BALTIMORE—Zinc supplementation for 18 months in HIV-infected adults appeared to substantially reduce the odds of immunological failure in a multi-university study, including researchers from Johns Hopkins University, University of Miami and Florida International University. In the study, published online ahead of print in Clinical Infectious Diseases journal, not only was long-term zinc supplementation found immune-supportive and safe, it also decreased incidence of diarrhea.
Not zinc deficiency plagues as much as 50 percent of adults with HIV, the researchers set out to examine the safety and efficacy of long-term zinc supplementation on HIV disease progression, primarily looking at immunological failure. Their prospective, randomized, controlled clinical trial involved 231 HIV-infected adults (average age of 43, 73 percent men) with low plasma zinc levels (<0.75 mg/L) randomly assigned to receive zinc (12 mg of elemental zinc for women and 15 mg for men) or placebo for 18 months. According to the researchers, 62 percent of the study participants were receiving antiretroviral (ARV) drug regimen, and 69 percent had detectable viral loads, indicating poor control of the virus with the regimens being used. About 34 percent of the patients had CD4 counts below 200 upon entering the study; 22 percent had CD4s between 200 and 350, and 44 percent had CD4s above 350.
The scientists recorded HIV viral load and CD4(+) cell counts every 6 months, using questionnaires, pill counts and plasma zinc and C-reactive protein levels to monitor adherence to study supplements and ARV therapy. Intent-to-treat analysis used multiple-event analysis, treating CD4(+) cell count <200 cells/mm(3) as a recurrent immunological failure event. Cox proportional hazard models and the general-linear model were used to analyze morbidity and mortality data.
The results revealed 18 months of zinc supplementation led to a 4-fold reduction in the likelihood of immunological failure, controlling for age, sex, food insecurity, baseline CD4(+) cell count, viral load, and ARV therapy. While viral load indicated poor control with ARV therapy, it was not affected by zinc supplementation. Zinc supplementation also reduced the rate of diarrhea by more than half, compared with placebo. However, there was no significant difference in mortality between the two groups. The researchers concluded zinc supplementation is safe and cost-effective adjunct therapy for HIV-infected adult cohorts with poor viral control.
