angiotensin receptors and age related mitochondrial decline in hiv patients

Conditions: HIV; Aging; Sarcopenia; Angiotensin Receptor Antagonists

Summary: this study is designed to evaluate specific factors in mitochondria that may precipitate premature aging and physical weakness in hiv patients. angiotensin receptors 1 and 2 (at1r and at2r) are found in virtually every cell type. this study will evaluate how the relationships among these receptors in immune and skeletal muscle cells change with hiv, and how these changes might trigger mitochondrial dysfunction, declines in muscle strength, and cellular decline in people living with hiv.

hiv related premature cellular aging and declines in mitochondrial function are closely linked. dysfunctional mitochondria generate higher levels of reactive oxygen species (ros) and provide less atp supply cellular energy. impaired turnover of damaged mitochondria leads to gradual but progressive decline in energy metabolism, increases in muscle fibrosis and clinically apparent weakness. the renin angiotensin system (ras) is a central hormonal system that contributes to mitochondrial dysfunction and impacts both lifespan and function across multiple organ systems. deletion of the angiotensin type 1 receptor (at1r) results in a 25-30% extension of lifespan in mouse models, partly through increasing mitochondrial numbers. blocking of at1r reduces a number of age-related morbidities in mice, and in human studies. a plethora of data implicates ras modulation in marked effects on fitness, frailty and beneficial responses to exercise in older adults. despite this, there are virtually no data examining ras biology in hiv+ vs. age-matched hivsubjects, no data of ras in relation to key hiv-specific variables (duration of hiv, treatment history, immune markers), and no data examining the effects of blocking at1r on physical function in hiv infected subjects. in this study, we will examine the ras and its contribution to premature mitochondrial failure in hiv patients. we will begin to fill this void by enrolling 40 hiv+ subjects in a randomized, double-blinded, placebo controlled pilot study of treatment with at1r blocker to determine the feasibility of a larger trial, estimate effect size, assess the correlation of angiotensin receptor (ar) expression in peripheral blood cells and muscle cells, and the association of ar expression with physical function measures and immunity.

Eligibility criteria:
inclusion criteria: * able to provide informed consent * able to attend an extended (\~4 hour) clinical research visit * documented hiv seropositivity * on a stable anti-retroviral therapy (art) regimen for at least 12 months * hiv plasma viral load \< 50 copies/ml for at least 6 months * systolic blood pressure \>110 exclusion criteria: * creatinine \> 1.5 uln (or creatinine clearance \< 60 ml/min) * anti-hypertensive therapy with ace-i or at1r-blockers * inability to perform functional measures (e.g. non-ambulatory without assistance, requires a prosthesis) * recent (within 30 days) acute illness requiring medical therapy or hospitalization * immunosuppressive agents (e.g. \> 20 mg/d x 2 or more weeks of prednisone or equivalent, chemotherapy) in the last 6 months * cancer requiring treatment w/in 3 yrs (except for non-melanoma skin cancer) * blood thinning medications such as coumadin or plavix or a bleeding disorder such as hemophilia that could cause complications during muscle biopsies * pregnancy (will provide urine test for females of child bearing potential) * regular use of non-steroidal anti-inflammatory drugs or other immune modulating agents.