Bone turnover markers in Spanish adult men The Camargo Cohort Study.

Background: This cross-sectional study was performed to determine the reference ranges for two bone turnover markers-aminoterminal propeptide of type I collagen (P1NP) and C-terminal telopeptide of type I collagen (beta-CTX)-in normal adult Spanish men as measured in serum by automated methods.

Methods: A community-based population of 660 healthy men > or = 50 years was evaluated. Fasting serum levels of P1NP, beta-CTX, 25-hydroxyvitamin D, and intact parathyroid hormone were measured on the Elecsys 2010 automated analyzer (Roche). BMD at lumbar spine, femoral neck and total hip was determined by DXA.

Results: Mean age of participants was 65 + or - 9 years. Logarithmic transformation of both markers was performed to allow for normal distribution. Mid-95% ranges for P1NP and beta-CTX were 15-78 ng/ml and 0.069-0.760 ng/ml, respectively. Median and interquartile range of serum P1NP and beta-CTX were 33.5 [25.5;44.4] ng/ml and 0.27 [0.19;0.38] ng/ml, respectively. Mean values of P1NP (37.1 + or - 16.7 ng/ml) were similar to those previously described. beta-CTX mean values (0.300 + or - 0.171 ng/ml) were also similar to those quoted by the manufacturers in men younger than 70 years, but slightly lower than those reported in subjects older than 70 years. Both markers were higher among osteoporotic men. After excluding from the analysis those men who were found to have BMD below -2.5 T-score, 25OHD serum level below 30 ng/ml or serum PTH above 65 pg/ml, P1NP and beta-CTX ranges were 17-71 ng/ml and 0.070-0.681 ng/ml, again respectively.

Conclusions: Values obtained from this well-characterized population study provide reference ranges for serum automated P1NP and beta-CTX in normal Spanish adult men.