title: Age-related changes in peripheral blood counts in humans.
abstract: Anaemia has become a common concern in geriatric health. Since its prevalence varies quite significantly among different groups depending on factors such as ethnicity, lifestyle or fitness, the appropriateness of the current WHO definition of anaemia in the elderly may be questioned. We evaluated peripheral blood parameters from 1,724 individuals (908 women aged 18-101 years and 816 men aged 18-96 years), who were treated at the University of Heidelberg Medical Center with no known haematological history. Patients with a known malignant haematological or oncological disease or with chronic infection or inflammation were excluded. Patients with disorders affecting the kidneys, thyroid or stomach, as well as patients with a bleeding history, haemolysis or who had been previously diagnosed with anaemia were excluded from the study. Average haemoglobin levels for men beyond the age of 70 and for women beyond the age of 80 were found to fulfill the WHO criteria for the diagnosis of anaemia. While in our cohort ∼20% of men and women between 60-69 years of age were by definition anaemic, these numbers steadily increased to 63% in females and 76% in males beyond the age of 90. Based on the results of our study and in accordance with the literature on this topic, we suggest age-adjusted criteria for the diagnosis of anaemia in the elderly in conjunction with a geriatric assessment.
authors.affiliation: Department of Immunotherapy and Gene Therapy, Saarland University Medical Center, Homburg/Saar; ; Department of Hematology/Oncology, University of Heidelberg Medical Center, Heidelberg,  Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Mahlknecht
authors.forename: Simone
authors.initials: S
authors.lastname: Kaiser