Lamb LS, et al. - Authors tested the presumption that bone turnover is differentially modulated and fracture risk in older men is predicted by circulating advanced glycation end products (AGEs) and endogenous secretory receptor for AGEs (esRAGE). Findings suggested a positive association of glycemia with carboxymethyllysine (CML) and reciprocally with esRAGE in older men. Bone turnover in older men is modulated by circulating esRAGE, whereas the incidence of hip fracture is predicted by CML. In men without and with diabetes, plasma CML, methylglyoxal, glyoxal, and esRAGE were similar.

Methods

• Experts assayed the collagen type I C-terminal cross-linked telopeptide, N-terminal propeptide of type I collagen (P1NP), and total osteocalcin (TOC) using immunoassay and undercarboxylated osteocalcin (ucOC) following hydroxyapatite binding.
• They assayed plasma N-carboxymethyllysine (CML) and esRAGE using immunoassay.
• Using mass spectrometry, they assayed methylglyoxal and glyoxal.
• They ascertained the incident hip fractures.

Results

• As per data, the median age was 76.3 years (interquartile range, 74.2 to 79.1 years).
• They measured plasma CML in 3011 men, methylglyoxal and glyoxal in 766 men, and esRAGE in 748 men.
• Findings suggested similar plasma CML, methylglyoxal, glyoxal, and esRAGE in men without and with diabetes (allP > 0.05).
• They noted a positive association of CML with fasting glucose (r = 0.06,P < 0.001), and esRAGE was inversely associated (r = −0.08, P=0.045).
• A positive association of esRAGE was seen with bone formation (P1NP, r = 0.17, P < 0.001; ucOC, r = 0.11, P=0.008; TOC, P=0.16, P < 0.001).
• Results demonstrated that in 106 men, incident hip fractures occurred during follow-up.
• Reduced incidence of hip fracture was seen in men with CML in the third quartile of values compared with men in the lowest quartile (hazard ratio, 0.49; 95% CI, 0.24 to 0.99;P= 0.045).