Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


The Serum Level of Undercarboxylated Osteocalcin (ucOC) in Patients with Rheumatoid Arthritis A High Dose of Predonisolone Decrease the Serum Level of ucOC.

Sakai2,  Yoshitada, Hashiramoto4,  Akira, Hashimoto4,  Teppei, Kawasaki4,  Yoshiko, Tanaka4,  Chihiro, Shiozawa3,  Shunichi, Kurosaka1,  Masahiro

Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine
The Center of Rheumatic Diseases, Kobe University Hospital, Kobe, Hyogo, Japan
The Center of Rheumatic Diseases, Kobe University Hospital, Kobe, Japan
The Center of Rheumatic Diseases, Kobe University Hospital

Purpose:

Rheumatiod arthritis (RA) causes systemic osteoporosis as well as periarticular osteoporosis, and becomes one of the risk factor of osteoporotic fracture. On the other hand, several previous studies have indicated that the higher serum level of undercarboxylated osteocalcin (ucOC) could be a risk factor for osteoporotic fracture. However, the relationship between the serum level of ucOC in patients with RA and the medication of DMARDs or predonisolone (PSL) were still unknown. In this study, we have evaluated the serum level of ucOC in patients with RA, and investigated the related factors, such as medications, biochemical markers and bone mineral density.

Methods:

88 patients with RA were enrolled in this study (83 females, 5 males, average age 63 yrs). We compared the ucOC levels with other biochemical marker (Serum cross-linked N-teropeptide of type1 collagen (NTx), Bone alkaline phosphatase (BAP), Calcium (Ca), phosphorus (P) and C reactive protein (CRP)). The examination of bone mineral density was performed with lumbar spine and femoral neck using dual energy X-ray absorptiometry (DEXA). Oral medications including PSL, methotrexate (MTX) and bisphosphonate (BP) were also examined. The statistical analysis was performed using Mann-Whitney U test.

Results:

The average of serum level of ucOC in all patients was 5.25±3.8(ng/ml), and then patients were categorized into high ucOC group (>=4.5ng/ml) and low ucOC group (<4.5ng/ml). The results of biochemical markers and BMD in these two groups were showed in Table1. These data showed that the patients with low serum ucOC level have low biochemical marker of bone metabolism and high dose of PSL (>=5mg/day). When compared the medications with the serum ucOC level in Table2, results indicated that medication of high dose PSL and medication of BP significantly decreased the serum ucOC level.

Conclusion:

Our results clearly showed that the serum levels of ucOC were increased in higher state of bone turnover as indicated by biochemical markers, and vice versa, decreased when the bone turnover was ameliorated by the high dose of PSL and BP. We should carefully evaluate the risk of osteoporotic fracture of the patient with RA who has a low level of serum ucOC during medication of high PSL and/or BP.

Table 1

 Low ucOC groupHigh ucOC groupp-value
Age (yrs)64.2 ± 9.861.3 ± 12.20.8116
Serum NTx15.3 ± 5.619.3 ± 5.90.021
Serum BAP(ug/l)15.6 ± 7.125.7 ± 9.50.0001
Serum Ca (mg/dl)9.2 ± 0.49.4 ± 0.30.039
Serum P (mg/dl)3.4 ± 0.53.6 ± 0.50.0622
Serum CRP (mg/dl)1.2 ± 1.60.7 ± 0.90.6267
BMD L-Spine (g/cm3)0.91 ± 0.20.81 ± 0.20.0175
BMD Femoral neck(g/cm3)0.61 ± 0.10.57 ± 0.10.1369
PSL amount (mg/day)3.7 ± 3.41.9 ± 2.50.067
MTX amount (mg/week)4.3 ± 3.23.6 ± 3.40.4196

Table 2

StageEarly (Stage1,2)Progressive (Stage3,4)p-value
ucOC(ng/ml)6.1 ± 2.36.3 ± 4.50.8022
PSL on/offNo PSLPSLp-value
ucOC(ng/ml)6.2 ± 3.44.5 ± 4.00.057
PSL doseLow dose (<5mg/day)High dose (>=5mg/day)p-value
ucOC(ng/ml)6.2 ± 4.03.3 ± 2.70.0004
MTX on/offNo MTXMTXp-value
ucOC(ng/ml)5.1 ± 3.25.3 ± 4.20.966
BP on/offNo BPBPp-value
ucOC(ng/ml)6.2 ± 3.82.4 ± 1.90.0001

To cite this abstract, please use the following information:
Sakai, Yoshitada, Hashiramoto, Akira, Hashimoto, Teppei, Kawasaki, Yoshiko, Tanaka, Chihiro, Shiozawa, Shunichi, et al; The Serum Level of Undercarboxylated Osteocalcin (ucOC) in Patients with Rheumatoid Arthritis A High Dose of Predonisolone Decrease the Serum Level of ucOC. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :983
DOI: 10.1002/art.28750

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