NFECTIONS, PARTICULARLY RESPIRAtory tract infections, are common in elderly individuals, resulting in decreased daily activity, prolonged recovery times, increased health care service use, and more frequent complications, including death. [1][2][3][4][5][6][7][8][9][10][11] In the United States, an estimated 43% of elderly persons will be admitted to a nursing home, with more than 85% of them admitted to long-term (Ͼ1 year) care facilities. 12 Infections occur more frequently in nursing home residents than among independent-living elderly, 2-10,13 and respiratory tract infections are a major cause of morbidity and mortality. 9,14,15 Contributing to the increased incidence of infection with age is the well-described decline in immune response. 16 For example, those who have diminished delayed-type hypersensitivity skin test responses have higher morbidity and mortality from cancer, pneumonia, and postoperative complications. [17][18][19] Nutritional status is an important determinant of immune function. 20,21 Nutritional supplementation has been shown to enhance the immune response in older persons. 22,23 In our earlier pla-Author Affiliations are listed at the end of this article.

Normal serum zinc concentrations in nursing home elderly are associated with a decreased incidence and duration of pneumonia, a decreased number of new antibiotic prescriptions, and a decrease in the days of antibiotic use. Zinc supplementation to maintain normal serum zinc concentrations in the elderly may help reduce the incidence of pneumonia and associated morbidity.

Background: Vitamin E supplementation may be a potential strategy to prevent respiratory tract infections (RIs) in the elderly. The efficacy of vitamin E supplementation may depend on individual factors including specific single nucleotide polymorphisms (SNPs) at immunoregulatory genes. Objective: We examined whether the effect of vitamin E on RIs in the elderly was dependent on genetic backgrounds as indicated by SNPs at cytokine genes. Design: We used data and DNA from a previous vitamin E intervention study (200 IU vitamin E or a placebo daily for 1 y) in elderly nursing home residents to examine vitamin E-gene interactions for incidence of RI. We determined the genotypes of common SNPs at IL-1b, IL-2, IL-6, IL-10, TNF-a, and IFN-c in 500 participants. We used negative binomial regression to analyze the association between genotype and incidence of infection. Results: The effect of vitamin E on lower RI depended on sex and the SNP at IL-10 2819G/A (P = 0.03 for interaction for lower RI). Furthermore, we observed that subjects with the least prevalent genotypes at IL-2 2330A/C (P = 0.02 for upper RI), IL-10 2819G/A (P = 0.08 for upper RI), and IL-10 21082C/T (P , 0.001 for lower RI in men) had a lower incidence of RI independent of vitamin E supplementation. Conclusions: Studies that evaluate the effect of vitamin E on RIs should consider both genetic factors and sex because our results suggest that both may have a significant bearing on the efficacy of vitamin E. Furthermore, common SNPs at cytokine genes may contribute to the individual risk of RIs in the elderly. This trial was registered at clinicaltrials.gov as NCT00758914.Am J Clin Nutr 2010;92:106-14.

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