John D Wark's research while affiliated with University of Melbourne and other places

Publications (417)

Article
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Purpose: The purpose of this study was to estimate the association between pain and the number, severity, and location of fractures in women with osteoporotic vertebral fractures. Method:We used an 11-point numeric pain rating scale to assess pain during movement in the preceding week and lateral spinal radiographs to confirm number, location, and...
Article
This systematic review examined the effect of Pilates on health-related outcomes in individuals with increased fracture risk to inform the 2021 Clinical Practice Guidelines for Management of Osteoporosis and Fracture Prevention in Canada. Seven electronic databases were searched to December 2020. Studies of Pilates in men and postmenopausal women a...
Article
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We summarized the effects of yoga on health-related outcomes and adverse events in men and postmenopausal women ≥50 years-old at increased risk of fracture, to inform the updated Osteoporosis Canada clinical practice guidelines. Six databases were searched for observational studies, randomized controlled trials and case series. Certainty of evidenc...
Article
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Vitamin D is important for bone health and strength. Previous studies report 25-hydroxyvitamin D (25(OH)D) exposure during pregnancy may impact offspring bone health later in life. In this study, maternal 25(OH)D at recruitment was associated with a lower fracture risk in boys and an increased fracture risk in girls at 28–32 weeks gestation.Purpose...
Article
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This study aimed to investigate the prevalence of fractures and non-fracture injuries, including associated risk factors, in children with epilepsy prescribed antiseizure medications (ASM). A controlled, cross-sectional study was conducted in a hospital outpatient setting, comparing children with epilepsy prescribed ASMs with their non-epileptic si...
Article
Breast milk is an emerging matrix for vitamin D assessment of breastfed infants and their mothers. It is considered a more reliable indicator of infant intake than the assessment of maternal circulating vitamin D. With the improved sensitivity of mass spectrometry-based technologies, this method principle has been the recent mainstay for the quanti...
Article
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Background Exercise is commonly recommended to prevent and manage osteoporosis. High magnitude strains at rapid rate and short bouts should theoretically elicit an osteogenic response; however, the effects of different levels of impact exercises on several outcomes in people at risk of fracture are still unknown.Objective To report the effect of im...
Article
Objective To prospectively measure cardiometabolic risk 12 months after premenopausal risk-reducing bilateral salpingo-oophorectomy (RRBSO) compared to a similar age comparison group, and the effects of Hormone Therapy (HT) on cardiometabolic risk. Methods Prospective observational study of 95 premenopausal women planning RRBSO and 99 comparisons...
Article
Objective: Adults born either extremely preterm (EP, <28 weeks gestation) or extremely low birthweight (ELBW, <1000 g birthweight) have more obstructive airflow than controls of normal birthweight (>2499 g). We compared self-reported adverse respiratory health outcomes in young adults born EP/ELBW with controls following smoke exposure from the 20...
Article
Walking is a common activity among older adults. However, the effects of walking on health-related outcomes in people with low bone mineral density (BMD) are unknown. The authors included randomized controlled trials comparing walking to control in individuals aged ≥50 years with low BMD and at risk of fractures. The authors identified 13 randomize...
Article
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Previously we have reported an association between maternal vitamin D and offspring bone as measured by dual-energy X-ray absorptiometry. It is plausible that shared genetics might confound associations between maternal vitamin D in pregnancy and offspring bone measures. We aimed to determine whether such associations are independent of maternal bo...
Article
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2021) The association between trunk muscle endurance, balance and falls self-efficacy in women with osteoporotic vertebral fractures: an exploratory analysis from a pilot randomized controlled trial, Disability and Rehabilitation, 43:16, 2268-2274, ABSTRACT Background: Trunk muscle endurance may be associated with balance and falls self-efficacy fo...
Article
Objective Osteoporosis clinical practice guidelines recommend exercise to prevent fractures, but the efficacy of exercise depends on the exercise types, the population studied, or the outcomes of interest. The purpose of this systematic review was to assess the effects of progressive resistance training (PRT) on health-related outcomes in people at...
Article
Background The prevalence of genital tract vaccine-type human papillomavirus (HPV) is on the decline due to high vaccine uptake through the national HPV immunisation program in Australia. The aim of this study was to investigate HPV vaccine coverage and factors associated with HPV in a vaccine-eligible sample of young Australian females. Methods:...
Article
Being born extremely preterm (EP; <28 weeks' gestation) or extremely low birthweight (ELBW; <1000 g birthweight) may predict increased cardiometabolic risk in adulthood, but other early life predictors are less well described. We aimed to (1) compare cardiovascular health profiles between 165 adults born EP/ELBW and 127 controls at age 25 years, dr...
Article
Background: Most infants born extremely preterm (EP; <28 weeks' gestation) or extremely low birthweight (ELBW; <1000 g birthweight) in the post surfactant era (early 1990s) are now surviving into adulthood. Preterm birth/low birthweight are risk factors for reduced bone growth and mineralisation in infants and children. However, little is known ab...
Article
Prophylactic oophorectomy is recommended for women at high risk for ovarian cancer, but the associated impact on bone health is of clinical concern. This prospective, controlled study demonstrated substantial loss of bone density and bone strength following surgical menopause. Postoperative hormone therapy alleviated, but not fully prevented, spina...
Article
Fear of falling is a common issue among older adults, which decreases quality of life and leads to an avoidance of activities they are still able to do. The goal of this secondary data analysis was to explore the relationship between fear of falling and exercise self-efficacy in 141 women with at least one nontraumatic Genant Grade 2 vertebral frac...
Article
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Post-puberty, bone mass displays clear sex-specific patterns. However, research has suggested that a sexual dimorphism in bone mass is evident in younger children and is likely attributable to differences in lean mass. Thus, we aimed to determine whether the association with both overall muscle mass and/or muscle strength was different between the...
Article
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Purpose The Vitamin D in Pregnancy Study is a long-term ongoing cohort study. It was conceived to explore relationships between maternal vitamin D status in pregnancy and offspring growth and development, and has since diversified to include a wide range of physical and mental health exposures and outcomes. Participants Recruitment was from the Un...
Article
Background Understanding bone fragility in young adult females with type 1 diabetes mellitus (T1DM) is of great clinical importance since the high fracture risk in this population remains unexplained. Methods This study aimed to investigate bone health in young adult T1DM females by comparing relevant variables determined by dual energy X-ray abso...
Article
This analysis examined costs/resources of 141 women with vertebral fractures, randomised to a home exercise programme or control group. Total, mean costs and the incremental cost-effectiveness ratio (ICER) were calculated. Quality of life was collected. Cost drivers were caregiver time, medications and adverse events (AEs). Results show adding an e...
Article
Objective: Facebook is a popular social media platform used globally to keep connected and informed. The aims of this study were to determine the contribution of Facebook to the participation rate of young adults enrolled in a longitudinal cohort study, and to examine systematic differences in participants recruited through Facebook compared with...
Article
Background: Regular exercise is advocated in osteoporosis guidelines to prevent fractures. Few studies have evaluated the effect of exercise on functional performance, posture and other outcomes that are important to patients after vertebral fractures. Objective: This pilot study will explore the effect of home exercise versus control on functio...
Article
This study of women with a suspected vertebral fracture determined the association between vertebral fracture characteristics and posture. The number of fractures was associated with posture. Severity of fracture was associated with posture when adjusting for pain. Fracture characteristics explain some variability in posture in women with a suspect...
Article
The main objective of this study was to explore whether vertebral fracture characteristics or posture is independently associated with physical performance. Posture was significantly associated with physical performance but fracture characteristics were not, suggesting posture should be the focus of physical performance variance. Purpose The main...
Article
Dual energy X-ray absorptiometry, the current clinical criterion method for osteoporosis diagnosis, has limitations in identifying individuals with increased fracture risk, especially at the distal radius. Peripheral quantitative computed tomography (pQCT) can provide volumetric bone density data, as well as information on bone geometry, which make...
Article
Background: Trunk muscle endurance may be associated with balance and falls self-efficacy for people with osteoporosis. However, all previous studies have examined trunk muscle strength rather than endurance. Purpose: To explore the relationships between trunk muscle endurance and standing balance and falls self-efficacy for women with vertebral fr...
Article
More infants born extremely preterm (<28 weeks' gestation) or extremely low birthweight (<1000 g) are surviving into adulthood in recent years. Preterm adolescents have higher blood pressure (BP) than normal birthweight controls, but how their BP changes with increasing age is not known. We compared BP at 25 years and trajectories of BP (change per...
Article
Due to limitations of the predominant clinical method for diagnosing osteoporosis, an engineering model based on a dedicated CT scanner for bone density and structure was applied in fracture patients and controls. Improved diagnostic performance was observed, which supports its potential use in future research and clinical practice. Introduction D...
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Rationale: Epilepsy patients often exhibit reduced bone mineral density and are at an increased risk of bone fracture. Whether these bone abnormalities are due to the use of anti-epileptic drugs (AED’s) or the disease itself is unknown. For example, although decreased bone health in epilepsy patients is generally attributed to the use of AED’s, sei...
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Growth restriction programs adult bone deficits and increases the risk of obesity, which may be exacerbated during pregnancy. We aimed to determine if high-fat feeding could exacerbate the bone deficits in pregnant growth restricted dams, and whether treadmill exercise would attenuate these deficits. Uteroplacental insufficiency was induced on embr...
Article
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Introduction Infants born extremely preterm (EP, <28 weeks’ gestation) or with extremely low birth weight (ELBW,<1000 g) in the era when surfactant has been available clinically are at high risk of health and developmental problems in childhood and adolescence. However, how their health and well-being may be affected in adulthood is not well known....
Article
Previously we have demonstrated an association between maternal serum 25-hydroxyvitamin D (25(OH)D) during pregnancy and knee-heel length in offspring at birth. However, it is unknown whether maternal serum 25(OH)D is associated with bone measures in childhood. Thus, we aimed to examine associations between 25(OH)D at two stages of pregnancy and of...
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Fracture risk assessment using dual-energy X-ray absorptiometry (DXA) frequently fails to diagnose osteoporosis amongst individuals who later experience fragility fractures. Hence, more reliable techniques that improve the prediction of fracture risk are needed. In this study, we evaluated a finite element (FE) modelling framework based on clinical...
Poster
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PURPOSE Dual energy x-ray absorptiometry (DXA) has limitations in identifying individuals with increased fracture risk. This study aimed to assess the ability of a finite element (FE) modeling based on single peripheral quantitative computed tomography (pQCT) cross-section in the classification of fracture patients and aged-matched healthy controls...
Article
We pilot-tested a trial of home exercise on individuals with osteoporosis and spine fracture. Our target enrollment was met, though it took longer than expected. Participants stayed in the study and completed the exercise program with no safety concerns. Future trials should expand the inclusion criteria and consider other changes. Purpose Osteopo...
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Background/objectives: Cardiovascular disease (CVD) is a major cause of mortality and morbidity globally. Results from previous studies are inconsistent and it remains unclear whether low-serum 25 OHD levels are associated with an increased risk of CVD. These associations have been little studied in young women. The aim of this study was to assess...
Conference Paper
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Access to knowledge forms an integral part of the continuous learning processes of medical and other health professionals throughout their career. Modern technologies have become instrumental in ex-tending learning processes to the online realm, particularly through the use of social media technologies. Health Practitioners’ (HPs) exploitation of o...
Article
Background Evidence regarding the association between gestational vitamin D status and offspring body composition during childhood is inconsistent. Therefore, we aimed to determine the association between maternal vitamin D and offspring lean and fat mass in the Vitamin D in Pregnancy birth cohort. Methods Subjects were mother–child pairs recruite...
Article
Low birth weight programs diseases in adulthood, including adverse bone health. These diseases can have intergenerational and transgenerational origins, whereby transmission to subsequent generations occurs via both parental lines. Uteroplacental insufficiency surgery (Restricted) or sham surgery (Control) was performed on gestational day 18, in F0...
Article
Objectives: The VACCINE [Vaccine Against Cervical Cancer Impact and Effectiveness] study evaluated the prevalence of quadrivalent vaccine-targeted human papillomavirus (HPV) genotypes (HPV 6, 11, 16, 18) amongst young women of vaccine-eligible age. Methods: Between October 2011 - June 2015, women aged 18-25 years from Victoria, Australia, were r...
Article
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Background: Identifying factors related to risky sexual behaviour may contribute to preventive and interventional approaches to reduce negative mental health outcomes among young women. The aim of this study was to investigate the association between psychological distress and risky sexual behaviours in females aged 16–25 years in Victoria, Austral...
Article
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Background: Poor bone health in adolescent and young adult females is a growing concern. Given the widespread use of mobile phones in this population, mobile health (mHealth) interventions may help improve health behaviors related to bone health in young women. Objective: The goal of the study was to determine the acceptability and feasibility o...
Preprint
BACKGROUND Poor bone health in adolescent and young adult females is a growing concern. Given the widespread use of mobile phones in this population, mobile health (mHealth) interventions may help improve health behaviors related to bone health in young women. OBJECTIVE The goal of the study was to determine the acceptability and feasibility of an...
Article
Background and purpose: We sought to evaluate the Balance Outcome Measure for Elder Rehabilitation (BOOMER) in community-dwelling women 65 years and older with vertebral fracture and to describe score distributions and potential ceiling and floor effects. Methods: This was a secondary data analysis of baseline data from the Build Better Bones wi...
Article
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Introduction Women at high inherited risk of ovarian cancer are advised to undergo risk-reducing bilateral salpingo-oophorectomy (RRBSO) at age 40–45 years or when their families are complete. Most women are premenopausal at this age, so RRBSO will induce surgical menopause. Despite the clear benefits of RRBSO for cancer risk reduction, much less i...
Article
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Background: Polycystic ovarian syndrome (PCOS) is the most common condition among reproductive-aged women. However, its exact prevalence is unknown. Aims: To determine the prevalence of PCOS in Australian women aged 16–29 years using the National Institutes of Health (NIH) criteria compared to self-reported PCOS, to compare co-morbidities between t...
Article
Females born growth restricted have poor adult bone health. Stress exposure during pregnancy increases risk of pregnancy complications. We determined whether maternal stress exposure in growth restricted females exacerbates long-term maternal and offspring bone phenotypes. On gestational day 18, bilateral uterine vessel ligation (Restricted) or sha...
Article
Objective: Antiepileptic drugs (AEDs) are associated with reduced bone density, balance impairment, and increased fracture risk in adults. However, pediatric data are limited. Therefore, we aimed to examine bone, muscle, and balance outcomes in young patients taking AEDs. Methods: We undertook a case-control study utilizing an AED exposure-disco...
Article
Introduction: Trabecular bone score (TBS), a novel tool derived from dual-energy X-ray absorptiometry (DXA), reflects the microarchitecture of the vertebrae. It has been shown to predict fracture independent of standard DXA parameters in adult populations. Previously, we demonstrated that maternal serum 25-hydroxyvitamin D (25(OH)D) during pregnan...
Article
Context: Vitamin D status and parathyroid hormone (PTH) levels influence the risk of accidental falls in older people, but the mechanisms underlying this effect remain unclear. Objective: Investigate the relationship between circulating PTH and 25 hydroxyvitamin D (25-OHD) levels and clinical tests of gait stability and balance as physical fall...
Article
Objective: To evaluate the contributions of shared but unmeasured genetic and environmental factors to hallux valgus (HV). Methods: Between 2011-2012, 74 monozygotic (MZ) and 56 dizygotic (DZ) female twin pairs self-reported HV and putative risk factors, including footwear use across their lifespan. Estimates of casewise concordance (PC ), corre...
Article
Vitamin D deficiency is a global public health concern. Studies of serum 25-hydroxyvitamin D (25(OH)D) determinants in young women are limited and few include objective covariates. Our aims were to define the prevalence of vitamin D deficiency and examine serum 25(OH)D correlates in an exploratory study of women aged 16–25 years. We studied 348 hea...
Article
As sources of medical information grow online, Virtual Communities of Practice (VCoPs) have evolved into a potential tool that allows General Practitioners (GPs) to interact through the sharing of their experience and knowledge. However, literature reports that GPs are reluctant to participate in VCoPs especially for their continuing medical educat...
Conference Paper
Introduction The National HPV Vaccination Program, utilising the quadrivalent HPV vaccine, was implemented in Australia in 2007. As the first country to introduce this scheme, Australia is ideally placed to identify changes in HPV genoprevalence in a vaccinated population, as well as in cervical intraepithelial neoplasia grade 3 (CIN3) lesions. Me...
Article
Background Bone turnover markers (BTMs) may provide insight into bone health in young women, but have been little studied in this demographic. We aimed to explore the association between body composition, hormonal contraception, bone mineral density and biochemical parameters and BTMs in young women. Methods Participants were community-dwelling fe...
Article
Introduction: The implementation of prevention strategies during young adulthood may be crucial for osteoporosis prevention in later life, yet literature examining the determinants of bone health in premenopausal women is limited. We aimed to assess determinants of bone health, including serum 25-hydroxyvitamin D (25OHD), in females aged 16-25 yea...
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Background Behavioural and lifestyle factors associated with childhood unwanted sexual experiences (USE) have yet to be investigated in Australian females aged less than 18 years. Methods: Women aged 16-25 years living in Victoria were recruited via targeted advertising on Facebook. A web-based validated questionnaire was used to collect informat...