Telomere shortening in peripheral blood cells was related with aging but not with white blood cell count

Telomeres in somatic cells are progressively shortened with aging. We investigated the relationship between the telomere length and other factors which may affect the frequency of cell divisions, in peripheral blood cells. Shortening of telomeric repeats was correlated with aging (p < 0.0001), but not with white blood cell count, neutrophil count, and smoking habit. Not only the number of cell divisions, but also some other factors, such as upregulation level of telomerase activity concomitant with the cell division in hematopoietic progenitor cells, might affect the length of telomeric repeats in blood cells.