Reference Intervals for Serum Concentrations of Three Bone Turnover Markers (PINP, BAP, CTX) in Male and Female Adults

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SAT 224-247-Osteoporosis I
Clinical
Saturday, June 15, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SAT-230
Julia Michelsen1, Henri Wallaschofski2, Nele Friedrich1, Christin Spielhagen1, Rainer Rettig1, Till Ittermann1, Matthias Nauck1 and Anke Hannemann*1
1University Medicine Greifswald, 2University Medicine Greifswald, Greifswald, Germany
Objective: Bone turnover markers (BTMs) reflect the metabolic activity of bone tissue and can be used to assess fracture risk and monitor treatment of osteoporosis. To adequately interpret BTMs, method-specific reference intervals are needed. We aimed to determine reference intervals for serum concentrations of two bone formation markers: procollagen type 1 N-terminal propepetide (PINP), and bone-specific alkaline phosphatase (BAP), and one bone resorption marker: C-terminal telopeptide of type 1 collagen (CTX).

Material and Methods: We established a healthy reference population from the participants of the first follow-up of the Study of Health in Pomerania. Serum PINP, BAP, and CTX concentrations were measured on the IDS-iSYS Automated System (Immunodiagnostic Systems, Frankfurt am Main, Germany). The reference interval was defined as the central 95% range. We determined age-specific reference intervals for PINP and CTX in men by quantile regression. Age-independent reference intervals were determined for BAP in men and for all three BTMs in pre- and postmenopausal women.

Results: In 1107 men, upper and lower reference limits for PINP and CTX decreased over the observed age range of 25-79 years (reference intervals for 25-29 year-old men: PINP 31.1-95.9 ng/mL and CTX: 0.12-0.83 ng/mL; 75-79 year-old men: PINP 15.7-68.1 ng/mL and CTX: 0.05-0.58 ng/mL). The reference interval for BAP was age independent (25-79 year-old men: 7.5-26.1 ng/mL). In 544 premenopausal women, the reference limits for PINP, BAP and CTX were lower (PINP:17.3-76.3 ng/mL; BAP: 5.8-23.8 ng/mL; CTX: 0.05-0.67 ng/mL) than in 498 postmenopausal women (PINP:17.3-100.9 ng/mL; BAP: 7.5-31.6 ng/mL; CTX: 0.08-1.05 ng/mL). Women taking sex hormones had lower BTMs than women not taking sex hormones.

Conclusion: Adult reference intervals for serum PINP, BAP, and CTX concentrations measured on the IDS-iSYS Automated System were successfully established in a population-based cohort free of bone-related diseases.

Nothing to Disclose: JM, HW, NF, CS, RR, TI, MN, AH

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: We received an independent research grant for determination of serum samples from Immunodiagnostic Systems.