NEW YORK (Reuters Health) – In HIV-infected adults with low plasma zinc levels, supplementation at nutritional levels for 18 months prevents immune failure during antiretroviral therapy and reduces diarrhea, according to research published online May 10th in Clinical Infectious Diseases.
Which HIV patients should receive zinc? “Those who have poor diet and are zinc deficient, as deficiency further impairs the immune response,” said lead author Dr. Marianna K. Baum from Florida International University in Miami in e-mail to Reuters Health.
Zinc is essential for immune function, yet more than half of HIV-infected adults are zinc-deficient.
“Zinc is immune-stimulatory, as it is the active part of many proteins needed to activate cytokines for the proliferation of immune cells,” Dr. Baum said. “Zinc is also the active part of Zn-Cu Superoxide, an important antioxidant enzyme that protects the cellular membranes and the mitochondria.”
In their randomized trial, Dr. Baum and her colleagues assigned 231 HIV-infected adults with plasma zinc levels < 0.75 mg/L to receive elemental zinc (12 mg for women, 15 for men) or placebo for 18 months. Ultimately, 104 of 115 in the zinc arm and 96 of 166 in the placebo arm completed the study. The two groups were well matched in demographic and other characteristics, including plasma zinc levels, disease stage, drug use, intermittent treatment, or adherence to antiretroviral therapy at baseline.
Zinc supplementation significantly raised plasma zinc levels over time and was free of adverse effects, the authors report. Moreover, it reduced fourfold the likelihood of immunological failure, defined as a decrease of CD4+ cell count to < 200 cells per microliter (relative rate, 0.24; p < 0.002).
At baseline, 32% of study subjects reported having diarrhea within the past 12 months, with nearly 12% reporting moderate or severe diarrhea. Although there were no between-group difference in the prevalence of diarrhea, zinc supplements reduced the rate of diarrhea by more than half (odds ratio, 0.4; p = 0.019).
Poor control of viral load was common and was not affected by zinc supplementation, the authors say. About 62% of study subjects reported using antiretroviral therapy; more than two-thirds of these patients (70%) had detectable viral load (> 400 copies/mL).
There were no significant between-group differences in respiratory diseases or other health events or mortality. During the study, 11 subjects in the zinc arm and 8 in the placebo arm died.
Dr. Baum and colleagues say the results of this study can be generalized