Novel Metabolic Pathways Associated with Serum Bone Turnover Markers in Healthy Young Adults

OBJECTIVES: Optimal bone health is maintained through a remodeling cycle consisting of resorption followed by formation. Procollagen type I N-terminal propeptide (P1NP) and C-terminal telopeptides of type I collagen (CTX) are biomarkers of bone metabolism that capture changes in bone formation and bone resorption, respectively. This study aimed to identify unique metabolic pathways related to bone turnover markers (BTMs) in healthy young adults. METHODS: This cross-sectional study included 34 healthy, young adults (19 females, average age 27.8 years). Bone mineral density (BMD) was assessed by dual-energy x-ray absorptiometry. Fasting plasma was analyzed using dual column liquid chromatography and ultra-high-resolution mass spectrometry for metabolomics. Serum levels of P1NP and CTX were measured with ELISA. Linear regression and pathway enrichment analyses were used to identify metabolic pathways related to the BTMs. RESULTS: All participants had a normal whole-body BMD T-score. Metabolites significantly associated with P1NP (at P