High Sclerostin and Dickkopf-1 ( DKK-1) Serum Levels in Children and Adolescents With Type 1 Diabetes Mellitus

Context: Childhood type 1 diabetes mellitus (T1DM) is associated with decreased bone mass. Sclerostin and dickkopf-1 (DKK-1) are Wnt inhibitors that regulate bone formation. Objective: To evaluate sclerostin and DKK-1 levels in T1DM children and to analyze the influence of glycemic control on bone health. Design and setting: Cross-sectional study conducted at a clinical research center. Participants: One hundred and six T1DM subjects (12.2 +/- 4 years), 66 on multiple daily injections (MDIs) and 40 on continuous subcutaneous infusion of insulin (CSII), and 80 controls. Results: The average bone transmission time (BTT) and amplitude-dependent speed of sound (ADSoS) z scores were lower in patients with diabetes than in controls. Significantly increased DKK-1 (3593 +/- 1172 vs 2652 +/- 689 pg/mL; P < 0.006) and sclerostin (29.45 +/- 12.32 vs 22.53 +/- 8.29; P < 0.001) levels were found in patients with diabetes with respect to controls, particularly in patients on MDI compared with ones on CSII. Glycemic control was improved in CSII patients compared with MDI ones (P < 0.001) and was also associated with significantly higher BMI-SDS (P < 0.002) and BTT z scores (P < 0.02). With adjustment for age, multiple linear regression analysis of DKK-1 and sclerostin as dependent variables showed that levels of glycated hemoglobin, glucose, 25(OH) vitamin D, osteocalcin, and parathyroid hormone; years of diabetes; and BMI-SDS and AD-SoS z score were the most important predictors (P < 0.0001). Conclusions: Our study highlighted (1) the high serum levels of DKK-1 and sclerostin in T1DM children and their relationship with altered glycemic control and (2) the effect of CSII on improvement of glycemic control and bone health in T1DM children.