Osteocalcin associates with bone mineral density and VDR gene polymorphisms in type 1 and type 2 diabetes

Abstract

Objectives Bone metabolism is impaired in diabetes mellitus (DM). Our objective is to evaluate the association of bone turnover markers (BTM) and vitamin D receptor (VDR) gene polymorphisms with bone mineral density (BMD) in DM type 1 (T1D) and DM type 2 (T2D). Methods 165 patients (53 T1D and 112 T2D) were enrolled. BMD was measured by dual-energy X-ray absorptiometry (DEXA). Plasma osteocalcin (OC), beta-CrossLaps (β-CTX) and N‐amino terminal propeptide of type I collagen (P1NP) and VDR gene polymorphisms were evaluated. Results Participants were 53 T1D (41 years [31–48]) and 112 T2D (60 years [51–66]). BMD were not statistically different between the groups. OC (p<0.001) and P1NP levels (p<0.001) were higher in patients with T1D. The areas under the curve for the prediction of bone pathology were 0.732 (p=0.038) for OC in T1D and 0.697 (p=0.007) in T2D. A significant association was found between lower lumbar BMD and the A allele of BsmI (p=0.03), the A allele of ApaI (p=0.04) and the allele C of the Taql (p=0.046). Also, a significant correlation was found with higher OC levels and the G allele of BsmI (p=0.044), C allele of ApaI (p=0.011), T allele of Taql (p=0.006) and with C allele of FokI (p=0.004). Conclusions The high negative predictive value of the cut-off point for OC suggests that could be useful in excluding the risk suffering bone loss, allowing offering a personalized clinical approach to prevent this pathology.

Effect of type 2 diabetes on biochemical markers of bone metabolism: a meta-analysis

“…In the subgroup analysis, we found no significant difference in OC results between obese T2DM patients and controls, but significant differences between non-obese T2DM patients and controls, indicating that obesity may play a role in promoting OC activity in T2DM patients, and OC activity is decreased in T2DM patients. Some researchers believe that although OC regulates bone formation, it is also regulated by other hormones (such as insulin), affecting adipose tissue ( Ramirez Ruiz et al, 2023 ). Insulin resistance reduces the binding of insulin to osteoblasts, and OC secretion is insufficient.…”