Age-related circadian rhythm of DHEAS plasma levels in male subjects

The aging influences the endocrine temporal structure, including DHEAS whic h can be considered as a biomarker of aging, since its levels gradually dec rease in older subjects. The aim of this work was to observe the circadian rhythms of DHEAS, prolactin, cortisol and body temperature, in healthy elde rly male subjects (73.7 +/- 2.5 years) compared with healthy young subjects (27.2 +/- 6.6 years). The results documented that in our subjects no signi ficant age-related differences in prolactin levels existed. In elderly subj ects cortisol levels were weakly enhanced in comparison with young subjects . DHEAS showed a preserved circadian rhythm, but markedly lower rhythm adju sted mean (74.38 +/- 10.29 versus 273.63 +/- 26.39) (p < 0.001) and decreas ed amplitude of oscillation (p < 0.001), when expressed as absolute value, in elderly subjects when compared with young subjects. In elderly subjects the DHEAS circadian rhythm modifications could represent an impairment of o f the endocrine temporal structure.