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Biomedical subjects

N E Lane

Publications and source records attributed to N E Lane.

At least 55 records · Page 3Linked to original sources
PubMed1999

Recreational physical activity and the risk of osteoarthritis of the hip in elderly women.

OBJECTIVE: The relationship between recreational physical activity and the risk of osteoarthritis (OA) of the hip in women is uncertain. We examined the cross sectional association of radiographic OA of the hip and past recreational and sports related physical activity in elderly women who are participants in the Study of Osteoporotic Fractures. METHODS: An anteroposterior pelvic radiograph of 5818 subjects was assessed for hip OA using reliable measurements of individual radiographic features. Hips were graded on a summary scale of 0 (no findings) to 4 (severe OA) based on the number and type of radiographic features present. Logistic regression was used to examine the association of self-reported recreational physical activity (times/week) as a teenager, at age 30, and at age 50 with hip OA. All analyses were adjusted for age and body mass index at age 25 years. RESULTS: The risk of moderate to severe radiographic hip OA in elderly women was modestly increased in elderly women who were in the highest quartile for all physical activities performed as a teenager (odds ratio 1.7, 95% confidence interval 1.1, 2.4), at age 50 (OR 1.4, 95% CI 1.0, 1.9) and weight bearing activities at age 30 (OR 1.4, 95% CI 1.0, 1.9) compared to women in the lowest quartile of activity. The risk of symptomatic hip OA (grade > or =2 hip OA + hip pain) was modestly increased in women who were in the highest quartile for all physical activities as a teenager (OR 2.0, 95% CI 1.2, 3.4), at age 50 (OR 1.6, 95% CI 1.0, 2.4), and weight bearing activities at age 30 (OR 1.6, 95% CI 1.0, 2.4) compared to women in the lowest quartile of activity. CONCLUSION: Recreational physical activities performed by women before menopause may increase the risk of radiographic and symptomatic hip OA.

Age Factors↗
PubMed1998

Parathyroid hormone treatment can reverse corticosteroid-induced osteoporosis. Results of a randomized controlled clinical trial.

Corticosteroid-induced osteoporosis is the most common secondary cause of osteoporosis. We conducted a 12-mo, randomized clinical trial of human parathyroid hormone 1-34 (hPTH 1-34) in postmenopausal women (mean age was 63 yr) with osteoporosis who were taking corticosteroids and hormone replacement therapy. Response to the treatment was assessed with bone mineral density (BMD) measurements of the lumbar spine by quantitative computed tomography (QCT); BMD measurements of the lumbar spine, hip, and forearm by dual-energy x-ray absorptiometry (DXA); and biochemical markers of bone turnover. The mean (+/-SE) changes in BMD of the lumbar spine by QCT and DXA in the PTH group were 35+/-5.5% and 11+/-1.4%, respectively, compared with a relatively small change of 1.7+/-1.8% and 0+/-0.9% in the estrogen-only group. The differences in mean percentage between the groups at 1 yr were 33.5% for the lumbar spine by QCT (P < 0.001) and 9.8% for the lumbar spine by DXA (P < 0.001). The changes in the hip and forearm were not significantly different between or within the groups. During the first 3 mo of PTH treatment, markers of bone formation increased to nearly 150%, whereas markers of bone resorption increased only 100%, suggesting an early uncoupling of bone turnover in favor of formation. These results suggest that parathyroid hormone dramatically increases bone mass in the central skeleton of postmenopausal women with corticosteroid- induced osteoporosis who are taking hormone replacement.

Absorptiometry, Photon↗
PubMed1998

Hip osteoarthritis prevalence estimates by three radiographic scoring systems.

OBJECTIVE: To estimate and compare the age- and sex-specific prevalence of radiographic hip osteoarthritis (RHOA) in a population-based study of the Pima Indians, using 3 atlas-based methods for assessing features of RHOA. METHODS: Pelvic radiographs from 755 Pima Indians age > or = 45 years enrolled in a population-based study were read using the Kellgren/Lawrence (K/L) grading scale (grade 0-4) and 2 validated individual-radiographic-features (IRF) scales (grades 0-3 for narrowing and osteophytes). RESULTS: The age- and sex-specific prevalence of RHOA among Pima Indians assessed using the K/L scale was < 10% in all age and sex groups. The prevalence of grade > or = 2 osteophytes assessed using the 2 IRF scales were similar to each other in all age and sex groups. However, differences between the 2 IRF scoring systems were found for the prevalence of grade > or = 2 joint space narrowing. CONCLUSION: Pima Indians have an age- and sex-specific prevalence of RHOA similar to that found in the US population. Our finding of different joint space narrowing prevalence by the 2 IRF grading scales supports the use of the same atlas-based case definitions for determining disease prevalence for comparative studies.

Age Distribution↗
PubMed1998

The science and therapy of glucocorticoid-induced bone loss.

Glucocorticoids are critical in the management of chronic, noninfectious, inflammatory diseases. Bone loss is a most devastating side effect of these powerful medications. Glucocorticoids produce bone loss by altering calcium metabolism, suppressing gonadal hormone production, and inhibiting bone formation. Now that the mechanism of glucocorticoid-induced bone loss is understood and effective medications are available, this disease can be prevented and reversed.

Bone Density↗
PubMed1998

Assessment of bone mineral at appendicular sites in females with fractures of the proximal femur.

The prediction of hip fractures by measurements at remote sites or the improvement of predictive power by measurements at multiple sites could potentially increase the success of osteoporosis screening programs. In a cross-sectional study on 137 postmenopausal women, we tested the hypothesis that bone assessment at the hip, the forearm, and the tibia are independently associated with osteoporotic fractures of the hip. Bone mineral densities, geometric features, and ultrasound properties were determined with hip dual X-ray absorptiometry, forearm peripheral quantitative computed tomography (QCT), and tibia speed of sound measurement. While the odds ratios for fracture discrimination per standard deviation decrease ranged between 3 and 4 for measurements at the hip, they were only 1.8 at the forearm and 1.4 at the tibia. Measurements at the tibia or the forearm were neither independently associated with osteoporotic hip fractures (p > 0.05) nor could any combination of measurements significantly increase the power for the identification of fractures as measured with receiver operating curves. Women who sustained trochanteric fractures were characterized by a generalized loss of bone mineral. Cervical fractures were associated with a decrease of bone mineral density at the hip, but no significant alterations in bone mass or geometric properties were observed at the tibia or at the forearm. Fracture risk prediction at the hip is therefore preferably performed by measurements at the hip itself. Peripheral QCT at the distal radius and tibial ultrasound seem capable of depicting women with an increased risk for trochanteric but not for cervical fractures. The risk assessment appears not to be improved by including information of cortical or geometric properties of the forearm.

Absorptiometry, Photon↗
PubMed1998

Trochanteric hip fracture: strong association with spinal trabecular bone mineral density measured with quantitative CT.

PURPOSE: To determine the discriminatory capability for hip fracture of trabecular and integral bone mineral density (BMD) measured with quantitative computed tomography (CT) of the spine. MATERIALS AND METHODS: Fifty-six women who had sustained hip fractures and 59 control subjects underwent volumetric quantitative CT of L1 and L2 and dual x-ray absorptiometry of the hip. BMD was measured in vertebral regions of interest that encompassed trabecular, cortical, and integral bone. Logistic regression analysis was applied to each BMD measure to derive age-, weight-, and height-adjusted relative risk (RR) factors for overall hip fracture and for trochanteric fracture and cervical fracture separately. RESULTS: Spinal trabecular BMD was modestly related to overall hip fracture (RR, 1.4-1.7; P < .05) and strongly associated with trochanteric fracture (RR, 4.2-4.5; P < .005). Spinal integral BMD related similarly to overall hip fracture (RR, 1.7-1.8; P < .05) but more weakly to trochanteric fracture (RR, 2.3-3.2; P < .01). No spinal BMD measures were significantly related to cervical fracture. BMD at the hip was strongly related to overall hip fracture (RR, 3.3-4.3; P < .001), cervical fracture (RR, 2.7-5.3; P < .001), and trochanteric fracture (RR, 2.9-7.2; P < .001). CONCLUSION: Spinal trabecular BMD is strongly associated with both trochanteric and vertebral fractures.

Absorptiometry, Photon↗
PubMed1998

Proximal femur: assessment for osteoporosis with T2* decay characteristics at MR imaging.

PURPOSE: To use T2* measurements at magnetic resonance (MR) imaging to investigate the trabecular structure of the hip in women with and women without osteoporotic hip fractures and to compare this technique with bone mineral density (BMD) measurements in the diagnosis of fractures. MATERIALS AND METHODS: T2* maps of the proximal femur were obtained at 1.5 T in 23 postmenopausal study patients with osteoporotic hip fractures, 27 age-matched healthy postmenopausal control subjects, and five healthy premenopausal control subjects. A modified gradient-recalled acquisition in the steady state, or GRASS, sequence was used with echo times of 4-40 msec at 4-msec increments. T2* values were measured in five regions of interest: femoral neck, the Ward triangle, trochanter, intertrochanteric region, and total proximal femur. Additionally, BMD measurements of the hip were obtained with dual x-ray absorptiometry. RESULTS: Significant differences between T2* measurements were obtained in all three groups (P < .05). BMD measurements of the hip also showed significant differences (P < .05). For T2* and BMD measurements, odds ratios and areas under the curve in receiver operating characteristic analysis were comparable. Correlations between 1/T2* values and BMD were significant (P < .05). T2* measurements in the proximal femur showed regional variations. CONCLUSION: MR imaging decay characteristics of bone marrow could be used to differentiate between postmenopausal women with and those without osteoporotic hip fractures.

Absorptiometry, Photon↗
PubMed1998

Acute changes in trabecular bone connectivity and osteoclast activity in the ovariectomized rat in vivo.

Estrogen deficiency results in a loss of trabecular bone mass and structure that leads to an increased incidence of osteoporotic fractures. The purpose of this study was to determine the time course for trabecular structure deterioration and changes in bone turnover just after ovariectomy in the rat. Six-month-old female virgin Sprague-Dawley rats had their right proximal tibia scanned by X-ray tomographic microscopy (XTM) at baseline (day 0). Animals were then randomized into two groups, and in each group 9 were sham-operated and 11 were ovariectomized and had repeat XTM scans on days 5, 13, 29, and 42 postovariectomy in group 1 and on days 8, 13, 33, and 50 postovariectomy in group 2. Urine was collected for deoxypyridinoline (DPD) cross-link measurements 24 h before each XTM scan and analyzed by ELISA. Trabecular bone structural variables and bone turnover endpoints were calculated from XTM data and standard histomorphometry. Trabecular connectivity decreased 27% by days 5 and 8 postovariectomy (p < 0.01) and continued to decrease up to day 50 postovariectomy (p < 0.01). The trabecular bone volume decreased 25% by 8 days postovariectomy (p < 0.01), and it continued to decrease through day 50. DPD cross-link excretion had increased 37% on day 13 (p < 0.01) and by over 100% of baseline by day 50 postovariectomy. Trabecular bone connectivity and volume deteriorate rapidly while DPD cross-link excretion increased more slowly in acute estrogen deficiency. These data suggest that if an agent is to preserve fully trabecular bone structure, it must be instituted very early in the estrogen-deficient state. They also suggest that a lag time exists before DPD excretion properly mirrors newly induced conditions of high bone turnover in this rat model.

Amino Acids↗
PubMed1998

In vivo high resolution MRI of the calcaneus: differences in trabecular structure in osteoporosis patients.

The purpose of this study was to use high resolution (HR) magnetic resonance (MR) images of the calcaneus to investigate the trabecular structure of patients with and without osteoporotic hip fractures and to compare these techniques with bone mineral density (BMD) in differentiating fracture and nonfracture patients. Axial and sagittal HR MR images of the calcaneus were obtained in 50 female (23 postmenopausal patients with osteoporotic hip fractures and 27 postmenopausal controls). A three-dimensional gradient-echo sequence was used with a slice thickness of 500 micron and in plane resolution of 195 x 195 micron. Texture analysis was performed using morphological features, analogous to standard histomorphometry and fractal dimension. Additionally, BMd measurements of the hip (dual-energy X-ray absorptiometry) were obtained in all patients. Significant differences between both patient groups were obtained using morphological parameters and fractal dimension as well as hip BMD (p < 0.05). Odds ratios for the texture parameters apparent (app.) bone volume/total volume and app. trabecular separation were higher than for hip BMD. Receiver operator characteristic values of texture measures and hip BMD were comparable. In conclusion, trabecular structure measures derived from HR MR images of the calcaneus can differentiate between postmenopausal women with and without osteoporotic hip fractures.

Absorptiometry, Photon↗
PubMed1998

Three-dimensional in vivo morphometry of trabecular bone in the OVX rat model of osteoporosis.

This paper describes the application of synchrotron radiation microtomography to osteoporosis research. By taking advantage of the high intensity, collimation, and monochromaticity of synchrotron radiation, we have been able to image the three-dimensional trabecular bone structure in living rats, thus providing serial data on the earliest architectural changes that occur with estrogen loss. Results from these in vivo animal experiments demonstrate that one of the earliest manifestations of estrogen loss, in addition to a decrease in the amount of trabecular bone, is decreased connectivity. We demonstrate that estrogen replacement therapy, when initiated soon after significant changes have occurred, restores bone mass to baseline levels but does not recover the trabecular connectivity. Even without an associated recovery in trabecular connectivity, finite element calculations on the three-dimensional images suggest that estrogen recovers the original structural modulus of elasticity. We believe the recovery of the elastic properties is due to an increase in trabecular thickness above baseline values.

Animals↗
PubMed1998

The relationship of running to osteoarthritis of the knee and hip and bone mineral density of the lumbar spine: a 9 year longitudinal study.

OBJECTIVE: To determine the associations between running and radiographic hip osteoarthritis (OA), the progression of radiographic knee OA, and changes in bone mineral density (BMD) after 9 year followup in 28 members of a running club now aged 60-77 years and 27 nonrunner controls. METHODS: Running subjects and nonrunning controls were matched for age (+/- 2 years), years of education, and occupation. All subjects underwent rheumatologic examination, completed annual questionnaires, and had radiographs taken of the knees in 1984, 1986, 1989, and 1993 and of the hips in 1993. BMD of the first lumbar spine vertebrae was obtained in 36 subjects by quantitative computed tomography (QCT) in 1984, 1986, 1989, and 1993. In 1993, knee radiographs were assessed in pairs (1984 and 1993), and hip radiographs were scored by 2 readers individually without knowledge of running status. RESULTS: Nine year radiographic results for both runners and nonrunners for the knees showed significant within-group progression of both osteophytes and total knee radiographic scores (p = 0.01 for runners and p = 0.05 for nonrunners) and joint space narrowing in nonrunners (p = 0.01). Runners tended to have higher radiographic scores, but no significant differences in between-group differences were seen in 1984 or 1993. Radiographic OA of the hip was not different between the groups. QCT of the first lumbar vertebrae for BMD in 1984, 1986, 1989, and 1993 was greater in runners than nonrunners (p = 0.01), but rates of change in QCT values were similar between the 2 groups (p < 0.001). CONCLUSION: The presence of radiographic hip OA and the progression of radiographic knee OA was similar for older runners and nonrunners. Lumbar spine BMD remained higher in runners, but changes in lumbar BMD were similar for runners and nonrunners over a 9 year period.

Aged↗
PubMed1997

Management of osteoarthritis in the primary-care setting: an evidence-based approach to treatment.

The most prevalent musculoskeletal condition that results in joint pain is osteoarthritis (OA), with nearly 70% of the population >65 years of age demonstrating radiographic evidence of this disease. The knee is the joint commonly affected. Therapy for OA of the knee is directed at decreasing joint pain and increasing function and includes both pharmacologic and nonpharmacologic interventions. Pharmacologic therapy begins with analgesic medications and proceeds to topical analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) as needed. Intra-articular injections of corticosteroids can relieve pain and inflammation but the effect is of very short duration and such therapy should only be employed infrequently. Nonpharmacologic therapy should include patient education, weight loss if clinically indicated, physical therapy directed at maintaining joint mobility and strengthening muscle groups or an organized low-impact exercise program, and assistive devices as needed. Total joint replacement appears to be a successful therapy when joint pain severely limits a patient's ability to function. Experimental therapies to modify pain and function in OA patients include intra-articular injections of hyaluronan or arthroscopic joint lavage and debridement. In summary, both pharmacologic and nonpharmacologic measures can contribute to the treatment of pain from OA of the knee.

Analgesics↗
PubMed1997

Not all postmenopausal women on chronic steroid and estrogen treatment are osteoporotic: predictors of bone mineral density.

Chronic steroid use results in osteoporosis, and postmenopausal women are believed to be at a high risk for steroid-induced bone loss. The purpose of this study was to determine predictors of bone mineral density (BMD) in postmenopausal women on both chronic steroid and hormone replacement therapy. Seventy-six postmenopausal women (> or = 3 years postmenopausal, > or = 2 years of steroid treatment of > or = 5 mg/day of prednisone, and > or 1 year of hormone replacement therapy) were recruited into this study. Measurements of BMD of the lumbar spine and femoral neck were obtained in all subjects. Risk factors for osteoporosis were obtained by questionnaire. Discriminant analysis was performed to determine predictors of BMD. Osteoporosis, defined by a T score of < -2.5, was present in the lumbar spine or femoral neck in 34 of the 76 subjects. Based on these criteria, women with osteoporosis were significantly older, were more years postmenopausal, and had a lower body mass index (BMI) than women who did not have osteoporosis. Predictors of osteoporosis for both the femoral neck and spine included a low BMI (P < 0.05), more years postmenopausal (P < 0.01), and more years on steroids (P < 0.01). Low BMI was the only significant predictor of osteoporosis in the lumbar spine (P < 0.05), whereas for the femoral neck both years on steroids (P < 0.05) and BMI (P < 0.05) were significant predictors of low BMD. In summary, not all postmenopausal women on chronic steroid and hormone replacement therapy are osteoporotic but a low BMI, more years on steroids, and more years postmenopausal were significant predictors of osteoporosis in these subjects.

Absorptiometry, Photon↗
PubMed1997

Sport practice and osteoarthritis of the limbs.

Participation in sports has evolved as a cause of osteoarthritis (OA), especially in hip and knee joints. OA often occurs at a relatively early age in adult life, in certain sports (soccer, rugby, racket sports and other track and field sports) and under certain conditions (high level of practice). We review preclinical considerations and published epidemiological studies. Joint overuse even without notable trauma is likely the main mechanism of OA both in these sports and in certain occupational activities (relative risk ranges from 1.5 to more than 5 depending chiefly on the category of sport and on the level and duration of practice). Irregular or sudden impacts, heavy load application on the dominant weight-bearing lower limb and the pre-existing state of the joint including dysplasia, dystrophy or previous trauma are risk factors for OA. However, recreational sport activities at a reasonable level are not likely to be harmful for most individuals, in most sport activities.

Case-Control Studies↗
PubMed1997

Changes in canine cortical and cancellous bone mechanical properties following immobilization and remobilization with exercise.

The purpose of this study was to assess cortical and cancellous bone responses to unilateral limb immobilization and, subsequently, to remobilization with exercise, in a young adult canine model. Right forelimbs of 14 1-2-year old mongrel dogs were immobilized in a non-weight-bearing position by a bandage for 16 weeks. Six control dogs were untreated. At 16 weeks, seven immobilized and three control dogs were euthanized. The remaining seven immobilized dogs began a recovery protocol consisting of 16 weeks of kennel confinement (without the right forelimb bandaged) followed by 16 weeks of treadmill exercise conducted three times per week. These seven dogs and three control dogs were euthanized at 48 weeks. Bone mineral density of the proximal radii was determined with dual-energy X-ray absorptiometry and humeral middiaphyseal cross-sectional areas were determined with computed tomography. Humeri were tested in cranio-caudal three-point bending to failure. Cancellous bone cores from the lateral humeral condyles had wet apparent density determined and were tested to failure in compression. Mechanical properties, bone density, and cross-sectional areas were compared between immobilized (right forelimb), contralateral weight bearing (left forelimb), and control forelimbs with Kruskal-Wallis and post hoc tests. At 16 weeks, bone mineral density, cortical load, yield, and stiffness as well as cancellous bone failure stress, yield stress, and modulus were significantly lower (p < 0.02) for immobilized limbs than control limbs. Immobilized limb cancellous bone mechanical properties were 28%-74% of control values, and cortical bone mechanical properties were 71%-98% of control values. After 32 weeks of remobilization, cortical and cancellous bone mechanical properties were not different from control values except that cortical bone failure stress and modulus were significantly higher (p < 0.01) between remobilized and control limbs. In summary, 16 weeks of forelimb immobilization was associated with significantly lower mechanical properties, and with greater differences in cancellous than cortical bone properties. Mechanical properties were not different from control values after 32 weeks of recovery that included 16 weeks of treadmill exercise.

Absorptiometry, Photon↗
PubMed1997

A survey of policies at children's hospitals regarding immunity of healthcare workers: are physicians protected?

OBJECTIVE: To determine policies at children's hospitals regarding immunizations, annual tuberculosis (TB) screening, and blood or body fluid exposure follow-up, particularly as they apply to physicians. DESIGN AND PARTICIPANTS: A three-page survey was sent to infection control practitioners (ICPs) in April 1994 at hospitals affiliated with the National Association of Children's Hospitals and Related Institutions. One follow-up mailing was sent to nonresponding ICPs. RESULTS: Responses were received from 62 (67%) of 93 ICPs. Thirty-five (66%) of 53 children's hospitals had an immunity policy that applied to medical students, 42 (79%) of 53 to resident physicians, 32 (52%) of 62 to hospital-based physicians, and 18 (29%) of 62 to private or community physicians (who admit patients to one hospital). Physicians were required to show evidence of an annual TB screen at 36 hospitals (58%). Immunity policies or TB screening were provided for the following physician groups: medical students, 13 (21%); resident physicians, 43 (69%); hospital-based physicians, 50 (81%); and private or community physicians, 23 (37%). Infection control practitioners reported that the following diseases had been identified within the past 5 years at their hospitals: measles, 82%; mumps, 40%; rubella, 31%; TB, 94%; hepatitis B, 94%; pertussis, 90%; varicella, 98%; and influenza, 94%. Physicians in these institutions were reported to have contracted the following diseases from patient exposure: measles, hepatitis B, TB, pertussis, varicella, and influenza. CONCLUSION: Children's hospitals vary widely in their policies regarding healthcare-worker immunity, and, in many cases, physicians may not be protected from nosocomial transmission of community infections.

Hospitals, Pediatric↗