Variation of hemoglobin levels in normal Italian populations from genetic isolates

Normal Hb levels vary greatly according to genetic and acquired factors. As a consequence there is no general agreement on the definition of anemia in terms of hemoglobin (Hb) levels. Here we compare the Hb levels of subjects recruited from normal genetically isolated Italian populations whose medical history, life style habits and results of laboratory tests are available. After the exclusion of pathological samples we analyzed the Hb levels of 3,849 subjects (1,661 males and 2,188 females) and evaluated the Hb heritability. Normal subjects of different age groups from a northern Italian isolate have significantly higher Hb levels when compared to matched subjects of southern Italian isolates. The estimated heritability of Hb levels ranges from 0.34 to 0.42 in the different isolates. Our study provides a dataset of Hb levels for normal subjects of different geographical origin and indicate that Hb levels are substantially influenced by heritable components.