Interrelations of immunological parameters, nutrition, and healthcare-associated infections: Prospective study in elderly in-patients

Summary Background & aims Healthcare-associated infections [HAI] are common in elderly individuals and may be related to both nutritional deficiencies and immunosenescence. Here, we assessed whether overall malnutrition and/or specific nutrient deficiencies were associated with HAI via alterations in immune parameters. Methods Prospective observational cohort study in patients aged ≥70 years admitted to the geriatric rehabilitation unit of a teaching hospital in France between July 2006 and November 2008. Clinical and laboratory parameters reflecting nutritional status and immune function were collected at baseline. Flow cytometry was used to assess blood lymphocyte subsets including the naive CD4 T-cell count, naive and memory CD8 T-cell counts, effector CD8 T-cell count, and CD4/CD8 ratio. Patients were monitored for HAI for 3 months or until discharge from the geriatric unit or death. Results Of 252 consecutive in-patients aged ≥70 years [mean age, 85 ± 6.2 years], 181 [72%] met French National Authority for Health criteria for malnutrition and 97 [38%] experienced one or more HAI. Patients who subsequently experienced HAI had significantly lower baseline values for energy intake [odds ratio (OR), 0.76; 95% confidence interval (95%CI), 0.59–0.99], serum albumin [OR, 0.43; 95%CI, 0.32–0.58], serum zinc [OR, 0.77; 95%CI, 0.62–0.97], selenium [OR, 0.76; 95%CI, 0.61–0.95], and vitamin C [OR, 0.71; 95%CI, 0.54–0.93]. Associations linking these five variables to HAI were not significantly changed by adjusting for flow cytometry T-cell subset values. Conclusion Our results suggest a direct effect of nutritional parameters on HAI rather than an indirect effect mediated by immune parameters.