Volumetric bone mineral density of the tibia is not increased in subjects with radiographic knee osteoarthritis

MRC Epidemiology Resource Centre, Southampton, United Kingdom.
Osteoarthritis and Cartilage (Impact Factor: 4.17). 09/2008; 17(2):174-7. DOI: 10.1016/j.joca.2008.06.004
Source: PubMed

ABSTRACT Radiographic osteoarthritis (ROA) has previously been shown to be associated with an increase in areal bone mineral density (BMD) as assessed by dual energy X-ray absorptiometry (DXA). Here we have assessed volumetric bone density, size and strength by peripheral quantitative computed tomography (pQCT) in a large population-based cohort study in which knee radiographs were available.
Two hundred and ninety-five men and 288 women from the MRC Hertfordshire Cohort Study underwent weight bearing extended knee X-rays and bone density measurement of the ipsi-lateral knee using pQCT.
Increasing radiographic grade in men but not women was associated with an increase in tibial total area at 38% site and cortical area at 14% site, but not with volumetric BMD. The tibial fracture loads as well as tibial polar strength strain index at 38% site were also increased. There were no significant associations of tibia bone area, BMD or strength with radiographic grade in women.
ROA is not associated with an increase in volumetric BMD as assessed by pQCT. It is, however, associated with a significant increase in bone area and strength, indicating that the association between ROA and areal BMD is mediated through bone size rather than volumetric BMD.

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    • "A large population-based study. Details of the study design have been published previously [16]. Ethical approval was obtained from East and North Hertfordshire ethical committees and all participants gave written informed consent. "
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    ABSTRACT: Osteoarthritis (OA) is the most common form of arthritis and a major cause of disability. This study evaluates the association in Caucasian populations of two single nucleotide polymorphisms (SNPs) mapping to the Human Leukocyte Antigen (HLA) region and deriving from a genome wide association scan (GWAS) of knee OA in Japanese populations. The frequencies for rs10947262 were compared in 36,408 controls and 5,749 knee OA cases from European-descent populations. rs7775228 was tested in 32,823 controls and 1,837 knee OA cases of European descent. The risk (major) allele at rs10947262 in Caucasian samples was not significantly associated with an odds ratio (OR)  = 1.07 (95%CI 0.94 -1.21; p = 0.28). For rs7775228 the meta-analysis resulted in OR = 0.94 (95%CI 0.81-1.09; p = 0.42) for the allele associated with risk in the Japanese GWAS. In Japanese individuals these two SNPs are in strong linkage disequilibrium (LD) (r(2) = 0.86) with the HLA class II haplotype DRB1*1502 DQA1*0103 DQB1*0601 (frequency 8%). In Caucasian and Chinese samples, using imputed data, these SNPs appear not to be in LD with that haplotype (r(2)<0.07). The rs10947262 and rs7775228 variants are not associated with risk of knee OA in European descent populations and they do not appear tag the same HLA class II haplotype as they do in Japanese individuals.
    PLoS ONE 08/2011; 6(8):e23371. DOI:10.1371/journal.pone.0023371 · 3.23 Impact Factor
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    • "Studies have shown that patients with knee OA might have a higher bone mineral content (BMC) and bone size, although the relation between knee OA and BMD remains to be established [25–34]. However, Weiss et al. [7] suggest that obese people might have a relatively low level of bone loss and a decreased risk of osteoporosis. "
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    ABSTRACT: The objective of the present study was to identify factors correlated with the serum leptin concentration in women with knee OA. Fifty postmenopausal Japanese women with knee OA (age: 50-88 years) were recruited in our outpatient clinic. Plain radiographs of the knee were taken, and urine and blood samples were collected. Dual-energy X-ray absorptiometry (DXA) scanning was performed for the whole body and lumbar spine, and factors correlated with the serum leptin concentration were identified. A simple linear regression analysis showed that body weight, body mass index, whole-body bone mineral density (BMD), total fat mass, and total fat percentage, but not age, height, lumbar spine BMD, lean body mass, serum and urinary bone turnover markers, or the radiographic grade of knee OA, were significantly correlated with the serum leptin concentration. A multiple regression analysis showed that among these factors, only body weight and total fat mass exhibited a significant positive correlation with the serum leptin concentration. These results suggest that the serum leptin concentration might be related to increases in body weight and total fat mass, but not to BMD or bone turnover markers, in postmenopausal women with OA.
    01/2011; 2011:580632. DOI:10.1155/2011/580632
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