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Biomedical subjects

O Johnell

Publications and source records attributed to O Johnell.

At least 19 recordsLinked to original sources

Cancer risk after hip replacement with metal implants: a population-based cohort study in Sweden.

BACKGROUND: Joint replacement with metal implants has been the standard procedure for surgical treatment of irreversible degeneration of hip and knee joints for more than two decades. However, reports of local malignancy after joint replacement and experimental studies that suggest a carcinogenic action of metal ions and polymethylmethacrylate (an acrylic compound used to stabilize the implant in the host) have raised concern about the possible long-term risks associated with metal implants. PURPOSE: Our aim was to study cancer risk in a Swedish cohort of patients who had hip replacement surgery during the period 1965 through 1983. METHODS: We studied the risk of cancer in a cohort of 39 154 patients (14 869 men and 24 285 women), identified in the nationwide Swedish Inpatient Register with at least one hip replacement during the period 1965 through 1983. The patients were followed through 1989 by means of record linkage to the Swedish Cancer Register. The cohort contributed a total of 327 922 person-years at risk. Standardized incidence ratios (SIRs) were computed using age-, sex-, and period-specific incidence rates derived from the entire Swedish population. RESULTS: The overall relative risk of cancer was increased by only 3%. Bone cancer--the focus of previous concerns--occurred in six cases versus 4.3 expected, and connective tissue cancer occurred in 28 cases versus 25.9 expected. Increased risks were observed for kidney cancer (SIR = 1.31; 95% confidence interval [CI] = 1.13-1.51), prostate cancer (SIR = 1.13; 95% CI = 1.04-1.22), and melanoma (SIR = 1.23; 95% CI = 1.00-1.50). The relative risk of gastric cancer steadily declined with increasing follow-up time, in both men and women (SIR = 0.58; 95% CI = 0.39-0.84 more than 10 years after hip replacement). CONCLUSION: In this study, the largest study to date to evaluate hip replacement and subsequent cancer risk, the overall cancer risk appears to be negligible from a public health perspective, and our results have not produced any strong evidence against the continued use of these devices. Nevertheless, the small but statistically significant increases in kidney and prostate cancers and the decrease in gastric cancer deserve further study.

Aged

Reduced bone mineral density in adults with growth hormone (GH) deficiency: increased bone turnover during 12 months of GH substitution therapy.

To evaluate the consequences of growth hormone (GH) deficiency on bone mineral density and to evaluate the effects of GH substitution therapy, 68 adults (25 females and 43 males) aged 22-61 (mean 44.2 +/- 1.2) years with GH deficiency (GHD) were studied. Fifty-eight patients had panhypopituitarism, three had isolated GHD and in seven patients at least one additional pituitary function was affected. Twenty-one patients had childhood onset GHD. The patients were randomized to receive either GH in daily injections (0.125 IU.kg-1. week-1 for the first 4 weeks and subsequently 0.25 IU.kg-1. week-1) or placebo for 6 months. The trial continued as an open study with GH treatment for 6 to 12 months, with data presented as compiled data of 12 months of GH treatment in 64 patients. Bone mineral density (BMD) was measured by dual energy x-ray absorptiometry and bone turnover was assessed by serum markers of bone metabolism (osteocalcin, procollagen I peptide, cross-linked telopeptide of type I collagen and alkaline phosphatase activity), In women with adult onset GHD (N = 19) and in men with childhood onset GHD (N = 15), total body, spine and hip BMD was significantly reduced at baseline compared to Swedish age- and sex-matched control material. In men with adult onset of GHD (N = 28), BMD did not differ from male controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Cost-effectiveness of fracture prevention in established osteoporosis.

This study presents the results of a computer simulation model for calculating the cost-effectiveness and cost-utility of treating patients with established osteoporosis in order to reduce the risk of fractures. The results are based on Swedish data for risk of fracture and costs. The treatment intervention modelled is based on treatment of a 62-year-old woman with established osteoporosis. The cost per hip fracture avoided is 350,000 SEK, assuming a 50% reduction in the risk of fracture due to 5 years of treatment. A sensitivity analysis for changes in the cost and effectiveness of treatment, the risk of fracture and the discount rate is performed. The cost per life-year gained and the cost per quality-adjusted life-year (QALY) gained is presented to enable comparison of the cost-effectiveness of treating osteoporosis with that of other health care interventions. A comparison between treating the same woman for osteoporosis and mild hypertension shows a cost per life-year gained of 220,000 SEK and 128,000 SEK respectively. Cost per QALY gained is very similar for the two interventions: 105,000 SEK and 103,000 SEK respectively. This model provides a tool to enable clinicians, administrators and health policy makers to analyze and understand the economic aspects of a major health policy issue.

Computer Simulation

Osteoarthrosis and late growth.

To examine the hypothesis that late growth of bone may occur, pelvic radiographs taken during 1990 to 1992 of patients born between 1901 and 1972 were studied. All radiographs were taken using the same equipment with constant exposure techniques. Films showing osteoarthrosis (obviously decreased joint space) or hip fracture were discarded. The remaining films of 116 women and 100 men divided into 3 age groups (18-39 years old, 40-59 years old, and > 60 years old) were measured. With a millimeter ruler and a circle template, the center and 5 radii of each femoral head, the width of the acetabulum, and the pelvic diameters, the femoral neck, and the height of the superior joint space were determined. Most of the measurements increased significantly with age, including those of the femoral head, the acetabulum, the femoral neck in women, and the pelvic diameters. The increase in superior joint space (the combined heights of the cartilage of the femoral head and acetabulum) with age was not significant, but in men between 50 and 70 years old there were cartilage measurements that were higher than in other age groups, and in women > 80 years of age there were significantly more single high values. The results are discussed against the background that growth of bone and of cartilage can hypothetically cause injuries of the cartilage.

Adult

Evidence for efficacy of drugs affecting bone metabolism in preventing hip fracture.

OBJECTIVE: To examine the effects of taking drugs affecting bone metabolism on the risk of hip fracture in women aged over 50 years. DESIGN: Retrospective, population based, case-control study by questionnaire. SETTING: 14 centres in six countries in southern Europe. SUBJECTS: 2086 women with hip fracture and 3532 control women matched for age. MAIN OUTCOME MEASURES: Number of drugs affecting bone metabolism taken and length taken for. RESULTS: Women taking drugs affecting bone metabolism had a significantly decreased risk of hip fracture. After adjustment for differences in other risk factors, the relative risk of hip fractures was 0.55 (95% confidence interval 0.31 to 0.85) in women taking oestrogens, 0.75 (0.60 to 0.94) in those taking calcium, and 0.69 (0.51 to 0.92) in those taking calcitonin. The fall in risk was not significant for anabolic steroids (0.6 (0.29 to 1.22)). Neither vitamin D nor fluorides were associated with a significant decrease in the risk of hip fracture. The effect on hip fracture risk increased significantly with increasing duration of exposure (risk ratio 0.8 (0.61 to 1.05) for less than median exposure v 0.66 (0.5 to 0.88) for greater than median exposure). Drugs were equally effective in older and younger women, with the exception of oestrogen. CONCLUSIONS: Oestrogen, calcium, and calcitonins significantly decrease the risk of hip fracture. Short term intervention late in the natural course of osteoporosis may have significant effects on the incidence of hip fracture.

Aged

Differences in fracture pattern between an urban and a rural population: a comparative population-based study in southern Sweden.

Differences in the incidence of hip fractures have been reported between urban and rural areas. In this population-based study the characteristics of fracture patterns between the city of Malmö and the nearby rural district of Sjöbo were compared. A total of 782 individuals in Malmö and 486 in Sjöbo were invited to participate. Fracture history for all invited was registered. The odds ratio for fracture was higher in Malmö, particularly for women over 70. More than half of the urban women aged 70 had a history of a fracture. A fourfold increase in fracture prevalence between the ages of 60 and 70 was observed in women in Malmö, whereas the prevalence doubled in Sjöbo. The differences in fracture patterns between these two urban and rural communities may be explained by different lifestyles.

Adult

The apparent incidence of hip fracture in Europe: a study of national register sources.

The objective of this study was to examine the apparent incidence of hip fracture from discharge rates in European countries. A request was sent to the Ministries of Health in all European countries, asking for the number of hip fracture patients by age and sex, between the years 1983 and 1985. Seventeen countries responded. As expected, hip fracture was most frequently found amongst the elderly, particularly women. The incidence of hip fracture rose exponentially with age in both sexes. It was higher in women than men and there was a three-fold range between countries in the female to male sex ratio. There was an eleven-fold range in apparent incidence amongst women and a seven-fold range amongst men between the various countries. The highest incidence was found in the northern part of Europe and the lowest in the Mediterranean area. There was a significant positive correlation between the age-standardized incidence rates reported in men from each country and that in women. There was a larger difference in incidence between countries than between sexes, which suggests important genetic or environmental factors in the causation of hip fracture. The extent to which this reflects imperfect capture of data is uncertain but will be important to determine in order to identify reasons for differences and to enable confident projections of the future magnitude of this disorder.

Adult

Earlier wrist fracture: a confounding factor in distal forearm bone screening.

Thirty-six women aged 60, 70 or 80 years who had fractured one of their distal radii (Colles' fracture) 0 to 35 (median 10) years earlier were examined in this population-based study. Single photon measurements (SPA) were performed on both arms 1 cm and 6 cm proximal to the styloid process of the ulna. All women were questioned about earlier wrist fractures and which, if any, side had been affected. Information about the type and site of the fracture was also gathered from the hospital records. The bone mineral content (BMC) was found to be increased by almost 20% in the once-fractured radius at the distal measuring site (1 cm) when compared with the unaffected side. This difference did not seem to diminish with time. At the proximal measuring site there was no difference between the once-fractured and the non-fractured side. There was a progressive loss of bone mineral in the once-fractured arm during the first years after the fracture however. This appeared to be reversed after about 10 years to a relative gain, even though the correlation was weak. Six of the 36 women could not remember which side had been fractured and five could not remember having had such a fracture at all. Determination of osteoporosis by measuring forearm BMC with single photon densitometry is therefore of limited value in some women of the oldest age groups.

Age Factors

Bone mineral content in women: trends of change.

Altogether 426 women had their forearm bone mineral content (BMC) measured with single photon absorptiometry (SPA): one group in the early 1970s, another about 18 years later. Both groups represented purportedly healthy subjects. A third group of 328 women, measured at the same time as the second group, was from the same population but chosen by random selection (the population-based group). In the two sets of non-population-based women there was a small percentage reduction in the cortical forearm bone mass in the recent measurement as compared with the earlier measurement. This was significant only in women below 70 years of age. The forearm BMC, both cortical and trabecular, was less in all age groups of women randomly selected from the same population as the healthy control sample. This difference emphasizes the importance of selecting normative data from a population-based sample.

Absorptiometry, Photon

Effects of physical activity on bone mineral content and muscle strength in women: a cross-sectional study.

Physical exercise is known to increase bone mass in men, whereas the effect is less predictable in women. In this cross-sectional report, effects of physical activity on women aged 38-64 years are studied. Bone mass and muscle strength were compared between 30 regularly exercising women jogging only once a week for at least three years and an equal number of controls matched for age. BMC of the distal third of the radius was significantly higher in the active women. The active women over age 50 also had higher trabecular bone mass in the distal end of the radius. Quadriceps strength and balance were also found to be better in the activity group. Active women had a different lifestyle than the non-active women, with less consumption of alcohol, oestrogens, and tobacco. This report supports the hypothesis that regular moderate physical activity might reduce bone loss in women.

Adult

Fracture risk in patients with parkinsonism: a population-based study in Olmsted County, Minnesota.

In this population-based retrospective cohort study, the 138 Olmsted County, Minnesota residents first diagnosed with Parkinson's disease during 1967-79 were matched by age and sex to an equal number of control subjects from the community. Fractures were assessed through review of each subject's complete (inpatient and outpatient) medical records. At the time of diagnosis, County residents with parkinsonism were no more likely to have a history of selected fractures than control subjects (32% in each group). Subsequently, 33% of cases and 20% of controls experienced one or more new fractures during 696 person-years of follow-up (p = 0.008). The greatest increase in risk was seen for proximal femur fractures, confirming previous case-control studies. By 10 years after diagnosis, an estimated 27% of the parkinsonism cohort had experienced a new hip fracture. The pattern of fractures that was observed suggested that the increased risk was due more to specific types of falls than to disuse osteoporosis.

Aged

The articular cartilage after osteotomy for medial gonarthrosis. Biopsies after 2 years in 19 cases.

In 19 consecutive patients with medial gonarthrosis, an arthroscopic examination with a biopsy of the load-bearing cartilage in the medial femoral condyle was undertaken at the same time as a proximal tibial osteotomy. A follow-up arthroscopic biopsy was performed on an average of 2 years after the osteotomy. In 9 knees there was an improvement in the cartilage quality, 8 knees were unchanged, whereas 2 knees had deteriorated. Radiographically, 6 knees had improved, 11 were unchanged and 2 had deteriorated. We found no correlation between cartilage improvement and the clinical and radiographic outcome. Our results confirm that an osteotomy has a beneficial effect on the load-bearing cartilage in the medial femoral condyle.

Adult

Bone mass in an urban and a rural population: a comparative, population-based study in southern Sweden.

Several previous studies have reported regional differences in the incidence of hip fractures. A population-based study was performed in the city of Malmö (urban population) and in the municipality of Sjöbo (rural population), 60 km apart. A total of 961 men and women, randomly selected and of Scandinavian ethnic background, participated in the study. Bone mineral content (BMC) of the forearm was measured with single-photon absorptiometry (SPA). Women and men in the city had significantly lower BMC compared with the rural population. The differences were even more pronounced when comparing a true urban population (lived their entire life in a city) with a true rural population (never lived in a city). The differences in BMC between Malmö and Sjöbo were more obvious in men. These data suggest that differences in bone mass between an urban and a rural population could to some extent explain differences in fracture incidence.

Adult

The impact of menopausal age on future fragility fracture risk.

Altogether 733 postmenopausal women were interviewed with regard to their age at menopause. Subsequent fragility fractures over an 11 year period were recorded. Fragility fractures had occurred in 212 women. These women had an earlier menopause, but the deviation from the nonfracture group was significant only in those who were less than 70 years at the beginning of the fracture catchment period. Women 50-69 years of age, in the lowest quartile of menopausal age, sustained 50% more fragility fractures than those in the highest quartile. In older women menopausal age does not predict fragility fractures. Women less than 70 with an early menopause had a significantly lower initial bone mass.

Age Factors

Synthetic human calcitonin in postmenopausal osteoporosis: a placebo-controlled, double-blind study.

A placebo-controlled, double-blind study was carried out over 4 months to evaluate two doses of synthetic human calcitonin (0.25 and 0.125 mg) given s.c. three times per week. Enrolled were 60 women, aged 56-82 years, who had experienced a vertebral fracture due to low-energy trauma within the preceding year. During active treatment there was within the first month a dose-dependent decrease of the indices of bone resorption (fasting urinary calcium and hydroxyproline excretions), whereas only the higher dose and a treatment period of 4 months produced a reduction of bone formation (serum osteocalcin). The bone mineral content (BMC) of the nondominant forearm was unchanged. Treatment with calcitonin also had significant, dose-dependent, analgetic effects. The amelioration of pain was, in multivariate analyses, related to a reduction in parameters felt to be markers for bone resorption. In the placebo group there was a significant reduction of the BMC of the forearm but no changes of any of the biochemical markers for bone turnover and no improvement of pain. In conclusion, treatment with two low doses of calcitonin induced changes of the biochemical markers of bone turnover in a dose-dependent manner. The analgetic properties of calcitonin were also of salient clinical importance. The knowledge derived from this study could be adapted to the dosage schedule in long-term trials in osteoporosis.

Aged

The predictive value of bone loss for fragility fractures in women: a longitudinal study over 15 years.

Fifteen years after their forearm bone mineral content was measured, 366 women were measured again with the same single photon technique. 96 of the women had sustained one or more fragility fractures during that period. The initial bone mineral content was less in those women who were to have fractures. The rate of loss over the years did not differ between fracture and non-fracture women--the initial bone mass was the better predictor. Peak bone mass in the women in this study occurred before the age of 40.

Adult