The effect of micronutrient supplementation on disease progression and death in simian immunodeficiency virus-infected juvenile male rhesus macaques.

BACKGROUND: We investigated the impact that micronutrient supplementation has on the progression of simian acquired immunodeficiency syndrome (SAIDS). METHODS: Twenty-four simian immunodeficiency virus-infected juvenile male rhesus macaques were randomized into 2 groups. One group was given certified chow, and the other group was given chow and a supplement that contained 2-3 times the estimated nutritional requirement of micronutrients. Virological, immunological, and body composition measurements were taken every 4 weeks for 120 weeks. RESULTS: There was no difference between groups in weight gain, body mass index (BMI), crown-heel length, waist circumference, total tissue mass, lean mass, bone mineral content, or bone mineral density. The rhesus macaques on the supplemented diet had a higher death rate (hazard ratio, 2.39; P<.001) than those on the nonsupplemented diet; death in both groups was associated with a higher viral load set point during the early phase of infection. Additionally, higher body weight, BMI, crown-rump length, and lower viral load set point were protective from death in both groups. CONCLUSIONS: Micronutrient supplementation did not significantly alter the progression of SAIDS with respect to changes in body composition and immunological characteristics. A significantly higher rate of death was observed in rhesus macaques on the supplemented diet.

Wasting syndrome and disruption of the somatotropic axis in simian immunodeficiency virus-infected macaques with Mycobacterium avium complex infection.

Mycobacterium avium is a common opportunistic infection of patients with acquired immunodeficiency syndrome (AIDS). We used the simian immunodeficiency virus (SIV)-infected rhesus macaque (Macaca mulatta) model to examine whether disseminated M. avium is associated with disruption of the somatotropic axis in AIDS. Macaques were followed prospectively, and body composition was determined by dual-energy x-ray absorption. Serum levels of insulin-like growth factor (IGF)-1, IGF binding protein-3, growth hormone (GH), and somatostatin were measured. SIV-infected macaques inoculated with mycobacteria had significant changes in body composition, perturbations of the somatotropic axis (characterized by increased GH/IGF-1 ratios) (day 0 [2.21] vs. day of death [DOD] [28.06]; P=.015, Mann-Whitney rank sum test), and increased serum somatostatin levels (day 0 [2.00 ng/mL] vs. DOD [8.58 ng/mL]; P=.026, Mann-Whitney rank sum test). These data document alterations in the somatotropic axis secondary to experimental disseminated M. avium infection and suggest that similar changes may contribute to alterations in body composition during AIDS.

Body-composition changes in the simian immunodeficiency virus-infected juvenile rhesus macaque.

BACKGROUND: Body-composition changes are common in individuals infected with human immunodeficiency virus. The purpose of the present study was to measure, as a model of wasting in acquired immunodeficiency syndrome (AIDS), longitudinal body-composition changes in macaques infected with simian immunodeficiency virus (SIV). METHODS: Twelve juvenile macaques were inoculated with SIVmac239. Immunologic, virologic, somatometric, and dual-energy x-ray-absorptiometry measurements were performed prospectively every 4 weeks for 72 weeks and were compared to measurements taken from 8 uninfected control macaques. RESULTS: During the first 4 weeks, body-fat percentage decreased in the SIV-infected macaques while lean-tissue percentage increased; during weeks 4-72, these macaques lost a greater percentage of total fat tissue but had more subcutaneous-fat deposition than did the uninfected control macaques. Just prior to death, the SIV-infected macaques that died (n=7) had a greater loss in body-mass index, abdominal fat, fat tissue, and lean tissue, compared with that in SIV-infected macaques that survived (n=5). CONCLUSIONS: Body-composition changes in SIV-infected juvenile macaques exhibit 3 phases: during acute infection, loss of body weight from fat tissue; a compensation period during which macaques grow, but at a reduced rate; and a terminal phase, during which tissue is lost from all body compartments. The SIV-infected juvenile macaque provides a useful model for the investigation of wasting in AIDS, particularly for pediatric AIDS wasting.