Telomeres and human somatic fitness

Mean leukocyte telomere length may be an indicator of biological age, and as such it appears to provide information over and above chronological age of the risk for developing diseases of aging in humans. Here I propose that the mean leukocyte telomere length is an index of somatic fitness, a concept that breaks down the artificial boundary between aging and diseases of aging. I also propose that, in exceptionally old humans, ultrashort leukocyte telomeres might be a determinant of life span.