Association of Glycemic Status with Bone Turnover Markers in Type 2 Diabetes Mellitus

CONTEXT: Type 2 diabetes mellitus has profound implications on the skeleton. Even though bone mineral density is increased in type 2 diabetes mellitus patients, they are more prone for fractures. The weakening of bone tissue in type 2 diabetes mellitus can be due to uncontrolled blood sugar levels leading to high levels of bone turnover markers in blood. AIMS: The aim of this study is to find the association between glycemic status and bone turnover markers in type 2 diabetes mellitus. SETTINGS AND DESIGN: This case–control study was carried out in a tertiary health care hospital. SUBJECTS AND METHODS: Fifty clinically diagnosed type 2 diabetes mellitus patients in the age group between 30 and 50 years were included as cases. Fifty age- and gender-matched healthy nondiabetics were included as controls. Patients with complications and chronic illness were excluded from the study. Depending on glycated hemoglobin (HbA1c) levels, patients were grouped into uncontrolled (HbA1c >7%, n = 36) and controlled (HbA1c <7%, n = 14) diabetics. Based on duration of diabetes, patients were grouped into newly diagnosed, 1–2 years, 3–5 years, and >5 years. Serum osteocalcin (OC), bone alkaline phosphatase (BAP), acid phosphatase (ACP), and HbA1c levels were estimated. OC/BAP and OC/ACP ratio was calculated. STATISTICAL ANALYSIS USED: Student's t-test, analysis of variance, and Chi-square tests were used for analysis. Receiver operating characteristic (ROC) curve analysis was done for OC/BAP and OC/ACP ratios. RESULTS: Serum OC, HbA1c, and OC/BAP ratio were increased in cases when compared to controls and were statistically significant (P < 0.001). OC/ACP ratio was decreased in type 2 diabetes mellitus and was statistically significant (P = 0.01). In patients with >5-year duration of diabetes, HbA1c level was high and was statistically significant (P < 0.042). BAP levels were high in uncontrolled diabetics but statistically not significant. ROC curve showed OC/BAP ratio better marker than OC/ACP ratio. CONCLUSIONS: Uncontrolled type 2 diabetes mellitus affects bone tissue resulting in variations in bone turnover markers. Bone turnover markers are better in predicting recent changes in bone morphology and are cost effective.