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M A Kotowicz

Publications and source records attributed to M A Kotowicz.

At least 19 recordsLinked to original sources
PubMed2006

The population burden of fractures originates in women with osteopenia, not osteoporosis.

INTRODUCTION: Osteoporosis is associated with increased risk for fracture. However, most postmenopausal women have bone mineral density (BMD) within the normal or osteopenic range. The aim of this study was to determine the proportion of the population burden of fragility fractures arising from women at modest risk for fracture. METHODS: We measured baseline BMD in a population-based random sample of 616 postmenopausal women aged 60-94 years and followed these individuals for a median of 5.6 years (IQR 3.9-6.5) to determine the incidence of fractures according to age, BMD and the presence of a prior fracture. RESULTS: Based on WHO criteria, 37.6% of the women had normal total hip BMD, 48.0% had osteopenia and 14.5% had osteoporosis. The incidence of fracture during follow-up was highest in women with osteoporosis, but only 26.9% of all fractures arose from this group; 73.1% occurred in women without osteoporosis (56.5% in women with osteopenia, 16.6% in women with normal BMD). Decreasing BMD, increasing age and prior fracture contributed independently to increased fracture risk; in a multivariate model, the relative risk for fracture increased 65% for each SD decrease in BMD (RR=1.65, 95%CI 1.32-2.05), increased 3% for every year of age (RR=1.03, 95%CI 1.01-1.06) and doubled with prevalent fracture (RR=2.01, 95% CI 1.40-2.88). A prevalent fracture increased the risk for fractures such that women with osteopenia and prevalent fracture had the same, if not greater, risk as women with osteoporosis alone. CONCLUSIONS: Reducing the population burden of fractures requires attention to women with osteopenia, as well as osteoporosis, because over half of the fragility fractures in the population arise in these individuals, and women with osteopenia plus a prevalent fracture have the same fracture risk as women with osteoporosis.

Aged↗
PubMed2005

Femoral neck geometry and hip fracture risk: the Geelong osteoporosis study.

To determine the relationship between femoral neck geometry and the risk of hip fracture in post-menopausal Caucasian women, we conducted a retrospective study comparing the femoral neck dimensions of 62 hip fracture cases to those of 608 randomly selected controls. Measurements were made from dual-energy X-ray absorptiometry scans (Lunar DPX-L), using the manufacturer's ruler function, and included: hip axis length (HAL), femoral neck axis length (FNAL), femoral neck width (FNW), femoral shaft width (FSW), medial femoral shaft cortical thickness (FSCT(med)), and lateral femoral shaft cortical thickness (FSCT(lat)). The fracture group was older (median age 78.3 years vs 73.8 years), lighter (median weight 59.9 kg vs 64.5 kg), and, after adjustment for age, taller (mean height 158.7+/-0.8 cm vs 156.7+/-0.2 cm) than the controls. Furthermore, bone mineral density was lower in this group (0.682+/-0.016 g/cm(2) vs 0.791+/-0.006 g/cm(2)). After adjustment for age, bone mineral content (BMC) or height, hip fracture patients had greater FNW (up to 6.6%) and FSW (up to 6.3%) than did the controls. Each standard deviation increase in FNW and FSW was associated with a 1.7-fold (95% CI 1.3-2.3) and a 2.4-fold (95% CI 1.8-3.2) increase in the fracture risk, respectively. BMC-adjusted FNAL was greater in the fracture group (+2.1%) than in the controls, while the age-adjusted FSCT(med) was reduced (-7.2%). There was a trend towards longer HAL (up to 2.1%) after adjustment for age or BMC, and thinner age-adjusted FSCT(lat) (-1.7%) in fracture patients that did not reach statistical significance. In multivariate analysis, the risk of hip fracture was predicted by the combination of age, FNW, FSW, BMC and FSCT(med). HAL was not analyzed because of the small number of HAL measurements among fracture cases. We conclude that post-menopausal women with hip fractures have wider femoral necks and shafts, thinner femoral cortices and longer femoral neck axis lengths than do women with no fractures. Alteration in hip geometry is associated with the risk of hip fracture.

Absorptiometry, Photon↗
PubMed2004

Dietary omega-3 fatty acids and depression in a community sample.

To evaluate the association between omega-3 polyunsaturated essential fatty acids and depression, data regarding prevalence rates of self-reported depression and median daily dietary intakes of these fatty acids were obtained from an age-stratified, population-based sample of women (n = 755; 23-97 year) in the Barwon Statistical Division of south-eastern Australia. A self-report questionnaire based on Diagnostic and Statistical Manual-IV criteria was utilised to determine 12-month prevalence rates of depression in this sample, and data from biennial food frequency questionnaires examining seafood and fish oil consumption over a 6-year period were examined. Differences in median dietary intakes of omega-3 fatty acids between the depressed and nondepressed cohorts were analysed and results were adjusted for age, weight and smoking status. No significant differences in median intakes were identified between the two groups of women (median, interquartile range; depressed = 0.09g/day, 0.04-0.18 versus nondepressed = 0.11 g/day, 0.05-0.22, p = 0.3), although overall average intakes of omega-3 fatty acids were lower than recommended and rates of depression within this sample higher than expected, based on previous data. Further research that takes into account ratios of omega-6 to omega-3 polyunsaturated essential fatty acids, as well as other dietary sources of omega-3 fatty acids, is warranted.

Adult↗
PubMed2004

Reference ranges for bone densitometers adopted Australia-wide: Geelong osteoporosis study.

Bone densitometry reports a measure of fracture risk in comparison with young adults (T-scores) and age-matched peers (Z-scores). To date, each manufacturer has provided its own reference range resulting in lack of uniformity. The Australia and New Zealand Bone and Mineral Society and Osteoporosis Australia have recognized the need to standardize the reference range and have recommended that data generated by the Geelong Osteoporosis Study (GOS) be used Australia-wide. The GOS recruited a random, population-based sample of adult women and measured bone mineral density (BMD) at the proximal femur and spine using a Lunar DPX-L. These data were used to establish reference ranges for Lunar machines and, using conversion equations, for Norland and Hologic machines. The new standardized Australian reference ranges for BMD will enable consistent diagnosis of osteoporosis and categorization of fracture risk across different types of densitometers.

Absorptiometry, Photon↗
PubMed2004

Paget disease of bone. Diagnosis and indications for treatment.

BACKGROUND: Paget disease was first described in 1877 by Sir James Paget. It is a focal disorder of bone remodelling, involving increased bone resorption and formation. The aetiology is uncertain but both environmental and genetic factors are thought to be involved in pathogenesis. OBJECTIVE: This article outlines the clinical presentation, diagnosis and treatment of Paget disease. DISCUSSION: Paget disease is associated with musculoskeletal pain, significant disability and impaired quality of life. Complications include pathological fracture, arthritis in adjacent joints, hearing loss, other neurological complications, heart failure and, rarely, osteosarcoma. Recent clinical trial data has demonstrated histological and radiological improvements in bone of patients treated with bisphosphonates. There is little data evaluating the long term effect of therapy on the risk of complications, however, restoration of normal bony architecture offers the prospect that complications related to deformity and increased bone fragility might be reduced by effective therapy.

Adult↗
PubMed2003

The Taq IA and Ser311 Cys polymorphisms in the dopamine D2 receptor gene and obesity.

Dopamine D2 receptors (DRD2) in the central nervous system are involved in the regulation of feeding. It remains to be elucidated if mutations in the DRD2 gene contribute to the development of obesity. The aim of the present study was to investigate whether the Taq IA and Ser311Cys polymorphisms in the DRD2 gene are associated with obesity in Nauruan and Australian subjects. Subjects were selected based on extremes of the body mass index (BMI) distribution. Two groups of Australian women were selected. The leanest group had a mean BMI of 22.5 kg/m2 (range: 20.3-24.3) and the heaviest group had a mean of 36.1 kg/m2 (32.5-44.1). Four groups of Nauruan subjects were selected. Leanest men had a mean BMI of 33.0 kg/m2 (28.4-36.9), heaviest men had a mean of 52.8 kg/m2 (46.5-69.2), leanest women had a mean of 34.8 kg/m2 (28.2-41.8) and heaviest women had a mean of 55.1 kg/m2 (49.3-73.8). Subjects were genotyped for the Taq IA and Ser311Cys polymorphisms using polymerase chain reaction (PCR) restriction fragment length polymorphism analysis and allelic discrimination Taqman PCR respectively. Leanest and heaviest groups were examined for differences in genotype frequency. Taq IA and Ser311Cys genotype frequencies did not differ significantly between leanest and heaviest Nauruan groups, or between leanest and heaviest Australians. Haplotype frequencies of these polymorphisms did not differ between leanest and heaviest groups. The Taq IA and Ser311Cys polymorphisms in the DRD2 gene are unlikely to be common causes of obesity in these populations.

Adult↗
PubMed2002

Fracture thresholds revisited. Geelong Osteoporosis Study.

Osteoporosis, in the absence of fracture, is defined as a deficit in bone mineral density (BMD) of 2.5 SD or more below the young adult reference mean in postmenopausal Caucasian populations. BMD is a measure of fracture risk but not the sole predictor. We have assessed a combination of easily accessible measures of age, height, weight, and BMD to improve fracture risk assessment. Women with low trauma fractures and a control group were recruited from south-eastern Australia. Discriminant analysis derived multivariate equations that assessed fracture risk. Age was not in the best models at the spine and forearm sites. Weight and height contributed to the relationship for the forearm sites only. At the proximal femur, the BMD level that separates fracture cases from nonfracture cases, increases with age. These separation levels of BMD were higher than the WHO's level of osteoporosis (T-score < -2.5 SD) at ages older than 62 years. This increasing BMD threshold with age suggests that other age-related risk factors assume increasing importance among the elderly.

Adult↗
PubMed2002

Fracture rates lower in rural than urban communities: the Geelong Osteoporosis Study.

BACKGROUND: Urban and rural communities differ in the incidence of several diseases including coronary heart disease and some cancers. Lower hip fracture rates among rural than urban populations have been reported but few studies have compared rural and urban fractures at sites other than the hip. OBJECTIVE: To compare total and site specific fracture rates among adult residents of rural and urban communities within the same population. DESIGN AND SETTING: This is a population based study on osteoporosis in Australia. All fractures occurring in adult residents over a two year period were ascertained using radiological reports. The rural and urban areas are in close proximity, with the same medical, hospital, and radiological facilities permitting uniform fracture ascertainment. MAIN OUTCOME MEASURES: All fracture rates were age adjusted and sex adjusted to the Australian population according to the 1996 census of the Australian Bureau of Statistics and described as the rate per 10 000 person years. The p values refer to the adjusted rate difference. RESULTS: The hip fracture rate (incidence per 10 000 person years) was 32% lower (39 v 57, p<0.001), and the total fracture rate 15% lower (160 v 188, p=0.004) among rural than urban residents, respectively. The lower fracture rates in the rural population were also apparent for pelvic fractures. CONCLUSION: In the older rural population, lower fracture rates at sites typically associated with osteoporosis suggest environmental factors may have a different impact on bone health in this community. If the national rate of hip fracture could be reduced to that of the rural population, the projected increase in hip fracture number attributable to aging of the population could be prevented.

Adult↗
PubMed2001

Vitamin D status of women in the Geelong Osteoporosis Study: association with diet and casual exposure to sunlight.

OBJECTIVE: To assess vitamin D intake and casual exposure to sunshine in relation to serum 25-hydroxyvitamin D (25OHD) levels. DESIGN: Cross-sectional study of a population-based, random sample of women aged 20-92 years, assessed between 1994 and 1997. SETTING AND PARTICIPANTS: 861 women from the Barwon Statistical Division (population, 218000), which includes the city of Geelong (latitude 38 degrees south) in Victoria. MAIN OUTCOME MEASURES: Vitamin D intake; serum 25OHD level; season of assessment; exposure to sunshine. RESULTS: Median intake of vitamin D was 1.2 microg/day (range, 0.0-11.4 microg/day). Vitamin D supplements, taken by 7.9% of participants, increased intake by 8.1% to 1.3 microg/day (range, 0.0-101.2 microg/day) (P< 0.001). A dose-response relationship in serum 25OHD levels was observed for sunbathing frequency before and after adjusting for age (P< 0.05). During winter (May-October), serum 25OHD levels were dependent on vitamin D intake (partial r2= 0.01; P<0.05) and were lower than during summer (November-April) (age-adjusted mean, 59nmol/L [95% Cl, 57-62] v 81 nmol/L [95% CI, 78-84]; P<0.05). No association was detected between serum 25OHD and vitamin D intake during summer. The prevalences of low concentrations of serum 25OHD were, for <28nmol/L, 7.2% and 11.3% overall and in winter, respectively; and, for <50 nmol/L, 30.0% and 43.2% overall and in winter, respectively. CONCLUSIONS: At latitude 38 degrees south, the contribution of vitamin D from dietary sources appears to be insignificant during summer. However, during winter vitamin D status is influenced by dietary intake. Australia has no recommended dietary intake (RDI) for vitamin D, in the belief that adequate vitamin D can be obtained from solar irradiation alone. Our results suggest that an RDI may be needed.

Adult↗
PubMed2001

Lifetime and five-year age-specific risks of first and subsequent osteoporotic fractures in postmenopausal women.

We examined the incidence of fragility fractures in Australian women 50 years of age and over using a Markov process with Monte Carlo simulations. The lifetime risks and the risks of sustaining first and subsequent clinically diagnosed fractures at osteoporotic sites were estimated according to age, nursing home entry and mortality rates. Hip and spine fractures were evaluated individually and fractures of humerus, forearm, wrist, ribs, pelvis, upper leg (excluding proximal femur) and tibia/fibula were considered in combination. The model predicted that 42.1% of women aged 50 years will sustain at least one fracture in their remaining lifetime, of whom half are expected to sustain multiple fractures. The lifetime risks of sustaining hip, clinical spine and other fractures were 17.0%, 9.6% and 30.4%, with the risks of multiple fractures at these sites estimated at 19.5%, 39.7% and 35.7% respectively. The proportion of women expected to sustain their first fracture increased from 1.9% of the population under 55 years of age up to 49.1% of women over 89 years of age. The 5-year age-specific risks of sustaining any subsequent fractures increased from 2.8% of women under the age of 55 years to 61.6% for women age 89 years and over. The increased risks of new fractures following a first fracture lead to a considerable burden of multiple fractures.

Age Factors↗
PubMed2001

Serum leptin levels are associated with bone mass in nonobese women.

Both serum leptin and bone mineral density are positively correlated with body fat, generating the hypothesis that leptin may be a systemic and/or local regulator of bone mass. We investigated 214 healthy, nonobese Australian women aged 20-91 yr. Bone mineral content, projected bone area, and body fat mass were measured by dual energy x-ray absorptiometry and fasting serum leptin levels by RIA. Associations between bone mineral content (adjusted for age, body weight, body fat mass, and bone area) and the natural logarithm of serum leptin concentrations were analyzed by multiple regression techniques. There was a significant positive association at the lateral spine, two proximal femur sites (Ward's triangle and trochanter), and whole body (partial r(2) = 0.019 to 0.036; all P < 0.05). Similar trends were observed at the femoral neck and posterior-anterior-spine. With bone mineral density the dependent variable (adjusted for age, body weight, and body fat mass), the association with the natural logarithm of leptin remained significant at the lateral spine (partial r(2) = 0.030; P = 0.011), was of borderline significance at the proximal femur sites (partial r(2) = 0.012 to 0.017; P = 0.058 to 0.120), and was not significant at the other sites. Our results demonstrate an association between serum leptin levels and bone mass consistent with the hypothesis that circulating leptin may play a role in regulating bone mass.

Adult↗
PubMed2001

Effects of calcitriol or calcium on bone mineral density, bone turnover, and fractures in men with primary osteoporosis: a two-year randomized, double blind, double placebo study.

Osteoporosis in men is an emerging public health problem. As calcitriol reduces the rate of vertebral fractures in osteoporotic postmenopausal women, we conducted a prospective study of this treatment in men with primary osteoporosis. Our study was a 2-yr, randomized, double masked, double placebo-controlled trial of calcitriol (0.25 microg twice daily) or calcium (500 mg twice daily) in 41 men with primary osteoporosis and at least 1 baseline fragility fracture. Thirty-three men (85%) completed the study. There were no differences in baseline characteristics. Spinal and femoral neck bone mineral densities at 2 yr were unchanged in both groups. Serum osteocalcin decreased in both groups by 30% (P < 0.05), whereas urine N-telopeptide cross-links decreased only in the calcium group by 30% (P < 0.05). After 2 yr, fractional calcium absorption increased by 34% (P < 0.01) in the calcitriol group. Nineteen incident fragility fractures occurred (14 vertebral and 5 nonvertebral) in 7 men. Over 2 yr, the number of men with vertebral fractures (6 vs. 1; P = 0.097) was similar in both groups. In conclusion, the efficacy of calcitriol remains unproven as a single agent for the treatment of osteoporosis in men.

Adult↗
PubMed2001

Assessment of fracture risk: value of random population-based samples--the Geelong Osteoporosis Study.

Fracture risk is determined by bone mineral density (BMD). The T-score, a measure of fracture risk, is the position of an individual's BMD in relation to a reference range. The aim of this study was to determine the magnitude of change in the T-score when different sampling techniques were used to produce the reference range. Reference ranges were derived from three samples, drawn from the same region: (1) an age-stratified population-based random sample, (2) unselected volunteers, and (3) a selected healthy subset of the population-based sample with no diseases or drugs known to affect bone. T-scores were calculated using the three reference ranges for a cohort of women who had sustained a fracture and as a group had a low mean BMD (ages 35-72 yr; n = 484). For most comparisons, the T-scores for the fracture cohort were more negative using the population reference range. The difference in T-scores reached 1.0 SD. The proportion of the fracture cohort classified as having osteoporosis at the spine was 26, 14, and 23% when the population, volunteer, and healthy reference ranges were applied, respectively. The use of inappropriate reference ranges results in substantial changes to T-scores and may lead to inappropriate management.

Absorptiometry, Photon↗
PubMed2000

Oral contraceptives and bone mineral density: A population-based study.

OBJECTIVE: We sought to test the hypothesis that exposure to oral contraceptives protects the skeleton. STUDY DESIGN: Multiple regression techniques were used to analyze data for a random sample of 710 Australian women (age range, 20-69 years). Bone mineral density was measured at the lumbar spine, proximal femur, whole body, and distal forearm. Oral contraceptive exposure was assessed by a questionnaire. RESULTS: Women exposed to oral contraceptives had a 3.3% greater mean bone mineral density adjusted for body mass index and age at the lumbar spine (partial r (2) = 0.009; P =.014). Adjusted mean vertebral bone mineral density was 3.3% greater for premenopausal women (partial r (2) = 0.008; P <.05), but the effect did not reach significance among postmenopausal women. Higher bone mineral density was associated with increased duration of exposure, with a mean increase of 3.2% associated with the first 5 years and a further 0.2% with >/=5 years of exposure. No association was detected at other sites. CONCLUSION: Exposure to oral contraceptives may be associated with higher lumbar spine bone mineral density.

Absorptiometry, Photon↗
PubMed2000

Calcium intakes among Australian women: Geelong Osteoporosis Study.

BACKGROUND: Dietary calcium deficiency may be a risk factor for osteoporosis. AIMS: To estimate habitual calcium intakes and prevalence of calcium supplementation among free-living Australian women and validate a calcium-specific food-frequency questionnaire. METHODS: Calcium intakes for 1045 randomly selected women (20-92 years) were estimated by questionnaire which was tested against estimates from four day weighed records kept by 32 randomly selected women. RESULTS: The mean difference between calcium estimates was not statistically significantly different from zero (mean difference=121 mg; standard deviation of differences=357 mg; p>0.05). There was moderate agreement (weighted kappa=0.4) between methods in ranking subjects into tertiles of calcium intake. Mean dietary calcium intakes were 615 mg/day for 20-54 years, 646 mg/day for 55-92 years and 782 mg/day for lactating women. Seventy-six per cent of women aged 20-54 years, 87% of older and 82% of lactating women had intakes below the recommended dietary intake (RDI). There was no association detected between calcium intake and age. Dairy foods provided 79.0% of dietary calcium intake. Calcium supplements were used by 6.6% and multivitamins by a further 4.3% of women. Supplementation was independent of dietary calcium intake and more likely used by postmenopausal women. CONCLUSIONS: Our results suggest that 76% of women consume less than the RDI even when supplemental calcium is included. Furthermore, 14% have less than the minimal requirement of 300 mg/day and would, therefore, be in negative calcium balance and at risk of bone loss. Despite advertising campaigns promoting better nutrition and increased awareness of osteoporosis, many women are failing to achieve an adequate calcium intake.

Adult↗
PubMed2000

Prevalence of osteoporosis in Australian women: Geelong Osteoporosis Study.

To evaluate the prevalence of osteoporosis at various sites among Australian women, cross-sectional bone mineral density (BMD) data for adult females was obtained from an age-stratified population-based sample (n = 1494; 20-94 yr) drawn at random from the Barwon Statistical Division, a population characteristic of Australia. Age- and weight- (and for three sites, height) matched reference ranges for BMD at the lumbar spine, proximal femur, forearm, and total body were developed using regression techniques. The cutoff BMD level for osteoporosis at the PA spine was 0. 917g/cm(2) and 0.713 g/cm(2) at the femoral neck according to the World Health Organization (WHO) guidelines. The upper cutoff level for osteopenia was 1.128 g/cm(2) at the PA spine and 0.913g/cm(2) for the femoral neck. The proportion of Australian women categorized as having osteoporosis at the PA spine, femoral neck, or midforearm ranged from 0.9% among those aged 40-44 yr to 87.0% for those older than 79 yr. This study provides reference data representative of the Australian female population. A large proportion of elderly Australian women has osteoporosis according to the WHO guidelines.

Absorptiometry, Photon↗