G Jones

University of Tasmania, Hobart Town, Tasmania, Australia

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Publications (162)736.41 Total impact

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    ABSTRACT: There is controversy about whether pain and radiographic osteoarthritis (ROA) predict subsequent cartilage loss. The aim of this study was to describe the relationship between ROA, pain and cartilage loss in the knee. We studied randomly selected subjects at baseline and approximately 2.9 years later (n= 399). The presence of ROA was assessed at baseline with a standing anteroposterior semiflexed radiograph scored using the Osteoarthritis Research Society International atlas for osteophytes (OP) and joint space narrowing (JSN). Pain was assessed by the Western Ontario McMaster Osteoarthritis Index. Subjects' medial and lateral tibial cartilage volumes were determined by magnetic resonance imaging at both time points. In cross-sectional analysis, both medial and lateral tibial cartilage volumes were lower in those with ROA. Any medial ROA predicted medial tibial cartilage loss (3.2% (standard deviation (SD) 5.6) vs 1.9% (SD 5.3) per annum) while any lateral ROA predicted both medial (4.0% (SD 6.0) vs 2.2% (SD 5.3) per annum) and lateral (3.5% (SD 5.8) vs 1.6% (SD 4.2) per annum) tibial cartilage loss (all P < 0.05). In multivariate analysis, JSN and OP at both medial and lateral sites had independent dose-response associations with tibial cartilage loss at both sites. Pain was an independent predictor of lateral, but not medial, tibial cartilage loss after taking ROA into account. Subjects with ROA (either JSN or OP) and, to a lesser extent, pain lose cartilage faster than subjects without ROA and the more severe the ROA the greater the rate of loss. These findings have implications for the design of clinical trials.
    Internal Medicine Journal 02/2011; 42(3):274-80. DOI:10.1111/j.1445-5994.2011.02438.x · 1.70 Impact Factor
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    ABSTRACT: There is considerable controversy whether maternal peanut ingestion during pregnancy might influence sensitization in later life. Objective To examine whether maternal peanut ingestion during pregnancy might increase sensitization in the offspring. A population-based longitudinal cohort study with 16 years follow-up was conducted (N=373). Subjects were recruited at birth as part of an infant health study. Maternal antenatal peanut consumption was documented at birth and peanut and rye sensitization were determined by measurement of serum-specific IgE at age 16. Peanut sensitization was common (14%). In the entire cohort (n=310), there was no association between antenatal peanut ingestion and peanut sensitization (P=0.17). However, there was a strong association between antenatal peanut ingestion and decreased risk of rye sensitization and peanut sensitization in those (n=201) without a family history (FH) of asthma (Rye OR 0.30, 95% CI 0.14-0.63, P=0.001 and Peanut OR 0.18, 95% CI 0.04-0.78, P=0.02). There was an increased risk of rye sensitization in those (n=108) with a FH of asthma and antenatal peanut ingestion (Rye OR 2.69, 95% CI 1.11-6.51 P=0.03). It was considered that these sensitizations were likely to be related to the presence of IgE antibodies to cross-reacting carbohydrate epitopes common to rye and peanut allergens. Antenatal peanut ingestion may influence the development of IgE antibody to cross-reacting carbohydrate epitopes in later life. Genetic factors may modify this association.
    Clinical & Experimental Allergy 02/2011; 41(2):224-31. DOI:10.1111/j.1365-2222.2010.03668.x · 4.32 Impact Factor
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    ABSTRACT: Objective. Although there is a well-established sex difference in the prevalence and severity of OA, the mechanism for this is not clear. The aim of this study was to examine the potential role of BMD and BMC in explaining gender differences in knee cartilage volume. Methods. A total of 153 subjects aged 25-60 years, 81% female, were recruited. MRI was performed of the dominant knee. Cartilage volume was measured using validated methods. Total body BMD and content was measured using DXA. Results. Total body BMC and BMD was significantly associated with medial cartilage volume in both sexes. However, the associations were stronger in men for BMC (B = 0.52; 95% CI 0.21, 0.83; P for difference = 0.001) and BMD (B = 2242; 95% CI 443, 4041; P for difference = 0.05). Similar results were obtained in the lateral tibial compartment. No significant association was obtained between total body BMD and BMC and patella cartilage volume in either men or women. Conclusions. In this relatively healthy population, we found a positive relationship between total body BMD and BMC and tibial cartilage volume in the medial and lateral compartments. These relationships were stronger in men than women. Thus, the results of this study may provide some insight into the sex differences in knee cartilage volume, which may in turn facilitate our understanding of the pathogenesis of OA.
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    ABSTRACT: Genomewide association studies (GWAS) are a powerful method for identifying genes of small to moderate effect involved in common heritable diseases. A phase 1 GWAS was performed in an Australian and UK cohort of postmenopausal female probands (age 50-85 years) with extreme truncate selection for FN BMD (1.5<|z-score|<4), with 317,000 SNPs genotyped using Illumina HumanHap300 chips. 130 SNPs, selected for further study based on the initial results, were genotyped in families selected from the FAMOS cohort (proband FN or LS BMD z-score <-1, n=429 families including 1286 individuals) using Sequenom MALDI-TOF technology. PLINK was used to test association in the GWA component, and QTDT to test total association controlling for linkage in the confirmation family study. For a range of different genetic models, the phase 1 component of 140 subjects has equivalent power to a cohort study of 850-920 unselected individuals. Overall genotyping success rate was 99.6% in phase 1 and 93.1% in phase 2. No gene achieved genomewide statistical significance in the phase 1 screen (as expected due to small sample size). However, 31 markers achieved p-values of 10-5 to 10-7. One SNP, rs10904952, was associated with FN BMD in both phase 1 (P=0.0021) and phase 2 (P=0.00072) studies. Combining these findings, the overall level of significance for this SNP is 4.86x10-6. This SNP lies in the gene encoding ST8 alpha-n-acetyl-neuraminide alpha-2,8-sialyltransferase 6 (ST8SIA6), a protein that interacts with fetuin-alpha, which controls apatite formation and bone and tissue mineralisation. Four other SNPs lying in ST8SIA6 were associated with FN BMD with p-values of 0.0078-0.00048 in the phase 1 study. This study suggests that polymorphisms of ST8SIA6 influence FN BMD in the general population. Whilst the finding did not achieve genomewide significance in the discovery cohort, association was confirmed in the replication cohort, despite modest study power. A much larger cohort of cases with extreme high and low BMD is being recruited for further studies. If confirmed, ST8SIA6 represents a novel gene associated with BMD. The mechanism underlying the association and its effect on fracture risk have yet to be determined.
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    ABSTRACT: Objectives This pilot study describes the physiological attributes of jockeys and track-work riders in Tasmania and investigates whether these attributes are associated with falls. Methods All jockeys and track-work riders licensed in Tasmania were invited to participate. The study group consisted of eight jockeys (two female, six male) and 20 track-work riders (14 female, six male). Measures of anthropometry, balance, reaction time, isometric strength, vertical jump, glycolytic and aerobic fitness, flexibility and body composition were conducted. Tests were designed to assess specific aspects of rider fitness and performance relevant to horse racing. For a subset of participants (n=14), the authors obtained information on falls and injuries. The authors used Poisson regression to estimate incidence rate ratios. Results Jockeys had better balance, a faster mean reaction time, a lower fatigue index and a higher estimated $${\stackrel{.}{\hbox{ V }}\hbox{ O }}_{2\hbox{ max }}$$ than their track-work riding counterparts. Jockeys were also younger and smaller in stature than track-work riders, and when differences in body mass were taken into account, they had a greater muscular strength and muscular (alactic) power. Important factors found to be associated with falls were lower aerobic and anaerobic fitness, greater muscular strength and power, and riding with the full foot in the stirrup irons compared with riding on the ball of the foot. Conclusion This pilot study shows that physiological attributes of jockeys and track-work riders can predict their risk of falling and are measurable using methods feasible for large-scale fieldwork.
    BMJ Open 01/2011; 1(1):e000142. DOI:10.1136/bmjopen-2011-000142 · 2.06 Impact Factor
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    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    ChemInform 12/2010; 28(49). DOI:10.1002/chin.199749196
  • Arthritis & Rheumatology 12/2010; 62(12):3831-3832. DOI:10.1002/art.27730 · 7.87 Impact Factor
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    ABSTRACT: To determine the associations between body adiposity and change in serum 25-(OH)D levels over 2.6 years, and if these associations are mediated by metabolic and inflammatory factors in older adults. This is a longitudinal study of 859 randomly selected subjects (mean 62 years, range 51-80, 49% women). Serum 25-hydroxyvitamin D [25-(OH)D] was assessed by radioimmunoassay at baseline and 2.6 years later. Baseline serum level of leptin was assessed by radioimmunoassay and interleukin (IL)-6 by a chemiluminescent immunoassay in the first 183 subjects. In multivariable analyses, body mass index, trunk fat percentage and waist-to-hip ratio were significant predictors of increased incident vitamin D deficiency [a 25-(OH)D < 50 nmol L⁻¹ at follow-up when ≥50 nmol L⁻¹ at baseline] and decreased recovery of vitamin D deficiency [a 25-(OH)D ≥ 50 nmol L⁻¹ at follow-up when < 50 nmol L⁻¹ at baseline]. Change in 25-(OH)D levels per annum was also independently predicted by baseline leptin (β: -0.09/unit, 95% CI: -0.17, -0.03), IL-6 (β: -0.68/quartile, 95% CI: -1.35, -0.02) and total cholesterol/high-density lipoprotein (HDL) ratio (β: -0.51, 95% CI: -0.88, -0.14). The associations between body adiposity measures and change in 25-(OH)D completely disappeared after adjustment for leptin, diminished after adjustment for IL-6, but remained unchanged after adjustment for total cholesterol/HDL ratio. All associations were independent of season and sun exposure. Body fat is not simply a passive reservoir for 25-(OH)D. In addition to season and sun exposure, 25-(OH)D levels appear to be determined by metabolic and, to a lesser extent, inflammatory factors, and these appear to mediate the effects of adiposity on change in 25-(OH)D.
    Journal of Internal Medicine 11/2010; 268(5):501-10. DOI:10.1111/j.1365-2796.2010.02267.x · 5.79 Impact Factor
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    ABSTRACT: The role of inflammation in osteoarthritis (OA) pathogenesis is unclear, and the associations between inflammatory cytokines and cartilage loss have not been reported. We determined the associations between serum levels of interleukin (IL)-6 and tumor necrosis factor-α (TNF-α), knee radiographic OA (ROA) and cartilage loss over 2.9 years in older adults. A total of 172 randomly selected subjects (mean 63 years, range 52-78, 47% female) were studied at baseline and approximately 3 (range 2.6-3.3) years later. IL-6 and TNF-α were assessed by radioimmunoassay. T1-weighted fat-suppressed magnetic resonance imaging of the right knee was performed at baseline and follow-up to determine knee cartilage volume. Knee ROA of both knees was assessed at baseline. At baseline, quartiles of IL-6 and TNF-α were associated with increased prevalence of medial tibiofemoral joint space narrowing (OARSI grade ≥ 1) in multivariate analyses [odds ratio (OR): 1.42 and 1.47 per quartile, respectively, both P<0.05]. Longitudinally, baseline IL-6 predicted loss of both medial and lateral tibial cartilage volume (β: -1.19% and -1.35% per annum per quartile, P<0.05 and P<0.01, respectively), independently of TNF-α. Change in IL-6 was associated with increased loss of medial and lateral tibial cartilage volume (β: -1.18% and -1.06% per annum per quartile, both P<0.05) and change in TNF-α was also negatively associated with change in medial cartilage volume (β: -1.27% per annum per quartile, P<0.05). Serum levels of IL-6 and TNF-α are associated with knee cartilage loss in older people suggesting low level inflammation plays a role in the pathogenesis of knee OA.
    Osteoarthritis and Cartilage 11/2010; 18(11):1441-7. DOI:10.1016/j.joca.2010.08.016 · 4.66 Impact Factor
  • C. Ding, F. Cicuttini, G. Jones
    Osteoarthritis and Cartilage 10/2010; 18. DOI:10.1016/S1063-4584(10)60321-4 · 4.66 Impact Factor
  • Osteoarthritis and Cartilage 10/2010; 18. DOI:10.1016/S1063-4584(10)60063-5 · 4.66 Impact Factor
  • Arthritis & Rheumatology 09/2010; · 7.87 Impact Factor
  • Annual Meeting of the British-Society-Rheumatology/Spring Meeting of; 04/2010
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    ABSTRACT: The association between hormonal contraceptive use and bone mineral density remains controversial. Hormonal contraceptive use is positively associated with bone mass in young premenopausal women. Cross-sectional analysis of data collected from women aged 26-36 years (n = 687) in the Childhood Determinants of Adult Health study-a longitudinal study investigating childhood determinants of cardiovascular disease, diabetes, and other chronic diseases in adulthood. Participants were not currently pregnant or breast-feeding. Contraceptive use was obtained by self-administered questionnaire. Women were categorized as combined oral contraceptive users (n = 219), progestogen-only contraceptive users (n = 43), and non-users of hormonal contraceptives (n = 425). Bone mass was measured by quantitative ultrasound. Compared with women who were not using any hormonal contraceptives, women using combined oral contraceptives had significantly higher values of broadband ultrasound attenuation (BUA), speed of sound, and quantitative ultrasound index. These associations remained after adjustment for confounders. Progestogen-only contraceptive users had higher BUA than non-users, but the differences were not statistically significant in this small group. Combined oral contraceptive use was associated with higher bone mass measured by quantitative ultrasound in this population-based sample of premenopausal women aged 26-36 while progestogen-only contraceptives appeared to have no deleterious effect on bone mass.
    Osteoporosis International 02/2010; 22(1):351-5. DOI:10.1007/s00198-010-1180-y · 4.17 Impact Factor
  • S Foley, S Quinn, G Jones
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    ABSTRACT: In this large population-based study, walking was assessed twice yearly for a week, each time by pedometer, had consistent clinically important associations with hip areal bone mineral density (aBMD) in both sexes which appears most important in those over 65 years of age suggesting that walking becomes more important with increasing age. Walking is advocated as a preventative strategy for osteoporosis but the evidence is conflicting in females and lacking in males. The aim of this population-based longitudinal study in community dwelling older people (n=875) was to determine the association between pedometer determined ambulatory activity (PAA) and bone mass. Bone mass was assessed as aBMD at the hip and spine using dual X-ray absorptiometry. Steps per day were measured using pedometers for 1 week on four occasions at least 6 months apart. Data were analysed using linear mixed models. At baseline, PAA was positively associated with hip aBMD. An age interaction was present with steps having a stronger association for those aged over 65 years. Longitudinally, the effect of steps on hip aBMD was constant, but not additive over time. For those over 65 years, the difference in hip aBMD between the lowest and highest steps quartiles ranged from 3.1% to 9.4%. With regard to the spine, the relationship between daily steps and spine aBMD was modified by sex. For males; there was no significant relationship between steps and spine aBMD. However, for females, higher steps were associated with higher spine aBMD with the effect being constant over time but not additive. There was no evidence of a threshold effect. In conclusion, pedometer-determined ambulatory activity has consistent clinically important associations with hip aBMD in both sexes which appears most important in those over 65 years of age. The associations for spine aBMD were both weaker and inconsistent suggesting site specificity.
    Osteoporosis International 12/2009; 21(11):1809-16. DOI:10.1007/s00198-009-1137-1 · 4.17 Impact Factor
  • Osteoarthritis and Cartilage 09/2009; 17. DOI:10.1016/S1063-4584(09)60037-6 · 4.66 Impact Factor
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    ABSTRACT: Fetal life may be a critical period for the development and/or programming of metabolic systems, including the skeleton. However, it is unclear on the association between maternal nutrition during pregnancy and bone mass in their offspring at adolescence. This was a birth cohort study of 216 adolescents (16.2+/-0.4 years). Dietary intake was measured by food frequency questionnaire. Bone densitometry was measured at the femoral neck, lumbar spine and total body by DXA. After adjustment for confounders, bone mineral density (BMD) of the femoral neck was positively associated with magnesium density and negatively associated with fat density (all P-values <0.05). BMD of the lumbar spine was positively associated with calcium, magnesium and phosphorus density and negatively associated with fat density (all P-values <0.05). Maternal milk intake was significantly positively associated with lumbar spine BMD. After considering all significant nutrients in the same model, fat density remained significant negatively for the femoral neck and lumbar spine, whereas magnesium density remained significant positively for the femoral neck. No nutrient was significant for the total body. Maternal intake of milk, fat and magnesium during the third trimester of pregnancy is predictive of BMD at age 16, suggesting that in utero diet influences peak bone mass possibly through programming bone responses.
    European journal of clinical nutrition 09/2009; 64(2):131-7. DOI:10.1038/ejcn.2009.117 · 2.95 Impact Factor
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    ABSTRACT: Serum 25(OH)D levels decline without sunlight exposure. We studied 120 expeditioners to Antarctica to determine the skeletal and hormonal responses to sunlight deprivation. With emerging vitamin D insufficiency, serum calcium decreased, PTH increased, and bone loss at the proximal femur was observed. Baseline serum 25(OH)D levels >100 nmol/L prevented vitamin D insufficiency. Vitamin D stores deplete without adequate sunlight exposure unless supplementation is provided. We studied 120 healthy adults who spent a year in Antarctica as a model for sunlight deprivation to define the timing and magnitude of the skeletal and hormonal responses to emerging vitamin D insufficiency. Fasting blood samples were assessed at baseline, 6 and 12 months for serum 25-hydroxyvitamin D (25(OH)D), osteocalcin (OC), bone formation (P1NP) and resorption (CTx), PTH and calcium. Lumbar spine and proximal femur BMD was measured using DXA. Differences over time were determined using repeated measures ANOVA. Percent changes were expressed as (Delta value/(value A + value B)/2) x 100. Relationships between outcome measures were determined using Spearman's correlations. Vitamin D insufficiency (<50 nmol/L) was observed in 85% of expeditioners by 6 months when serum calcium decreased and PTH increased (p < 0.01). By 12 months, OC increased by 7.4 +/- 3.0% (p < 0.05), and BMD decreased by 1.0 +/- 2.0% at the total proximal femur (p < 0.05). For those with vitamin D sufficiency at baseline (>50 nmol/L), sunlight deprivation produced vitamin D insufficiency within 4 months unless baseline values were >100 nmol/L. Supplementation may be necessary for expeditioners with limited access to UV light.
    Osteoporosis International 09/2009; 20(9):1523-8. DOI:10.1007/s00198-008-0830-9 · 4.17 Impact Factor
  • D. Dore, C. Ding, G. Jones
    Osteoarthritis and Cartilage 09/2009; 17. DOI:10.1016/S1063-4584(09)60082-0 · 4.66 Impact Factor
  • Osteoarthritis and Cartilage 09/2009; 17. DOI:10.1016/S1063-4584(09)60068-6 · 4.66 Impact Factor

Publication Stats

4k Citations
736.41 Total Impact Points

Institutions

  • 1999–2014
    • 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
      Budapeŝto, Budapest, Hungary
  • 1995–2009
    • Garvan Institute of Medical Research
      • Cancer Research Program
      Darlinghurst, New South Wales, Australia
    • St. Vincent Hospital
      Green Bay, Wisconsin, United States
  • 2008
    • Alfred Hospital
      • Department of Department of Epidemiology and Preventive Medicine (DEPM)
      Melbourne, Victoria, Australia
  • 2001
    • University of Saskatchewan
      • College of Pharmacy and Nutrition
      Saskatoon, Saskatchewan, Canada
  • 1997–1999
    • Menzies Centre for Health Policy
      Sydney, New South Wales, Australia