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Biomedical subjects

O Johnell

Publications and source records attributed to O Johnell.

At least 91 records · Page 5Linked to original sources
PubMed2001

Acute and long-term increase in fracture risk after hospitalization for stroke.

BACKGROUND AND PURPOSE: The aims of this study were to determine the magnitude of the increase in fracture risk after hospitalization for stroke, and in particular to determine the time course of this risk. METHODS: The records of the Swedish register of patients admitted during 1987-1996 were examined to identify all patients who were admitted to the hospital for stroke. Patients were followed for subsequent hospitalizations for hip and all fractures combined. We analyzed 16.3 million hospitalizations, from which 273 288 individuals with stroke were identified. A Poisson model was used to determine the absolute risk of subsequent fractures and the risk compared with that of the general population. RESULTS: After hospitalization for stroke, there was a >7-fold increase in fracture risk, including that for hip fracture within the first year after hospitalization for stroke. Thereafter, fracture risk declined toward, but did not attain, the baseline risk except in men and women aged >/=80 years. CONCLUSIONS: The high incidence of new fractures within the first year of hospitalization for stroke suggests that such patients should be preferentially targeted for treatment. It is possible that short courses of treatment at the time of stroke would provide important therapeutic dividends.

Acute Disease↗
PubMed2001

Osteoporosis in Sweden.

Sweden has one of the highest incidences of hip fractures in the world and we have started to consider osteoporosis as an important disease. We have created guidelines for BMD measurements and the recommendations for treatment are based on risk assessment. New guidelines for treatment with drugs will soon be developed by the Swedish FDA.

Journal Article↗
PubMed2000

[The value of bone density measurement--a follow-up of the conclusions in the earlier SBU report].

Osteoporotic fractures are common primarily among elderly Swedish women. Vertebral compression fractures can occur spontaneously without trauma, while wrist and hip fractures are nearly always the result of trauma. The risk of fracture increases in skeletal wasting. If bone density measurement can demonstrate osteoporosis already before fractures occur, then preventive measures could be set in. The present study, which is a systematic review of articles published from 1994 to the spring of 1998, confirms the conclusions of the 1995 report "Bone Density Measurement" from SBU, the Swedish Council on Technology Assessment in Health Care, that the relative risk of fracture can be predicted utilizing bone density measurement. The best risk assessment is achieved by taking into account both clinical risk factors and bone density.

Adult↗
PubMed2000

Exercise during growth and bone mineral density and fractures in old age.

If exercise is to be recommended during growth, benefits in bone mineral density (BMD) must be maintained in old age and shown to prevent fractures. Our cross-sectional study of soccer players suggests that a high BMD is no longer recorded after retirement and fracture frequency is no less than predicted in old age.

Aged↗
PubMed2000

Risk of hip fracture derived from relative risks: an analysis applied to the population of Sweden.

Bone mineral density measurements are widely used to estimate the relative risk of hip fracture. In addition, many other risk factors have been identified, some of which are known to add to the risk independently of other risk factors, including bone mineral density measurements. In this paper we develop an algorithm that converts relative risks for hip fracture to absolute (15 years and lifetime) risks, modeled on the population of Sweden. Lifetime risks increased as expected with increments in relative risk. Average lifetime risk in women at the age of 50 years was 22.7%, which increased to 64.9% when the relative risk was 6.0. In men the risk increased from 11.1% to 41.3%. The identification of high-risk groups had little effect on the specificity of assessments but increased the sensitivity over a wide range of assumptions. The increment in lifetime risk was relatively stable across all ages, reducing the complexity of computing lifetime risks from relative risk. The derivation of absolute risk from relative risk permits the optimization of selection of individuals or populations either for further risk assessment or for treatment.

Age Factors↗
PubMed2000

Validity of self-report of fractures: results from a prospective study in men and women across Europe. EPOS Study Group. European Prospective Osteoporosis Study Group.

In population-based studies of osteoporosis, ascertainment of fractures is typically based on self-report, with subsequent verification by medical records. The aim of this analysis was to assess the validity of self-report of incident nonspine fractures using a postal questionnaire. The degree of overreporting of fracture (false positives) was assessed by comparing self-reports of new fracture from respondents in the multicenter European Prospective Osteoporosis Study with data from other sources including radiographs and medical records. In the analysis, 563 subjects reported nonspine fractures. Verification of the presence of fracture was possible in 510 subjects. Of these, fractures were not confirmed in 11% (false positives). The percentage of false positives was greater in men than in women (15% vs 9%, p = 0.04), and less for fractures of the distal forearm and hip than for fractures at other sites. In a separate study, the degree of underreporting (false negatives) was assessed by follow-up of 251 individuals with confirmed fracture ascertained from the records of fracture clinics in three European centers (Lubeck, Oviedo, Warsaw). Questionnaire responses were received from 174 (69%) subjects. Of these, 12 (7%) did not recall sustaining a fracture (false negatives). The percentage of false negatives was lower for hip and distal forearm fractures with only 3 of 90 (3%) such fractures not recalled. Using the combined data from both studies, of those who reported a 'date' of fracture on the questionnaire, 91% of subjects were correct to within 1 month of the actual date of the fracture. A postal questionnaire is a relatively simple and accurate method for obtaining information about the occurrence of hip and distal forearm fractures, including their timing. Accuracy of ascertainment of fractures at other sites is less good and where possible self-reported fractures at such sites should be verified from other sources.

Aged↗
PubMed2000

Bone mineral density of the Lebanese reference population.

We determined the bone mineral density (BMD) of normal Lebanese subjects and compared results with US/European reference data. The investigation was conducted at one center, and included 858 women and 165 men aged 20-79 years. Spine, femoral and radial BMD measurements were made using dual-energy X-ray absorptiometry. Age-related changes in BMD were similar in form to those of US/European reference data. However, BMD values of Lebanese were generally lower than US/European values. Spine BMD of Lebanese women was about 8% lower than US/European values between ages 20 and 59 years, and 5-6% lower for ages 60-79 years. Femoral neck BMD values for Lebanese women were 8% lower in the young adult years (age 20-39 years), but only 2-3% lower in the postmenopausal years, compared with US/European women. There were smaller postmenopausal decreases in femoral and radial BMD in Lebanese women compared with US/European women, which led to a convergence of BMD after age 70 years. The BMD of Lebanese men was 5-8% lower than US/European values throughout the age range (20-79 years). The effect of weight on BMD ranged from 0.2% to 0.4% per kilogram. Height was not significantly associated with BMD when both height and weight were entered in multiple regression analyses. The prevalence of osteoporosis appeared to be overestimated if the US/European reference data, rather than Lebanese reference data, were used to calculate T-scores.

Absorptiometry, Photon↗
PubMed2000

Long-term risk of osteoporotic fracture in Malmö.

The objectives of the present study were to estimate long-term risks of osteoporotic fractures. The incidence of hip, distal forearm, proximal humerus and vertebral fracture were obtained from patient records in Malmö, Sweden. Vertebral fractures were confined to those coming to clinical attention, either as an inpatient or an outpatient case. Patient records were examined to exclude individuals with prior fractures at the same site. Future mortality rates were computed for each year of age from Poisson models using the Swedish Patient Register and the Statistical Year Book. The incidence and lifetime risk of any fracture were determined from the proportion of individuals fracture-free from the age of 45 years. Lifetime risk of shoulder, forearm, hip and spine fracture were 13.3%, 21.5%, 23.3% and 15.4% respectively in women at the age of 45 years. Corresponding values for men at the age of 45 years were 4.4%, 5.2%, 11.2% and 8.6%. The risk of any of these fractures was 47.3% and 23.8% in women and men respectively. Remaining lifetime risk was stable with age for hip fracture, but decreased by 20-30% by the age of 70 years in the case of other fractures. Ten and 15 year risks for all types of fractures increased with age until the age of 80 years, when they approached lifetime risks because of the competing probabilities of fracture and death. We conclude that fractures of the hip and spine carry higher risks than fractures at other sites, and that lifetime risks of fracture of the hip in particular have been underestimated.

Age Factors↗
PubMed2000

Critical role of P-selectin-dependent rolling in tumor necrosis factor-alpha-induced leukocyte adhesion and extravascular recruitment in vivo.

Leukocyte-endothelium interactions are dependent on a coordinated expression and function of specific adhesion molecules. The objective of the present study was to examine the role of selectin function and leukocyte rolling in tumor necrosis factor-alpha (TNF-alpha)-induced leukocyte adhesion and extravasation in venules in vivo. For this purpose, we used intravital microscopy in the mouse cremaster muscle stimulated for 2-3 h with TNF-alpha intrascrotally. Pretreatment with fucoidan, which inhibits P- and L-selectin, and a P-selectin monoclonal antibody (RB40.34) abolished TNF-alpha-stimulated leukocyte rolling. This great reduction in rolling caused a marked attenuation of firm adhesion and extravascular accumulation of leukocytes. When fucoidan and RB40.34 were administrated after stimulation with TNF-alpha, it was found that leukocyte rolling was greatly reduced whereas the number of firmly adherent leukocytes was completely unchanged, suggesting that the inhibitory effect of blocking P-selectin function on firm leukocyte adhesion and recruitment was due to the reduction in leukocyte rolling along the endothelium. Moreover, pretreatment with a monoclonal antibody against intercellular adhesion molecule-1 (ICAM-1) and a platelet-activating factor (PAF)-receptor antagonist had no effect of TNF-alpha-induced leukocyte rolling and adhesion, indicating that molecules other than ICAM-1 and PAF mediate firm adhesion and recruitment of leukocytes in TNF-alpha-activated tissues. Taken together, our data demonstrate that P-selectin function plays an important role in TNF-alpha-induced inflammatory cell recruitment by mediating leukocyte rolling as a precondition for cytokine-provoked firm adhesion and transmigration in vivo. These findings, thus, suggest that inhibition of P-selectin may be a central target for pharmacological intervention in inflammatory diseases.

Adhesiveness↗
PubMed2000

Changes in bone mineral, lean body mass and fat content as measured by dual energy X-ray absorptiometry: a longitudinal study.

Bone mineral density (BMD) and soft tissue composition were measured by dual energy X-ray absorptiometry (DXA) 3-4 years apart in 273 men and women aged 23-90. We found different rates of BMD loss in different skeletal regions. There were also different rates of BMD loss in different regions within the hip. Average rates of loss for male subjects 50 years of age and above for BMD total body were 0.1%/year and for femoral neck 1.5%/year, whereas lumbar spine (L2-L4) increased by 0.4%/year. Average rates of loss for female subjects 50 years of age and above for BMD total body were 0.0%/year, femoral neck 0.9%/year, and lumbar spine (L2-L4) 0.1%/year.

Absorptiometry, Photon↗
PubMed2000

Prediction of fracture from low bone mineral density measurements overestimates risk.

There is a well-established relationship between bone mineral density (BMD) and fracture risk. Estimates of the relative risk of fracture from BMD have been derived mainly from short-term studies in which the correlation between BMD at assessment and BMD in later life ranged from 0.8 to 0.9. Because individuals lose bone mineral at different rates throughout later life, the long-term predictive value of low BMD is likely to decrease progressively with time. This article examines and formalizes the relationship between current BMD, correlation coefficients, and long-term risk. The loss of predictive value has important implications for early assessment and supports the view that measurements should be optimally targeted at the time interventions are contemplated and, when necessary, repeated in later life.

Age Distribution↗
PubMed2000

Risk of hip fracture according to the World Health Organization criteria for osteopenia and osteoporosis.

The risk of hip fracture is commonly expressed as a relative risk. The aim of this study was to examine the utility of relative risks of hip fracture in men and women using World Health Organization (WHO) diagnostic criteria for low bone mass and osteoporosis. Reference data for bone mineral density (BMD) at the femoral neck, from the third National Health and Nutrition Examination Survey (NHANES III), were applied to the population of Sweden. Relative risks (RRs) were calculated from the known relationship between BMD at the femoral neck and hip fracture risk. The apparent prevalence of low bone mass and osteoporosis depended on the segment of the young population chosen for reference ranges. Using a reference derived from women aged 20-29 years, the prevalence of osteoporosis was 21.2% in women between the ages of 50 and 84 years and 6.3% in men. The RRs associated with osteoporosis depended markedly on the risk comparison. For example, in men or women aged 50 years, the RR of hip fracture in those with osteoporosis compared to those without osteoporosis was 7.4 and 6.1, respectively. The RR of those at the threshold value for osteoporosis compared to those with an average value for BMD at that age was 6.6 and 4.6 in men and women, respectively. RRs were lower comparing those at the threshold value compared to the risk of the general population at that age (4.2 and 2.9, respectively). When RR was expressed in relation to the population risk rather than to the risk at the average value for BMD, RR decreased at all ages by 37%. Such adjustments are required for risk assessment in individuals and for the combined use of different risk factors. Because the average T score at each age decreased with age, the RR of hip fracture at any age decreased with advancing age in the presence of osteoporosis. The decrease in relative risk with age is, however, associated with an increase in absolute risk. Thus, for clinical use, the expression of absolute risks may be preferred to relative risks.

Adult↗
PubMed2000

Are the findings in the Swedish National Total Hip Arthroplasty Register valid? A comparison between the Swedish National Total Hip Arthroplasty Register, the National Discharge Register, and the National Death Register.

The Swedish National Total Hip Arthroplasty (THA) Register was initiated in 1979, and it is one of the oldest quality registers in the world. The register covers all hospitals in Sweden, and today it contains > 205,000 hip arthroplasties. The failure endpoint definition in the register is revision. There is no information about quality of life and mortality. The aim of this study was to validate the results presented by the Swedish THA register by comparison with the Discharge register (the Swedish National Board of Health and Welfare) and to study mortality after hip arthroplasties. All hip arthroplasties from the Discharge register, performed in 1986 and thereafter, were compared with the Swedish THA register. Epidemiologic parameters, including mortality, were documented from the Swedish Death register. The mortality for primary THAs for men was 1% higher and for women 6% higher when compared with an age-matched and sex-matched cohort. For revision, the numbers were 7% and 9% higher. The risk for death compared with an age-matched and sex-matched population was lower for patients with osteoarthrosis treated with hip arthroplasty. The results with revision as failure endpoint showed that the Swedish THA register is reliable. The register includes >95% of the primary and revision THAs performed in Sweden between 1986 and 1995.

Aged↗
PubMed2000

Background for studies on the treatment of male osteoporosis: state of the art.

Male osteoporosis represents an important, although long underestimated, public health problem. Both in men and in women aging is accompanied by continuous bone loss and by an exponential increase in the incidence of osteoporotic fracture, with a female to male incidence ratio of about 2 to 3 to 1 in the elderly for hip and vertebral fractures. Morbidity after osteoporotic fractures appears to be more serious and mortality more common in men than in women. To date, no single treatment has been proved to be effective and safe in published prospective studies. The present report, based on a systematic search of the literature on male osteoporosis, summarises the state of the art on the clinical consequences of male osteoporosis and its risk factors, in relation to the present state of knowledge about female osteoporosis. This constitutes the background for the design of rational clinical development strategies for therapeutic interventions in male osteoporosis. From this review of the literature it is apparent that notwithstanding the existing sex differences in pathophysiology of osteoporosis and the difference in age-specific incidence of osteoporotic fractures, there are also important similarities between osteoporosis in women and men. The higher incidence of fracture in women than in men results from quantitative differences in risk factors rather than from different risk factors. Even though there are sex differences in bone geometry, incidence of fracture seems to be similar in men and women for a same absolute areal bone mineral density. However, the lack of data on the changes in fracture rates in men resulting from pharmacological intervention, leading to changes in bone mineral density or bone turnover, remains the main limitation for extrapolation of established treatment outcomes from women to men.

Age Factors↗
PubMed2000

Interindividual and intra-articular variation of proinflammatory cytokines in patients with rheumatoid arthritis: potential implications for treatment.

OBJECTIVES: Assessment of the numbers and spatial distribution of cells producing interleukin 1alpha (IL1alpha), interleukin 1beta (IL1beta), tumour necrosis factor alpha (TNFalpha), and interleukin 6 (IL6) in the synovial membranes of patients with rheumatoid arthritis (RA). METHODS: Synovial tissue specimens from 40 patients with RA and eight patients with non-rheumatic disease were obtained by arthroscopy guided biopsy techniques or during joint surgery. A modified immunohistochemical method detecting cytokine producing rather than cytokine binding cells was applied to determine cytokine synthesis in fixed cryopreserved sections. Computerised image analysis methods provided comparative quantitative assessments. RESULTS: A wide variation between subjects was recorded for both quantities and profiles of expressed cytokines, despite similar macroscopic and histopathological features of inflammation. IL1alpha and IL1beta were the most abundant monokines identified, though produced at different sites. IL1alpha was predominantly seen in vascular endothelial cells, whereas IL1beta staining was mainly shown in macrophages and fibroblasts. Concordant results for the detection of TNFalpha at protein and mRNA levels were obtained with an unexpectedly low number of TNFalpha producing cells compared with IL1 expressing cells in many patients with RA. Specimens acquired arthroscopically from areas with maximum signs of macroscopic inflammation showed an increased number of TNFalpha producing cells in pannus tissue compared with that occurring in synovial villi of a given joint. This clustered distribution was not found for cells expressing any of the other studied cytokines. CONCLUSION: The recorded heterogeneous profile of proinflammatory cytokine synthesis in the synovial membrane among patients with RA may provide a clue for an understanding of the wide variation in responsiveness to different modes of antirheumatic treatment between patients.

Adult↗
PubMed1999

Risk factors for hip fracture in men from southern Europe: the MEDOS study. Mediterranean Osteoporosis Study.

The aims of this study were to identify risk factors for hip fracture in men aged 50 years or more. We identified 730 men with hip fracture from 14 centers from Portugal, Spain, France, Italy, Greece and Turkey during the course of a prospective study of hip fracture incidence and 1132 age-stratified controls selected from the neighborhood or population registers. The questionnaire examined aspects of work, physical activity past and present, diseases and drugs, height, weight, indices of co-morbidity and consumption of tobacco, alcohol, calcium, coffee and tea. Significant risk factors identified by univariate analysis included low body mass index (BMI), low sunlight exposure, a low degree of recreational physical activity, low consumption of milk and cheese, and a poor mental score. Co-morbidity including sleep disturbances, loss of weight, impaired mental status and poor appetite were also significant risk factors. Previous stroke with hemiplegia, prior fragility fractures, senile dementia, alcoholism and gastrectomy were associated with significant risk, whereas osteoarthrosis, nephrolithiasis and myocardial infarction were associated with lower risks. Taking medications was not associated with a difference in risk apart from a protective effect with the use of analgesics independent of co-existing osteoarthrosis and an increased risk with the use of anti-epileptic agents. Of the potentially 'reversible' risk factors, BMI, leisure exercise, exposure to sunlight and consumption of tea and alcohol and tobacco remained independent risk factors after multivariate analysis, accounting for 54% of hip fractures. Excluding BMI, 46% of fractures could be explained on the basis of the risk factors sought. Of the remaining factors low exposure to sunlight and decreased physical activity accounted for the highest attributable risks (14% and 9% respectively). The use of risk factors to predict hip fractures had relatively low sensitivity and specificity (59.6% and 61.0% respectively). We conclude that lifestyle factors are associated with significant differences in the risk of hip fracture. Potentially remediable factors including a low degree of physical exercise and a low BMI account for a large component of the total risk.

Aged↗