La obesidad abdominal es esencial para el riesgo de tromboembolismo venoso en el síndrome metabólico: el estudio de tromso / Abdominal obesity is essential for the risk of venous thromboembolism in the metabolic syndrome: the thrombus study

ANTECEDENTES: el síndrome metabólico es un conjunto de factoresde riesgo cardiovascular, como la obesidad abdominal, hipertensión, dislipidemia y resistenciaa la insulina, asociado con un mayor riesgo de enfermedades cardiovasculares y mortalidad porcualquier causa. OBJETIVOS: el propósito del estudio fue evaluar el impacto del síndrome metabólico y sus componentes individuales, sobre el riesgo de tromboembolismo venoso (TEV) en un estudio poblacional prospectivo. MÉTODOS: Los componentes individuales del síndrome metabólico se registraron en 6170 sujetos de 25 a84 años en el Estudio de Tromsø en 1994-1995, y por primera vez los eventos de TEV se registraron hasta el 1 de septiembre de 2007...

BMI change is associated with fracture incidence, but only in non-smokers. The Tromsø Study.

UNLABELLED: Few studies have examined the association between body mass index (BMI) change and fracture in a general population. We observed that BMI loss was associated with increased fracture risk in non-smoking men and women, but not in smokers. BMI gain was associated with decreased fracture risk in women. INTRODUCTION: Weight loss has been associated with increased fracture risk, but few studies have included men. The aim of this study was to examine the association between BMI change and fracture risk in both genders. METHODS: A population-based cohort study in Tromsø, Norway, of adults, aged 20 to 54 years in 1979, who participated in two or three health surveys in 1979-1980, 1986-1987, and 1994-1995. Weight and height were measured at each survey. Information about lifestyle was obtained by questionnaires. Poisson regression was used to estimate incidence rates and Cox proportional hazards regression model to assess the association between fracture risk and BMI change. Fractional polynomials were used to accommodate non-linear associations. RESULTS: A total of 5,549 men and 5,428 women participated. There were 1,135 fractures during 10 years of follow-up. Reduction in BMI was associated with increased non-vertebral fracture risk in non-smokers, but not in smokers. The hazard ratio in male and female non-smokers per 10-year BMI decrease of 2 kg/m(2) versus a BMI increase of 1 kg/m(2) was 1.79 (95% confidence interval (CI), 1.17-2.75) and 1.60 (95% CI, 1.28-1.99), respectively. The association was not significantly modified by initial BMI or age or by exclusion of subjects with cardiovascular diseases, diabetes, or cancer. In female non-smokers, weight gain was inversely associated with fracture risk. CONCLUSIONS: In a general Norwegian population, reduction in BMI was significantly associated with increased fracture risk in male and female non-smokers, but not in smokers. These findings could not be explained by preexisting disease.

Smoking is a strong risk factor for non-vertebral fractures in women with diabetes: the Tromsø Study.

UNLABELLED: In this longitudinal study of 4,160 postmenopausal women (3,947 without and 213 with self-reported diabetes), smoking was strongly related to fracture risk in those with diabetes. INTRODUCTION: Smoking is related to low bone mass and increased risk of fracture risk in postmenopausal women of the general population. The aim of the present longitudinal population-based study was to examine the effect of smoking on the risk of non-vertebral fractures in women ≥ 55 years of age, with specific focus on its relationship with diabetes. METHODS: A total of 4,160 women (3,947 without and 213 with self-reported diabetes) from the municipality of Tromsø, Norway, were followed for a mean of 7.6 years. Measurements of height and weight and questionnaire information concerning smoking and alcohol consumption habits, physical activity, prevalent diseases, and use of medication were collected before the start of follow-up. Non-vertebral fractures were registered during follow-up. RESULTS: A total of 1,015 without and 66 with diabetes sustained a new non-vertebral fracture. Smoking status (never, past, and current) was significantly associated with an increased risk of fracture both in women with and without diabetes (p values for trend 0.02 and <0.001, respectively, after adjustments for age), but in women without diabetes, the relationship was no longer significant after multiple adjustments. There was a strong interaction between smoking status and diabetes on fracture risk (p= 0.004). Women with diabetes who were current smokers had a 3.47 (95% CI 1.82-6.62) higher risk of non-vertebral fractures than diabetic women who were never smokers (p value for linear trend = 0.001, after multiple adjustments). CONCLUSION: We conclude that smoking is strongly related to fracture risk in postmenopausal women with self-reported diabetes.

Bone loss and the risk of non-vertebral fractures in women and men: the Tromsø study.

SUMMARY: We assessed the association between the rate of forearm bone loss and non-vertebral fracture. Bone loss at the distal forearm predicted fractures, independently of baseline BMD, but not independently of follow-up BMD in women. The BMD level where an individual ends up is the significant predictor of fracture risk. INTRODUCTION: Bone loss may predict fracture risk independently of baseline BMD. The influence of follow-up BMD on this prediction is unknown. The aim of this study was to assess the association between bone loss and fracture risk in both sexes in a prospective population-based study. METHODS: We included 1,208 postmenopausal women (50 to 74 years), and 1,336 men (55 to 74 years) from the Tromsø Study, who had repeated distal and ultra-distal forearm BMD measurements. Non-vertebral fractures were registered from 2001 to 2005. RESULTS: A total of 100 women and 46 men sustained fractures during the follow-up time. Independent of baseline BMD, the RR associated with distal site bone loss of 1 SD %/year was 1.23 (1.01-1.50) for low-trauma fractures (excluding hand, foot, skull & high-trauma) and 1.32 (1.07-1.62) for osteoporotic fractures (hip, wrist and shoulder). However, bone loss did not predict fracture after adjusting for follow-up BMD. The BMD level where an individual ends up became the significant predictor of fracture risk and not the rate of bone loss. Follow-up BMD at ultra-distal site was associated with low-trauma fractures in both sexes. While ultra-distal site BMD changes were not associated with fracture risk in both sexes. CONCLUSION: Bone loss at the distal forearm predicted non-vertebral fractures, independently of baseline BMD, but not independently of follow-up BMD, in women. The BMD level where an individual ends up is the significant predictor of fracture risk and not the rate of bone loss.

Mean platelet volume is a risk factor for venous thromboembolism: the Tromsø Study, Tromsø, Norway.

BACKGROUND: Platelet size, measured as mean platelet volume (MPV), is associated with platelet reactivity. MPV is increased in acute myocardial infarction, and has been identified as an independent risk factor for future myocardial infarction and stroke. OBJECTIVES: The purpose of the study was to determine the impact of platelet count and MPV on the incidence of venous thromboembolism (VTE) in a prospective, population-based study. METHODS: Platelet count, MPV and baseline characteristics were registered in 25 923 subjects aged 25-96 years who participated in the Tromsø Study in 1994-1995. Incident VTE events were registered to the end of follow-up (1 September 2007). RESULTS: There were 445 validated incident VTE events (1.6 per 1000 person-years), of which 186 (42%) were unprovoked, during a mean of 10.8 years of follow-up. Subjects with MPV >or= 9.5 fL had a 1.3-fold [95% confidence interval (CI) 1.0-1.7] higher risk of total VTE and a 1.5-fold (95% CI 1.1-2.3) higher risk of unprovoked VTE than subjects with MPV < 8.5 fL in analyses adjusted for age, sex, smoking, body mass index, and platelet count. Increasing MPV was associated with increased risk of total VTE (P for trend = 0.09) and unprovoked VTE (P for trend = 0.03) in analyses adjusted for age and sex. There was no significant association between increasing platelet count and risk of VTE. CONCLUSIONS: An increasing MPV was identified as a predictor for VTE, in particular VTE of unprovoked origin. The present findings support the concept that platelet reactivity is important in the pathogenesis of VTE.

Abdominal obesity is essential for the risk of venous thromboembolism in the metabolic syndrome: the Tromsø study.

SUMMARY BACKGROUND: The metabolic syndrome is a cluster of cardiovascular risk factors, including abdominal obesity, hypertension, dyslipidemia and insulin resistance, associated with increased risk of cardiovascular diseases and all cause mortality. OBJECTIVES: The purpose of the study was to assess the impact of the metabolic syndrome, and its individual components, on the risk of venous thromboembolism (VTE) in a prospective population-based study. METHODS: Individual components of the metabolic syndrome were registered in 6170 subjects aged 25-84 years in the Tromsø Study in 1994-1995, and first ever VTE events were registered until 1 September 2007. RESULTS: The metabolic syndrome was present in 21.9% (1350 subjects) of the population. There were 194 validated first VTE events (2.92 per 1000 person-years) during a mean of 10.8 years of follow-up. Presence of metabolic syndrome was associated with increased risk of VTE (HR, 1.65; 95% CI, 1.22-2.23) in age- and gender-adjusted analysis. The risk of VTE increased with the number of components in the metabolic syndrome (P < 0.001). Abdominal obesity was the only component significantly associated with VTE in multivariable analysis including age, gender, and the individual components of the syndrome (HR, 2.03; 95% CI, 1.49-2.75). When abdominal obesity was omitted as a diagnostic criterion, none of the other components, alone or in cluster, was associated with increased risk of VTE. CONCLUSIONS: Our study provides evidence for the metabolic syndrome as a risk factor for TE. Abdominal obesity appeared to be the pivotal risk factor among the individual components of the syndrome.

Family history of myocardial infarction is an independent risk factor for venous thromboembolism: the Tromsø study.

BACKGROUND: Recent studies indicate that arterial cardiovascular diseases and venous thromboembolism (VTE) share common risk factors. A family history of myocardial infarction (MI) is a strong and independent risk factor for future MI. OBJECTIVES: The purpose of the present study was to determine the impact of cardiovascular risk factors, including family history of MI, on the incidence of VTE in a prospective, population-based study. PATIENTS AND METHODS: Traditional cardiovascular risk factors and family history of MI were registered in 21,330 subjects, aged 25-96 years, enrolled in the Tromsø study in 1994-95. First-lifetime VTE events during follow-up were registered up to 1 September 2007. RESULTS: There were 327 VTE events (1.40 per 1000 person-years), 138 (42%) unprovoked, during a mean of 10.9 years of follow-up. In age- and gender-adjusted analysis, age [hazard ratio (HR) per decade, 1.97; 95% confidence interval (CI), 1.82-2.12], gender (men vs. women; HR, 1.25; 95% CI, 1.01-1.55), body mass index (BMI; HR per 3 kg m(-2), 1.21; 95% CI, 1.13-1.31), and family history of MI (HR, 1.31; 95% CI, 1.04-1.65) were significantly associated with VTE. Family history of MI remained a significant risk factor for total VTE (HR, 1.27; 95% CI, 1.01-1.60) and unprovoked VTE (HR, 1.46; 95% CI, 1.03-2.07) in multivariable analysis. Blood pressure, total cholesterol, HDL-cholesterol, triglycerides, and smoking were not independently associated with total VTE. CONCLUSIONS: Family history of MI is a risk factor for both MI and VTE, and provides further evidence of a link between venous and arterial thrombosis.

The Tromsø study: registration of fractures, how good are self-reports, a computerized radiographic register and a discharge register?

In order to compare different methods of fracture registration, we sought all nonvertebral fractures suffered during 8 years (1988-95) among 21,441 persons invited to a survey in 1979/80. We registered a total of 54 hip fracture cases through three separate sources (self-report, computer linkage to the local radiographic archives, discharge register), whereas forearm fractures (a total of 291 cases) were registered through two separate sources (self-report, computer linkage to the radiographic archives). The registration of fractures at other sites (a total of 1321 cases) were from one source (computer linkage to the local radiographic archives), and we have compared three ways of obtaining data from this single source (no ascertainment, ascertainment of records coded as fracture, ascertainment of all records). Ninety-three percent of all hip fractures and 97% of all wrist fractures in the entire study population were found by computer linkage to the radiographic archives, whereas the discharge register detected 87% of all the hip fractures. Computer linkage with ascertainment gave no overreporting of fractures. Among the 11,626 persons who answered a follow-up questionnaire in 1994/95, 97% (CI 84-100%) of all hip fractures and 72% (CI 66-78%) of all wrist fractures were self-reported. We conclude that a computerized search of radiographic archives is a viable method of fracture registration.

The Tromsø Study: physical activity and the incidence of fractures in a middle-aged population.

We have studied the relation of occupational and recreational physical activity to fractures at different locations. All men born between 1925 and 1959 and all women born between 1930 and 1959 in the city of Tromsø were invited to participate in surveys in 1979-1980 and 1986-1987 (The Tromsø Study). Of 16,676 invited persons, 12,270 (73.6%) attended both surveys. All nonvertebral fractures (n = 1435) sustained from 1988 to 1995 were registered in the only hospital in the area. Average age in the middle of the follow-up period (December 31, 1991) was 47.3 years among men and 4501 years among women, ranging from 32 to 66 years. Fracture incidence increased with age at all locations among women, but it decreased with or was independent of age among men. Low-energetic fractures constituted 74.4% of all fractures among women and 55.2% among men. When stratifying by fracture location, the most physically active persons among those 45 years or older suffered fewer fractures in the weight-bearing skeleton (relative risk [RR] 0.6, confidence interval [CI] 0.4-0.9, age-adjusted), but not in the non-weight-bearing skeleton (RR 1.0, CI 0.7-1.2, age-adjusted) compared with sedentary persons. The relative-risk of a low-energetic fracture in the weight-bearing skeleton among the most physically active middle-aged was 0.3 (CI 0.1-0.7) among men and 0.9 (CI 0.4-1.8) among women compared with the sedentary when adjusted for age, body mass index, body height, tobacco smoking, and alcohol and milk consumption. It seems that the beneficial effect on the skeleton of weight-bearing activity is reflected also in the incidence of fractures at different sites.

[Introduction of teleradiology]. / Oppstart av teleradiologi.

Against the background of Norwegian conditions, the authors outline the equipment needed to launch a teleradiology unit, and what the clinician using the unit might expect of such an imaging facility. They also discuss whether the unit should be organised with the needs of emergency care in mind or as an integrated part of everyday routine at the radiology department, how financing and judicial issues have been managed so far, and whether the introduction of teleradiology might effect relationships between health care personnel and patients.

Receiver operating characteristic study of image preprocessing for teleradiology and digital workstations.

The purpose of this study was to evaluate whether digitized analog images displayed on a digital workstation can be improved by using a preprocessing algorithm, and if so, whether the quality of the resulting images can reach that of the original films. The material contained 120 difficult cases (about 50% with selected pathology). Four radiologists each evaluated half of the randomly ordered cases with the digital workstation and half of the cases with the original radiographs. The data were compared with a previous similar study, where the workstation had no option for preprocessed images. Preprocessed digital images were clearly superior to digital images without preprocessing, although for those of the highest diagnostic difficulty they were inferior to the original films. The preprocessing algorithm has improved the diagnostic quality of the digital workstation. There is room yet for improvement compared to plain films, although the current setup may be sufficient in some settings.

ROC-study of a teleradiology workstation versus film readings.

PURPOSE: We have used receiver operating characteristic (ROC) analysis to compare screen assessment of digitized radiographic films transmitted by a teleradiology system, with evaluation of the original radiographs on film. MATERIAL AND METHODS: The material contained 120 cases (about 50% with selected pathology) that were difficult to diagnose. Four radiologists each evaluated half of the cases on film, and half on computer screen. The screen display was 1024 x 836 pixels with 8 bits/pixel. RESULTS: We found the accuracy and sensitivity of the teleradiology system to be clearly inferior to film evaluation. CONCLUSION: Improvement is needed both in the teleradiology system, and in the training of radiologists to work on the electronic workstation.

Four years with teleradiology: a technical description.

Since September 1992, Troms Military Hospital (Norway) has been connected to the larger University Hospital of Tromsø by a teleradiology link transmitting about 6000 examinations annually. In the spring of 1995, the system was upgraded with a digital X-ray unit, thereby almost eliminating the scanning of analog radiographs. This article describes the technical development of the link. The discussion suggests ways of improving the teleradiology link, particularly in terms of integrating the radiology information system (RIS) and picture archiving and communication system (PACS).

Short-term treatment of Graves' disease with methimazole in high versus low doses.

OBJECTIVES: To compare the relapse rates in Graves' disease the first 2 years after methimazole 60 mg day-1 combined with thyroxine versus a titration regimen with methimazole alone, and to look for possible prognostic factors. DESIGN: A randomized, open, prospective study. Methimazole was given for 6 months in both groups, and thyroid status evaluated every 3rd month during the first year, and every 6th month during the second year. SETTING: The study was performed at our outpatient clinic with patients referred from primary care. SUBJECTS: Fifty-six patients were included. One became pregnant and one dropped out during the treatment period. Furthermore, nine patients in the high-dose and four in the low-dose group stopped the treatment because of side-effects. Thus, 19 patients in the high- and 22 in the low-dose group completed 6 months with methimazole. RESULTS: In those tolerating the treatment, the relapse rates in the high- and low-dose groups were 26.3 vs. 59.1% (P < 0.05), 42.1 vs. 77.3% (P < 0.02); and 57.9 vs. 77.3% (NS) after 3, 12 and 24 months, respectively. The corresponding relapse rates calculated on an 'intention to treat' basis were: 51.7 vs. 66.7%; 62.1 vs. 81.5%: 72.4 vs. 81.5% (NS). The thyroid volume was significantly (P < 0.05) larger in those that relapsed (17.8 +/- 2.9 vs. 11.6 +/- 1.2 mL; mean +/- SEM). CONCLUSIONS: In those tolerating the treatment, methimazole significantly reduced the relapse rate the 1st year when given in a high dose. However, the relapse rates in both groups, and the number of side-effects in the high-dose group, were unacceptably high.