Biomedical subjects

I Vuori

Publications and source records attributed to I Vuori.

16 recordsLinked to original sources

PubMed1992

A cruciate ligament injury produces considerable, permanent osteoporosis in the affected knee.

Bone mineral density (BMD) and clinical status of 42 patients treated surgically 10-11 years earlier for an acute knee ligament injury were determined. The BMD was measured at the spine (L2-4) and the femoral neck, distal femur, patella, proximal tibia, and calcaneus of both lower extremities using dual-energy x-ray absorptiometric (DXA) scanner. The relative BMD results of the injured knee were correlated with sex, age, activity level, knee stability, and functional scores of the patient. In the 11 patients with moderate injury (isolated rupture of the medial collateral ligament), the BMDs of the injured and uninjured extremities were equal. In the 31 patients with severe injury (cruciate ligament rupture), the BMDs were significantly lower in the injured knee: distal femur, -6.0% (p = 0.0000); patella, -9.0% (p = 0.0000); and proximal tibia, -3.3% (p = 0.0012). Neither the femoral neck nor the calcaneus showed any differences. There were no significant differences either between men and women or between patients with different activity levels. The relative BMDs of the injured knee did not correlate with age or static knee stability but correlated significantly (r = 0.42-0.78, p < 0.01-0.001) with the functional scores of the same knee: the better the knee function in comparison with the healthy knee, the higher the relative BMD. The spinal BMDs corresponded with the age-adjusted reference values of the used densitometry. In conclusion, a severe knee ligament injury results in permanently decreased BMD in the injured knee. Other parts of the same extremity and lumbar spine are not affected.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1992

Evaluation of a model for prediction of lumbar bone mineral density.

A mathematical model with adequate clinical accuracy would be useful for predicting life-long bone mass behaviour in various skeletal sites. We have tested the performance of a multivariate nonlinear model, recently developed by an Italian research group for predicting lumbar bone mass and density, in a sample of 239 pre- or post-menopausal healthy Finnish women whose lumbar bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry. The model, which was based on height, weight, body mass index, age and years since menopause, predicted poorly (R-squared = 0.14) the measured BMD. Furthermore, it compressed strongly the actual variation of the BMD values resulting in a considerable overestimation or underestimation (about 30%) of low or high BMD values, respectively. Our results indicated that the predictive value of a simple model is not clinically acceptable and therefore the usefulness of this kind of model remains questionable.

Absorptiometry, Photon↗

PubMed1992

Daytime sleepiness: a risk factor in community life.

The prevalence of daytime sleepiness and background factors associated with it were investigated in a study carried out at the UKK Institute. The inquiry took the form of a questionnaire mailed to 1600 people of middle age. Daytime sleepiness was found to be associated with disturbed night sleep. Women were more tired than men, but men slept more frequently during the day. Those suffering from tiredness complained of poor health more than other respondents. Traffic accidents and other mishaps attributable to tiredness had occurred in 1.3% of cases, and almost 5% of male respondents had dozed off while driving at least five times in their lives. The findings indicate a need for increased attention to disturbance of sleep and daytime sleepiness in routine health screening.

Accidents, Traffic↗

PubMed1992

Validity of a two kilometre walking test for estimating maximal aerobic power in overweight adults.

In our earlier study a regression model, with heart rate and time in a 2 km fast walk, body mass index (BMI) or weight (kg) and age as explanatory variables, explained 75% of the variation in the VO2max of adults with normal weight. The present study was designed to test whether the prediction model based on a 2km fast walk and simple site measurements is valid in estimating the VO2max of overweight men and women and to compare 1km and 2km test distances. Forty-five women and thirty-two men, BMI 27-40, aged 20-65 years, with no cardiorespiratory or musculoskeletal restrictions for a maximal stress test and fast walk, were studied. The VO2max was determined in an uphill walk to maximal effort on a treadmill. Two walking tests, 1km and 2km, were conducted on a flat dirt road. Heart rate was recorded during the walks, and the mean rate during the last 30 seconds was used in the model. The correlation coefficients between the measured and predicted VO2max in the 2km test were 0.77 for the women and 0.75 for men, corrected for body weight (ml/kg/min), and 0.77 and 0.69 respectively in absolute values (1/min). These results suggest that the 2km walk test previously developed for adults within normal weight limits is a reasonably valid test of the cardiorespiratory fitness of overweight, but otherwise healthy, women and men.

Adult↗

PubMed1992

Precision of dual-energy x-ray absorptiometry in determining bone mineral density and content of various skeletal sites.

Repeated measurements of bone mineral density (BMD) by dual-energy x-ray absorptiometry (DEXA) reliably indicate changes in the bone mineral content (BMC) of the lumbar spine and proximal femur, but its applicability to other sites has not been properly determined. The in-vivo day-to-day precision of DEXA (Norland XR-26) for lumbar spine, femoral neck, distal femur, patella, proximal tibia, calcaneus and distal radius was evaluated for 15 subjects who were scanned three times for 2 wk. Intra- and interobserver errors were also determined for image analysis. For clearly defined regions of interest, the following precision values were obtained for BMD with low intra- and interobserver error: 1.7% (lumbar spine), 1.3% (femoral neck), 1.2% (distal femur), 1.0% (patella), 0.7% (proximal tibia), 1.3% (calcaneus) and 1.9% (distal radius). The precision for BMC was lower. The results indicate that DEXA can successfully and precisely measure BMD of sites not commonly assessed by this technique.

Absorptiometry, Photon↗

PubMed1991

Improved diagnostic performance of the exercise ECG test by computerized multivariate ST-segment/heart rate analysis.

The exercise ECG test is the most widely used noninvasive method of evaluating myocardial ischemia. To determine whether it is possible to enhance its diagnostic power, the authors carried out computerized ECG measurements on 118 nonischemic patients and 38 ischemic patients with or without myocardial infarctions (MIs). Forty-seven (all ischemic and nine normal cases) underwent T1-201 SPECT. The diagnostic variables include ST-segment deviation, modified ST/HR-slope, ST-segment shape, and maximum heart rate. These variables are interrelated by means of compartmental and specific decision rules by computer. The diagnostic method discussed in this article is called the multivariate ST/HR analysis (MUSTA). When compared with MUSTA, the T1-201 SPECT images detected myocardial ischemia with a sensitivity of 100% and a specificity of 89%. Its diagnostic performance was influenced by neither previous MIs nor cardiac medication of the 47 patients tested. MUSTA was also compared to the nonmodified ST/HR analyses (ST60/HR and ST80/HR) and the standard exercise ECG test. It performed significantly better than these methods. The authors conclude that the multivariate ST/HR analysis is comparable to T1-201 SPECT in diagnosing myocardial ischemia among the study subjects. Furthermore, MUSTA is executed during the noninvasive exercise ECG test and is easily applied using an IBM/AT-compatible microcomputer. However, further evaluation of MUSTA with a separate and unselected patient population is needed.

Adult↗

PubMed1991

A 2-km walking test for assessing the cardiorespiratory fitness of healthy adults.

A simple walking test was developed with 159 (females = 80, males = 79) healthy 20-65-year-old subjects. All the subjects first walked the distances of 1.0, 1.5 and 2.0 km on a flat dirt road. Half of the participants were tested in the laboratory for maximal oxygen uptake (VO2max), and the 2-km test was repeated again twice. In a comparison of the three distances, the 2-km test was repeatable, the most preferable subjectively and the most accurate in predicting VO2max. A sex-specific prediction model including walking time, heart rate at the end of the walk, age and body mass index predicted 73-75% of the variance in VO2max (ml.kg-1.min-1) and that with body weight 66-76%, with a standard error of estimate of the order of 9-15% of the mean. The cross-validation of the models yielded reasonable accuracy in obese men and women and in moderately active men, and less accuracy in moderately active women and highly active men. These results suggest that a fast 2-km walk supplemented with simple measurements is a feasible and accurate alternative for determining the cardiorespiratory fitness of healthy adults.

Adult↗

PubMed1989

Prognostic value of an exercise test one year after myocardial infarction.

An exercise test was performed in 306 patients who had had acute myocardial infarction one year previously. The five year cumulative coronary heart disease mortality was 40.0%, when the test had to be discontinued because of ventricular arrhythmias but only 13.0% if discontinued because of fatigue (P less than 0.05). If the maximum work load was less than 80 W the mortality was 30.7% compared with 16.6% in patients who exercised at least 80 W (P less than 0.01). If maximum systolic blood pressure was less than or equal to 150 mmHg mortality was 40.3% compared with 8.5% in patients with greater than 200 mgHg (P less than 0.001). The mortality was 38.2% in patients having single monoform ventricular ectopic beats at a rate of three or more per minute or multiform, paired or early cycle ventricular ectopic beats or ventricular tachycardias: this compared with 14.1% (P less than 0.001) in patients having no or only single monoform ventricular ectopic beats at a rate of less than three per minute. ST-segment depression in univariate testing had no prognostic value. When both exercise test and clinical variables were used in survival analysis (Cox's regression) the most important variable was heart volume and after that ventricular arrhythmias. In multivariate regression analysis ST segment depression also had additional prognostic value. Thus ventricular arrhythmias turned out to be the most important prognostic factor measured during exercise test.

Aged↗

PubMed1979

The effect of a six-day ski-hike on plasma catecholamine concentrations and on their response to submaximal exercise.

Plasma catecholamine concentrations and dopamine-beta-hydroxylase activities were studied in 29 participants of a six-day cross-country ski-hike (260 km) to elucidate the adaptive responses of the sympatho-adrenal system to prolonged heavy exercise. Immediately after skiing on the first skiing day plasma noradrenaline concentrations appeared to be over twice as high as in the morning. On the morning of the fourth day noradrenaline levels had increased significantly when compared to those of the first morning. Concentrations after skiing on the fourth day were, however, about the same as in the first evening. After a submaximal ergometer test performed immediately after the skiing concentrations were still raised and the relative enhancement by this short-term exercise was about the same magnitude (40--60 %) on every test day. On the sixth day noradrenaline concentrations were about the same level as on the fourth day. Eleven days after the hike the basal noradrenaline levels were still about 25 % higher than before it. The changes of plasma adrenaline concentrations were in the same direction although not as striking as those of noradrenaline. Dopamine alterations were negligible. A significant but reversible decrease in plasma dopamine-beta-hydroxylase activities and cholesterol concentrations was found during the hike. The present results show that the sympatho-adrenal system is activated during the first few days of a ski-hike type prolonged exercise. A plateau developed in about four days. There were no signs of a decreased sympatho-adrenal response to a short-term heavy load.

Adult↗

PubMed1978