Title:Relation of the Serum Levels of DKK-1 and Osteoprotegerin with Bone Mass in Tightly Controlled Rheumatoid Arthritis
Volume: 17
Issue: 1
Author(s): Carmen Gómez-Vaquero*, Irene Martín, Andrea Zacarías, Pedro Alía, Estíbaliz Loza, Loreto Carmona and Javier Narváez
Affiliation:
- Rheumatology and Clinical Laboratory Services, Hospital Universitari de Bellvitge-IDIBELL, L'Hospitalet, Barcelona,Spain
Keywords:
Rheumatoid arthritis, osteoporosis, bone density, osteoprotegerin, DKK-1, β coefficient.
Abstract:
Objective: To analyze the association between serum levels of osteoprotegerin (OPG)
and Dickkopf-related protein 1 (DKK-1) and the annual percent change (Δ%) in bone mineral density
(BMD) in patients with tightly controlled rheumatoid arthritis (RA).
Methods: Observational mixed-study. RA patients followed-up with a tight-control strategy were
included. Bone densitometries were performed at baseline (T0) and follow-up (T1) and serum levels
of OPG and DKK-1 were measured by ELISA also in T0 and T1; additional clinical variables
included disease activity measures, and treatment for RA and osteoporosis. Descriptive bivariate
and multivariate analyses, stratified by gender, were performed.
Results: We included 97 RA patients (70% female, with a mean age of 53 years, and 76% with low
activity by DAS28); 95% were treated with DMARDs and 37% with anti-osteoporotic drugs. Mean
time between T0 and T1 was 2.7 years. Most patients had their BMD improved. The mean Δ%BMD
was +0.42% for lumbar spine, +0.15% for femoral neck and +0.91% for total femur. In men,
baseline OPG was significantly associated with higher BMD loss (β coefficient -0.64) at the femoral
neck. In women, DKK-1 was associated with higher BMD loss at the femoral neck (β coefficient
-0.09), and total femur (β coefficient -0.11); however, DKK-1 was associated with lower
BMD loss at the lumbar spine (β coefficient 0.06).
Conclusion: In tightly controlled RA patients, we have found no evidence of bone loss. The role of
DKK1 and OPG seems small and might be related to sex and location.
