Biomedical subjects
Publications and source records attributed to L Sandvik.
The hypothesis that ocular pseudo-exfoliation syndrome is part of a generalized disorder has been tested by suggesting that subjects having this syndrome would have increased mortality. However, no association was found between presence of ocular pseudo-exfoliation syndrome and mortality.
In a study of the relationship between social support and smoking behaviour, 1046 parents coming with their children for well-child control at health centres in Oslo, Norway, completed a questionnaire. The prevalence of daily smoking increased with decreasing social support. However, this association did not remain significant when adjusting for demographic and household characteristics. Among smoking parents, indoor smoking at home was related to medium (OR = 1.97; CI: 1.01-3.81) and low social support (OR = 2.35; CI: 1.19-4.63) when adjusting for demographic and household characteristics. Smoking parents smoked more cigarettes per day when they had low social support. However, this association was only seen in parents with several children. In this group, smoking 10 cigarettes per day or more was strongly related to medium (OR = 5.05; CI: 1.66-15.35) and low social support (OR = 7.81; CI: 2.44-25.01).
It has been suggested that seasonal changes in cardiovascular risk factors may explain simultaneous seasonal variations in cardiovascular diseases. Since systolic blood pressure (SBP) during an ergometer exercise test adds prognostic information beyond that of BP at rest we aimed to study whether SBP during exercise also demonstrates similar seasonal variation after adjustment for covariates. Blood pressures of 1574 apparently healthy men aged 40-59 years examined throughout two consecutive years showed a seasonal variation, with higher SBP during the period September-December compared with the rest of the year, 2.8 mmHg (p = 0.003) at rest and 4.2 mmHg (p < 0.001) during ergometer exercise at 600 kpm min-1. After adjustment for a parallel marked drop in physical fitness, these differences were no longer significant. Thus, the seasonal variation in SBP at rest and during exercise in apparently healthy middle-aged men may be explained by a parallel seasonal variation in physical fitness. A seasonal covariation in long-term cardiovascular mortality in the same study suggests that the parallel variation of independent risk factors is of clinical significance.
OBJECTIVE: To investigate whether the exercise systolic blood pressure predicts cardiovascular morbidity and mortality and in particular myocardial infarction beyond that prediction provided by the casual blood pressure at rest and independently of other cardiovascular risk factors. METHODS: We performed an average 16-year follow-up of 1999 middle-aged healthy men. RESULTS: We found that the systolic blood pressure during 6 min on a moderate load during a bicycle ergometer exercise test was a stronger predictor of total cardiovascular mortality and of morbidity and mortality from myocardial infarction than was the blood pressure of the subjects at rest. Furthermore, an early rise in systolic blood pressure during exercise seems to add prognostic information only when the systolic blood pressure of the subject at rest is elevated mildly (>/= 140 mmHg). Subjects whose systolic blood pressure increased to >/= 200 mmHg had a more than twofold greater risk of dying from cardiovascular causes and from myocardial infarction in particular within 16 years than did normotensives and men whose systolic blood pressure was >/= 140 mmHg when they were at rest whose systolic blood pressure did not increase to a similar extent, after we had adjusted for differences in age and a rather large number of traditional risk factors for cardiovascular disease. CONCLUSION: We suggest that systolic blood pressures recorded during standardized ergometer exercise testing may help one to distinguish between severe and less severe cases of hypertension among middle-aged men.
The assessment of sample size in clinical trials comparing population means requires a variance estimate of the main efficacy variable. When this variance estimate has a low precision, it may be appropriate to use the data from the first patients entered in the trial ('internal pilot study') to estimate the sample size. We suggest a method for determining the size of internal pilot studies, which aims at ensuring that this size is as large as possible, but not larger than 'the optimal size' of the planned study. Advantages and limitations of the method are discussed.
BACKGROUND AND OBJECTIVES: The success of national breast screening programmes hinges on women's adherence. By monitoring patients' perceptions, potential barriers to attendance may be detected, measured and possibly alleviated. Consequently a new questionnaire MGQ, measuring patients' experience of and satisfaction with mammography, has been developed. As discomfort is a predictor of non-attendance, a dimension measuring physical and psychological discomfort was included. METHODS: The internal structure of observed variables was tested using factor analysis as part of the validation process. The study was conducted in six radiological departments in Norway including 550 patients presenting for mammography. The analysis suggested eight factors explaining 56.7% of the variance. RESULTS: Construct validity was supported since the factor scales covered all hypothesized dimensions and all but one subdimension. The factors were internally consistent and externally independent, indicating that distinct aspects of patients' experience with mammography may be assessed and thus possibly improved. CONCLUSIONS: A relationship between pain and re-attendance was suggested as pain and worries about the next mammography belonged to the same factor. This underlines the importance of including a discomfort dimension when monitoring patient satisfaction with mammography.
OBJECTIVES: The aim of the present study was to determine whether simple clinical variables can predict the effect of intensive exercise training in an unselected population early after myocardial infarction. METHODS: Starting 5 weeks after the qualifying myocardial infarction, 105 patients, 68 years old or younger, completed a 4 week period of intensive exercise training. The training effect was defined as an absolute increase in cumulative work at bicycle ergometry. Using univariate and multivariate analysis, 28 variables were tested against the training effect. RESULTS: The mean exercise capacity increased from 46.7 +/- 22.7 kJ to 69.5 +/- 31.1 kJ (P = 0.0001). Multivariate analysis identified five independent predictors of the training effect. Myocardial infarct size was associated with a better training effect (P = 0.0018), as was male gender (P = 0.0042) and ability to exercise to exhaustion at the baseline exercise test (P = 0.0124). Older age (P = 0.0017) and treatment with beta-adrenergic blocking agents (P = 0.0241) were associated with a lower effect from training. These five variables explained 33% of the variations in effect from training. Patients suffering in-hospital cardiac complications or congestive heart failure achieved a training effect at least as great as patients without cardiac complications. CONCLUSIONS: Five simple clinical variables, including infarct size, can assist in the selection of patients for exercise training after myocardial infarction.
The effect of dry-cow therapy was evaluated on the basis of the culling rate, occurrence of clinical mastitis, mean of cow milk somatic cell counts (CMSCC), and milk yield, in a trial including 608 cows. The cows were randomly divided into four groups: control group A (92 cows), group B treated with placebo (base ointment of Benestermycin (Leo) without antibiotics) (105 cows), one intramammary dose per infected quarter, group C treated with Benestermycin (Leo), one intramammary dose being infused in each infected quarter (196 cows); and group D treated with Leocillin with dihydrostreptomycin (Leo); one intramammary dose being used every second day, on four occasions per infected quarter (215 cows). The study included infected cows. If less than three of the quarters of the udder were diagnosed as having mastitis at first sampling, only infected quarters were treated. Otherwise, all quarters were treated. Multivariable analysis showed no significant effect of therapy on culling rate. The control groups (A + B) had a greater increase of cows having at least one case of clinical mastitis compared to the therapy groups (C + D), (from 0.26 to 0.57 in controls comparing to 0.38 to 0.43 in therapy groups). The difference between control and therapy groups during lactation was close to significant both before and after in the lactation after therapy (P < 0.10). The multivariable analysis showed a significant benefit of dry-cow therapy of 0.409 In unit in geometric mean CMSCC (corresponding to 125,000/ml), 200,000/ml in weighted CMSCC and 189 kg milk yield per lactation. According to these results selective dry-cow therapy for cows included in this study is recommended.
Apparently healthy men (n=1999, 40 to 59 years old) were investigated from 1972 through 1975 to determine whether systolic blood pressure during bicycle ergometer exercise predicts morbidity and mortality from myocardial infarction beyond that of casual blood pressure taken after 5 minutes of supine rest. During a follow-up of 31 984 patient-years (average, 16 years), 235 subjects had myocardial infarctions, of which 143 were nonfatal and 92 were fatal. Exercise blood pressure was more strongly related than casual blood pressure to both morbidity and mortality from myocardial infarction. Among 520 men with casual systolic blood pressure = 140 mm Hg, 304 increased their systolic blood pressure to > or = 200 mm Hg during 6 minutes of exercise at an initial workload of 600 kpm/min. These 304 men had an excessive risk of myocardial infarction (18.8% versus 9.5% among the 1294 men with casual blood pressure < 140 mm Hg and exercise blood pressure < 200 mm Hg; P < .001). As many as 58% of those with myocardial infarction in this group died, compared with 33% (range, 26% to 35%) for all other groups (P=.0011), including those with casual blood pressure > or = 140 mm Hg and exercise blood pressure < 200 mm Hg. Thus, exercise blood pressure is a stronger predictor than casual blood pressure of morbidity and mortality from myocardial infarction, and an early rise in systolic blood pressure during exercise adds prognostic information about mortality from myocardial infarction among otherwise healthy middle-aged men with mildly elevated casual blood pressure. We suggest that blood pressure taken during standardized exercise testing may distinguish between severe and less severe hypertension.
PURPOSE: This Swedish multicenter trial was performed on patients with known or suspected lesions of the CNS for which an MR examination using a contrast medium was indicated. A total of 8 MR centers participated in the study to establish the safety and efficacy of Omniscan (gadodiamide injection) in clinical routine using a standard dose of 0.1 mmol Gd/kg b.w. MATERIAL AND METHODS: Seven hundred adult patients who had been referred for MR investigation of suspected CNS lesions were included in the study. Since most patients were examined on an outpatient basis, it was decided to use an explicit questionnaire regarding adverse events that developed within 24 h after examination. The efficacy evaluation involved comparisons of detectability, delineation, and number of lesions before and after injection of Omniscan. RESULTS: No serious or unexpected adverse event was found. There were a total of 70 (10.2%) patients with adverse events, excluding those judged not to be contrast media-related. However, only 15 patients (2.2%) had adverse events that possibly or probably were related to the contrast medium. Usually, the symptoms were headache, dizziness, abnormal taste, and nausea. Two patients complained of itching, but only one developed urticaria. The efficacy was similar to that of other currently used Gd-based MR agents. Lesions were more often seen on T2-weighted images, but the contrast medium improved lesion delineation, contributing to higher certainty in diagnosis, and provided more confidence in excluding suspected abnormality. CONCLUSION: Omniscan was found to be a safe and clinically valuable contrast medium for MR imaging of the CNS.
OBJECTIVE: To investigate the relationship between dietary supplementation of cod liver oil and the intensity of pain in people with musculoskeletal pain. DESIGN: Cross-sectional study. SETTING: Data from the Norwegian Health Survey 1985. SUBJECTS: All adult respondents who had reported musculoskeletal pain (n = 4490). MAIN OUTCOME MEASURES: Intensity of musculoskeletal pain as assessed by self reports during an interview. RESULTS: In logistic regression analyses (adjusting for age, gender, socioeconomic status, civil status, smoking habits, physical exercise, mental distress, and use of medicines), there was a negative association between regular intake of cod liver oil during the previous week and intense pain (OR = 0.75; 95% CI: 0.56-1.00; P = 0.048) and considerable/intense pain (OR = 0.81; 95% CI: 0.67-1.00; P = 0.045). The association was stronger in the 33% of the respondents who reported a musculoskeletal disease, as expressed by the relationship of cod liver oil to intense pain (OR = 0.64; 95% CI: 0.43-0.95; P = 0.028) and considerable/intense pain (OR = 0.74; 95% CI: 0.54-1.03; P = 0.076). The association varied between diagnostic groups, and was not seen in people who did not report a musculoskeletal disease. CONCLUSION: The study suggests that people with musculoskeletal pain experience less pain if they take cod liver oil.
OBJECTIVE: To study association between smoking habits and long term decline in physical fitness and lung function in middle aged men who remained healthy. DESIGN: Baseline and follow up measurements performed during 1972-5 and 1980-2 respectively. SETTING: National University Hospital of Oslo, Norway. SUBJECTS: 1393 men aged 40-59 at baseline who were all healthy at baseline and at follow up. MAIN OUTCOME MEASURES: Forced expiratory volume in one second and physical fitness (defined as total work done during a symptom limited bicycle ergometer test divided by body weight. RESULTS: Initial fitness was substantially lower among 347 persistent smokers than among 791 persistent non-smokers (1349 J/kg v 1618 J/kg), as was initial forced expiratory volume (3341 ml v 3638 ml). Mean (95% confidence interval) decline in fitness over 7.2 years was 217 (185 to 249) J/kg among smokers compared with 86 (59 to 113) J/kg among non-smokers (P < 0.001). Corresponding declines in forced expiratory volume were 271 (226 to 316) ml in smokers and 116 (85 to 147) ml in non-smokers (P < 0.001). Differences between smokers and non-smokers remained practically unchanged after adjustment for age and level of physical activity. Changes in fitness and forced expiratory volume among 199 men who had stopped smoking mimicked the findings for persistent non-smokers, and 56 men who started smoking presented findings close to those of persistent smokers. CONCLUSION: Decline in physical fitness and lung function among healthy middle aged men was considerably greater among smokers than among non-smokers and could not be explained by differences in age and physical activity.
Four different field studies including 64, 140, 850 and 180 herds were used to investigate the association between pulsator characteristics and udder health. The results indicate that the best udder health is found in herds with a d phase > 330 ms and a pulsation rate > 55 min-1. A d phase of < 250 ms was associated with significant elevation in bulk milk somatic cell count, a higher incidence of acute clinical mastitis and a higher frequency of cows having mastitis associated with major pathogens (mainly Staphylococcus aureus) as compared with a d phase of > 331 ms. There was also a significant positive association between a shorter d phase and a high incidence of teat lesions needing veterinary treatment. Herds having no such teat lesions had pulsators with significantly longer d phase than herds with teat lesions (300 ms v. 288 ms). These results strongly suggest that in high-line milking machines the d phase should not be as short as 250 ms and should preferably be approximately 300 ms, and the pulsation rate should be at least > 55 cycles min-1. There was a strong relationship between the effect of d phase and the rate of pulsation.
BACKGROUND: Resting heart rate is directly associated and maximal exercise-induced heart rate inversely associated with cardiovascular mortality, and therefore their difference might contain prognostic information from both variables. The comparative long-term prognostic values of maximal exercise-induced heart rate and of the difference between it and resting heart rate were studied in apparently healthy middle-aged men. METHODS: Resting heart rate and maximal exercise-induced heart rate were measured, and their difference calculated, in 1960 apparently healthy men aged 40-59 years, and mortality was recorded over a period of 16 years. Conventional coronary risk factors were assessed at baseline. RESULTS: Both the difference between the two heart rates and the maximal exercise-induced heart rate were strongly, independently and inversely associated with cardiovascular mortality after adjustment for age, smoking, systolic blood pressure, lung function, glucose tolerance, serum cholesterol level, serum triglycerides level, physical fitness and exercise ECG findings. The adjusted relative risk of cardiovascular death in heart-rate difference quartiles 3 and 4 compared with that in quartile 1 (the lowest heart-rate difference quartile) was 0.54 (95% confidence interval 0.33-0.86; P = 0.009). The corresponding value for maximal exercise-induced heart rate was 0.56 (95% confidence interval 0.34-0.89; P = 0.018). Within the lowest heart-rate difference quartile, but not within the lowest maximal exercise-induced heart rate quartile, a further, strong, negative gradient in cardiovascular mortality was observed. In the high working capacity range, low heart-rate difference but not low maximal exercise-induced heart rate predicted very high cardiovascular disease mortality. Heart-rate difference and maximal exercise-induced heart rate were also inversely associated with non-cardiovascular disease mortality. CONCLUSIONS: Both heart-rate difference and maximal exercise-induced heart rate were strong, graded, long-term predictors of cardiovascular mortality among apparently healthy middle-aged men, independent of age, physical fitness and conventional coronary risk factors. However, low heart-rate difference was a better predictor than low maximal exercise-induced heart rate for recognizing individuals who were at particularly high risk of dying prematurely from cardiovascular diseases.
We have investigated the effect of long-term strict glycaemic control on peripheral and autonomic nerve function in 45 IDDM patients (age 18-42 years, diabetes duration 7-23 years) without clinical signs of neuropathy or other neurological disease. They were randomly assigned to treatment either with continuous insulin infusion, multiple injections (4-6 times daily), or conventional treatment (twice daily) for 4 years and followed prospectively for 8 years. Motor and sensory nerve conduction velocities were measured at the start and after 8 years. Autonomic nerve function tests were performed only once, after 8 years. A significant reduction of nerve conduction velocity was observed during 8 years in patients with mean HbA1 more than 10% (n = 12, group mean 10.9%, range 10.1-13.2%) compared to patients with HbA1 less than 10% (n = 33, group mean 9.0%, range 7.5-9.9%). Change of motor nerve conduction velocity in the peroneal nerve was: -4.8 +/- 4.9 (SD) vs -2.2 +/- 5.3 m/s (p < 0.01). Change of motor nerve conduction velocity in the posterior tibial nerve was: -6.8 +/- 5.7 vs- 3.9 +/- 5.1 m/s (p < 0.05). No significant changes were observed in the ulnar nerve. Change of sensoric nerve conduction velocity in the sural nerve was: -8.9 +/- 8.0 vs -4.6 +/- 5.3 m/s (p < 0.05). Multiple regression analysis showed that a change in HbA1 of 1% resulted in a 1.3 m/s change in nerve conduction velocity during 8 years.(ABSTRACT TRUNCATED AT 250 WORDS)
The outcome of 1999 apparently healthy men aged 40 to 59 years investigated from 1972 through 1975 was ascertained after 16 years to determine whether systolic blood pressure measured with subjects in the sitting position during a bicycle ergometer exercise test adds prognostic information on cardiovascular mortality beyond that of casual blood pressure measured after 5 minutes of supine rest. During a total follow-up of 31,984 patient years, 278 patients died, 150 from cardiovascular causes. Casual blood pressure and pulse pressure as well as peak exercise systolic blood pressure during 6 minutes on the starting workload of 600 kpm/min (approximately 100 W, 5880 J/min) were all related to cardiovascular mortality. The relative risk (RR) of dying from cardiovascular causes associated with an increment of 48.5 mmHg (= 2 SD) in systolic blood pressure at 600 kilopondmeter (kpm)/min was significant (RR = 1.5, 95% confidence interval [CI] = 1.1-2.3, P = .040) even when adjusting for a large number of variables measured in the present study, including age, exercise capacity, smoking habits, and casual blood pressures. The influence of blood pressure at 600 kpm/min was so strong that the predictive value of resting casual blood pressures became nonsignificant when these were analyzed as continuous variables also including exercise blood pressure as a covariate. However, the maximal systolic blood pressure during the exercise test was unrelated to cardiovascular mortality.(ABSTRACT TRUNCATED AT 250 WORDS)
Data concerning the natural history of asymptomatic coronary artery disease (CAD) has been limited to epidemiologic rather than angiographic studies, thus leading to uncertainty as to whether warning symptoms and signs will identify subjects with silent myocardial ischemia before morbid events. To address this issue, 50 apparently healthy men with angiographically proven CAD and asymptomatic exercise-induced ST depression have been followed prospectively for 15 years in the Oslo Ischemia Study. Fourteen men died. The initial presenting clinical event in these 14 men was chest pain in 4 (30%)--but in only 1 case was it recognized as typical angina--silent myocardial infarction in 5 (35%) and sudden death in 5 (35%). Thirty-six men survived, with 19 developing symptoms. Overall, chest pain was the first clinical event in 22 of the total of 33 men with symptoms (66%), whereas myocardial infarction occurred in 6 (18%) and sudden death in 5 (16%). Although chest pain occurred in 22 men, it was clinically diagnosed as typical angina pectoris in only 6. These observations suggest that there is an absence of clear-cut ischemic symptoms in many asymptomatic patients before morbid events.
BACKGROUND: Despite many studies suggesting that poor physical fitness is an independent risk factor for death from cardiovascular causes, the matter has remained controversial. We studied this question in a 16-year follow-up investigation of Norwegian men that began in 1972. METHODS: Our study included 1960 healthy men 40 to 59 years of age (84 percent of those invited to participate). Conventional coronary risk factors and physical fitness were assessed at base line, with physical fitness measured as the total work performed on a bicycle ergometer during a symptom-limited exercise-tolerance test. RESULTS: After an average follow-up time of 16 years, 271 men had died, 53 percent of them from cardiovascular disease. The relative risk of death from any cause in fitness quartile 4 (highest) as compared with quartile 1 (lowest) was 0.54 (95 percent confidence interval, 0.32 to 0.89; P = 0.015) after adjustment for age, smoking status, serum lipids, blood pressure, resting heart rate, vital capacity, body-mass index, level of physical activity, and glucose tolerance. Total mortality was similar among the subjects in fitness quartiles 1, 2, and 3 when the data were adjusted for these same variables. The adjusted relative risk of death from cardiovascular causes in fitness quartile 4 as compared with quartile 1 was 0.41 (95 percent confidence interval, 0.20 to 0.84; P = 0.013). The corresponding relative risks for quartiles 3 and 2 (as compared with quartile 1) were 0.45 (95 percent confidence interval, 0.22 to 0.92; P = 0.026) and 0.59 (95 percent confidence interval, 0.28 to 1.22; P = 0.15), respectively. CONCLUSIONS: Physical fitness appears to be a graded, independent, long-term predictor of mortality from cardiovascular causes in healthy, middle-aged men. A high level of fitness was also associated with lower mortality from any cause.