Frailty and leucocyte count are predictors of all-cause mortality and hospitalization length in non-demented institutionalized older women.

Alteration in the immune system such as the number of white blood cells count (WBC) has been associated with frailty syndrome but their role in institutionalized older individuals have been rarely investigated. We evaluated the relationships between white blood cell subtypes, geriatric assessment, depression and frailty syndrome based on the criteria of physical phenotype. In particular, we aimed to analyze by a two-year follow-up and prospective study the predictive value of alterations in WBC, frailty and functional impairment in terms of hospitalizations and all-cause mortality in institutionalized older women. There was a significant and inverse correlation between the frailty score and lymphocyte count at baseline but it did not display any predictive effect for the outcomes (hospitalizations and mortality). In contrast, monocytes count was significantly correlated with number of hospital stays and predicted hospitalizations in the follow-up. High frailty score directly and better functional status (Barthel score) inversely predicted mortality in the follow-up with an HR of 1.87 (95%CI: 1.04-3.35), and 0.97 (95% CI: 0.96-0.99) (p < .05 in both cases). Further investigation into the role of white blood cell subtypes in aging and its associated adverse outcomes in older adults is warranted. Physical phenotype of frailty besides general population, also predicted mortality in older institutionalized women and deserves specific intervention in this subgroup of older individuals.