Open AccessSerum Glycine Levels Are Associated With Cortical Bone Properties and Fracture Risk in Men
Author(s) -
Anna L. Eriksson,
Nele Friedrich,
Magnus K. Karlsson,
Östen Ljunggren,
Mattias Lorentzon,
Maria Nethander,
Henri Wallaschofski,
Dan Mellström,
Claes Ohlsson
Publication year - 2021
Publication title -
the journal of clinical endocrinology and metabolism/journal of clinical endocrinology and metabolism
Language(s) - English
Resource type - Journals
eISSN - 1945-7197
pISSN - 0021-972X
DOI - 10.1210/clinem/dgab544
Subject(s) - medicine , bone mineral , endocrinology , quantitative computed tomography , femoral neck , osteoporosis , cortical bone , bone density , hazard ratio , population , urology , confidence interval , pathology , environmental health
Context In a recent study a pattern of 27 metabolites, including serum glycine, associated with bone mineral density (BMD). Objective To investigate associations for serum and urinary glycine levels with BMD, bone microstructure, and fracture risk in men. Methods In the population-based Osteoporotic Fractures in Men (MrOS) Sweden study (men, 69-81 years) serum glycine and BMD were measured at baseline (n = 965) and 5-year follow-up (n = 546). Cortical and trabecular bone parameters of the distal tibia were measured at follow-up using high-resolution peripheral quantitative computed tomography. Urinary (n = 2682) glycine was analyzed at baseline. X-ray-validated fractures (n = 594) were ascertained during a median follow-up of 9.6 years. Associations were evaluated using linear regression (bone parameters) or Cox regression (fractures). Results Circulating glycine levels were inversely associated with femoral neck (FN)-BMD. A meta-analysis (n = 7543) combining MrOS Sweden data with data from 3 other cohorts confirmed a robust inverse association between serum glycine levels and FN-BMD (P = 7.7 × 10-9). Serum glycine was inversely associated with the bone strength parameter failure load in the distal tibia (P = 0.002), mainly as a consequence of an inverse association with cortical cross-sectional area and a direct association with cortical porosity. Both serum and urinary glycine levels predicted major osteoporotic fractures (serum: hazard ratio [HR] per SD increase = 1.22, 95% CI, 1.05-1.43; urine: HR = 1.13, 95% CI, 1.02-1.24). These fracture associations were only marginally reduced in models adjusted by FRAX with BMD. Conclusions Serum and urinary glycine are indirectly associated with FN-BMD and cortical bone strength, and directly associated with fracture risk in men.