RESUMEN
Autonomic dysfunction decreases within-subject correlation between R-R interval length (RRi) and vagally mediated RRi variability in cardiac disease. We tested the hypothesis that overtraining syndrome (OTS) may also weaken this relationship. Nine OTS and 10 control endurance athletes underwent 24-h electrocardiogram monitoring, which was repeated in eight OTS and nine control athletes after 6 months, when two OTS athletes still had symptoms of OTS. The power of high-frequency (HF) oscillations of RRi was analyzed in 5-min epochs over the whole recording. Quadratic regression was performed between 5-min values of RRi and log-transformed (ln) HF to obtain R(2) for each recording. The relationship between RRi and HFln was higher in the OTS athletes than controls [R(2): 0.87 (90% confidence interval, CI: 0.84-0.89) vs 0.78 (90% CI: 0.72-0.84); P = 0.034; effect size = 1.22]. Large decrease in R(2) was observed in six recovered OTS athletes after 6 months follow-up [ΔR(2): -0.12 (90% CI: -0.25-0.01); P = 0.11; effect size = 1.44] with no changes in the controls. Mean values of RRi and its variability did not differ between the groups. The within-subject correlation between RRi and vagally mediated RRi variability was stronger in endurance athletes with OTS compared with controls. The present findings may improve the detection of OTS and recovery from OTS in endurance athletes.
Asunto(s)
Frecuencia Cardíaca/fisiología , Corazón/fisiopatología , Acondicionamiento Físico Humano/efectos adversos , Acondicionamiento Físico Humano/fisiología , Resistencia Física/fisiología , Adolescente , Adulto , Sistema Nervioso Autónomo/fisiopatología , Estudios de Casos y Controles , Electrocardiografía Ambulatoria , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Consumo de Oxígeno/fisiología , Valor Predictivo de las Pruebas , Deportes/fisiología , Síndrome , Adulto JovenRESUMEN
BACKGROUND AND AIMS: Inflammation may be one mediating mechanism for cardiovascular diseases in obstructive sleep apnea (OSA). However, little is known about subclinical inflammation or the effect of lifestyle intervention on inflammation in early stages of OSA. The aim of this substudy of an existing randomized controlled trial, with post hoc analyses, was to determine the impact of lifestyle changes aimed at weight reduction on inflammatory biomarkers in overweight patients with mild OSA. METHODS AND RESULTS: Patients were randomized to supervised intensive lifestyle intervention group (N=28) or to control group (N=31), which received routine lifestyle advices. Circulating concentrations of pro- and anti-inflammatory mediators were measured before and after the 1-year intervention. The concentrations of two pro-inflammatory mediators, high-sensitivity C-reactive protein (hsCRP) and interleukin (IL)-6, decreased significantly in both groups. Although the changes in inflammatory biomarkers favored the supervised lifestyle intervention, the only significant reduction observed between the groups was for the anti-inflammatory IL-1 receptor antagonist (IL-1RA). The change in hsCRP was associated with apnea-hypopnea index, and improving night-time oxygen saturation was related to tumor necrosis factor alpha. IL-1RA and IL-6 were associated with insulin metabolism. CONCLUSION: Weight loss resulted in reductions in concentrations of some pro- and anti-inflammatory mediators in overweight patients with mild OSA, overall favoring the supervised lifestyle intervention. These findings suggest that more intensive treatment of obesity in OSA patients might be well-justified.
Asunto(s)
Inflamación/fisiopatología , Apnea Obstructiva del Sueño/fisiopatología , Pérdida de Peso , Adolescente , Adulto , Anciano , Biomarcadores/sangre , Proteína C-Reactiva/metabolismo , Femenino , Estudios de Seguimiento , Humanos , Inflamación/complicaciones , Inflamación/terapia , Mediadores de Inflamación/sangre , Proteína Antagonista del Receptor de Interleucina 1/sangre , Interleucina-6/sangre , Estilo de Vida , Masculino , Persona de Mediana Edad , Sobrepeso/fisiopatología , Apnea Obstructiva del Sueño/complicaciones , Apnea Obstructiva del Sueño/terapia , Factor de Necrosis Tumoral alfa/sangre , Adulto JovenRESUMEN
OBJECTIVES: To evaluate apparent diffusion coefficient (ADC) in cerebellar subregions in patients with stroke. MATERIALS AND METHODS: The total counts and ADCs were bilaterally measured on cerebellar white matter, gray matters of medial (G1), intermediate (G2), and lateral zones (G3) on SPECT and ADC maps from 20 patients with supratentorial ischemic stroke within the first 48 h and on day 8 after onset. ADCs were also obtained from 15 age-matched controls. RESULTS: Within 48 h, the ADCs were significantly increased bilaterally in the G3, and tended to be increased bilaterally in the white matter and G1, and contralateral G2 compared with controls. On day 8, the ADCs were significantly increased in all contralateral cerebellar subregions and in ipsilateral G1 and G2, and tended to be increased in ipsilateral G3. The ADC value was significantly higher in contralateral than in ipsilateral white matter on day 8. The interhemispheric asymmetry indices (AIs) of ADC and SPECT were significantly associated with each other in G2 and G3 within 48 h, but not on day 8. The AIs of ADC and SPECT were significantly related to each other in the G3 within 48 h and on day 8. CONCLUSIONS: Supratentorial ischemic stroke may cause mild cerebellar vasogenic edema.
Asunto(s)
Cerebelo/metabolismo , Imagen de Difusión por Resonancia Magnética , Accidente Cerebrovascular/patología , Anciano , Isquemia Encefálica/complicaciones , Mapeo Encefálico , Estudios de Casos y Controles , Cerebelo/diagnóstico por imagen , Cerebelo/patología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Fibras Nerviosas Mielínicas/diagnóstico por imagen , Fibras Nerviosas Mielínicas/patología , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/etiología , Tomografía Computarizada de Emisión de Fotón Único/métodosRESUMEN
BACKGROUND AND PURPOSE: Aneurysmal subarachnoid haemorrhage (aSAH) can be associated with acute global and regional decrease in cerebral perfusion. Furthermore, cerebral vasospasm may lead to development of delayed ischaemic deficits. The aim of the study was to find out whether cerebral perfusion heterogeneity, an indicator of cerebral microvascular function and autoregulation, measured by single-photon emission tomography (SPET), is able to predict the long-term clinical outcome of aSAH. METHODS: The perfusion SPET data of 55 patients with aSAH were analysed by dividing the brain into 384 regions of interest. Spatial perfusion heterogeneity was assessed by calculating the relative dispersions (RD, coefficient of variation) from the SPETs performed before treatment (RD1) and 1 week after early surgical or endovascular treatment of the ruptured aneurysm (RD2). Both RDs were compared to the clinical outcome (Glasgow Outcome Scale, GOS), neuropsychological test scores and late ischaemic findings in MRI 1 year after SAH. RESULTS: High RD2 (OR 1.96; 95% CI 1.18-3.26; p = 0.009) and poor clinical condition (Hunt and Hess grade) on admission (OR 6.60; 95% CI 1.78-24.52; p = 0.005) proved to be independent predictors of poor or moderate clinical outcome (GOS 1-4). RD2 was higher in patients with ischaemic findings in 12-month MRI than in those without ischaemic findings (p = 0.008). RD2 also correlated with neuropsychological outcome 1 year after aSAH. CONCLUSIONS: Perfusion heterogeneity is an independent predictor of the clinical outcome of aSAH and may thus be a valuable measure in the assessment of the disease.
Asunto(s)
Encéfalo/irrigación sanguínea , Aneurisma Intracraneal/complicaciones , Aneurisma Intracraneal/diagnóstico , Hemorragia Subaracnoidea/diagnóstico , Hemorragia Subaracnoidea/etiología , Adolescente , Adulto , Anciano , Aneurisma Roto/complicaciones , Aneurisma Roto/diagnóstico , Aneurisma Roto/cirugía , Encéfalo/anatomía & histología , Circulación Cerebrovascular/fisiología , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/epidemiología , Trastornos del Conocimiento/etiología , Femenino , Lateralidad Funcional/fisiología , Homeostasis/fisiología , Humanos , Aneurisma Intracraneal/cirugía , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Procedimientos Neuroquirúrgicos , Valor Predictivo de las Pruebas , Prevalencia , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Hemorragia Subaracnoidea/cirugía , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
OBJECTIVES: To evaluate whether hourly changes in fine particle (PM(2.5), diameter<2.5 microm) exposure or outdoor particle concentrations are associated with rapid ischaemic responses. METHODS: 41 non-smoking elderly people with coronary heart disease were followed up with biweekly clinic visits in Helsinki, Finland. The occurrence of ST segment depressions >0.1 mV was recorded during submaximal exercise tests. Hourly variations in personal PM(2.5) exposure and outdoor levels of PM(2.5) and ultrafine particles (<0.1 microm) were recorded for 24 h before a clinic visit. Associations between particulate air pollution and ST segment depressions were evaluated using logistic regression. RESULTS: Both personal and outdoor PM(2.5) concentrations, but not outdoor ultrafine particle counts, were associated with ST segment depressions. The odds ratio (per 10 microg/m(3)) for personal PM(2.5) concentration during the hour preceding a clinic visit was 3.26 (95% CI 1.07 to 9.99) and for 4 h average outdoor PM(2.5) it was 2.47 (95% CI 1.05 to 5.85). CONCLUSIONS: Even very short-term elevations in fine particle exposure might increase the risk of myocardial ischaemia. The precise mechanism is still unknown but could involve changes in autonomic nervous control of the heart.
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Contaminantes Atmosféricos/efectos adversos , Isquemia Miocárdica/etiología , Material Particulado/efectos adversos , Anciano , Contaminantes Atmosféricos/análisis , Electrocardiografía , Exposición a Riesgos Ambientales/efectos adversos , Exposición a Riesgos Ambientales/análisis , Monitoreo del Ambiente/métodos , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tamaño de la Partícula , Material Particulado/análisis , PeriodicidadRESUMEN
No studies are available that have compared early defects in glucose metabolism in the offspring of insulin-deficient and insulin-resistant probands with non-insulin-dependent diabetes mellitus (NIDDM). To investigate this issue, we evaluated insulin secretion capacity with oral and intravenous glucose tolerance tests and with the hyperglycemic clamp, and insulin action with the euglycemic insulin clamp in 20 offspring of NIDDM patients with low fasting C-peptide (+/-450 pmol/liter), reflecting deficient insulin secretion (IS-group), 18 offspring of NIDDM patients with high fasting C-peptide (>/= 880 pmol/liter), reflecting insulin resistance (IR-group), and 14 healthy control subjects without a family history of NIDDM. The frequency of impaired glucose tolerance was 45.0% in the IS-group and 50% in the IR-group. The IS-group had lower insulin-glucose response at 30 min in the oral glucose tolerance test (85.2+/-10.0 pmol insulin per mmol glucose) than the control group (136.4+/-23.1 pmol insulin per mmol glucose; P < 0.05) and the IR-group (115.6+/-11.8 pmol insulin per mmol glucose; P = 0.05). Furthermore, the acute insulin response during the first 10 min of an intravenous glucose tolerance test was lower in the IS-group than in the IR-group. Maximal insulin secretion capacity evaluated by C-peptide levels during the hyperglycemic clamp did not differ between the groups. The IR-group had lower rates of whole body glucose uptake (60.1+/-4.6 micromol per lean body mass per minute) than did the control group (84.2+/-5.0 micromol per lean body mass per minute; P < 0.001) or the IS-group (82.6+/-5.9 micromol per lean body mass per minute; P < 0.01) and this was due to reduced glucose nonoxidation. To conclude, both impaired insulin secretion and insulin action seem to be inherited and could represent the primary defects in glucose metabolism in the offspring of NIDDM probands.
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Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Resistencia a la Insulina/fisiología , Insulina/metabolismo , Tejido Adiposo/anatomía & histología , Adulto , Anciano , Composición Corporal , Diabetes Mellitus Tipo 2/fisiopatología , Metabolismo Energético , Ácidos Grasos no Esterificados/sangre , Femenino , Estudios de Seguimiento , Técnica de Clampeo de la Glucosa , Prueba de Tolerancia a la Glucosa , Humanos , Secreción de Insulina , Ácido Láctico/sangre , Metabolismo de los Lípidos , Masculino , Persona de Mediana Edad , Oxidación-ReducciónRESUMEN
BACKGROUND: Diagnostic assessment of lung function necessitates up-to-date reference values. The aim of this study was to estimate reference values for spirometry for the Finnish population between 18 and 80 years and to compare them with the existing Finnish, European and the recently published global GLI2012 reference values. METHODS: Spirometry was performed for 1380 adults in the population-based FinEsS studies and for 662 healthy non-smoking volunteer adults. Detailed predefined questionnaire screening of diseases and symptoms, and quality control of spirometry yielded a sample of 1000 native Finns (387 men) healthy non-smokers aged 18-83 years. Sex-specific reference values, which are estimated using the GAMLSS method and adjusted for age and height, are provided. RESULTS: The predicted values for lung volumes are larger than those obtained by GLI2012 prediction for the Caucasian subgroup for forced vital capacity (FVC) by an average 6·2% and 5·1% and forced expiratory volume in 1 s (FEV1) by an average 4·2% and 3·0% in men and women, respectively. GLI2012 slightly overestimated the ratio FEV1/FVC with an age-dependent trend. Most reference equations from other European countries, with the exception of the Swiss SAPALDIA study, showed an underestimation of FVC and FEV1 to varying degrees, and a slight overestimation of FEV1/FVC. CONCLUSION: This study offers up-to-date reference values of spirometry for native Finns with a wide age range. The GLI2012 predictions seem not to be suitable for clinical use for native Finns due to underestimation of lung volumes.
Asunto(s)
Pulmón/fisiología , Respiración , Espirometría/normas , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Femenino , Finlandia , Volumen Espiratorio Forzado , Humanos , Mediciones del Volumen Pulmonar , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Valores de Referencia , Reproducibilidad de los Resultados , Factores Sexuales , Encuestas y Cuestionarios , Capacidad Vital , Adulto JovenRESUMEN
The association between clinical autonomic dysfunction and myocardial MIBG accumulation was investigated. The study groups comprised 6 male diabetic patients with autonomic neuropathy (ANP+ group), 6 male diabetic patients without autonomic neuropathy (ANP-group), and 6 male nondiabetic control subjects. The mean age was comparable in all groups, and the subjects had no evidence of coronary heart disease. Reduced heart-rate variation in a deep-breathing test was used as a criterion for autonomic neuropathy. Immediately after injection, the peak net influx rate of MIBG to myocardium was significantly (P less than 0.05) reduced in both diabetic groups. At 6 hr after MIBG injection, the MIBG uptake of the myocardium was significantly (P less than 0.05) smaller in the ANP+ group than in the control group. In the ANP- group, the MIBG uptake of the myocardium was between that of the ANP+ group and that of the control group. Our data show that reduced myocardial MIBG accumulation is associated with autonomic dysfunction in diabetic patients, but it can occur to a lesser extent also in diabetic patients without apparent autonomic neuropathy. The measurement of the myocardial MIBG accumulation is a promising new method to detect cardiac sympathetic nervous dysfunction in diabetic patients.
Asunto(s)
Diabetes Mellitus/fisiopatología , Neuropatías Diabéticas/diagnóstico , Yodobencenos , Sistema Nervioso Simpático/fisiología , Simpaticolíticos , 3-Yodobencilguanidina , Sistema Nervioso Autónomo/fisiología , Catecolaminas/sangre , Neuropatías Diabéticas/sangre , Neuropatías Diabéticas/fisiopatología , Frecuencia Cardíaca/fisiología , Humanos , Inyecciones Intravenosas , Radioisótopos de Yodo , Yodobencenos/administración & dosificación , Yodobencenos/análisis , Contracción Isométrica/fisiología , Masculino , Persona de Mediana Edad , Miocardio/química , Miocardio/metabolismo , Simpaticolíticos/administración & dosificación , Simpaticolíticos/análisisRESUMEN
When dual-energy X-ray absorptiometry (DXA) instruments are replaced, it is essential to determine if systematic differences in measurements occur. As a part of the Kuopio Osteoporosis Risk Factor and Prevention study (N=14,220), a group of women, aged 36 to 69 yr underwent anteroposterior lumbar spine L2 to L4 (n=89) and proximal femur scans (n=88) by the Lunar DPX and DPX-IQ, respectively, during the same visit. A high linear association (r from 0.944 to 0.989, p<0.001) between the two scanners was established for lumbar spine and proximal femur bone mineral density (BMD). The average DPX values for BMD were 1.1% and 2.0% higher than those of DPX-IQ for the lumbar spine (p<0.001) and Ward's triangle (p=0.001), respectively. Femoral neck BMD values by the DPX were 1.4% lower (p<0.001) compared to DPX-IQ. The difference between trochanter BMD results (0.1%) was not significant (p=0.809). In the femoral neck and trochanter, but not in the lumbar spine or Ward's triangle, the differences in BMD values of the two machines were found to depend on body mass index. After linear formulas based on simple and multivariate linear regression analyses were calculated, the differences were negligible, enabling objective comparison of longitudinal measurements.
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Absorciometría de Fotón/normas , Densidad Ósea , Fémur/diagnóstico por imagen , Vértebras Lumbares/diagnóstico por imagen , Adulto , Anciano , Calibración , Femenino , Humanos , Persona de Mediana Edad , Osteoporosis/diagnóstico por imagen , Análisis de Regresión , Reproducibilidad de los ResultadosRESUMEN
The aim of the study was to characterize the electromechanical properties of skeletal muscle during isometric loading as well as to assess the potential of estimating intramuscular pressure by electrical and mechanical methods. Simultaneous electromyography (EMG), mechanical myotonometry (MYO, frequency and decrement of decay) and intramuscular pressure (IMP) measurements were conducted at rest and during short-term and long-term isometric contractions in patients with chronic pain in the anterior leg or dorsal forearm. The EMG amplitude and MYO(freq) accounted significantly (24-73%, p < 0.0001) for the variations in the IMP under short-term isometric loading. The IMP, EMG and MYO(freq) increased linearly with the relative muscle load (r = 0.868-0.993, p < 0.05). Mean values of EMG amplitudes at the contraction levels of 75% and 100% maximum voluntary contraction (MVC) and MYO(freq) values at all contraction levels (0-100% MVC) were higher for subjects with pathological values of IMP than for those with IMP values in the normal range. Total changes in IMP and EMG amplitude during 1 min isometric contraction were linearly interrelated (r = 0.747, p < 0.0001). We conclude that both surface electromyography and myotonometry parameters are indicative of intramuscular pressure, but neither of these methods can be used alone to diagnose non-invasively chronic compartment syndrome with acceptable accuracy.
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Síndromes Compartimentales/diagnóstico , Síndromes Compartimentales/fisiopatología , Diagnóstico por Computador/métodos , Electromiografía/métodos , Contracción Isométrica , Manometría/métodos , Músculo Esquelético/fisiopatología , Adolescente , Adulto , Fenómenos Biomecánicos/métodos , Femenino , Humanos , Masculino , Presión , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Estrés MecánicoRESUMEN
OBJECTIVE: To evaluate whether plasma fibrinogen concentration is correlated with the level of physical activity and aerobic power in patients with newly diagnosed non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS: We studied 78 middle-aged (54 +/- 6 years, mean +/- SD), obese (body mass index [BMI] 32+/- 5 kg/m2) patients (45 men and 33 women) before and after a 12-month treatment period consisting of either conventional treatment given by community health centers or intensified dietary and exercise education given by a university outpatient clinic. Plasma fibrinogen concentration was measured by using a coagulometer. Physical activity was assessed by a questionnaire, and the patients were classified into a sedentary group or moderately or intensively exercising groups. Aerobic power (maximum oxygen uptake [VO2max], anaerobic threshold [VO2at]) was measured by direct breath-by-breath technique. RESULTS: At baseline, the sedentary patients had higher fibrinogen concentration than those with moderate or high physical activities (3.8 +/- 0.8 vs. 3.3 +/- 0.7 g/l, P < 0.01). Both VO2max and VO2at (ml.min-1.kg-1) showed an inverse linear correlation with fibrinogen (r = -0.38, P < or = 0.001, and r = -0.29, P < 0.01, respectively). In the stepwise multiple regression analysis, BMI, VO2 (ml/min), and smoking were the only significant independent factors explaining 23% of the variance in fibrinogen concentration. In sedentary patients, poor glycemic control was related with high fibrinogen concentration. During the follow-up period, patients maintained, on the average, good to moderate glycemic control. The originally sedentary group showed a decrease in fibrinogen concentration (to 3.3 +/- 0.7 g/l, P < or = 0.001) that reached the same level that the physically more active groups had at baseline. This change was associated with improved glycemic control, but not with any of the other assessed factors, including fatty acid composition of serum lipids reflecting dietary intake of fats. CONCLUSIONS: In addition to BMI and smoking, low reported physical activity and low aerobic power are independently associated with high plasma fibrinogen concentration in newly diagnosed NIDDM.
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Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/fisiopatología , Ejercicio Físico/fisiología , Fibrinógeno/análisis , Adulto , Índice de Masa Corporal , Terapia Combinada , Diabetes Mellitus Tipo 2/terapia , Dieta con Restricción de Grasas , Metabolismo Energético/fisiología , Ácidos Grasos/sangre , Femenino , Humanos , Lípidos/sangre , Masculino , Persona de Mediana Edad , Análisis de Regresión , Fumar/efectos adversos , Factores de TiempoRESUMEN
OBJECTIVE: Global myocardial uptake of 123I-metaiodobenzylguanidine (MIBG) has been shown to be decreased in diabetic patients with autonomic neuropathy, indicating cardiac sympathetic dysfunction. However, possible differences in myocardial MIBG distribution between NIDDM and IDDM diabetic patients are not known. RESEARCH DESIGN AND METHODS: Regional myocardial distribution of 123I-MIBG was studied in seven male IDDM patients (age 45 +/- 2 years, duration of diabetes 30 +/- 3 years, means +/- SE) and 13 NIDDM patients (8 men, 5 women, age 59 +/- 2 years, duration of diabetes 10 +/- 1 years). A dual-tracer single-photon emission tomography was carried out with 123I-MIBG and 99mTc-methoxyisobutylisonitrrile to asses simultaneously myocardial sympathetic innervation and perfusion at rest. Conventional autonomic nervous function tests, power spectral analysis of heart rate variability, and echocardiography were performed for assessments of autonomic function and cardiac dimensions and function. RESULTS: Autonomic nervous function tests and echocardiography showed similar results in IDDM and NIDDM patients. Despite this, global myocardial MIBG uptake (0.43 +/- 0.04 vs. 0.59 +/- 0.06, P = 0.03) and MIBG heart-to-liver ratio (0.59 +/- 0.03 vs. 0.68 = 0.03, P = 0.05) were lower in NIDDM compared with IDDM patients. Regional distribution of MIBG uptake and regional MIBG/perfusion ratio revealed significantly reduced uptake in NIDDM patients especially in the inferoposterior segments of the left ventricle compared with IDDM patients. Difference in age between NIDDM and IDDM patients did not explain the results. CONCLUSIONS: Reduced myocardial MIBG uptake was found in NIDDM patients compared with the uptake in IDDM patients, particularly involving inferoposterior segments. Regional sympathetic damage not detectable with conventional autonomic function tests is relatively common in NIDDM.
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Sistema Nervioso Autónomo/fisiopatología , Diabetes Mellitus Tipo 1/fisiopatología , Diabetes Mellitus Tipo 2/fisiopatología , Corazón/diagnóstico por imagen , Corazón/inervación , Desnervación Muscular , 3-Yodobencilguanidina , Adulto , Anciano , Presión Sanguínea , Medios de Contraste , Ecocardiografía , Epinefrina/sangre , Femenino , Frecuencia Cardíaca , Humanos , Radioisótopos de Yodo , Yodobencenos , Masculino , Persona de Mediana Edad , Norepinefrina/sangre , Tecnecio Tc 99m Sestamibi , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
Single photon emission computed tomography (SPECT) at 6 and 12 months and dual-energy X-ray absorptiometry (DXA) at 0, 6, and 12 months were performed prospectively in 15 patients who had undergone uncemented total hip arthroplasty (THA) without any complications. Periprosthetic bone mineral density (BMD) decreased significantly in all regions of interests (ROIs) during 1 year of follow-up. The greatest annual decrease was found in the lesser trochanter region (22.1%). From 6-12 months, SPECT activity in the operated side decreased significantly (10-24%) in all ROIs, with the exception of the medial cortex ROI. In contrast, increases (8-36%) were found in the contralateral side. At 12 months, the operated versus control difference was still 10% in the lesser trochanter ROI, but as much as about 70% in the greater trochanter and tip ROIs. The decrease in BMD was significantly related to an increase in SPECT activity in the lesser trochanter region (r = -0.589, p < 0.05). In conclusion, increased periprosthetic SPECT activity seems to be associated with increased bone loss. We suggest that increased SPECT activity and subsequent bone loss reflect altered stress distribution and bone remodeling in the femur after prosthesis implantation.
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Absorciometría de Fotón , Densidad Ósea/fisiología , Remodelación Ósea/fisiología , Prótesis de Cadera , Tomografía Computarizada de Emisión de Fotón Único , Cementos para Huesos , Femenino , Fémur/fisiopatología , Humanos , Masculino , Estudios ProspectivosRESUMEN
Nineteen patients with acute ischemic stroke (<24 hours) underwent diffusion-weighted and perfusion-weighted (PWI) magnetic resonance imaging at the acute stage and 1 week later. Eleven patients also underwent technetium-99m ethyl cysteinate dimer single-photon emission computed tomography (SPECT) at the acute stage. Relative (ischemic vs. contralateral control) cerebral blood flow (relCBF), relative cerebral blood volume, and relative mean transit time were measured in the ischemic core, in the area of infarct growth, and in the eventually viable ischemic tissue on PWI maps. The relCBF was also measured from SPECT. There was a curvilinear relationship between the relCBF measured from PWI and SPECT (r = 0.854; P < 0.001). The tissue proceeding to infarction during the follow-up had significantly lower initial CBF and cerebral blood volume values on PWI maps (P < 0.001) than the eventually viable ischemic tissue had. The best value for discriminating the area of infarct growth from the eventually viable ischemic tissue was 48% for PWI relCBF and 87% for PWI relative cerebral blood volume. Combined diffusion and perfusion-weighted imaging enables one to detect hemodynamically different subregions inside the initial perfusion abnormality. Tissue survival may be different in these subregions and may be predicted.
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Isquemia Encefálica/diagnóstico por imagen , Circulación Cerebrovascular , Imagen por Resonancia Magnética/métodos , Tomografía Computarizada de Emisión de Fotón Único/normas , Enfermedad Aguda , Anciano , Infarto Cerebral/diagnóstico por imagen , Difusión , Femenino , Humanos , Imagen por Resonancia Magnética/normas , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Accidente Cerebrovascular/diagnóstico por imagenRESUMEN
UNLABELLED: In acute ischemic stroke, the infarcted core is surrounded by a zone of tissue that has decreased perfusion. Some of this tissue may be salvaged by prompt, effective treatment. Diffusion-weighted MRI is sensitive in detecting the infarcted tissue, whereas SPECT also detects the hypoperfused tissue around the infarcted core. We studied the potential of combined diffusion-weighted MRI and SPECT to predict infarct growth and clinical outcome in patients not receiving thrombolytic treatment. METHODS: Sixteen patients with acute stroke were examined consecutively with diffusion-weighted MRI and 99mTc-ethyl cysteinate dimer (99mTc-ECD) SPECT within 24 h of the onset of symptoms. Follow-up diffusion-weighted MRI was performed on the second day and after 1 wk. The volumes of infarcted and hypoperfused brain tissue were measured from diffusion-weighted MRI and SPECT, respectively. The volume difference between the hypoperfused and infarcted tissue on the first day was compared with the possible increase in infarct volume during the follow-up. Each patient's neurologic status was assessed with the National Institutes of Health Stroke Scale (NIHSS). RESULTS: The volume of infarcted tissue increased from 48 +/- 54 cm3 (mean +/- SD) on the first day to 88 +/- 93 cm3 on the second day (P = 0.001) and to 110 +/- 121 cm3 at 1 wk (P = 0.001). The volume of hypoperfused tissue on the first day was significantly greater than the infarct volume (102 +/- 135 cm3; P = 0.001). The volume difference between the hypoperfused and infarcted tissue on the first day correlated significantly with the infarct growth between the first day and 1 wk (r = 0.71; P < 0.01). Between the first day and 1 wk, the increase of the infarct volume correlated significantly with the change in the NIHSS (r = 0.54; P < 0.05). CONCLUSION: A large hypoperfusion zone around the infarct core in the acute phase of ischemic stroke predicts the infarct growth during the first week, and this correlates significantly with the change in the neurologic status of the patient. Combined diffusion-weighted MRI and SPECT performed within 24 h after the onset of symptoms can be useful in the evaluation of acute stroke to predict infarct growth.
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Isquemia Encefálica/complicaciones , Encéfalo/patología , Infarto Cerebral/diagnóstico , Imagen por Resonancia Magnética , Tomografía Computarizada de Emisión de Fotón Único , Enfermedad Aguda , Anciano , Anciano de 80 o más Años , Encéfalo/diagnóstico por imagen , Infarto Cerebral/diagnóstico por imagen , Infarto Cerebral/etiología , Circulación Cerebrovascular , Cisteína/análogos & derivados , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Compuestos de Organotecnecio , RadiofármacosRESUMEN
Left ventricular (LV) function and dimensions were assessed with Doppler and M-mode echocardiography in 26 men and 17 women with newly diagnosed non-insulin-dependent diabetes mellitus, and in 13 healthy control men and 13 women. The diabetic men had lower peak filling rate normalized to mitral stroke volume than the control men (mean +/- standard error of the mean, 4.2 +/- 0.1 vs 4.9 +/- 0.3 stroke volume/s, p less than 0.01). The diabetic women had increased LV mass (102 +/- 12 vs 86 +/- 8 g/m2, p less than 0.01) and decreased fractional shortening (34 +/- 1 vs 38 +/- 1%, p less than 0.05) when compared with control women. At 3 and 15 months, 23 diabetic men and 15 women were reexamined. Concomitantly with decreasing blood glucose levels, fractional shortening improved mainly during the first 3 months and was significantly higher in both diabetic men (36 +/- 2 vs 30 +/- 2%, p less than 0.05) and women (38 +/- 1 vs 34 +/- 1%, p less than 0.05) at 15 months than at baseline. In the diabetic men, peak filling rate increased from 4.3 +/- 0.1 stroke volume/s at baseline to 4.8 +/- 0.2 stroke volume/s at 15 months (p less than 0.05). At 15 months, peak filling rate was correlated (r = 0.61, p less than or equal to 0.001) with autonomic nervous function assessed as heart rate variability during deep breathing test in diabetic men who also showed an inverse correlation between LV hypertrophy and heart rate variability throughout the follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)
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Diabetes Mellitus Tipo 2/fisiopatología , Ecocardiografía , Función Ventricular Izquierda , Adulto , Diabetes Mellitus Tipo 2/diagnóstico por imagen , Diabetes Mellitus Tipo 2/patología , Femenino , Estudios de Seguimiento , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/patología , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , SístoleRESUMEN
Myocardial infarction damages sympathetic nerve fibers coursing through the infarct zone. In this study we investigated whether coronary artery disease without myocardial infarction results in sympathetic denervation. We examined 12 patients without a history of previous myocardial infarction and 19 postinfarction patients. 1-123 metaiodobenzylguanidine (MIBG) and technetium-99m sestamibi (MIBI) single-photon emission tomography were conducted at rest to determine the extent of denervated myocardium and the extent of myocardium with reduced perfusion, respectively. In addition, myocardial perfusion during exercise was assessed with MIBI. A MIBG or MIBI defect was determined as being regional uptake of < or =30% of the maximal myocardial activity. All but 1 patient without previous infarction had MIBG defects. MIBG defects (10.3 +/- 8.5% of left ventricular mass) were significantly larger than MIBI defects at rest (2.4 +/- 3.2%, p <0.001) and during exercise (4.8 +/- 6.1%, p <0.05). In multiregression analysis, the size of an MIBG defect was associated with severity of coronary stenoses (> or =90% of lumen diameter; p <0.05), but not with age, number of significant stenoses (> or =50% of lumen diameter), left main disease, functional class, left ventricular ejection fraction, angina pectoris, maximal ST depression, or mean workload during exercise test. MIBG and MIBI defects were significantly larger in patients with severe coronary stenoses than in patients with moderate stenoses (50% to 89% of lumen diameter) (16.4 +/- 8.9% vs 6.0 +/- 5.2% [p <0.05] and 5.0 +/- 3.1% vs 0.6 +/- 1.3% [p <0.001], respectively). The size of MIBG (16.1 +/- 8.9%) and MIBI defects (7.3 +/- 6.5%) at rest in postinfarction patients did not differ from patients with severe stenoses. Our study demonstrates that cardiac adrenergic tissue is very sensitive to ischemia and that regional cardiac sympathetic denervation can occur in patients with stable coronary artery disease without previous myocardial infarction.
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Enfermedad Coronaria/patología , Corazón/inervación , Sistema Nervioso Simpático/patología , Adulto , Anciano , Enfermedad Coronaria/fisiopatología , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Miocardio/patología , Radiofármacos , Tecnecio Tc 99m Sestamibi , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
The incidence of permanent atrioventricular conduction defects (CDs) caused by coronary artery bypass grafting (CABG) varies from 5% to 43% if cold crystalloid or blood cardioplegia is used for myocardial preservation. However, the long-term effects of CDs on clinical outcome are not well known. In this study we compared the outcome of 52 patients with permanent CABG-associated CDs (CD+) to 47 patients without CDs (CD-) after a 3-year follow-up. Recovery of CDs was found in 2 patients during the follow-up. There were no significant differences between groups in late mortality, cardiac or neurologic events, or capability to work. Although exercise capacity was similar, the exercise-limiting symptom more often was chest pain or dyspnea in the CD+ group than in the CD- group (p = 0.001). Left ventricular ejection fractions at rest and at 50-W workload level were lower in the CD+ group (p = 0.03 to 0.05). In addition, CD+ patients with left bundle branch block or cardiac pacemaker had significantly lower ejection fraction at maximal workload level than patients without CDs (p = 0.03). No significant differences were observed between the groups in the potential risk for ventricular arrhythmias according to signal-averaged electrocardiograms. In conclusion, the clinical outcome of patients with CDs after CABG operations is almost comparable to those without CDs during a 3-year follow-up. However, patients with CDs have lower left ventricular systolic function and more often have chest pain or dyspnea as the exercise-limiting symptom than patients without CDs.
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Arritmias Cardíacas/etiología , Puente de Arteria Coronaria/efectos adversos , Anciano , Arritmias Cardíacas/fisiopatología , Electrocardiografía , Prueba de Esfuerzo , Femenino , Imagen de Acumulación Sanguínea de Compuerta , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Procesamiento de Señales Asistido por Computador , Función Ventricular IzquierdaRESUMEN
In cross-sectional studies of asymptomatic diabetic patients, multiple abnormalities in left ventricular (LV) function have been found. Long-term significance of these abnormalities is unknown because follow-up studies have not been previously performed. LV ejection fraction (EF) by radionuclide angiocardiography was examined in middle-aged control subjects (n = 44), in patients with insulin-dependent (IDDM) (n = 32) and non-insulin-dependent (NIDDM) (n = 32) diabetes mellitus at baseline and after 4-year follow-up. At baseline, all study subjects were free from cardiovascular disease. LVEF at rest did not differ between the groups at baseline. The decrease in LVEF at rest during follow-up was 1.1 +/- 1.1% (mean +/- SEM) in control subjects, 3.1 +/- 1.3% (p = NS, compared with control subjects) in patients with IDDM, and 7.2 +/- 1.4% (p < 0.01) in patients with NIDDM. At follow-up examination, abnormally low LVEF at rest (< 50%) was found in 7% of control subjects, 13% of patients with IDDM (p = NS), and in 31% of patients with NIDDM (p < 0.05). Compared with control subjects, the prevalence of an abnormal LVEF response to exercise (an increase by < 5%, or a decrease) was higher in diabetic groups at both examinations. This prevalence increased in control subjects from 10% at baseline to 26% at follow-up examination.(ABSTRACT TRUNCATED AT 250 WORDS)
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Diabetes Mellitus Tipo 1/fisiopatología , Diabetes Mellitus Tipo 2/fisiopatología , Sístole/fisiología , Función Ventricular Izquierda/fisiología , Anciano , Glucemia/análisis , Presión Sanguínea/fisiología , Causas de Muerte , Enfermedad Coronaria/complicaciones , Enfermedad Coronaria/fisiopatología , Estudios Transversales , Muerte Súbita Cardíaca , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/diagnóstico por imagen , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/diagnóstico por imagen , Prueba de Esfuerzo , Femenino , Estudios de Seguimiento , Hemoglobina Glucada/análisis , Frecuencia Cardíaca/fisiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Angiografía por RadionúclidosRESUMEN
RATIONALE: There is evidence that abnormalities in brain dopamine, norepinephrine and serotonin metabolism may play an important role in binge eating. Serotonin-active antidepressant drugs have also been found to decrease binge eating. OBJECTIVE: We investigated serotonin transporter binding in obese binge-eating women. Eleven obese binge-eating and seven obese control women participated in the study. The subjects were not taking any medication known to affect serotonin (5-HT) transporters. METHODS: We used single-photon emission tomography (SPECT) with the radioligand 123I-labelled nor-beta-CIT, which specifically labels 5-HT transporters. RESULTS: Obese binge-eating women showed significantly decreased 5-HT transporter binding in the mid-brain compared with obese controls (2.1 +/- 0.5 versus 2.9 +/- 0.5, respectively). CONCLUSIONS: SPECT imaging with a ligand specific for 5-HT transporters can be used to assess altered serotonin transporter binding in the living human brain. The results tentatively suggest that 5-HT transporter binding is decreased in binge-eating women.