Low T3 Syndrome is Associated with Imbalance of Bone Turnover Biomarker in Patients with Type 2 Diabetes

Objectives: To investigate the variation in bone turnover biomarkers among patients with type 2 diabetes (T2D) and low Materials and Methods: This retrospective analytic study included 418 inpatient records from Shanghai Pudong Hospital covering the years 2021 to 2023. Laboratory data related to metabolic and bone turnover biomarkers in patients were analyzed with T2D and the Results: The results indicated that patients with reduced serum T3 levels exhibited statistically significant variations in thyroid function, age, fasting plasma glucose (FPG), glycated hemoglobin A1c (HbA1c), and the proportion of medication history associated with diabetes in comparison to euthyroid patients. In addition to parathyroid hormones, bone turnover biomarkers including N-terminal middle molecular fragment of osteocalcin (NMID), plasma calcium (Ca2+), beta C-terminal cross-linking telopeptide of type 1 collagen (beta-CTX), and 25-hydroxyvitamin D3 (25 OH VitD3) exhibited significant changes in patients with decreased T3 levels. Evident irregularities were observed in patients with a decreased T3 level, including elevated serum creatinine (SCr), decreased concentrations of albumin and total protein, and a decreased estimated glomerular filtration rate (eGFR), as assessed through hepatic and renal testing, respectively. Significant associations between bone turnover biomarkers and the subsequent variables (gender, adiposity, hepatic, renal, and thyroid function) were revealed through the correlational analysis. Further investigation utilized multivariate linear regression to determine that, in addition to thyroid function, several other factors such as age, gender, bodyweight, pancreatic, hepatic, and renal function, affected the variability in bone turnover biomarkers among patients demonstrating a low serum T3 level. Conclusions: This comparative study demonstrated that despite age, gender, bodyweight, hepatic, renal function, thyroid hormone and pancreatic function were significant factors associated with bone metabolism in patients with T2D and Low T3 syndrome, which may increase the risk of osteoporosis.