LPS and insulin (r = 0.52, p = 0.0003), and between LPS and HOMA-IR (r = 0.52, p = 0.0005), in HIV patients.

CONCLUSIONS

Our results showed a clear correlation between plasma LPS and markers of insulin resistance, suggesting a relationship between LPS levels and metabolic alterations, particularly affecting lipids and insulin resistance in HIV patients.

Safety and efficacy of darunavir (TMC114) with low-dose ritonavir in treatment-experienced patients: 24-week results of POWER 3

OBJECTIVE

In POWER 1 and POWER 2, darunavir (TMC114) with low-dose ritonavir (darunavir/r) demonstrated greater efficacy versus control protease inhibitors (PIs). To examine the efficacy and safety of the selected darunavir/r dose further, additional patients were analyzed.

METHODS

Treatment-experienced HIV-1-infected patients received darunavir/r at a dose of 600/100 mg twice daily plus an optimized background regimen. The primary intent-to-treat analysis was the proportion of patients with an HIV-1 RNA reduction >or=1 log10 at week 24.

RESULTS

Three hundred twenty-seven patients were treated; the baseline mean HIV-1 RNA was 4.6 log10 copies/mL, and the median CD4 count was 115 cells/mm3 (median primary PI mutations = 3, PI resistance-associated mutations = 9). Two hundred forty-six patients reached week 24 by the cutoff date and were included in the efficacy analysis: 65% and 40% achieved HIV-1 RNA reductions of >or=1 log10 and <50 copies/mL, respectively, at week 24. The mean CD4 count increase was 80 cells/mm3. The most common adverse events (AEs) were diarrhea (14%), nasopharyngitis (11%), and nausea (10%). Nine (3%) patients discontinued treatment because of AEs or HIV-1-related events. Six treatment-unrelated deaths (2%) were reported.

CONCLUSIONS

These results corroborate POWER 1 and POWER 2. In this larger set of treatment-experienced patients, darunavir/r at a dose of 600/100 mg twice daily provided substantial virologic and immunologic responses and was generally safe and well tolerated.