Increased matrix concentrations of IGFBP-5 in cancellous bone in osteoarthritis.

Abstract

BACKGROUND:

In osteoarthritis cancellous bone adapts to meet altered mechanical loading. These changes may be mediated by insulin-like growth factors (IGF-I and IGF-II), but the matrix bound binding protein, IGFBP-5 has not been investigated.

OBJECTIVES:

To measure IGF-I, IGF-II, and IGFBP-5 in femoral head bone from non-OA controls and patients with OA, and to relate these to apparent density (rhoA) and elastic modulus (Ec).

METHODS:

rhoA, Ec, and IGF system components were measured in cancellous bone from superior and inferior regions of femoral heads from 31 patients with OA and 11 age selected controls.

RESULTS:

Ec and rhoA were greater (p<0.05) in the superior region of all femoral heads. In primary OA, rhoA was increased in the inferior region (p<0.05). IGFBP-5 was increased, about twofold, at superior and inferior regions in primary OA (1.60 and 1.54 ng/mg bone, respectively, both p<0.05) and in Paget's disease (2.44 and 1.75 ng/mg bone, both p<0.05) compared with controls (0.73 and 0.95 ng/mg bone). In controls, inverse correlations between IGFBP-5 and both rhoA and Ec at superior (rs = -0.64 and -0.73, both p<0.05) and inferior regions (rs = -0.72, p<0.05 and -0.24 (NS)) were seen, but these were lost in OA.

CONCLUSIONS:

IGFBP-5 may modulate cancellous bone formation by negative feedback. In end stage OA this is disrupted, but has little influence on material properties.

• Authors: C A Sharp, S J Brown, M W J Davie, P Magnusson, S Mohan
• Journal: Annals of the rheumatic diseases (Ann Rheum Dis) Vol. 63 Issue 9 Pg. 1162-5 (Sep 2004) ISSN: 0003-4967 [Print] England
• PMID: 15308529 (Publication Type: Journal Article)

Chemical References

• Insulin-Like Growth Factor Binding Protein 5
• Insulin-Like Growth Factor I
• Insulin-Like Growth Factor II

Topics

• Aged
• Aged, 80 and over
• Bone Density
• Compressive Strength
• Female
• Femur Head (chemistry)
• Humans
• Insulin-Like Growth Factor Binding Protein 5 (analysis)
• Insulin-Like Growth Factor I (analysis)
• Insulin-Like Growth Factor II (analysis)
• Male
• Middle Aged
• Osteoarthritis, Hip (metabolism, physiopathology)