Changes in Collagen Type I C-Telopeptide and Procollagen Type I N-Terminal Propeptide During the Menopause Transition

Abstract

Context: Collagen type I C-telopeptide (CTX) and procollagen type I N-terminal propeptide (PINP) are reference bone resorption and formation markers, respectively.

Objective: To characterize CTX and PINP trajectories across the menopause transition (MT).

Methods: This 18-year longitudinal analysis of a community-based cohort from the Study of Women's Health Across the Nation included 541 women (126 Black, 90 Chinese, 87 Japanese, 238 White) who transitioned from pre- to postmenopause. Multivariable mixed effects regression fit piecewise linear models of CTX or PINP relative to years from final menstrual period (FMP); covariates were race/ethnicity, body mass index (BMI), and age at FMP. In the referent participant (White, 52.46 years at FMP, BMI 27.12 kg/m2), CTX and PINP were stable until 3 years pre-FMP (premenopause). During the MT (3 years before to 3 years after the FMP), CTX and PINP increased 10.3% (P < .0001) and 7.5% (P < .0001) per year, respectively; MT-related gains totaled 61.9% for CTX and 45.2% for PINP. Starting 3 years post-FMP (postmenopause), CTX and PINP decreased 3.1% (P < .0001) and 2.9% (P < .0001) per year, respectively. Compared with the White participants, during the MT, Chinese participants had larger gains in CTX (P = .01), and Japanese women experienced greater increases in CTX (P < .0001) and PINP (P = .02). In postmenopause, CTX (P = .01) and PINP (P = .01) rose more in Japanese relative to White women.

Conclusion: CTX and PINP are stable in premenopause, increase during the MT, and decrease in postmenopause. During the MT and postmenopause, bone turnover change rates vary by race/ethnicity.

Keywords: bone turnover; bone turnover markers; cohort; epidemiology; longitudinal; menopause.