ABSTRACT
PURPOSE OF THE STUDY: In a population-based sample of older persons, we studied the relationship between tibial bone density and geometry and factors potentially affecting osteoporosis. METHODS: Of the 1260 participants aged 65 years or older eligible for the InCHIANTI study, 1155 received an interview and 915 (79.2%) had complete data on tibial QCT scans and other variables used in the analysis presented here. The final study population included 807 persons (372 men and 435 women, age range 65-96 years) after exclusion of participants affected by bone diseases or treated with drugs that interfere with bone metabolism. RESULTS: In both sexes, calf cross-sectional muscle area (CSMA) was significantly and independently associated with total bone cross-sectional area (tCSA) and cortical bone cross-sectional area (cCSA) but not with trabecular or cortical volumetric bone mineral density (vBMD). Bioavailable testosterone (Bio-T) was independently associated with both trabecular and cortical vBMD in both sexes. In women, independently of confounders, 25(OH)-vitamin D was positively associated with tCSA and cortical vBMD, while PTH was negatively associated with cortical vBMD. IL-1 beta was negatively correlated with cortical vBMD in women, while TNF-alpha was associated with enhanced bone geometrical adaptation in men. CONCLUSIONS: Physiological parameters that are generically considered risk factors for osteoporosis were associated with specific bone parameters assessed by tibial QCT. Factors known to be associated with increased bone reabsorption, such as 25(OH)-vitamin D, PTH and Bio-T, affected mainly volumetric BMD, while factors associated with bone mechanical stimulation, such as CSMA, affected primarily bone geometry. Our results also suggested that pro-inflammatory cytokines might be considered as markers of bone resorption.
Subject(s)
Bone Density/physiology , Tibia/pathology , Aged , Aged, 80 and over , Biomechanical Phenomena , Bone Resorption/blood , Bone Resorption/pathology , Bone Resorption/physiopathology , Calcifediol/blood , Diet Records , Female , Humans , Interleukin-1beta/blood , Interleukin-6/blood , Male , Osteoporosis/blood , Osteoporosis/pathology , Osteoporosis/physiopathology , Risk Factors , Sex Factors , Surveys and Questionnaires , Tibia/metabolism , Tibia/physiopathology , Tomography, X-Ray Computed/methods , Tumor Necrosis Factor-alpha/bloodABSTRACT
A durable, portable, and field-hardened computerized neurocognitive test (CNT) called the Defense Automated Neurobehavioral Assessment (DANA) tool was recently developed to provide a practical means to conduct neurological and psychological assessment in situ. The psychometric properties of the DANA have been previously described. This present work discusses the test-retest reliability of the DANA Rapid test battery, as administered to a homogeneous population of U.S. Air Force Academy football team players (N = 162) across the duration of the season. The intraclass correlation coefficient (ICC) metric of the DANA is compared with that from two different CNTs recently reported in Cole et al., and the implications of using the metric to interpret comparative test reliability among different CNTs are discussed.
ABSTRACT
Thirty patients thyroidectomized for differentiated thyroid cancer were studied. Serum TSH was assayed in basal conditions and after TRH stimulation, while patients were in suppressive therapy with thyroid hormones. The basal TSH was normal in all the patients and less than 2 microU/ml in 20 patients. The TRH test was negative (no TSH response) in 27 patients and in all the cases with the basal TSH lower than 2 microU/ml.
Subject(s)
Thyroid Neoplasms/therapy , Thyrotropin-Releasing Hormone , Thyrotropin/blood , Adult , Aged , Female , Humans , Male , Middle Aged , Thyroid Neoplasms/blood , Thyroidectomy , Thyroxine/bloodABSTRACT
The increased potential for growth of vascular smooth muscle cells in one of the key abnormalities in the development of essential hypertension, diabetic microangiopathy and atherosclerosis. The underlying mechanisms seem to be extrinsic (increased platelet-derived growth factor-like activity) and intrinsic (increased rate of growth, greater maximal response to growth factors and less contact inhibition). In this article, the authors discuss the primary role of an alteration in vascular smooth muscle cellular proliferation in hypertension, the extrinsic growth factors contained in platelet extracts of diabetic and hypertensive subjects and the specific effects of insulin and antihypertensive therapy on this pro-mitotic platelet activity. The result of experimental studies in our laboratory and in other studies suggest that genetic factors and therapeutic intervention could control the growth of vascular smooth muscle cells and that further evaluation of anti-hypertensive therapy may be necessary.
Subject(s)
Diabetes Mellitus/pathology , Hypertension/pathology , Muscle, Smooth, Vascular/pathology , Animals , Blood Platelets/physiology , Cell Division , Diabetes Mellitus/physiopathology , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 2/blood , Humans , Hypertension/blood , Hypertension/physiopathology , Muscle, Smooth, Vascular/physiopathology , Rats , Rats, Inbred SHRABSTRACT
This study was carried out to assess the sensitivity of single photon bone absorptiometry (SPBA) as an early screening tool for osteoporosis and select the optimum site for measurement. We measured bone mineral density (BMD) at the distal tenth of both radius and ulna (D-BMD) and at the ultradistal radius, a site distal to the point at which the radius and ulna are 8 mm apart (UD-BMD). Our study group consisted of 107 healthy women aged 25-60 years (mean +/- SD: 45.8 +/- 10.0), subdivided according to age into 3 groups: Group 1: 25-40 years, Group 2: 41-50 years, Group 3: 51-60 years. When comparison was made to Group 1, D-BMD was found significantly reduced only in Group 3 (p < 0.0001), while UD-BMD was found reduced in both Groups 2 (p < 0.02) and 3 (p < 0.0001). The percent reduction of BMD in Groups 2 and 3 with respect to Group 1 was significantly greater at the ultradistal site than at the distal tenth of the radius and ulna (p < 0.0001 versus D-BMD). Despite limits inherent in the cross-sectional study design, our results suggest that forearm SPBA indicates post-menopausal bone loss irrespective of scanning site, but detects pre-menopausal loss sensitively only at the ultradistal site. Ultradistal measurement would therefore seem suitable for early screening for osteoporosis as an alternative or in addition to the generally used more proximal site.
Subject(s)
Bone Density , Osteoporosis, Postmenopausal/diagnosis , Radius/chemistry , Absorptiometry, Photon/methods , Absorptiometry, Photon/statistics & numerical data , Adult , Cross-Sectional Studies , Evaluation Studies as Topic , Female , Humans , Middle Aged , Osteoporosis, Postmenopausal/epidemiology , Sensitivity and Specificity , Time FactorsABSTRACT
In a multicenter evaluation the precision and stability of single slice peripheral Quantitative Computed Tomography (pQCT) systems were assessed. Compared to central Europe the peripheral QCT device is also widely used in the Italian health care system. Phantoms were measured frequently on each machine in four pQCT scanners over a two-year period using an identical automated software program. Intrasite and intersite phantom mineral densities, expressed in units of mg/cm3, were analyzed and examined. The short and long term precision were estimated from the consistency of these measurements using the root mean square error and expressed as coefficient of variation in percent (% CV). Short term precision was good (mean intrasite coefficient of variation (CV) 0.21 +/- 0.056 standard deviation (SD)). Intersite measurements of a single phantom revealed differences between machines of the same type of not more than 2.9 mg/cm3. At four sites frequent phantom measurements revealed a mean CV of 0.18% (range 0.12-0.28). No significant changes in the regression slopes (drift of the machine versus time) were observed. We conclude that the in vitro precision and stability of the single slice pQCT systems are sufficiently high and unlikely to negatively affect the in vivo precision.
Subject(s)
Bone and Bones/diagnostic imaging , Phantoms, Imaging , Tomography, X-Ray Computed/methods , Absorptiometry, Photon , Bone Density/physiology , Humans , In Vitro Techniques , Linear Models , Reproducibility of ResultsSubject(s)
Bone Diseases, Metabolic/diagnosis , Muscular Atrophy/complications , Muscular Atrophy/diagnosis , Osteoporosis, Postmenopausal/complications , Osteoporosis, Postmenopausal/diagnosis , Aged , Biomechanical Phenomena , Bone Density , Bone Remodeling , Case-Control Studies , Diagnosis, Differential , Female , Fractures, Bone/etiology , Humans , Osteoporosis, Postmenopausal/metabolism , Tomography, X-Ray ComputedABSTRACT
The aim of this study was to establish, by means of peripheral quantitative computed tomography (pQCT) at the distal radius, the existence of cortical and/or trabecular osteopenia, and to assess the integrity of bone geometry in uremic patients undergoing maintenance hemodialysis. Our results show a clearcut selective reduction in volumetric cortical density, more evident in women (p = -0.0001) than men (p = 0.030), which appears to be independent of age and menopausal status. Trabecular density was not significantly changed in either sex. Cortical density of the patients correlated inversely with age (p = 0.003), duration of dialysis (p = 0.002) and parathyroid hormone (PTH) levels (p = 0.03). Trabecular density correlated only with age. Normally, cortical density is age-dependent and its reduction is accompanied by compensatory geometry changes. Compared with control subjects, in our female patients both cortical area and cortical thickness were reduced (p = 0.02 and 0.008), while cross-sectional area did not change (p = 0.67). Conversely, in the males only cross-sectional area was reduced (p = 0.02). In conclusion, in uremic patients we observed a selective cortical osteopenia, more evident in the female sex, and a sex-specific pattern of geometry impairment, with resultant apparent increased bone fragility in the uremic women. We suggest that the prolonged PTH excess could be responsible, directly and/or interacting with estrogen deficiency.
Subject(s)
Bone Density , Bone Diseases, Metabolic/etiology , Renal Dialysis , Uremia/complications , Adult , Aged , Anthropometry , Bone Diseases, Metabolic/diagnostic imaging , Female , Humans , Male , Middle Aged , Parathyroid Hormone/blood , Radius/diagnostic imaging , Radius/physiopathology , Time Factors , Tomography, X-Ray Computed , Uremia/physiopathology , Uremia/therapyABSTRACT
Trajectories of health and functioning with age show extreme variability among different individuals. Normal aging implies a progressive decline of physiological reserve and ability to compensate, but it is compatible with autonomy over the entire life span. In frail, older persons the decline in functional reserve is accelerated and compensatory mechanisms start failing, with high risk of homeostasis disruption and consequent negative health outcomes. Frailty is currently conceptualized as an age-related alteration in physiology and pathology that results into a typical constellation of signs and symptoms. Although current attempts to identify frail, older individuals for clinical purposes are based on measures of mobility and motor performance, candidate biological markers that may characterize the frailty syndrome start to emerge in the literature. These potential markers include, but are not limited to, soluble mediators of the inflammatory response, hormones, free radicals, antioxidants and macro- and micro-nutrients. This is a research area undergoing a rapid, dynamic development that may profit from new ways of defining disability outcomes in epidemiological studies of the elderly.
Subject(s)
Aging/metabolism , Biomarkers/analysis , Frail Elderly , Aged , Antioxidants/metabolism , Free Radicals/metabolism , Hormones/metabolism , Humans , Inflammation Mediators/metabolismABSTRACT
One of the key paradoxes in gerontology is that, despite a higher longevity, aging women experience worse health and longer disability than men. However, there is growing evidence that changes in life-style, medical interventions and systematic screening for certain diseases may substantially reduce the excess risk of major chronic conditions and disability in aging women, and therefore improve the quality of their late life. The potentials and public health implications of prevention in older women have been recently emphasized, not only by the scientific literature, but also by the media. More and more women are turning to their primary care physicians or other health professionals to seek counselling and help on how to reduce the burden of chronic disease and disability in old age by quitting smoking, eating a healthy diet, increasing physical activity, and coping with stress. Hormone replacement therapy also has a central role in this action of prevention. To maximize compliance, women should be provided a few guidelines that are easy to understand, and can be followed without interfering too much with their daily life activities. This article reviews the current literature on prevention in older women to select preventive strategies that are based on robust scientific evidence. This list of guidelines should be considered as a starting point for all those who are in charge of caring for middle-aged and older women.
Subject(s)
Aging , Delivery of Health Care , Life Style , Preventive Medicine , Aged , Depression/prevention & control , Diet , Exercise , Female , Hormone Replacement Therapy , Humans , Neoplasms/prevention & control , Osteoporosis, Postmenopausal/prevention & control , Sleep Wake Disorders/prevention & control , SmokingABSTRACT
Using peripheral quantitative computed tomography (pQCT) we assessed trabecular and cortical bone density, mass and geometric distribution at the tibia level in 512 men and 693 women, age range 20-102 years, randomly selected from the population living in the Chianti area, Tuscany, Italy. Total, trabecular and cortical bone density decreased linearly with age ( p<0.0001 in both sexes), and the slope of age-associated decline was steeper in women than in men. In men, the cortical bone area was similar in different age groups, while in women older than 60 years it was significantly smaller by approximately 1% per year. The total cross-sectional area of the bone became progressively wider with age, but the magnitude of the age-associated increment was significantly higher in men than in women ( p<0.001). The minimum moment of inertia, an index of mechanical resistance to bending, remained stable with age in men, while it was significantly lower in older compared with younger women (0.5% per year). The increase in bone cross-sectional area in aging men may contribute to the maintenance of adequate bone mechanical competence in the face of declining bone density. In women this compensatory mechanism appears to be less efficient and, accordingly, the bone mechanical competence declines with age. The geometric adaptation of increasing cross-sectional bone size is an important component in the assessment of bone mechanical resistance which is completely overlooked, and potentially misinterpreted, by traditional planar densitometry.