V Naganathan

Concord Hospital, Concord, New Hampshire, United States

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Publications (16)69.01 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: The aim of this population-based prospective observational study was to examine the relationship between serum levels of 25-hydroxyvitamin D (25OHD) and fracture risk in a cohort of 1662 community-dwelling men aged 70–97 years followed for a mean of 4.3 years. Data about mobility, muscle strength, balance, medication use, cognition, medical history, lifestyle factors, renal function and serum 25OHD were collected at baseline. Data on radiologically verified fractures were collected every 4 months. The relationship between fractures and serum 25OHD levels was analyzed using Cox's proportional hazard regression.We accounted for bone mineral density, falls, physical activity, sun exposure, season of blood draw, in addition to anthropometric and lifestyle factors, medical history, muscle strength, balance, medication and supplement use.There were 123 first incident fragility fractures. The relationship between baseline 25OHD and fracture risk was U-shaped, with increased fracture risk in men with either low or high serum 25OHD levels. In multivariate analysis, the risk of fracture was greatest in men with 25OHD levels in the lowest quintile (25OHD ≤ 36nmol/L; hazard ratio (HR) = 3.5 (95% confidence interval (CI): 1.7–7.0) and in men in the highest quintile (25OHD >72nmol/L; HR = 2.7, 95% CI: 1.4–5.4) compared to men in the 4th quintile (25OHD ≥60 to ≤72nmol/L). These associations were not explained by lower BMD, increased physical activity, falls' risk or other lifestyle or anthropomorphic factors.In community-dwelling older men, there appears to be a healthy target range for serum 25OHD concentrations. Thus, serum 25OHD levels too high and too low may be harmful in regards to fracture risk. © 2014 American Society for Bone and Mineral Research
    Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research 03/2014; · 6.04 Impact Factor
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    ABSTRACT: We aim to determine the relationship between season, personal solar UV exposure, serum 25(OH)D and 1,25(OH)2D and serum prostate-specific antigen (PSA) levels. Questionnaire data and blood samples were collected at baseline from participants of the Concord Health and Ageing in Men Project (n = 1,705), aged 70 and above. They were grouped as men 'free of prostate disease' for those with no record of having prostate cancer, benign prostatic hyperplasia, or prostatitis and with serum PSA levels below 20 ng/mL, and 'with prostate disease' for those with a record of either of these diseases or with serum PSA levels 20 ng/mL or above. Personal solar UV exposure (sUV) was estimated from recalled hours of outdoor exposure and weighted against ambient solar UV radiation. Sera were analysed to determine levels of PSA, 25(OH)D and 1,25(OH)2D, and analysed using multiple regression, adjusting for age, BMI and region of birth. The association between sUV and serum PSA levels was conditional upon season (p interaction = 0.04). There was no direct association between serum PSA and 25(OH)D in both groups of men. There was a positive association between serum PSA and 1,25(OH)2D in men with prostate disease (mean = 110.6 pmol/L; p heterogeneity = 0.03), but there was no such association in men free of prostate disease (mean = 109.3 pmol/L; p heterogeneity = 0.8). The association between PSA and sUV may only be evident at low solar UV irradiance, and this effect may be independent of serum vitamin D levels.
    World Journal of Urology 11/2013; · 2.89 Impact Factor
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    ABSTRACT: Objectives: Inadequate vitamin D status (25-hydroxyvitamin D (25(OH)D) concentrations <50 nmol/L) is an increasingly important public health issue in Australia. The aim of this analysis is to describe 25(OH)D levels in community dwelling men aged ≥70 years in Sydney, Australia, and to determine associations between serum 25(OH)D levels and socioeconomic and lifestyle factors. Design: A population-based, cross-sectional analysis of the baseline phase of the Concord Health and Ageing in Men Project (CHAMP), a large epidemiological study conducted in Sydney between January 2005 and May 2007. Participants: 1659 non-institutionalised men aged ≥70 years. Methods: The cross-sectional analysis of the baseline phase of the Concord Health and Ageing in Men Project (CHAMP), a large epidemiological study conducted in Sydney between January 2005 and May 2007. Participants included 1659 community dwelling men who were interviewed and had clinical assessments. Main outcome measurements included serum 25(OH)D levels measured in blood samples using a radioimmunoassay kit (DiaSorin Inc., Stillwater, MN). Covariates included age, socioeconomic measures, season of blood sample, physical activity, sun exposure, vitamin D supplement use, cigarette smoking status, alcohol consumption, obesity and measures of health. Results: Prevalence of vitamin D insufficiency was 43.0%; highest in winter (55.5%) and spring (53.9%), and was associated with season (winter and spring), low physical activity, avoidance of sun exposure, current smoking and obesity, even after adjustment for confounding factors. Conclusion: Inadequate vitamin D status is highly prevalent among Australian older men and is associated with specific lifestyle factors. These findings emphasize the need to screen and monitor 25(OH)D levels in this population group, despite living in a sunny country such as Australia.
    The Journal of Nutrition Health and Aging 01/2013; 17(7):587-93. · 2.39 Impact Factor
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    ABSTRACT: Though bone loss tends to accelerate with age there are modifiable factors that may influence the rate of bone loss even in very old men. INTRODUCTION: The aim of this 2-year longitudinal study was to examine potential predictors of change in total hip bone mineral density (BMD) in older men. METHODS: The Concord Health and Ageing in Men Project is a population-based study in Sydney, Australia. For this study, 1,122 men aged 70-97 years had baseline and follow-up measures of total hip BMD measured with dual X-ray absorptiometry. Data about mobility, muscle strength, balance, medication use, cognition, medical history and lifestyle factors were collected using questionnaires and clinical assessments. Serum 25-hydroxyvitamin D [25(OH)D] was also measured. Multivariate linear regression models were used to assess relationships between baseline predictors and change in BMD. RESULTS: Over a mean of 2.2 years, there was a mean annualised loss of total hip BMD of 0.006 g/cm(2)/year (0.6 %) and hip BMC of 0.14 g/year (0.3 %). Annual BMD loss accelerated with increasing age, from 0.4 % in men aged between 70 and 75 years, to 1.2 % in men aged 85+ years. In multivariate regression models, predictors of faster BMD loss were anti-androgen, thiazolidinedione and loop-diuretic medications, kidney disease, poor dynamic balance, larger hip bone area, older age and lower serum 25(OH)D. Factors associated with attenuated bone loss were walking for exercise and use of beta-blocker medications. Change in BMD was not associated with baseline BMD, smoking, alcohol consumption, BMI, frailty, or osteoarthritis. CONCLUSION: There was considerable variation in the rate of hip bone loss in older men. Walking, better balance and beta blockers may attenuate the acceleration of BMD loss that occurs with age.
    Osteoporosis International 12/2012; · 4.04 Impact Factor
  • Osteoporosis International 05/2012; · 4.04 Impact Factor
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    ABSTRACT: Evidence about the association between treatment with high-risk medicines and frailty in older individuals is limited. We investigated the relationship between high-risk prescribing and frailty at baseline, as well as 2-year incident frailty, in 1,662 men ≥70 years of age. High-risk prescribing was defined as polypharmacy (≥5 medicines), hyperpolypharmacy (≥10 medicines), and by the Drug Burden Index (DBI), a dose-normalized measure of anticholinergic and sedative medicines. At baseline, frail participants had adjusted odds ratios (ORs) of 2.55 (95% confidence interval, CI: 1.69-3.84) for polypharmacy, 5.80 (95% CI: 2.90-11.61) for hyperpolypharmacy, and 2.33 (95% CI: 1.58-3.45) for DBI exposure, as compared with robust participants. Of the 1,242 men who were robust at baseline, 6.2% developed frailty over two years. Adjusted ORs of incident frailty were 2.45 (95% CI: 1.42-4.23) for polypharmacy, 2.50 (95% CI: 0.76-8.26) for hyperpolypharmacy, and 2.14 (95% CI: 1.25-3.64) for DBI exposure. High-risk prescribing may contribute to frailty in community-dwelling older men.
    Clinical Pharmacology &#38 Therapeutics 03/2012; 91(3):521-8. · 6.85 Impact Factor
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    ABSTRACT: Weight loss is associated with bone loss; however, it is unclear whether loss of fat or loss of lean body mass plays the key role in this relationship. The aim of this longitudinal analysis was to clarify the relationship between hip BMD, hip BMC and whole body BMC with changes in fat and lean tissue mass in older men. The Concord Health and Aging in Men Project (CHAMP) is a population-based study in Sydney, Australia, involving 1705 men aged 70-97 years. Bone mineral density (BMD) of the total hip, and bone mineral content (BMC) of the hip and whole body (WB), lean mass and fat mass were measured with Dual X-ray Absorptiometry (DXA). Multivariate linear regression models were used to assess relationships. Over 2.2 years of follow-up, 368(33%) men lost at least 2% of their body weight, which included a mean loss of 0.8 kg/year of lean body mass and 0.9 kg/year of fat body mass. Fat loss was strongly associated with BMD loss in men who lost weight. As a group, weight losers lost 1.0% of hip BMD annually compared to 0.2% in men who gained weight, with each kilo of fat loss associated with 0.6%/year hip BMD loss (p<0.0001). Lean mass was not associated with hip BMD loss in weight losers, however, lean mass change was associated with BMD change in men who gained weight (0.3% hip BMD increase per kilo increase of lean mass p<0.01). Maintaining body weight is important for bone health in elderly men. Body fat plays an important role in this relationship, which may reflect the additional metabolic function of adipose tissue.
    Bone 09/2011; 49(6):1299-305. · 3.82 Impact Factor
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    ABSTRACT: The association between socioeconomic status (SES) and bone health, specifically in men, is unclear. Based upon data from the large prospective Concord Health in Ageing Men Project (CHAMP) Study of community-dwelling men aged 70 years or over, we found that specific sub-characteristics of SES, namely, marital status, living circumstances, and acculturation, reflected bone health in older Australian men. Previous studies reported conflicting results regarding the relationship between SES and bone health, specifically in men. The main objective of this study was to investigate associations of SES with bone health in community-dwelling men aged 70 years or over who participated in the baseline phase of the CHAMP Study in Sydney, Australia. The Australian Socioeconomic Index 2006 (AUSEI06) based on the Australian and New Zealand Standard Classification of Occupations was used to determine SES in 1,705 men. Bone mineral density and bone mineral content (BMC) were determined by dual-energy X-ray absorptiometry. Bone-related biochemical and hormonal parameters, including markers of bone turnover, parathyroid hormone, and vitamin D, were measured in all men. General linear models adjusted for age, weight, height, and bone area revealed no significant differences across crude AUSEI06 score quintiles for BMC at any skeletal site or for any of the bone-related biochemical measures. However, multivariate regression models revealed that in Australian-born men, marital status was a predictor of higher lumbar BMC (β = 0.07, p = 0.002), higher total body BMC (β = 0.05, p = 0.03), and lower urinary NTX-I levels (β=-0.08, p = 0.03), while living alone was associated with lower BMC at the lumbar spine (β=-0.05, p = 0.04) and higher urinary NTX-I levels (β=0.07, p = 0.04). Marital status was also a predictor of higher total body BMC (β = 0.14, p = 0.003) in immigrants from Eastern and South Eastern Europe. However, in immigrants from Southern Europe, living alone and acculturation were predictors of higher femoral neck BMC (β = 0.11, p = 0.03) and lumbar spine BMC (β = 0.10, p = 0.008), respectively. Although crude occupation-based SES scores were not significantly associated with bone health in older Australian men, specific sub-characteristics of SES, namely, marital status, living circumstances, and acculturation, were predictors of bone health in both Australia-born men and European immigrants.
    Osteoporosis International 05/2011; 22(5):1343-53. · 4.04 Impact Factor
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    ABSTRACT: The role of anxiety in pain is less well understood than the role of depression. Based on recent conceptual thinking about worry and pain, we explored the relationship between pain status and worry about health and anxiety in 1217 community-dwelling men aged 70 years or older who participated in the baseline phase of the Concord Health and Ageing in Men Project study, a large population-based epidemiological study of healthy ageing based in Sydney, Australia. We hypothesised that worry about health would be associated with having persistent pain, and that the association would be stronger in the presence of co-existing pain-related interference with activities (intrusive pain). Of men in the study, 12.5% had persistent and intrusive pain, 22.4% were worried about their health, and 6.3% had anxiety. We found a strong association between worry about health and pain that was both persistent and intrusive, and that remained after accounting for age, number of comorbidities, depression, self-rated health status, arthritis, and gait speed (adjusted odds ratio 2.9; 95% confidence interval 1.8-4.7), P<0.0001). The corresponding adjusted odds ratio for the association between anxiety and pain was 2.3 (95% confidence interval 1.0-4.8; P=0.0363). These findings suggest that at a population level, subthreshold anxiety and pain are strongly related, and worry about health occurs much more commonly than anxiety itself. To our knowledge, this is the first study to explore, specifically, the relationship between pain status and worry about health in older men. In older community-dwelling men, pain was robustly associated with worry about health, highlighting the potential importance of subthreshold anxiety-related psychological factors.
    Pain 02/2011; 152(2):447-52. · 5.64 Impact Factor
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    ABSTRACT: Aims and Method. The Developmental Disability Database in the Department of Rehabilitation Medicine at a metropolitan hospital was audited for observations on adults with Intellectual Disability living in the local region (total population 180,000) who were seen in an identified multidisciplinary specialist clinic, during 2006-2010. Results. There were 162 people (representing half the known number of adults with Intellectual Disability living in the region): 77 females, 85 males, age range 16-86 years. The most common complex disabilities referred to the specialists in this clinic were epilepsy (52%), challenging or changing behavior (42%) and movement disorders (34%). Early onset dementia was a feature of the group (7%). The prevalence of prescription of medications for gastro-oesophageal reflux was high (36%) and similar to the numbers of people taking psychotropic medications. The rates of chronic cardiovascular disease (2%), chronic respiratory disease (10%) and generalised arthritis (11%) were low overall, but did rise with increasing age. Conclusions. Complex neurological disabilities are common, and chronic medical illnesses are uncommon in adults with Intellectual Disability referred to specialist clinicians in this region. A combined, coordinated, multidisciplinary clinic model addresses some of the barriers experienced by adults with Intellectual Disability in the secondary health system.
    International journal of family medicine. 01/2011; 2011:312492.
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    ABSTRACT: Aging alone is not the only factor accounting for poor bone health in older men. There are modifiable factors and lifestyle choices that may influence bone health and result in higher bone density and lower fracture risk even in very old men. The aim of this cross-sectional analysis was to identify the factors associated with areal bone mineral density (BMD) and their relative contribution in older men. The Concord Health and Ageing in Men Project is a population-based study in Sydney, Australia, involving 1,705 men aged 70-97. Data were collected using questionnaires and clinical assessments. BMD of the hip and spine was measured by dual X-ray absorptiometry. In multivariate regression models, BMD of the hip was associated with body weight and bone loading physical activities, but not independently with age. The positive relationship between higher BMD and recreational activities is attenuated with age. Factors independently associated with lower BMD at the hip were inability to stand from sitting, a history of kidney stones, thyroxine use, and Asian birth and at the spine, chronic obstructive pulmonary disease, paternal fracture history, and thyroxine use. Higher body weight, participation in dancing, tennis or jogging, quadriceps strength, alcohol consumption, and statin use were associated with higher hip BMD, while older age, osteoarthritis, higher body weight, and aspirin use were associated with higher spinal BMD. Maintaining body weight, physical activity, and strength were positively associated with BMD even in very elderly men. Other parameters were also found to influence BMD, and once these were included in multivariate analysis, age was no longer associated with BMD. This suggests that age-related diseases, lifestyle choices, and medications influence BMD rather than age per se.
    Osteoporosis International 11/2010; 22(9):2421-37. · 4.04 Impact Factor
  • V Naganathan, J Zochling, L March, P N Sambrook
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    ABSTRACT: The mechanism behind the inverse association between osteoporosis and osteoarthritis shown in large epidemiological studies remains unclear. Because both diseases often demonstrate a family history, the objective of the present study was to compare peak bone density in daughters categorized according to the presence or absence of hand osteoarthritis in their mothers. Radiographs of the hands were obtained in women aged 50-75 years from a well-defined community population group. X-rays were graded for hand osteoarthritis (OA) using the Kellgren and Lawrence criteria. In 60 daughters (mean age 33.6 years) of these women, bone mineral density (BMD) was measured at five regions of the hip and lumbar spine and quantitative ultrasound (QUS) at the calcaneus. Daughters whose mothers had hand OA (i.e., OA at either the carpometacarpal [CMC] or distal interphalageal [DIP] joints) had significantly higher mean BMD, when adjusted for body mass index (BMI) (5.1%-8.1%, p < 0.05), at all hip regions except the trochanter. However, differences in lumbar BMD and calcaneal QUS were not statistically significant. In multiple regression analysis, maternal hand OA status was found to be a significant predictor of daughters' hip BMD when daughters' BMI and mothers' BMD were included in the model. These findings suggest that the observation of higher BMD in older patients with OA may be due in part to achievement of a higher peak bone mass at some sites.
    Bone 01/2002; 30(1):287-92. · 3.82 Impact Factor
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    ABSTRACT: Corticosteroid use is associated with rapid bone loss, but the effect of low dose corticosteroids (CS) remains controversial and the extent to which increased fracture risk relates to quantitative effects, as reflected by change in bone mineral density (BMD), or to qualitative effects due to altered microarchitecture is unclear. Moreover the contribution of the underlying disease, for which CS are used, confounds the assessment of CS effects on bone. Our aim was to examine these effects of CS on bone. We measured BMD, quantitative ultrasound (US), and clinical and radiological disease indices in 76 patients with rheumatoid arthritis (RA) treated with or without low dose CS. Disease effects were quantitated using the Health Assessment Questionnaire and radiological scores. BMD and US measures were significantly reduced in RA patients compared to age matched controls. Low dose CS use was associated with a further small but nonsignificant reduction in BMD, and US measures did not further discriminate CS effects on bone. Radiological score was an independent predictor of US measures, suggesting that in RA, calcaneal bone may reflect both systemic and local disease effects. US did not appear to discriminate effects of low dose CS on bone better than BMD. However, underlying RA disease effects on bone are detectable by US. Quantitative US should be investigated for its utility in assessing disease activity or progress in RA.
    The Journal of Rheumatology 06/2001; 28(5):1063-7. · 3.26 Impact Factor
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    ABSTRACT: Few data are available regarding vertebral fracture risk in patients treated with oral corticosteroids. The aim of this study was to determine the prevalence and the role of risk factors such as age, bone mineral density (BMD), and corticosteroid use for vertebral deformity in patients receiving long-term corticosteroid therapy. Thoracolumbar x-ray films, BMD, and details on corticosteroid use were obtained on 229 consecutive patients treated with long-term corticosteroid regimens (> or = 6 months of prednisone, > or = 5mg/d or equivalent) seen at 4 referral centers. Comparisons were made with a population control group of 286 male and female controls not taking corticosteroids (aged > or = 60 years). Sixty-five patients (28%) had at least 1 vertebral deformity and 25 (11%) had 2 or more vertebral deformities. Older age, independent of BMD, was a significant risk factor for deformity. Patients aged 70 to 79 years had a 5-fold increased risk of deformity compared with patients younger than 60 years (odds ratio, 5.13; 95% confidence interval, 2.03-13.0). Compared with the population controls, the prevalence of deformities increased to a greater extent with each decade of age in the corticosteroid group (P =.005). Mean lumbar spine and femoral neck BMD Z scores were lower in the steroid-treated patients with deformities compared with the nonsteroid control group with deformities. When the effects of age, sex, body mass index, and duration of corticosteroid use were adjusted for in logistic regression analysis, low BMD was a modest predictor of deformity (for a 1-SD decrease in lumbar spine BMD: odds ratio, 1.31; 95% confidence interval, 1.02-1.68) and for a 1-SD decrease in femoral neck BMD: odds ratio, 1.77; 95% confidence interval, 1.07-2.94). The combination of increasing age and corticosteroid use is associated with a marked increase in the risk of vertebral deformity. Elderly patients commencing long-term corticosteroid therapy should be considered for antiosteoporotic therapy independently of their BMD. Arch Intern Med. 2000;160:2917-2922
    Archives of Internal Medicine 11/2000; 160(19):2917-22. · 11.46 Impact Factor
  • V. Naganathan, T. Nguyen, P. Sambrook
    Bone 01/2000; 27(4):15-15. · 3.82 Impact Factor
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    ABSTRACT: To determine the diagnostic value of quantitative ultrasound (QUS) to predict bone mineral density (BMD) categories as defined by dual-energy x-ray absorptiometry. Cross-sectional survey. Rheumatology department of a tertiary care hospital (Royal North Shore Hospital, Sydney, NSW), 1997-1998. 326 healthy women aged 45-80 years who had volunteered for a twin study. Our study included both members of non-identical twin pairs but only one randomly selected member of identical twin pairs. BMD categories as defined by dual-energy x-ray absorptiometry of lumbar spine and left hip, and QUS of calcaneus; sensitivity, specificity and likelihood ratios (LRs) of QUS parameters to diagnose osteoporosis as defined by BMD. The sensitivity of QUS to diagnose BMD osteoporosis varied between 9% and 47%, depending on the QUS parameter. The specificity of QUS was high (88%-100%). If all QUS parameters were normal, osteoporosis was unlikely (LR, 0-0.2). One QUS parameter, broadband ultrasound attenuation (BUA), was highly predictive of osteoporosis by BMD when in the osteoporotic range (LR, infinity), but had low sensitivity (9%). QUS results in the osteoporotic range for other parameters and all QUS results in the osteopenic range were less predictive (LR, 1.0-5.2) of osteoporotic BMD. These results suggest that, for most of those tested for osteoporosis by QUS in the community, uncertainty remains about expected BMD.
    The Medical journal of Australia 10/1999; 171(6):297-300. · 2.85 Impact Factor

Publication Stats

141 Citations
808 Views
69.01 Total Impact Points

Institutions

  • 2014
    • Concord Hospital
      Concord, New Hampshire, United States
  • 2010–2013
    • University of Sydney
      • • Centre for Education and Research on Ageing
      • • School of Public Health
      • • Eye disease Research Program
      Sydney, New South Wales, Australia
  • 2012
    • Garvan Institute of Medical Research
      • Cancer Research Program
      Darlinghurst, New South Wales, Australia
  • 1999–2002
    • Royal North Shore Hospital
      Sydney, New South Wales, Australia