Total lymphocyte count and in-hospital mortality in older persons with multimorbidity.
OBJECTIVE
Low total lymphocyte count (TLC) has been found to be a poor prognostic factor in adults affected by heart diseases, malignancy, and renal failure. The aims of this study were to verify if a low TLC was associated with in-hospital mortality in older persons and to evaluate whether this association was independent of the presence of multiple co-existing diseases (multimorbidity).


METHODS
The authors carried out a cross-section analysis of data of 65+ years old patients (n=596) admitted to a Geriatric Unit in Northern Italy. TLC, total white blood cell count (WBC) and serum albumin were assayed the day after admission. The presence and severity of diseases were evaluated with the Geriatric Index of Comorbidity (GIC). Other covariates included age, gender, cigarette smoking, cognition (Mini-Mental State Examination) and function (Activities of Daily Living). Logistic regression models were created to study factors affecting in-hospital death.


RESULTS
TLC was inversely correlated with both age and multimorbidity. Patients in the lowest tertile of TLC had the highest association with death during hospitalization (OR 6.1, 95% CI 1.1-33.6) independently of multimorbidity and all the other covariates. Stratifying the sample by degree of multimorbidity, this association was clearest in patients with the least severe multimorbidity (GIC <or=3).


CONCLUSIONS
Although TLC and multimorbidity were correlated, they emerged as independent predictors of in-hospital death. Further investigations into possible biological mechanisms underlying the association of lymphocytes and adverse outcomes in old persons are needed.
Marengoni
Alessandra
A
Geriatric Unit, Internal Medicine I, Civili Hospital, Department of Medical and Surgery Sciences, University of Brescia, 25123 Brescia, Italy. alessandra.marengoni@ki.se
Petroboni
Beatrice
B
Casella
Silvia
S
Martinelli
Daniela
D
Cossi
Stefania
S
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D018655:Lymphocyte Count; D008297:Male