Bone Abstracts

Background: Several bone metabolic pathways are disrupted in diabetes mellitus (DM), leading to reduced bone mass. Increased fracture risk and elevated Dickkopf-1, which is an inhibitor of the Wnt/b-catenin bone metabolic pathway, have been documented in adult patients with type 2 DM. No relevant data exist on childhood type 1 DM (T1DM).

Objective and hypotheses: We aimed at studying plasma Dickkopf-1 concentration in children and adolescents with T1DM and controls. We subsequently correlated Dickkopf-1 levels with metabolic bone markers and bone mineral density (BMD).

Methods: We evaluated 40 children and adolescents with T1DM (mean±S.D. age: 13.04±3.53 years,T1DM duration: 5.15±3.33 years), along with 40 healthy matched controls (age: 12.99±3.3 years). Serum Dickkopf-1, Sclerostin, Osteocalcin, C-telopeptide crosslinks (CTX), electrolytes, PTH, total 25(OH) D were measured and lumbar spine and total body BMD were evaluated.

Results: BMD was found lower and Dickkopf-1 levels were found higher (13.56±5.34 vs 11.35±3.76 pmol/l, P=0.0194) in T1DM patients. A trend for lower values was found in girls (13.36±4.04 vs 11.72±5.14 pmol/l, P=0.06) and in pubertal children (13.61±4.87 vs 11.83±4.56 pmol/l, P=0.054). Dickkopf-1 correlated with Sclerostin and L1–L4 BMD z-score only in controls and with Osteoprotegerin and i-Phosphorus only in patients, while in both groups a significant correlation with log (CTX) and √ALP was documented. A significant correlation of Dickkopf-1 with IGF1 and insulin dose was also found in patients.

Conclusion: Higher levels of Dickkopf-1 were found in T1DM children and adolescents, indicating a down-regulated Wnt signaling system and possible lower osteoblast activation that could be associated with T1DM osteopathy.

Disclosure: The authors declared no competing interests.