Characteristics of bone metabolism parameters in urban citizens

Abstract

Aim. To reveal the features of age-dependent changes of bone tissue in urban citizens.

Methods. The study of bone metabolism parameters was performed on 629 healthy subjects of middle, elderly and senile age living in Vladivostok for longer than 10 years (55 males and 573 females). Concentration of C-terminal telopeptide of type II collagen, osteocalcin, calcitonin, parathyroid hormone, 1,25(OH)2-vitamin D, and bone isoenzyme of alkaline phosphotase were measured by ELISA. Concentration of C-terminal telopeptide of type I collagen was measured in urine.

Results. Biochemical markers of bone metabolism in older age groups are different from the parameters of middle age. In the second period of middle age statistically significant decrease of C-terminal telopeptides level (z=2.88, p <0.05) and increase of parathyroid hormone level (z=-3.04, p <0.01) were revealed. With age, people of elderly and senile age have increasing bone isoenzyme of alkaline phosphatase level (z=-3.28, p <0.01; z=-2.58, p <0.05) reflecting prevalence of mineralizing properties of bone matrix. In people of elderly and senile age misbalance of hormonal regulation of bone-tissue metabolism was revealed presenting as a decrease of somatotropic hormone level (z=2.87, p <0.05; z=2.12, p <0.05) and escalation of parathyroid hormone (z=-4.49, p <0.001; z=-3.10, p <0.01).

Conclusion. Bone metabolism changes occur already in the second period of middle age; bone matrix mineralization is changed due to reduced level of matrix proteins functioning as domains of mineralization; as they age, misbalance develops in hormonal factors regulating bone metabolism eventually leading to the reduction of bone regeneration intensity.

Keywords

bone metabolism / bone tissue markers / parathyroid hormone / aging / vitamin D / osteocalcin

RIGHTS & PERMISSIONS

Kabalyk M.A.