G Jones

University of Tasmania, Hobart Town, Tasmania, Australia

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Publications (144)636.84 Total impact

  • D. Dore, C. Ding, G. Jones
    Osteoarthritis and Cartilage 09/2009; 17. DOI:10.1016/S1063-4584(09)60082-0 · 4.26 Impact Factor
  • Osteoarthritis and Cartilage 09/2009; 17. DOI:10.1016/S1063-4584(09)60068-6 · 4.26 Impact Factor
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    ABSTRACT: Statin therapy can cause myopathy, however it is unclear whether this exacerbates age-related muscle function declines. To describe differences between statin users and non-users in muscle mass, muscle function and falls risk in a group of community-dwelling older adults. A prospective, population-based cohort study with a mean follow-up of 2.6 years. Total 774 older adults [48% female; mean (standard deviation) age = 62 (7) years] were examined at baseline and follow-up. Differences in percentage appendicular lean mass (%ALM), leg strength, leg muscle quality (LMQ; specific force) and falls risk were compared for statin users and non-users. There were 147 (19%) statin users at baseline and 179 (23%) at follow-up. Longitudinal analyses revealed statin use at baseline predicted increased falls risk scores over 2.6 years (0.14, 95% CI 0.01 to 0.27) and a trend towards increased %ALM (0.45%, 95% CI -0.01 to 0.92). Statin users at both time points demonstrated decreased leg strength (-5.02 kg, 95% CI -9.65 to -0.40) and LMQ (-0.30 kg/kg, 95% CI -0.59 to -0.01), and trended towards increased falls risk (0.13, 95% CI -0.01 to 0.26) compared to controls. Finally, statin users at both baseline and follow-up demonstrated decreased leg strength (-16.17 kg, 95% CI -30.19 to -2.15) and LMQ (-1.13 kg/kg, 95% CI -2.02 to -0.24) compared to those who had ceased statin use at follow-up. Statin use may exacerbate muscle performance declines and falls risk associated with aging without a concomitant decrease in muscle mass, and this effect may be reversible with cessation.
    QJM: monthly journal of the Association of Physicians 08/2009; 102(9):625-33. DOI:10.1093/qjmed/hcp093 · 2.46 Impact Factor
  • C. Ding, F. Cicuttini, G. Jones
    Bone 05/2009; 44. DOI:10.1016/j.bone.2009.01.269 · 4.46 Impact Factor
  • D. Dore, C. Ding, G. Jones
    Bone 05/2009; 44. DOI:10.1016/j.bone.2009.01.313 · 4.46 Impact Factor
  • T. Winzenberg, S. Quinn, G. Jones
    Bone 05/2009; 44. DOI:10.1016/j.bone.2009.01.431 · 4.46 Impact Factor
  • Bone 05/2009; 44. DOI:10.1016/j.bone.2009.01.255 · 4.46 Impact Factor
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    ABSTRACT: The anti-interleukin (IL) 6 receptor antibody tocilizumab inhibits signalling of IL6, a key cytokine in rheumatoid arthritis (RA) pathogenesis. To evaluate through the AMBITION study the efficacy and safety of tocilizumab monotherapy versus methotrexate in patients with active RA for whom previous treatment with methotrexate/biological agents had not failed. This 24-week, double-blind, double-dummy, parallel-group study, randomised 673 patients to either tocilizumab 8 mg/kg every 4 weeks, or methotrexate, starting at 7.5 mg/week and titrated to 20 mg/week within 8 weeks, or placebo for 8 weeks followed by tocilizumab 8 mg/kg. The primary end point was the proportion of patients achieving American College of Rheumatology (ACR) 20 response at week 24. The intention-to-treat analysis demonstrated that tocilizumab was better than methotrexate treatment with a higher ACR20 response (69.9 vs 52.5%; p<0.001), and 28-joint Disease Activity Score (DAS28) <2.6 rate (33.6 vs 12.1%) at week 24. Mean high-sensitivity C-reactive protein was within the normal range from week 12 with tocilizumab, whereas levels remained elevated with methotrexate. The incidence of serious adverse events with tocilizumab was 3.8% versus 2.8% with methotrexate (p = 0.50), and of serious infections, 1.4% versus 0.7%, respectively. There was a higher incidence of reversible grade 3 neutropenia (3.1% vs 0.4%) and increased total cholesterol > or =240 mg/dl (13.2% vs 0.4%), and a lower incidence of alanine aminotransferase elevations >3x-<5x upper limit of normal (1.0% vs 2.5%), respectively. Tocilizumab monotherapy is better than methotrexate monotherapy, with rapid improvement in RA signs and symptoms, and a favourable benefit-risk, in patients for whom treatment with methotrexate or biological agents has not previously failed.
    Annals of the rheumatic diseases 03/2009; 69(1):88-96. DOI:10.1136/ard.2008.105197 · 9.27 Impact Factor
    This article is viewable in ResearchGate's enriched format
  • C. Ding, F. Cicuttini, G. Jones
    Osteoarthritis and Cartilage 09/2008; 16. DOI:10.1016/S1063-4584(08)60317-9 · 4.26 Impact Factor
  • Osteoarthritis and Cartilage 09/2008; 16. DOI:10.1016/S1063-4584(08)60377-5 · 4.26 Impact Factor
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    ABSTRACT: Identifying factors that influence the rate of cartilage loss at the knee may help to prevent or delay the progression of knee osteoarthritis (OA). Changes in knee alignment alter knee joint load and may affect the rate of cartilage loss. The aim of this study was to determine whether change in knee alignment between baseline and 2 years is associated with a change in knee cartilage volume in knee OA in the subsequent 2.5 years. Seventy-eight adults with symptomatic knee OA were recruited using a combined strategy. Radiographs were performed at time 0 and 2 years to determine change in knee alignment, measured on a continuous scale. Magnetic Resonance Imaging was performed at 2 and 4.5 years to determine annual percentage change in medial and lateral tibial cartilage volumes. In multivariate analyses, for every 1 degrees change toward genu valgum, there is an associated 0.44% reduction in the rate of annual medial tibial cartilage volume loss (95% CI: -0.85%, -0.04%, P=0.03). Similarly, because our measures of change in alignment and cartilage volume were continuous, these results also implied that for every 1 degrees change toward genu varum, there was an associated 0.44% increase in the rate of annual medial tibial cartilage volume loss. Change in knee angle did not significantly affect the rate of loss of the lateral tibial cartilage volume (P=0.95). Our results have demonstrated that progressive change toward genu valgum reduced the annual rate of medial tibial cartilage volume loss in people with knee OA, without expediting the rate of lateral tibial cartilage volume loss. These findings suggest that methods to reduce varus alignment may delay the progression of medial tibiofemoral OA and warrant further investigation.
    Osteoarthritis and Cartilage 07/2008; 17(1):8-11. DOI:10.1016/j.joca.2008.05.013 · 4.26 Impact Factor
  • D Dore, C Ding, G Jones
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    ABSTRACT: To describe the reproducibility and validity of six different measurement techniques for knee subchondral bone mineral density (sBMD). A consecutive sample of 50 male and female participants from a population-based longitudinal study had sBMD assessed using dual energy X-ray absorptiometry scans. Anthropometric, knee pain, cartilage and bone measures by magnetic resonance imaging and radiographic osteoarthritis (OA) were assessed. The six methods were defined as: (1) the midpoint of one intercondylar spine, across the tibial surface and descending 10mm; from the midpoint of the two intercondylar spines (2) the top of the spine descending 20mm, (3) 10-20mm beneath the top of the spine; from the tibial surface descending, (4) 10mm, (5) 15 mm, and (6) 20mm. All six methods had excellent reproducibility (intra-class correlation coefficient 0.98-1.00). sBMD was higher in males (methods 2-4) and higher in those with medial tibial osteophytes (methods 1, 3 and 4). Medial tibial cartilage defects and overall cartilage defects correlated with sBMD (methods 3 and 4). Method 2, which includes the intercondylar spine, correlated with medial tibial bone size. Measuring sBMD using methods 3 and 4 produced the greatest number of associations with joint features of OA. These preliminary results need confirmation in larger longitudinal samples but suggest that sBMD can be accurately measured and plays a role in knee OA. Methods 3 and 4 had the best concurrent validity; however, method 2 adds additional information on tibial bone size, suggesting that two measures are necessary in clinical studies.
    Osteoarthritis and Cartilage 06/2008; 16(12):1539-44. DOI:10.1016/j.joca.2008.04.012 · 4.26 Impact Factor
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    ABSTRACT: To identify factors associated with change in femoral cartilage volume over 2 years in a cohort largely without knee radiographic osteoarthritis. A total of 252 subjects (mean 45 years, range 28-60) were used for this study. T1-weighted fat saturation magnetic resonance imaging was performed at baseline and approximately 2 years later. Knee femoral condyle cartilage volume, femoral cartilage defect (0-4 scale) and tibial bone size were determined. The total femoral cartilage volume loss was 6.3% for the 2.3-year period. Factors associated with this annual change were female gender (females vs males: -1.69%, P<0.01), age (over vs under 40 years: -0.96%, P=0.01), smoking (beta: -0.04% per pack-years, P<0.01), as well as lower limb muscle strength (r: +0.32, P<0.01) and its change (beta: +0.34% per quartile, P<0.05). Structural factors associated with change included baseline femoral cartilage volume (beta: -0.36% per ml, P<0.01), femoral cartilage defects (beta: +1.07% per grade, P<0.01), tibial bone area (beta: +0.13% per cm(2), P<0.05), lateral osteophytes (beta: -1.91% per grade, P<0.01) and change in femoral cartilage defects (beta: -0.8% per grade, P<0.001). This study provides evidence confirming that significant risk factors are associated with femoral cartilage loss and these include gender (female), age, smoking, and severity of lower limb muscle weakness. It also supports the hypothesis that femoral cartilage swelling reflected by an increased baseline cartilage volume could be a predictor of disease progression. Our findings also provide interesting clues to implement preventive measures that can possibly prevent or reduce knee cartilage loss.
    Osteoarthritis and Cartilage 04/2008; 16(4):443-9. DOI:10.1016/j.joca.2007.08.009 · 4.66 Impact Factor
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    G Jones, P Boon
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    ABSTRACT: This study of 415 adolescent children examined the association between four different measures of bone mass and prevalent fracture (N = 160 children). DXA measures and calcaneal ultrasound (but not radial ultrasound or metacarpal index) were associated with upper limb fracture, suggesting heel ultrasound is also a discriminator of fractures in children. The aim of the study was to describe the association between different measures of bone mass and prevalent fracture in adolescents. A total of 415 adolescents (150 girls and 265 boys), mean age 16.3 years were examined. Dual energy X-ray absorptiometry (DXA) measures were performed at hip, spine, radius and total body. Calcaneal bone ultrasound attenuation (BUA), speed of sound (SOS), and stiffness were assessed by a Sahara densitometer. Radial ultrasound SOS was assessed by a Sunlight 8000P machine. Metacarpal index was calculated from a left hand X-ray. Prevalent fractures were assessed by questionnaire. A total of 160 adolescents (39%) reported at least one previous fracture (106 upper limb, 53 lower limb, one other for first fracture). Significantly lower DXA measures, heel BUA, and heel stiffness was observed in those with a history of upper limb fracture (all P < 0.05). Despite significant correlations between all the bone mass measures, radial ultrasound and metacarpal index did not discriminate those with fracture from those without. Similar associations were present for number of fractures. No bone measure was able to discriminate lower limb fracture. Both calcaneal quantitative ultrasound and DXA are able to discriminate adolescents with a history of upper limb fracture from those without.
    Osteoporosis International 03/2008; 19(2):251-5. DOI:10.1007/s00198-007-0458-1 · 4.17 Impact Factor
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    ABSTRACT: We have reported that a lifestyle intervention with mothers improved calcium intake and physical activity in both mothers and their children. In this study, we aimed to describe the strategies and approaches used by these mothers to improve their children's calcium intake and physical activity. A qualitative study using semistructured interviews. Population-based convenience sample. Subjects: A subsample of 39 mothers were taken from a population-based random sample of 354 mothers who had participated in the original osteoporosis-prevention trial. Mothers described specific dietary changes they made to increase their children's calcium intake. They also described strategies for improving calcium intake and physical activity such as raising awareness of the importance of calcium; ensuring calcium-rich foods were accessible; assessing their children's likes and dislikes and working within these; role modelling; information provision; taking a balanced approach to attempting behaviour change; and encouraging activities that they could do with their children. Mothers emphasized the general importance of a balanced diet and lifestyle, rather than just focussing on lifestyle factors specific to osteoporosis prevention. Even without specific guidance, mothers are adept at developing strategies to apply to changing lifestyle behaviours in their children and identifying barriers to change. These results provide information, which could be incorporated into future interventions for lifestyle change in children and also provide further support for considering parent-focused approaches to this problem.
    European Journal of Clinical Nutrition 03/2008; 62(3):379-85. DOI:10.1038/sj.ejcn.1602730 · 2.95 Impact Factor
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    ABSTRACT: Cartilage defects are highly prevalent in subjects with knee osteoarthritis (OA). Although they are associated with increased cartilage loss and joint replacement, there is little data on the natural history of cartilage defects. The aim of this study was to examine the progression of cartilage defects over 2 years in people with knee OA and to identify factors associated with progression. One hundred and seventeen subjects with OA underwent magnetic resonance imaging of their dominant knee at baseline and follow-up. Cartilage defects were scored (0-4) at four sites. Bone size of the medial and lateral tibial plateau was determined. Height, weight, body mass index and physical activity were measured by standard protocols. The mean cartilage defect score increased significantly over the 2-year study period in all tibiofemoral compartments (all P<0.001), except the lateral tibial compartment with age and tibial plateau bone area at baseline being predictors of progression. However, there was heterogeneity with 81% progressing at any site, 15% remaining stable and 4% decreasing. Over 2 years, cartilage defects tend to progress in people with symptomatic OA, with only a small percentage decreasing in severity. Increasing age and increased bone area are risk factors for progression. Interventions aimed at preventing cartilage defects from occurring and reducing their severity may result in a reduction in the severity of OA, by reducing loss of articular cartilage and subsequent requirement for knee joint replacement.
    Osteoarthritis and Cartilage 03/2008; 16(3):337-42. DOI:10.1016/j.joca.2007.07.005 · 4.66 Impact Factor
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    ABSTRACT: Meniscal tears detected using magnetic resonance imaging (MRI) have been identified as a risk factor for the development and progression of Osteoarthritis, however the prevalence and significance of meniscal tears in healthy, asymptomatic adults remains to be studied. We investigated the prevalence of meniscal tears in a healthy pain free population of post-menopausal women and whether meniscal tears in this population are associated with changes in cartilage volume and defects and tibial plateau bone area over 2 years. Fifty-seven post-menopausal women underwent MRI of their dominant knee at baseline line and approximately 2 years later to assess meniscal tears, cartilage volume, cartilage defects and tibial plateau bone area. Forty-six percent of women had a meniscal tear in either the medial and/or lateral compartment. Women who had a tear were older (P=0.01) and had more lateral cartilage defects (P=0.02). Medial meniscal tear was associated with 103 mm(2) greater tibial plateau bone area within the medial [95% confidence of interval (CI) 6.2, 200.3; P=0.04] and a lateral meniscal tear with a 120 mm(2) greater area within the lateral compartment (95% CI 45.5, 195.2; P=0.002). This study demonstrates that meniscal tears are common in asymptomatic post-menopausal women and that they become more common with age. Meniscal tears were also associated with greater tibial plateau bone area but not cartilage volume, providing support to the hypothesis that tibial plateau bone changes occur before significant pathological changes in cartilage. Whether increased tibial plateau bone area predisposes to an increased risk of degenerative meniscal tears or whether it is a consequence of altered biomechanical forces in relation to meniscal tear will need to be determined.
    Osteoarthritis and Cartilage 03/2008; 16(2):268-71. DOI:10.1016/j.joca.2007.10.018 · 4.66 Impact Factor
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    ABSTRACT: To describe the associations between leptin, body composition, sex and knee cartilage volume/defects in older adults. A cross-sectional sample of 190 randomly selected subjects (mean 63 years, range 52-78, 48% female) were studied. Knee cartilage volume and defects were determined using T1-weighted fat saturation MRI. Serum leptin levels were measured by radioimmunoassay. Fat and lean mass were measured by dual energy x ray absorptiometry (DXA). Body mass index (BMI) was calculated. In multivariable analysis, serum levels of leptin were negatively associated with total cartilage volume (beta: -541 mm3/log transformed unit, 95% CI -861 to -221) but not with prevalent knee cartilage defects. BMI was negatively associated with cartilage volume after adjustment for total lean mass and positively with prevalent knee cartilage defects. However, the association between BMI and cartilage volume disappeared after adjustment for leptin while the association between BMI and cartilage defects remained unchanged. Lastly, sex differences in total cartilage volume decreased substantially after adjustment for leptin (R2 from 51% to 30%). This cross-sectional study suggests cartilage volume loss with obesity and female sex is related to leptin and, thus, is hormonally mediated in older adults. By contrast, obesity related knee focal cartilage defects may be more related to non-hormonal factors.
    Annals of the rheumatic diseases 02/2008; 67(9):1256-61. DOI:10.1136/ard.2007.082651 · 9.27 Impact Factor
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    ABSTRACT: Osteoporosis is a highly heritable disease, with estimates of genetic contribution to variance of BMD up to 80%. Genetic studies aiming to identify loci influencing BMD variation have had little success to date, largely due to inadequate power to detect the genes of small to moderate effect size likely to be involved. Adequately powered genome-wide association studies [GWAS] have successfully identified disease-associated genes in complex polygenic disorders. We performed a GWAS to search for BMD loci.
  • G Jones, F M Cicuttini
    Internal Medicine Journal 10/2007; 37(9):587-8. DOI:10.1111/j.1445-5994.2007.01460.x · 1.70 Impact Factor

Publication Stats

4k Citations
636.84 Total Impact Points

Institutions

  • 1999–2015
    • University of Tasmania
      • Menzies Research Institute
      Hobart Town, Tasmania, Australia
  • 2004–2013
    • Menzies Research Institute
      Hobart Town, Tasmania, Australia
  • 2010
    • Keele University
      • Department of Chemistry
      Newcastle-under-Lyme, England, United Kingdom
  • 2009
    • Semmelweis University
      Budape┼Łto, Budapest, Hungary
  • 2001
    • University of Saskatchewan
      • College of Pharmacy and Nutrition
      Saskatoon, Saskatchewan, Canada
  • 1997
    • Menzies Centre for Health Policy
      Sydney, New South Wales, Australia
  • 1995
    • Garvan Institute of Medical Research
      • Cancer Research Program
      Darlinghurst, New South Wales, Australia
    • St. Vincent Hospital
      Green Bay, Wisconsin, United States