Immune response in relation to zinc status, sex and antioxidant defence in Italian elderly population: the ZENITH study

Abstract

Objective: Evaluation of some immune markers in Italian elderly population in relation to zinc status, gender and antioxidant defence. Design: Observational study. Setting: Italian population. Subjects: Apparently healthy, free-living subjects, 56 men and 52 women, aged 70-85 y, enrolled in Italy. Methods: Lymphocytes were unstimulated or stimulated with the mitogen phytohemoagglutinin (PHA). The proliferative capacity was measured as incorporation of [ 3 H]-thymidine and reported as stimulation index (SI). Cytokine secretion by lymphocytes was determined by ELISA. The antioxidant enzyme activities were measured using commercial kits. Results: Dietary zinc intake, as well as zinc in serum, red blood cells and urine were on the normal range of values and did not show any difference between men and women. The proliferative response showed a high variability without significant differences between men and women. The amount of secreted pro-and anti-inflammatory cytokines was similar in men and women. No differences were found in the activity of antioxidant enzymes in lymphocytes, namely superoxide dismutase, glutathione peroxidase and catalase, between men and women. An association between SI and serum zinc level in men was found. SI resulted negatively correlated with interleukin (IL)-1b (R 2 ¼ 0.036 and P ¼ 0.012) and IL-10 (R 2 ¼ 0.34 and P ¼ 0.040) only in men. IL-10 of PHA-stimulated lymphocytes was negatively correlated with red blood zinc in men (R 2 ¼ 0.41 and P ¼ 0.008), while IL-10 of unstimulated and PHA-stimulated lymphocytes were negatively correlated with serum zinc in women (R 2 ¼ 0.38 and P ¼ 0.020; R 2 ¼ 0.31 and P ¼ 0.040, respectively). No correlation was observed between immune markers and antioxidant enzyme activities. Conclusions: Only weak differences on immune response between men and women were observed. However, zinc status appears to have more influence on the ability of lymphocytes to proliferate in men than in women.

Introduction to the ZENITH study and summary of baseline results

“…Clearly, further research is needed to explore the effect of improved Zn status on emerging immune deficiencies in cell-mediated immunity in healthy 55-70 y olds. In the Zenith study, the influence of Zn status, sex and antioxidant defence on immune response have also been investigated (Finamore et al, 2005). The results obtained did not show a different proliferative capacity between men and women.…”

The Stoichiometric Transition from Zn6Cu1-Metallothionein to Zn7-Metallothionein Underlies the Up-regulation of Metallothionein (MT) Expression

“…However, precisely how zinc supplementation helps to slow down the progression of AMD is not quite understood at the cellular and molecular levels. It has been speculated that aging is associated with a deficiency in zinc, leading to chronic inflammation and oxidative stress in the immune system (21,22). Likewise, zinc supplementation was associated with higher protection against protein oxidation (23).…”

The Association of Geriatric Nutritional Risk Index and Total Lymphocyte Count with Short-Term Nutrition-Related Complications in Institutionalised Elderly

“…In the past, attention was paid not only to TLC but also, and particularly, to the lymphocytes function (e.g. cytokine release, proliferation or delayed hypersensitivity) whose impairment have already been demonstrated both with the occurring of protein-calorie malnutrition and the impairment of several nutrients (protein, iron and zinc) [2,7,8,12,[32][33][34][35]. Accordingly, an improvement of cell-mediated immune function has been Lymphocyte Count and Nutritional Risk in the Elderly demonstrated in both human and animal-model studies when nutritional repletion [5], micronutrients supplementation [36,37] or immune-enhancing diet administration are provided [38].…”