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Biomedical subjects

M Jensen-Urstad

Publications and source records attributed to M Jensen-Urstad.

At least 19 recordsLinked to original sources
PubMed2003

Influence of glucose control, lipoproteins, and haemostasis function on brachial endothelial reactivity and carotid intima-media area, stiffness and diameter in Type 1 diabetes mellitus patients.

BACKGROUND: The objectives of this study were to determine the influence of glucose control on lipoprotein and haemostasis variables in Type 1 diabetes mellitus patients and to evaluate the global impact of these metabolic risk factors on brachial artery reactivity and carotid artery atherosclerosis, stiffness and diameter. DESIGN: Follow up of Type 1 diabetes patients randomized to insulin-intensive conventional treatment (ICT, n = 29) or insulin-standard treatment (ST, n = 25) in the Stockholm Diabetes Intervention Study (SDIS) more than 14 years ago. RESULTS: The intensive conventional treatment patients had lower glycosylated haemoglobin (HbA1c) compared with the ST patients, i.e. 7.01 (SD 0.51) vs. 8.31 (0.97), while concentrations of the lipoprotein and haemostasis variables analyzed were virtually similar. The carotid artery intima-media area was associated with high HbA1c, high serum (S)-cholesterol levels, and low high-density lipoprotein (HDL)-cholesterol levels. Carotid artery stiffness was associated with high systolic blood pressure, high HbA1c, high fibrinogen, and high HDL-cholesterol. Brachial artery endothelial reactivity was higher for women and those with low S-cholesterol. CONCLUSION: In patients with Type 1 diabetes, glucose control appeared to have no effect on either lipoproteins or haemostasis variable concentrations. Poor glucose control, and high levels of S-cholesterol, systolic blood pressure and plasma fibrinogen were associated with development of atherosclerosis, thus emphasising the importance of global risk factor control in patients with Type 1 diabetes mellitus.

Adult↗
PubMed2002

Leg and arm lactate and substrate kinetics during exercise.

To study the role of muscle mass and muscle activity on lactate and energy kinetics during exercise, whole body and limb lactate, glucose, and fatty acid fluxes were determined in six elite cross-country skiers during roller-skiing for 40 min with the diagonal stride (Continuous Arm + Leg) followed by 10 min of double poling and diagonal stride at 72-76% maximal O(2) uptake. A high lactate appearance rate (R(a), 184 +/- 17 micromol x kg(-1) x min(-1)) but a low arterial lactate concentration ( approximately 2.5 mmol/l) were observed during Continuous Arm + Leg despite a substantial net lactate release by the arm of approximately 2.1 mmol/min, which was balanced by a similar net lactate uptake by the leg. Whole body and limb lactate oxidation during Continuous Arm + Leg was approximately 45% at rest and approximately 95% of disappearance rate and limb lactate uptake, respectively. Limb lactate kinetics changed multiple times when exercise mode was changed. Whole body glucose and glycerol turnover was unchanged during the different skiing modes; however, limb net glucose uptake changed severalfold. In conclusion, the arterial lactate concentration can be maintained at a relatively low level despite high lactate R(a) during exercise with a large muscle mass because of the large capacity of active skeletal muscle to take up lactate, which is tightly correlated with lactate delivery. The limb lactate uptake during exercise is oxidized at rates far above resting oxygen consumption, implying that lactate uptake and subsequent oxidation are also dependent on an elevated metabolic rate. The relative contribution of whole body and limb lactate oxidation is between 20 and 30% of total carbohydrate oxidation at rest and during exercise under the various conditions. Skeletal muscle can change its limb net glucose uptake severalfold within minutes, causing a redistribution of the available glucose because whole body glucose turnover was unchanged.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed2002

Left ventricular diastolic function is related to glucose in a middle-aged population.

OBJECTIVES: To examine the relation between left ventricular (LV) diastolic function and glucose metabolism in individuals without previously diagnosed diabetes mellitus. DESIGN: A cross-sectional population-based study. SETTING: A university hospital. SUBJECTS: Thirty-five men and women 56-58 years of age without previously diagnosed diabetes or heart disease. MAIN OUTCOME MEASURES: Left ventricular diastolic function assessed by pulsed Doppler tissue imaging and its relation to fasting plasma glucose, glucose postload and glycated haemoglobin. LV diastolic function was determined by measuring early diastolic filling peak velocity (Em wave cm s-1), late diastolic filling peak velocity (Am wave cm s-1) and their ratio Em/Am. RESULTS: Peak Em velocity, peak Am velocity and their ratio Em/Am correlated with fasting plasma glucose (r=-0.42, P=0.01; r=0.47, P=0.04 and r=-0.53, P=0.001, respectively). There was a correlation between peak Em velocity, the ratio of Em/Am and glycated haemoglobin. LV diastolic function was also related to glucose postload. CONCLUSIONS: Left ventricular diastolic function is related to concentrations of fasting plasma glucose, glucose postload and glycated haemoglobin even below the threshold of diabetes. This indicates that glucose concentrations already in the upper end of the normal range has negative impact on cardiac function.

Blood Glucose↗
PubMed2002

Risk factors for coronary heart disease in 55- and 35-year-old men and women in Sweden and Estonia.

OBJECTIVE: To illustrate the geographical West-to-East division of coronary heart disease (CHD) by comparing a population from Sweden, that represents a Western country to a population from Estonia, that represents an Eastern country. Estonia has an approximately 2-4-fold higher CHD prevalence for 55-year-old women and men, respectively, than Sweden. DESIGN: Randomized screening of 35- and 55-year-old men and women in Sollentuna county, Sweden and Tartu county, Estonia. Eight hundred subjects, 100 from each cohort, were invited to participate in the study, 272 Swedes and 277 Estonians participated. SETTING: Preventive cardiology, administered by a primary health care centre at the Karolinska Hospital, Sweden and a cardiology centre at Tartu University Hospital, Estonia. MAIN OUTCOME MEASURES: The CHD risk factors (smoking, blood pressure, concentrations of lipoproteins, fibrinogen, and glucose) and certain environmental factors and attitudes related to CHD risk by questionnaires (fat-type and alcohol ingestion, self-assessed rating of CHD susceptibility). RESULTS: Of the 55-year-old men, 57% smoked in Estonia and 20% smoked in Sweden. Similar, although less pronounced differences showing higher smoking prevalence, were seen for 35-year-old Estonian men and women, whilst for 55-year-old women, less than 20% smoked in either country. Estonian 55-year-old women had lower HDL cholesterol and higher LDL cholesterol serum concentrations than Swedish 55-year-old women. Estonians reportedly ate food containing more saturated fats than Swedes, as indicated by the scale-score questionnaire. Estonians, relative to Swedes, rated their chance of developing CHD higher, and paradoxically, Estonians did to a much lesser degree believe that life style influences the risk of developing CHD. CONCLUSIONS: Elevated smoking prevalence is a striking difference between the Estonian and Swedish populations likely to explain the much higher CHD prevalence in Estonian men. The lower HDL cholesterol and higher LDL cholesterol in Estonian 55-year-old women may explain the higher CHD prevalence in Estonian women. Furthermore, the SWESTONIA CHD study (i.e. comparison between Sweden and Estonia) shows several environmental differences between the countries populations related to fat content in food, alcohol drinking patterns, and views on CHD risk and the importance of lifestyle intervention, that could contribute to the higher CHD prevalence in Estonia.

Adult↗
PubMed2001

Myocardial viability in patients with thrombolyzed myocardial infarction: is it assessable by predischarge exercise electrocardiography test?

BACKGROUND: Most studies concerning exercise electrocardiography (ECG) testing after acute myocardial infarction (AMI) were carried out in the prethrombolytic era. ST-segment elevation in the infarction area during exercise has usually been interpreted as indicating the presence of dyskinesia as a result of extensive left ventricle damage. HYPOTHESIS: This study was undertaken to evaluate the contributions of exercise-induced ST-segment elevation and T-wave pseudonormalization to the assessment of myocardial viability in patients with thrombolyzed myocardial infarction (MI), compared with low-dose dobutamine echocardiography. METHODS: The study comprised 52 consecutive patients with AMI treated with thrombolysis. All patients underwent low-dose dobutamine echocardiography and symptom-limited exercise testing before discharge. RESULTS: Nineteen patients showed ST-segment elevation (Group 1), 9 showed isolated T-wave pseudonormalization (Group 2), and 24 patients did not exhibit either of these ST-T segment changes (Group 3). Low-dose dobutamine echocardiography revealed evidence of viability in 16 patients (84%) in Group I (p = 0.01), 5 (56%) in Group 2 (p = NS), and 11 patients (46%) in Group 3 (p = NS). CONCLUSION: Exercise-induced ST-segment elevation may contribute to the evaluation of myocardial viability in patients with AMI treated with thrombolysis. However, in the absence of exercise-induced ST-segment elevation, further noninvasive studies might be indicated to assess myocardial viability.

Aged↗
PubMed2001

Factors predicting success rate and recurrence of atrial fibrillation after first electrical cardioversion in patients with persistent atrial fibrillation.

BACKGROUND: The recurrence rate of atrial fibrillation (AF) after elective cardioversion is high. HYPOTHESIS: The study aimed to identify clinical predictors for successful electrical cardioversion and maintenance of sinus rhythm after a first electrical cardioversion in patients with persistent AF without concomitant antiarrhythmic drugs of class I and III. METHODS: Consecutive outpatients (n = 166) with persistent AF for > 1 month, scheduled for elective cardioversion, were prospectively included in the study. A clinical investigation, echocardiographic assay, and Holter electrocardiogram (ECG) before and ECG 4 weeks after cardioversion, were performed in all patients. RESULTS: The mean age of the patients was 68 years (range 45-83) and duration of AF was 5 (1-48) months. Sinus rhythm was established in 124 (75%) patients. In multivariate analysis, only duration of AF < 6 months (p < 0.04, odds ratio [OR] 2.2, 95% confidence interval [CI] 1.1 to 4.7) and patients weight (p < 0.03, OR 2.3, 95% CI 1.1 to 4.8 for weight < 80 kg) were identified as independent predictors of successful cardioversion. At 4 weeks after cardioversion, only 46 (37%) of 124 patients maintained sinus rhythm. Independent factors for maintenance of sinus rhythm, in multivariate analysis, were AF <3 months (p < 0.04, OR 2.5, 95% CI 1.1 to 5.6), treatment with beta blockers (p < 0.00001, OR 7.0, 95% CI 3.0 to 16.3) or verapamil/diltiazem (p < 0.04, OR 3.6, 95% CI 1.1 to 12.1), and right atrial dimension < 37 mm (p < 0.02, OR 5.9, 95% CI 1.4 to 25.4). CONCLUSIONS: In patients with persistent AF, the patient's weight and the duration of AF are independent predictors for a successful cardioversion. Short duration of AF, treatment with beta blockers or verapamil/diltiazem, and right atrial area/dimension are independent predictors for maintenance of sinus rhythm.

Adult↗
PubMed2001

Deterioration in peak systolic velocity is closely related to ischaemia during angioplasty: a vectorcardiographic and tissue Doppler imaging study.

We tested the hypothesis that the extent of signs of ischaemia detected by vectorcardiography (VCG) during elective coronary angioplasty (percutaneous transluminal coronary angioplasty; PTCA) is related to systolic and diastolic myocardial velocities, as determined by tissue Doppler echocardiography. A total of 15 patients undergoing PTCA (12 men/three women; age 61+/-9 years), without prior myocardial infarction and with an ejection fraction of >50%, were included. The balloon inflation was repeated three times, with minimum intervals of 2 min between inflations. Tissue Doppler echocardiography was performed, in an apical two- or four-chamber view, before and at the end of each inflation. Peak systolic velocity, time-to-peak systolic velocity (TTP), peak early (E(m)) and late (A(m)) diastolic velocities, the E(m)/A(m) ratio and isovolumic relaxation time were measured in the basal segments of the left ventricle. VCG recordings were carried out during the whole procedure. ST vector magnitude (ST-VM) and ST change vector magnitude (STC-VM) were monitored. The total duration and area of each VCG change during inflation were calculated for each patient. Isovolumic relaxation time, peak E(m) and A(m) values and the E(m)/A(m) ratio did not change significantly during inflation. Peak systolic velocity decreased (6.7+/-2.0 to 5.3+/-1.9 cm/s; P<0.001) and TTP increased (157+/-60 to 192+/-60 ms; P<0.01) during inflation. Both STC-VM time (r=-0.68, P<0.01) and STC-VM area (r=-0.68, P<0.01) were related to peak systolic velocity during inflation. STC-VM time was also related (r=0.55, P<0.05) to the difference in peak systolic velocity during compared with before inflation. ST-VM was less closely related to peak systolic velocity. Thus the duration and degree of ischaemia, as measured by VCG, are related to peak systolic velocity in the basal segments of the left ventricle.

Aged↗
PubMed2001

Automatic computerized analysis of heart rate variability with digital filtering of ectopic beats.

Analysis of heart rate variability (HRV) has been used in studies of autonomic function and risk assessment in different patient groups such as in patients with diabetes mellitus, after myocardial infarction (MI) and other cardiovascular disease. Ectopic beats can, however, interfere with HRV analysis and give erroneous results. We have therefore studied the impact of ectopic beats on HRV analysis and the ability of a filter algorithm to correct this. Power spectral analysis of synthetic data with an increasing proportion of ectopic beats and 24-h Holter recordings from 98 healthy subjects and 93 post MI patients was done with and without digital filtering and interpolation of errors in the data stream. The analysis of HRV was seriously hampered by less than 1% of ectopic beats. A filter algorithm based on detection and linear interpolation of ectopic beats and other noise in the data stream corrected effectively for this in the synthetic data employed. In the healthy subjects and the post MI patients, filtering markedly reduced the extra variability related to non-normal beats. The software could automatically analyse over one hundred 24-h files in one batch. HRV analysis should include filtering for ectopic beats even with a small number of such beats. It is possible to make a fast analysis automatically even in huge clinical series, which makes it possible to use the method both clinically and in epidemiological studies.

Adult↗
PubMed2001

Risk assessment in patients with acute myocardial infarction treated with thrombolytic therapy.

OBJECTIVE: Several noninvasive methods have prognostic information regarding mortality and new coronary events after an acute myocardial infarction (AMI). The practical for clinical decision-making in the immediate postmyocardial infarction (MI) period is, however, less evident. We investigated consecutive patients with AMI treated with thrombolysis to further clarify this issue. DESIGN: A total of 100 patients (27% women) aged 64 +/- 9 years (mean +/- SD) were studied. Risk assessment based on a clinical score system, myocardial perfusion scintigraphy single photon emission computed tomography (SPECT) at rest and during adenosine stress, echocardiography, radionuclide angiography, symptom-limited exercise stress test, and 24-h Holter ECG recording with ST-analysis and analysis of heart rate variability (HRV) were performed 5-8 days after hospital admission. Mortality, nonfatal reinfarction, and the need for revascularization were followed during 12 months. SETTING: A university hospital. RESULTS: A total of 6 patients died, seven had a nonfatal reinfarction, and 23 were revascularized. Inability to perform an exercise test (P = 0.004) and an ejection fraction (EF) < 40% (P = 0.002) were the only parameters separating those who died from the survivors. No method could predict a nonfatal reinfarction. Patients suffering either death or nonfatal reinfarction had a clinical risk assessment score 2 points higher (8.8 vs. 6.7, P = 0.05) than the group without such events. A positive symptom-limited exercise stress test (P = 0.027), ST-depressions on Holter ECG (P = 0.04), and reversibility on myocardial perfusion scintigraphy (P = 0.029) predicted the need for revascularization. CONCLUSION: Risk assessment based on clinical information, exercise stress testing, and an estimate of left ventricular function (e.g. via echocardiography) contribute with prognostic information in thrombolysed MI-patients. Additional noninvasive investigations such as adenosine-SPECT, analysis of HRV, and Holter-monitoring do not add to these commonly available tools in risk stratification of subjects at low to medium risk.

Aged↗
PubMed2001

Asymptomatic versus symptomatic persistent atrial fibrillation: clinical and noninvasive characteristics.

OBJECTIVE: This prospective study was designed to investigate the differences between asymptomatic versus symptomatic arrhythmia as well as left ventricular dysfunction in a consecutive population of patients with persistent atrial fibrillation. DESIGN: A total of 282 consecutive outpatients referred with persistent atrial fibrillation formed the study population. A structured medical history was obtained. A two-dimensional transthoracic echocardiography to assess the left ventricular function and a 24-h electrocardiogram (ECG) recording were performed. Irregularity of the heart rhythm was analysed with heart rate variability (HRV) in the time domain as well as maximum and minimum heart rate and the longest pause. SETTING: Three university hospitals. RESULTS: The mean age of the patients was 69 years and the mean duration of atrial fibrillation was 7 months. The prevalence of symptomatic patients was 68%, while 32% had no symptoms from atrial fibrillation, left ventricular dysfunction was observed in 20%. Asymptomatic subjects had more often lone atrial fibrillation than those with symptoms. Valvular heart disease was an independent predictor of symptoms while male gender, ischaemic heart disease and a high heart rate were independent predictors of impaired left ventricular function. CONCLUSION: Valvular heart disease is related to symptoms in persistent atrial fibrillation. Ischaemic heart disease, male gender and a high heart rate are more common in patients with impaired left ventricular function. Compromised left ventricular function does, occur also in asymptomatic subjects underlining the importance of a careful investigation including echocardiography in all subjects with persistent atrial fibrillation.

Adult↗
PubMed2001

Spontaneous delayed recovery of perfusion after thrombolyzed acute myocardial infarction: is it predictable before discharge?

In patients with thrombolyzed acute myocardial infarction, early assessment of the final infarct size is difficult because spontaneous recovery of perfusion and function of the left ventricle may be delayed. This study was undertaken to evaluate the ability of predischarge low-dose dobutamine echocardiography to predict late spontaneous recovery of perfusion assessed by single-photon emission computed tomography after acute myocardial infarction. We prospectively studied 53 consecutive patients with myocardial infarction treated with thrombolysis. Low-dose dobutamine echocardiography and resting (99m)Tc-sestamibi single-photon emission computed tomography (MIBI SPECT) were performed 4 +/- 2 days after infarction. A follow-up SPECT study was carried out in 45 patients after 6 months. Myocardial recovery was defined as a reduction of SPECT defect size by more than 10% at follow-up compared with the early study. In 25 of the 45 patients, the size of the left ventricular perfusion defect decreased significantly from 42% +/- 16% to 27% +/- 10% (group 1), whereas in the remaining 20 patients it showed no significant change (group 2). Predischarge low-dose dobutamine echocardiography showed a significant improvement in wall motion score index compared with baseline in group 1, from 1.62 +/- 0.28 to 1.41 +/- 0.24, P <.001, whereas in group 2 this index remained without significant change. Predischarge low-dose dobutamine echocardiography is an accurate tool for prediction of late recovery of myocardial perfusion after acute myocardial infarction treated with thrombolysis.

Adrenergic beta-Agonists↗
PubMed2001

Left ventricular function and perfusion in elderly endurance athletes.

PURPOSE: To study the extent to which lifelong physical training can affect cardiovascular capacity, left ventricular function, and myocardial perfusion in elderly men. METHODS AND RESULTS: Ten healthy male veteran endurance athletes aged 73 +/- 3 yr (mean +/- SD) and a control group of 12 sedentary or moderately physically active healthy subjects aged 75 +/- 2 yr were studied. Echocardiographic examinations at rest and exercise stress tests were performed. Gated blood pool scans and myocardial perfusion scintigraphy were recorded at rest and during exercise. Maximal VO2 was 41 +/- 7 mL.kg-1.min-1 in the athletes and 26 +/- 5 mL.kg-1.min-1 in the controls (P < 0.001). Echocardiographic measures of systolic and diastolic function at rest were better in the athletes. The ejection fraction during exercise was also higher in the athletes (P = 0.003). Seven of the 10 athletes, but none of the controls, had pathological myocardial perfusion findings. CONCLUSIONS: By endurance training, a high level of physical capacity can be maintained late in life. The superior cardiovascular function in the veteran athletes, compared with the untrained controls was due to both better systolic and diastolic left ventricular function. Myocardial perfusion defects in athletes should be judged with caution, as this finding is common both in veteran athletes and as previously shown, in young athletes.

Aged↗
PubMed2000

Physical training in Syndrome X: physical training counteracts deconditioning and pain in Syndrome X.

OBJECTIVES: The aim of this study was to evaluate the effects of exercise training and body-awareness training in female patients with Syndrome X. BACKGROUND: Patients with Syndrome X, defined as effort-induced angina pectoris, a positive exercise test and a normal coronary angiogram, suffer from a chronic pain disorder. We hypothesized that this disorder results in physical deconditioning with decreased exertional pain threshold. METHODS: Twenty-six patients were randomly assigned to two training groups (A, B) and a control group (C). Group A (n = 8) started, after baseline measurements, with eight weeks of body-awareness training followed by eight weeks of exercise training on a bicycle ergometer three times a week for 30 min at an intensity of 50% of peak work rate. Group B (n = 8) performed only eight weeks of exercise training. Group C (n = 10) acted as controls without any intervention whatsoever. The effects on exercise performance, hormonal secretion, vascular function, adenosine sensitivity and quality of life were evaluated. RESULTS: Body-awareness training did not change the pain response. The two training groups did not differ in effects of exercise training. Exercise capacity before training was below the gender- and age-matched reference range and improved by 34% with training to a level not different from the reference range. Onset of pain was delayed by 100% from 3 +/- 2 to 6 +/- 3 min (p < 0.05) while maximum pain did not change. Thus the pain-response-to-exercise curve was shifted to the right. Syndrome X patients showed a hypersensitivity to low-dose adenosine infusion compared to healthy age- and gender-matched controls (p < 0.0001) that did not change with exercise training. Endothelium-dependent blood flow increase was at baseline within reference range and tended to increase (p < 0.06) following training. In Group A the concentration of cortisol in urine decreased by 53% after body-awareness training (p < 0.05), and this change from baseline remained after physical exercise training (p < 0.05). A similar decrease occurred with only exercise training (Group B). CONCLUSIONS: Physical deconditioning with lower exertional threshold for pain is a prominent feature in Syndrome X. Physical training in Syndrome X results in an increased exercise capacity with lesser anginal pain. We suggest physical training as an effective treatment in Syndrome X.

Exercise Therapy↗
PubMed2000

Autonomic neuropathy--a complication less pronounced in patients with Type 1 diabetes mellitus who have lower blood glucose levels.

AIMS: Autonomic neuropathy is a serious diabetic complication, probably contributing to the death of many young people with Type 1 diabetes mellitus. It is often not diagnosed. METHODS: Patients with Type 1 diabetes from the Stockholm Diabetes Intervention Study were investigated with power spectral analysis (n = 88), heart rate and blood pressure reactions to tilting (n = 66), and heart rate variability during deep breathing (n = 70) a mean of 11.4 years after randomization to intensified conventional treatment (ICT) or standard treatment (ST), the treatment groups similar with regard to age, duration of diabetes and metabolic control at baseline (HbA1c 9.4 (1.3)%, mean (SD)). Blood glucose levels (mean of 29 HbA1c values) during the 10 years were lower in the patients from the ICT group (7.2 (0.6) vs. 8.3 (1.0)%, P = 0.001). RESULTS: Heart rate variability (HRV) in the high frequency range (P = 0.034), the expiration-inspiration ratio (P = 0.020), and the brake index during tilt (P = 0.044) were lower in the ST group, indicating more pronounced parasympathetic insufficiency. Systolic blood pressure fell by 10 (16) mmHg in the ST group, and by 2.5 (15) mmHg in the ICT group 8 min after rising from the supine to a 70 degrees upright position (P = 0.034). A decreased autonomic function was associated with age and higher HbA1c. CONCLUSION: Better autonomic nerve function is associated with lower HbA1c and lower age which were both the same in the intensively and the conventionally treatment groups at baseline. After a mean of 11.4 years autonomic function was better in the intensively treated group.

Adult↗
PubMed1999

Aerobic training involving a minor muscle mass shows greater efficiency than training involving a major muscle mass in chronic heart failure patients.

BACKGROUND: Beneficial training outcomes have been reported in sedentary patients with chronic heart failure (CHF) after exercise training. However, data on training effects in previously trained patients, as well as comparisons of different exercise modes, are lacking. The aim of this study is to compare exercise training on a cycle ergometer (major muscle mass) and aerobic knee-extensor training (minor muscle mass) in previously trained patients with CHF. METHODS AND RESULTS: Twenty-four men and women (age, 63 +/- 10 years [mean +/- SD]) with stable, moderate CHF (left ventricular ejection fraction, 30% +/- 11%) who had completed their first exercise training period more than 1 year ago were allocated to either the exercise or control group. After stratification for sex, age, ejection fraction, and cardiac output response, the training group was further randomized to either cycle ergometer or knee-extensor training for 8 weeks. The control and training patients did not differ at baseline, and the measured variables did not change in the control group during the 8 weeks. Citrate synthase activity in skeletal muscle increased after cycle training (23%; P < .02) and knee-extensor training (45%; P < .008), and blood lactate concentration at submaximal intensities decreased (P < .04) in both groups. However, only after knee-extensor training did the peak oxygen uptake increase (19%; P < .01) and sympathetic nervous system activity, measured as plasma norepinephrine concentration at rest (P < .05) and during exercise (P < .008), decrease. Minnesota Living with Heart Failure questionnaire scores also showed improvement in the health-related quality of life (P < .05) only after knee-extensor training. CONCLUSION: Physical training is beneficial in previously trained patients with CHF. Aerobic training involving a minor muscle mass shows greater efficiency than training involving a major muscle mass.

Aged↗
PubMed1999

Myocardial sestamibi uptake in healthy subjects is related to age, gender and habitus.

The object of this study was to evaluate the effect of gender, age and anthropometric data on regional isotope uptake in myocardial perfusion scintigraphy using 99mTc-MIBI-SPECT (myocardial sestamibi single-photon emission technique). Seventy-one healthy, non-smoking subjects, 42 men and 29 women between 40 and 80 years of age, with less than 5% likelihood of having coronary artery disease were studied. All subjects underwent a maximal exercise and rest MIBI-SPECT using a 2-day protocol and a 180 degrees anterior circular rotation. No correction for scatter or attenuation was made. Normalized regional activity was different in men and women in the anterior and inferior regions, with higher values anteriorly in men and inferiorly in women. Regional activity also differed with age in both women and men with higher relative activity in the anterior regions in the oldest age groups. Higher activities were seen in the basal parts of the left ventricle at rest compared with stress in both men and women. Regional isotope uptake was significantly affected by habitus expressed as body mass index (BMI) and thoracic circumference. Different protocols for stress and rest seem to be needed for men and women in different age groups, and for stress and rest when performing semiquantitative MIBI-SPECT and comparing data with a normal file of healthy subjects. Furthermore, such anthropometric data as BMI and/or thoracic circumference should be considered in order to minimize the risk for false-positive or false-negative scintigraphic results.

Adult↗
PubMed1999

Decreased heart rate variability in patients with type 1 diabetes mellitus is related to arterial wall stiffness.

OBJECTIVE: Low heart rate variability (HRV) is, in several patient groups, related to poor prognosis. The underlying mechanisms are still unclear. The aim was to study if there is a relationship between HRV, which is a measure of baroreceptor function, and atherosclerosis. DESIGN: The relationship between heart rate variability and carotid arterial wall stiffness was studied in subjects with type 1 diabetes mellitus in which autonomic dysfunction and early atherosclerosis are common. HRV was assessed from power spectral analysis of 24-h Holter recordings and arterial wall stiffness was assessed from an ultrasound study of the right common carotid artery. SETTING: A university hospital. SUBJECTS: Fifty-nine patients (41 +/- 8 years) from the Stockholm Diabetes Intervention Study (SDIS) were investigated. These patients were randomized to intensified conventional treatment or standard treatment approximately 12 years before this study. RESULTS: Patients with stiffer arteries had lower HRV in all spectral bands (r = -0.32 to -0.40, P = 0.06-0.001). This relation remained on correcting for age. All spectral parameters of HRV correlated with the mean HbA1c from 10 years of study (r = -0.37 to -0.40, P = 0.004-0.001). CONCLUSIONS: In patients with type 1 diabetes mellitus, heart rate variability and arterial wall stiffness are related to each other. The results suggests that the autonomic nervous system could be a link between diabetes and vascular disease.

Adult↗