Association of skin autofluorescence with low bone density/osteoporosis and osteoporotic fractures in type 2 diabetes mellitus

Abstract

Background: Advanced glycation end products (AGEs) that abnormally accumulate in diabetic patients have been reported to damage bone health. We aimed to investigate the association between skin autofluorescence (SAF)-AGEage (SAF − AGEs × age/100) and low bone density (LBD)/osteoporosis or major osteoporotic fractures (MOFs) in patients with type 2 diabetes mellitus (T2DM). Methods: This study was nested in the prospective REACTION (Risk Evaluation of Cancers in Chinese Diabetic Individuals) study and included 1214 eligible participants. SAF was used to measure skin AGEs (SAF-AGEs). Fracture events were determined by an in-person clinical follow-up. Binary logistic regression analysis, linear regression analysis, and a restricted cubic spline nested in logistic models were used to test outcomes. Results: The overall prevalence of LBD/osteoporosis in middle-aged or elderly T2DM patients was 35.7% (n = 434), and the overall incidence of MOFs was 10.5% (n = 116). Logistic analysis showed a significantly positive relationship between quartiles of SAF-AGEage and the risk of LBD/osteoporosis (odds ratio [OR] 2.02, 95% CI 1.34–3.03; OR 3.63, CI 2.44–5.39; and OR 6.51, CI 4.34–9.78) for the multivariate-adjusted models, respectively. SAF-AGEage was associated with MOFs with a multivariate-adjusted OR of 1.02 (CI 0.52–2.02), 2.42 (CI 1.32–4.46), and 2.70 (CI 1.48–4.91), respectively. Stratified analyses showed that SAF-AGEage was significantly associated with MOFs only in females, nonsmokers, nondrinkers, individuals with lower body mass index, and those without LBD/osteoporosis. Linear regression analyses showed that higher SAF-AGEs were associated with a higher level of serum N-terminal propeptide of type I procollagen (s-PINP) and serum carboxy-terminal cross-linking peptide of type I collagen (s-CTX), with a multivariate-adjusted OR of 1.02 (CI 0.24–1.80) and 6.30 (CI 1.77–10.83), respectively. Conclusions: In conclusion, SAF-AGEage was positively associated with the prevalence of LBD/osteoporosis or MOFs in patients with T2DM. A positive association between SAF-AGEs and the level of s-PINP and s-CTX was found.