OBJECTIVETo investigate the age- and gender-related changes in serum biochemical markers for bone metabolic turnover to establish the reference ranges for these markers for osteoporosis prevention and monitoring.

METHODSIn 276 healthy individuals, serum type I collagen C-telopeptide (beta-Crosslaps), osteocalin and alkaline phosphatase levels were measured by electrochemiluminescence immunoassay, radioimmunoassay and consecutive monitoring, respectively.

RESULTSNo significant changes in serum phosphatase was found in relation to age and gender. Serum beta-crosslaps levels tended to increase with age in male and female subjects, but only until the age of 50-59 years, such changes began to be statistically significant (P<0.05) as compared with the levels in the youngest group. Above this age range, beta-crosslaps level in female subjects increased dramatically, showing significant difference between adjacent age groups (P<0.05), which, however, was out observed in male subjects. Serum osteocalin level was lowered with age in female subjects before the age of 50 years, but a significant increase occurred at the age of 50-59 years (P<0.05) followed by a relatively stable and mild increase that did not result in significant difference between adjacent age groups. In male subjects, serum osteocalin level reached the peak level at the age of 30-39 years followed by stable and mild decrease with age. The ratio of beta-crosslaps/osteocalin tended to increase with age in both male and female subjects.

CONCLUSIONThere are age- and gender-related changes in serum beta-crosslaps, osteocalin and especially beta-crosslaps/osteocalin ratio, suggesting the value of testing serum beta-crosslaps and osteocalin in the prevention and treatment of osteoporosis.