Serum Glycine Levels Are Associated With Cortical Bone Properties and Fracture Risk in Men

Area of Science:

• Metabolomics
• Bone Biology
• Gerontology

Background:

• A previous study identified 27 metabolites, including serum glycine, associated with bone mineral density (BMD).
• Glycine, an amino acid, plays a role in collagen synthesis, a key component of bone.

Purpose of the Study:

• To investigate the association of serum and urinary glycine levels with BMD, bone microstructure, and fracture risk in older men.
• To determine if glycine can serve as a predictive biomarker for bone health outcomes.

Main Methods:

• The study utilized data from the Osteoporotic Fractures in Men (MrOS) Sweden cohort, including serum and urinary glycine measurements, BMD, bone microarchitecture (high-resolution peripheral quantitative computed tomography), and fracture data.
• Linear and Cox regression models were used to evaluate associations, with a meta-analysis combining data from multiple cohorts.

Main Results:

• Serum glycine levels showed a significant inverse association with femoral neck BMD.
• Glycine levels were also inversely associated with bone strength parameters, specifically cortical cross-sectional area, and directly associated with cortical porosity.
• Both serum and urinary glycine levels independently predicted an increased risk of major osteoporotic fractures, even after adjusting for BMD and FRAX scores.

Conclusions:

• Serum and urinary glycine levels are indirectly associated with femoral neck BMD and cortical bone strength.
• Glycine levels are directly associated with an increased risk of fractures in men.
• Glycine may serve as a potential biomarker for assessing bone health and fracture risk in aging men.