Résumé : Background/objectives: Geriatric patients are highly susceptible to infections. While reduced lymphocyte count has been associated with age, other studies found no change in WBC counts with age. Increased circulating white blood cell (WBC) count has been associated with cardiovascular (CV) diseases and frailty but there are discrepancies. Frailty, geriatric conditions, cardiovascular diseases and WBC count have also been associated with low grade inflammation. Association between geriatric conditions and WBC has been scarcely studied. The aim of the study is to assess the association between WBC and geriatric conditions, CV diseases, and seric IL-6 levels. Design, setting, participants, measurements: We recruited 100 subjects in the general population and hospitalized for chronic medical conditions (age, 23-96. years). We collected information on clinical status (medical history, comorbidities, treatments and geriatric syndromes), biological parameters (hematological tests, cytomegalovirus serology) and cytokine production (basal IL-6). Using stepwise backward multivariate analyses, we defined which set of clinical and biological variables could be predictive of increased total and differential WBC counts. Results: We found that low-grade inflammation is independently associated with total WBC, monocyte and neutrophil counts, but not geriatric conditions. CV diseases were the only significant associated factor for high monocyte count. Conclusion: In this study, we observed that differential and total WBC counts do not seem to be associated with geriatric conditions but with CV diseases, low-grade inflammation and telomere length.