Background: In experimental ageing models an inverse relationship between age and alkaline phosphatase activity has been observed.
Objective: To characterize serum levels of alkaline phosphatase activity in humans according to age and gender.
Methods: Serum alkaline phosphatase was determined in a random sample of 203 community dwellers aged 40 or more years.
Results: In men (n=87) total serum alkaline phosphatase markedly increased from the 5th to the 6th decade and then stabilized. For women (n=116) there was a slight increase in total serum alkaline phosphatase from the 5th to the 6th decade, followed by a bend upward after 69 years of age. There was a significant positive correlation between total serum alkaline phosphatase and age for the whole population.
Conclusions: Serum alkaline phosphatase activity appears as a biomarker of age in humans, similarly to what has been described for experimental animal models.