RESUMEN
The aim of this study was to establish the relation between noninvasive Doppler ultrasound assessments of aortic compliance, based on "foot-to-foot" aortic pulse wave velocity measurements, and presumed atherosclerotic load in patients with vascular disease and/or diabetes mellitus. One hundred ten patients with vascular disease and/or diabetes mellitus (arteriopaths) underwent measurement of in vivo aortic compliance using Doppler ultrasound. Demographic data on these subjects were recorded along with details of cardiovascular risk factors and events. Aortic compliance values were compared with data from 51 age-matched healthy, asymptomatic subjects putatively free of vascular disease (controls). Data are expressed as mean+/-SD. Arteriopaths were aged 64.1+/-8.4 years and had total cholesterol levels of 5.9+/-1.1 mmol/L and aortic compliance of 0.78+/-0.42%/10 mm Hg [1.33 kPa]. Most arteriopaths had 2 or more cardiovascular risk factors and events: diabetes (n=41), hypertension (n=45), smoking (n=86), cerebrovascular/transient ischemic event (n=13), myocardial infarction (n=44), angina (n=51), and/or peripheral vascular disease (n=33). Controls were aged 64.3+/-12.1 years with total cholesterol of 6.1+/-1.1 mmol/L and aortic compliance of 1.14+/-0.46%/10 mm Hg [1.33 kPa] (P<0.002 versus arteriopaths). Subset analysis revealed that patients with the greatest number of cardiovascular risk factors and events (n=5) had the stiffest aortas (aortic compliance, 0.58+/-0.15%/10 mm Hg [1.33 kPa]) compared with those patients with the median and mean (n=2) number of risk factors and events (aortic compliance, 0.80+/-0.50%/10 mm Hg [1.33 kPa]; P<0.02). The data suggest that a significant inverse relation exists between presumed atherosclerotic load (as assessed by the number of cardiovascular risk factors and events) and aortic compliance determined noninvasively based on aortic pulse wave velocity measurements. If these findings are confirmed by prospective, longitudinal follow-up studies, such measurements may prove useful as a noninvasive marker of vascular risk.
Asunto(s)
Aorta/diagnóstico por imagen , Enfermedades Cardiovasculares , Diabetes Mellitus/fisiopatología , Enfermedades Vasculares/fisiopatología , Adulto , Anciano , Aorta/fisiopatología , Presión Sanguínea , Estudios de Casos y Controles , Colesterol/sangre , Adaptabilidad , Complicaciones de la Diabetes , Diabetes Mellitus/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pulso Arterial , Reproducibilidad de los Resultados , Factores de Riesgo , Ultrasonografía Doppler , Enfermedades Vasculares/complicaciones , Enfermedades Vasculares/diagnóstico por imagenRESUMEN
Hormones such as melatonin whose serum concentrations vary seasonally have been previously implicated in the growth of breast cancer. The present study was undertaken to identify possible seasonal variation in a range of mammotrophic hormones which could exert a chronobiologic influence in women with breast tumours. Fifteen premenopausal women with a history of previous breast cancer (BC subjects) and 10 control women underwent 2-hourly serum sampling for 24 h at both summer and winter solstice for measurement of melatonin, growth hormone (GH), insulin-like growth factor-I (IGF-I), cortisol, prolactin and thyrotrophin (TSH). Hormone secretion at the different seasons was compared by measuring the area under the 24 h serum hormone concentration x time curves and by time series analysis of summer-to-winter differences in hormone concentration. Control women had significantly higher GH and IGF-I levels in summer compared to winter and significantly higher cortisol secretion in winter than summer. In contrast, BC women had no significant seasonal difference in IGF-I concentrations and had a reversal of the normal seasonal pattern of melatonin secretion, although seasonal changes in GH production were similar to controls. Prolactin and TSH showed no significant summer/winter variation in either group. Thus, seasonal variations in hormone secretion seen in normal women were, with exception of GH, absent or reversed in women with a previous history of breast cancer. As a result these individuals may be exposed to an asynchronous hormonal stimulus which could influence tumour growth. These changes could reflect a constitutional abnormality in BC women or may have been induced by the previous breast tumour.
Asunto(s)
Neoplasias de la Mama/fisiopatología , Hormonas/metabolismo , Estaciones del Año , Femenino , Hormona de Crecimiento Humana/metabolismo , Humanos , Hidrocortisona/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Melatonina/metabolismo , Persona de Mediana Edad , Premenopausia , Prolactina/metabolismo , Tirotropina/metabolismoRESUMEN
OBJECTIVE: While the effects of age on the growth hormone/insulin-like growth factor (IGF) axis are well documented, the influence of ethnic background is unknown. The differences in IGF and IGF binding proteins (IGFBPs) were investigated in two ethnic groups. DESIGN: A cross-sectional study of an age-selected cohort of healthy, normoglycaemic, non-obese Caucasian (C) and Asian (A) subjects. PATIENTS: Fifty-three (27 C, 26 A) subjects with a mean age (+/- SD) of 20.6 +/- 0.8 years were studied. MEASUREMENTS: Fasting measurements of glucose, insulin, IGF-I, IGF-II, IGFBP-1 and IGFBP-3. Western ligand blotting and immunoblotting with IGFBP-2 and IGFBP-3 of serum samples. RESULTS: There were no significant differences in IGF-I levels between Caucasian and Asian subjects (C 218 +/- 55 vs A 229 +/- 40 micrograms/l; P = 0.44). IGF-II (C 707 +/- 110 vs A 583 +/- 75 micrograms/l; P < 0.0001) and IGFBP-3 (C 5.9 +/- 1.2 vs A 5.12 +/- 1.17 mg/l; P = 0.01) levels were significantly higher in Caucasian subjects. Immunoblotting of ligand blots revealed no protease activity on either IGFBP-3 or IGFBP-2 to account for these ethnic differences. CONCLUSIONS: Ethnic differences in IGFBP-3 and associated IGF-II levels may affect the inter-relationships of IGFs and their binding proteins and need to be considered when interpreting IGF data on growth and metabolism.
Asunto(s)
Pueblo Asiatico , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Factor II del Crecimiento Similar a la Insulina/análisis , Población Blanca , Adulto , Estudios Transversales , Femenino , Humanos , Immunoblotting , Proteína 2 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Factor I del Crecimiento Similar a la Insulina/análisis , MasculinoAsunto(s)
Aorta Torácica/fisiología , Ultrasonido , Adulto , Aorta Torácica/diagnóstico por imagen , Arteriosclerosis/etiología , Australia , Velocidad del Flujo Sanguíneo , Presión Sanguínea , China/etnología , Colesterol/sangre , Dieta , Elasticidad , Humanos , Hiperlipoproteinemia Tipo II/complicaciones , Lípidos/sangre , Masculino , Persona de Mediana Edad , Pulso Arterial , UltrasonografíaRESUMEN
OBJECTIVE: NIDDM is associated with stiffer arteries and an increased incidence of macrovascular disease. NIDDM has strong familial inheritance. We studied the associations of a family history of NIDDM with blood pressure-corrected aortic distensibility (Cp). RESEARCH DESIGN AND METHODS: Because age is a strong determinant of arterial distensibility, we studied an age-select cohort of 67 healthy normotensive normoglycemic young adults along with fasting measurements of glucose and insulin concentrations. Cp was calculated from noninvasive Doppler ultrasound measurements of pulse wave velocity along the descending thoracoabdominal aorta. RESULTS: The mean age of the subjects was 20.6 +/- 0.7 (mean +/- SD) years. A total of 22 subjects gave a positive family history of NIDDM in a parent or grandparent. Subjects with a positive family history of NIDDM had significantly less distensible (i.e., stiffer) aortas than their age- and sex-matched counterparts who gave no family history of NIDDM (Cp [dimensionless]: 0.22 +/- 0.04 vs. 0.25 +/- 0.04, P = 0.02). Subjects with a positive family history of NIDDM also had significantly higher fasting glucose (5.1 +/- 0.4 vs. 4.9 +/- 0.4 mmol/l, P = 0.009) and insulin (7.5 +/- 5.5 vs. 4.2 +/- 2.0 mU/l, P = 0.02) levels and BMIs (23.2 +/- 2.3 vs 21.1 +/- 2.5 kg/m2, P = 0.002). On multivariate regression analysis, family history of NIDDM (P = 0.03) was the only significant independent predictor of Cp. CONCLUSIONS: A positive family history of NIDDM is associated with decreased aortic distensibility in early adult life. The relevance of these observations to future cardiovascular events merits further investigation.
Asunto(s)
Aorta/fisiología , Presión Sanguínea , Diabetes Mellitus Tipo 2/genética , Adulto , Aorta/diagnóstico por imagen , Glucemia/análisis , Colesterol/sangre , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Estudios de Cohortes , Familia , Femenino , Humanos , Insulina/sangre , Masculino , Análisis Multivariante , Músculo Liso Vascular/diagnóstico por imagen , Músculo Liso Vascular/fisiología , Núcleo Familiar , Valores de Referencia , Análisis de Regresión , Triglicéridos/sangre , Ultrasonografía DopplerRESUMEN
1. Non-invasive aortic compliance measurements have been used previously to assess the distensibility of the aorta in several pathological conditions associated with increased cardiovascular risk. We set out to establish whether aortic compliance is abnormal in patients with stroke. 2. Pulse wave velocity measurements of thoraco-abdominal aortic compliance were made in 20 stroke patients and 25 age- and sex-matched hospitalized, non-stroke control subjects putatively free of cardiovascular disease. Since compliance varies with non-chronic changes in blood pressure, a blood pressure corrected index of aortic distensibility, Cp, was calculated. 3. Aortic compliance was significantly reduced in patients with stroke compared with non-stroke control subjects (0.46 +/- 0.27 versus 0.86 +/- 0.34%/10 mmHg, P < 0.0002), corresponding with higher values for pulse wave velocity. Stroke patients also had significantly higher systolic and diastolic blood pressures (P < 0.02 and P < 0.002 respectively) and total cholesterol levels (P < 0.004) than the control subjects. Calculation of Cp did not alter the observation of stiffer aortas in the stroke cohort (P < 0.0007). 4. In both stroke patient and control cohorts, as expected, inverse trends were observed between aortic compliance and blood pressure. Also as expected, in the control group Cp values did not show a relationship with blood pressure (r = 0.02, P = 0.092, not significant). However, in the stroke cohort a marked dependence of Cp on blood pressure was observed (r = -0.48, P = 0.03). 5. Transoesophageal echocardiographic studies have recently identified advanced atherosclerosis in the ascending aorta as a possible source of cerebral emboli and an independent risk factor for ischaemic stroke.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Aorta/fisiopatología , Trastornos Cerebrovasculares/fisiopatología , Anciano , Presión Sanguínea/fisiología , Adaptabilidad , Femenino , Humanos , MasculinoAsunto(s)
Personajes , Obesidad/historia , Historia Medieval , Humanos , Obesidad/tratamiento farmacológico , EspañaRESUMEN
The metabolic and cardiovascular effects of recombinant human IGF-I were compared to insulin in six normal subjects. Subjects were studied twice and intravenously received an infusion of [6,6-2H2]glucose (0-480 min) and in random order either IGF-I 20 micrograms kg-1 h-1 (43.7 pmol kg-1 min-1 or insulin 0.5 mU kg-1 min-1 (3.4 pmol kg-1 min-1) with an euglycaemic clamp. One subject was withdrawn following a serious adverse event. During the IGF-I infusion glucose appearance rate (Ra) decreased from 1.79 +/- 0.13 at baseline (150-180 min) to 0.35 +/- 0.26 mg kg-1 min-1 (P < 0.01) at 360 min, and glucose utilization rate (Rd) increased from 1.79 +/- 0.28 to 4.17 +/- 0.84 mg kg-1 min-1 (P < 0.01). There was no change in free fatty acids (FFA) and an increase (percentage change from pre-infusion mean) in cardiac output +l37.3% +/- 9% (P < 0.01), heart rate +13% +/- 2% (P < 0.01) and stroke volume +21% +/- 7% (P < 0.05). During the insulin infusion glucose Ra decreased from 1.89 +/- 0.13 to 0.34 +/- 0.33 mg kg-1 min-1 (P < 0.01) and FFA from 0.546 mmol l-1 to 0.198 mmol l-1 (P < 0.01), glucose Rd increased from 1.89 +/- 0.18 to 5.41 +/- 1.47 mg kg-1 min-1 (P < 0.01) and there were no significant changes in the cardiovascular variables.