RESUMEN
BACKGROUND: Elevated levels of cardiac troponin T has been observed in patients seeking care at the emergency department (ED) presenting with chest pain but without myocardial infarction (MI). The clinical importance of this observation remains, however, still unclear. Our main aim was to study the role of cardiac troponin T in patients admitted to the emergency department with acute dyspnea, a group of patients with a high cardiovascular comorbidity, but no primary acute MI. POPULATION AND METHODS: Patients from the age of 18 seeking care at the ED for dyspnea, without an acute cardiac syndrome, and with a recorded assessment of high-sensitivity cardiac troponin T (hs-cTnT), were included (n = 1001). Patients were categorized into 3 groups by hs-cTnT level, i.e. <15, 15-100 and > 100 µg/l. Cox regression with Hazard Ratios (HRs) and 95% Confidence Intervals (CI) for 3-months mortality was performed, with adjustment for sex, age, respiratory frequency, saturation, CHF, renal disease, and BMI. RESULTS: Fully adjusted HRs (95% CI) for 3-month mortality, with hs-cTnT < 15 µg/l as reference level, showed for hs-cTnT 15-100 a HR of 3.682 (1.729-7.844), and for hs-cTnT > 100 a HR of 10.523 (4.465-24.803). CONCLUSION: Elevated hs-cTnT seems to be a relevant marker of poor prognosis in patients with acute dyspnea without MI and warrants further validation and clinical testing.
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Síndrome Coronario Agudo , Infarto del Miocardio , Humanos , Troponina T , Síndrome Coronario Agudo/diagnóstico , Disnea , Servicio de Urgencia en Hospital , BiomarcadoresRESUMEN
BACKGROUND: Circulating levels of TNF alpha receptor 1 (TNFR1) and 2 (TNFR2) are associated with increased long-term mortality and impaired kidney function. AIM: To study association between circulating levels of TNFR1 and TNFR2 and short-term mortality in patients with diabetes and dyspnea. POPULATION AND METHODS: Patients aged ≥ 18 years seeking at emergency department (ED) during daytime on weekdays between December 2013 and July 2018, with diabetes and acute dyspnea, identified at the triage process, were included. Participants (n = 291) were triaged according to Medical Emergency Triage and Treatment System-Adult score, and blood samples were collected. Association between TNFR1 and TNFR2, respectively, and 90-day mortality were estimated by Cox regression models adjusted for age, sex, BMI, creatinine and CRP. RESULTS: Univariate models showed significant associations between TNFR1 and TNFR2, respectively, and CRP, age and creatinine. TNFR1 and TNFR2 tended to be elevated in patients with the highest triage level, compared to patients with lower triage levels (ns). In longitudinal analyses, TNFR1 but not TNFR2 was associated with increased short-term mortality, HR adjusted for age, BMI and creatinine 1.43 (95% CI 1.07-1.91), but not in the model also adjusted for CRP, HR 1.29 (95% CI 0.94-1.77). In secondary analysis for quartile 4 versus quartiles 1-3 of TNFR1, corresponding HRs were 2.46 (95% CI 1.27-5.15) and 2.21 (95% CI 1.07-2.56). CONCLUSIONS: We found a trend for the association between circulating TNFR1 levels and short-term mortality in patients with diabetes and acute dyspnea at the ED, possibly suggesting an inflammatory pathway for the association.
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Diabetes Mellitus/diagnóstico , Diabetes Mellitus/mortalidad , Disnea/diagnóstico , Disnea/mortalidad , Receptores Tipo I de Factores de Necrosis Tumoral/sangre , Enfermedad Aguda , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Estudios Transversales , Diabetes Mellitus/sangre , Diabetes Mellitus/terapia , Disnea/sangre , Disnea/terapia , Servicio de Urgencia en Hospital , Femenino , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Factores de TiempoRESUMEN
BACKGROUND: Increased levels of circulating endostatin predicts cardiovascular morbidity and impaired kidney function in the general population. The utility of endostatin as a risk marker for mortality in the emergency department (ED) has not been reported. AIM: Our main aim was to study the association between plasma endostatin and 90-day mortality in an unselected cohort of patients admitted to the ED for acute dyspnea. Design Circulating endostatin was analyzed in plasma from 1710 adults and related to 90-day mortality in Cox proportional hazard models adjusted for age, sex, body mass index, oxygen saturation, respiratory rate, body temperature, C-reactive protein, lactate, creatinine and medical priority according to the Medical Emergency Triage and Treatment System-Adult score (METTS-A). The predictive value of endostatin for mortality was evaluated with receiver operating characteristic (ROC) analysis and compared with the clinical triage scoring system and age. RESULTS: Each one standard deviation increment of endostatin was associated with a HR of 2.12 (95% CI 1.31-3.44 pâ¯<â¯0.01) for 90-day mortality after full adjustment. Levels of endostatin were significantly increased in the group of patients with highest METTS-A (pâ¯<â¯0.001). When tested for the outcome 90-day mortality, the area under the ROC curve (AUC) was 0.616 for METTS-A, 0.701 for endostatin, 0.708 for METTS -A and age and 0.738 for METTS-A, age and levels of endostatin. CONCLUSIONS: In an unselected cohort of patients admitted to the ED with acute dyspnea, endostatin had a string association to 90-day mortality and improved prediction of 90-day mortality in the ED beyond the clinical triage scoring system and age with 3%.
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Disnea/mortalidad , Endostatinas/sangre , Enfermedad Aguda , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Estudios de Cohortes , Disnea/sangre , Servicio de Urgencia en Hospital , Femenino , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Triage is widely used in the emergency department (ED) in order to identify the patient's level of urgency and often based on the patient's chief complaint and vital signs. Age has been shown to be independently associated with short term mortality following an ED visit. However, the most commonly used ED triage tools do not include age as an independent core variable. The aim of this study was to investigate the relationship between age and 7- and 30-day mortality across the triage priority level groups according to Rapid Emergency Triage and Treatment System - Adult (RETTS-A), the most widely used triage tool in Sweden. METHODS: In this cohort, we included all adult patients visiting the ED at the Karolinska University Hospital, Sweden, from 1/1/2010 to 1/1/2015, n = 639,387. All patients were triaged according to the RETTS-A and subsequently separated into three age strata: 18-59, 60-79 and ≥ 80 years. Descriptive analyses and logistic regression was used. The primary outcome measures were 7- and 30-day mortality. RESULTS: We observed that age was associated with both 7 and 30-day mortality in each triage priority level group. Mortality was higher in older patients across all triage priority levels but the association with age was stronger in the lowest triage group (p-value for interaction = < 0.001). Comparing patients ≥80 years with patients 18-59 years, older patients had a 16 and 7 fold higher risk for 7 day mortality in the lowest and highest triage priority groups, respectively. The corresponding numbers for 30-d mortality were a 21- and 8-foldincreased risk, respectively. CONCLUSION: Compared to younger patients, patients above 60 years have an increased short term mortality across the RETTS-A triage priority level groups and this was most pronounced in the lowest triage level. The reason for our findings are unclear and data suggest a validation of RETTS-A in aged patients.
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Envejecimiento/patología , Servicio de Urgencia en Hospital , Tratamiento de Urgencia/mortalidad , Triaje , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Servicio de Urgencia en Hospital/tendencias , Tratamiento de Urgencia/tendencias , Femenino , Hospitales Universitarios/tendencias , Humanos , Masculino , Persona de Mediana Edad , Mortalidad/tendencias , Suecia/epidemiología , Triaje/tendencias , Adulto JovenRESUMEN
OBJECTIVE: The present study aimed to describe contact made by the elderly to Sweden's nationwide medical helpline, Healthcare Guide 1177 by Phone (HGP). Other objectives were to study potential gender differences and the association between different HGP referral levels and acute visits to hospital-based emergency departments and acute visits to primary care centres. DESIGN: De-identified data from recorded calls to HGP was extracted for analysis (n = 7477 for the oldest age group). Information about acute visits to emergency departments and to primary care reception was extracted from the patient administration system. SETTING: Västerbotten County, Sweden. SUBJECTS: Patients over 80 years. MAIN OUTCOME MEASURES: Calling and visiting frequencies for different age groups as well as reasons for contact and individual recommendations. RESULTS: The utilisation rate of the telephone advice service for the oldest age group was high, with an incidence rate of 533 per 1000 person-years. Women had a 1.17 times higher incidence rate compared with men. The most common reason for contact was drug-related questions (17% of all contacts). Calls that were recommended to care by a medical specialist correlated with total emergency department visits (r = 0.30, p < 0.05) and calls that were given advice correlated with acute primary healthcare visits (r = 0.38, p = 0.005). CONCLUSION: The high utilisation of the telephone advice service by the elderly gives the telephone advice service a unique ability to function as a gatekeeper to further healthcare. Our data suggest that with the telephone advice service's present guidelines, a significant proportion of all calls are being directed to further medical help. The high frequency of drug-related questions raises concerns about the elderly's medication regimens. Key points Patients over 80 years of age had a high utilisation of the telephone medical advice service compared with other age groups. Drug-related questions were the most common reason for contact. A significant proportion of all calls made resulted in further heatlhcare contacts.
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Control de Acceso , Servicios de Salud/estadística & datos numéricos , Conducta en la Búsqueda de Información , Teléfono , Factores de Edad , Anciano de 80 o más Años , Consejo , Atención a la Salud , Prescripciones de Medicamentos , Servicio de Urgencia en Hospital , Femenino , Personal de Salud , Humanos , Masculino , Atención Primaria de Salud , Factores Sexuales , Suecia , Telemedicina , TriajeRESUMEN
BACKGROUND: Rheumatoid arthritis (RA) is characterized by chronic synovitis and articular cartilage destruction. Increased activities of cathepsin S and cathepsin L, two potent cysteine proteases, are thought to play a role in the pathogenesis of the irreversible articular cartilage destruction. Nevertheless, data regarding the potential importance of the cathepsins as circulating biomarkers in RA patients are limited. METHOD: Subjects enrolled in this study are part of a larger study where patients from the three northern counties of Sweden diagnosed with early RA are followed in an ongoing prospective study. In total, 71 patients were included, along with 44 age- and sex-matched control subjects. Plasma levels of cathepsin S and L were analysed. Disease severity was assessed using the 28-joint count Disease Activity Score (DAS28). RESULTS: Plasma levels of cathepsin S and L were significantly increased in patients with RA compared to healthy controls (p < 0.05 for both). However, in the patients with RA, no association between the cathepsins and the severity of the disease, as characterized by DAS28, was observed (p > 0.51). CONCLUSIONS: Although circulating levels of cathepsin S and L were significantly increased in patients with recently diagnosed RA, our data do not support the notion that circulating levels of cathepsins are relevant biomarkers for disease severity.
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Artritis Reumatoide/sangre , Artritis Reumatoide/diagnóstico , Catepsina L/sangre , Catepsinas/sangre , Adulto , Artritis Reumatoide/fisiopatología , Biomarcadores/sangre , Cartílago Articular/fisiopatología , Estudios de Casos y Controles , Evaluación de la Discapacidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Suecia , Membrana Sinovial/fisiopatologíaRESUMEN
The purpose of this investigation was to explore interactions between adrenergic stimulation, glucocorticoids, and insulin on the lipolytic rate in isolated human adipocytes from subcutaneous and omental fat depots, and to address possible sex differences. Fat biopsies were obtained from 48 nondiabetic subjects undergoing elective abdominal surgery. Lipolysis rate was measured as glycerol release from isolated cells and proteins involved in lipolysis regulation were assessed by immunoblots. Fasting blood samples were obtained and metabolic and inflammatory variables were analyzed. In women, the rate of 8-bromo-cAMP- and isoprenaline-stimulated lipolysis was approximately 2- and 1.5-fold higher, respectively, in subcutaneous compared to omental adipocytes, whereas there was no difference between the two depots in men. Dexamethasone treatment increased the ability of 8-bromo-cAMP to stimulate lipolysis in the subcutaneous depot in women, but had no consistent effects in fat cells from men. Protein kinase A, Perilipin A, and hormone sensitive lipase content in adipocytes was not affected by adipose depot, sex, or glucocorticoid treatment. In conclusion, catecholamine and glucocorticoid regulation of lipolysis in isolated human adipocytes differs between adipose tissue depots and also between sexes. These findings may be of relevance for the interaction between endogenous stress hormones and adipose tissue function in visceral adiposity and the metabolic syndrome.
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Adipocitos/metabolismo , Agonistas Adrenérgicos/farmacología , Glucocorticoides/farmacología , Lipólisis/fisiología , 8-Bromo Monofosfato de Adenosina Cíclica/farmacología , Adolescente , Agonistas Adrenérgicos beta/farmacología , Adulto , Anciano , Anciano de 80 o más Años , Western Blotting , Proteínas Portadoras , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Dexametasona/farmacología , Femenino , Humanos , Isoproterenol/farmacología , Masculino , Síndrome Metabólico/metabolismo , Persona de Mediana Edad , Perilipina-1 , Cavidad Peritoneal/citología , Fosfoproteínas/metabolismo , Caracteres Sexuales , Esterol Esterasa/metabolismo , Grasa Subcutánea/citología , Adulto JovenRESUMEN
AIMS/HYPOTHESIS: The aim of this study was to explore whether fat cell size in human subcutaneous and omental adipose tissue is independently related to insulin action and adipokine levels. MATERIALS AND METHODS: Fat cells were prepared from abdominal subcutaneous biopsies obtained from 49 type 2 diabetic and 83 non-diabetic subjects and from omental biopsies obtained from 37 non-diabetic subjects. Cell size and insulin action on glucose uptake capacity in vitro were assessed in isolated fat cells. Insulin sensitivity in vivo was assessed with euglycaemic-hyperinsulinaemic clamps. Fasting blood samples were collected and adipokines and NEFA were measured. RESULTS: Negative correlations were found between subcutaneous fat cell size and insulin sensitivity assessed as M-value during clamp and as insulin action on glucose uptake in fat cells in vitro. This was seen in non-diabetic subjects after including age, sex and BMI in the analyses. No such relationship was found in type 2 diabetic subjects. In both groups, subcutaneous fat cell size correlated positively and independently with plasma levels of leptin but not to any of the other assessed adipokines. In non-diabetic subjects, omental fat cell size was independently and negatively correlated with insulin action in subcutaneous, but not omental, fat cells in vitro. CONCLUSIONS/INTERPRETATION: Fat cell enlargement is associated with insulin resistance in non-diabetic individuals independently of BMI. This was not seen in type 2 diabetic subjects, suggesting that after development of type 2 diabetes other factors, not related to fat cell size, become more important for the modulation of insulin resistance.
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Tejido Adiposo/citología , Diabetes Mellitus Tipo 2/patología , Resistencia a la Insulina/fisiología , Leptina/sangre , Tejido Adiposo/patología , Presión Sanguínea , Tamaño de la Célula , Diabetes Mellitus Tipo 2/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/epidemiología , Epiplón/citología , Epiplón/patología , Valores de ReferenciaRESUMEN
BACKGROUND: Lipoprotein lipase (LPL) is important for lipid deposition in adipose tissue (AT) and responds rapidly to changes in the nutritional state. Animal experiments indicate that short-term regulation of LPL is mainly post-translational. Different processing of LPL in different AT depots may play a role in the distribution of lipids in the body. MATERIALS AND METHODS: Lipoprotein lipase mRNA, mass and activity were measured in pieces of omental adipose tissue (OAT) and subcutaneous adipose tissue (SAT) from 15 subjects undergoing gastrointestinal surgery (four male and 11 female subjects, mean age 54 +/- 5 years, BMI 28 +/- 2 kg m(-2)). RESULTS: Lipoprotein lipase activity was higher in OAT than in SAT (18 +/- 2.1 compared with 12 +/- 1.6 mU g(-1), P < 0.01), whereas LPL mass was lower in OAT than in SAT (100 +/- 9 compared with 137 +/- 16 mU g(-1), P < 0.05). Consequently, the specific LPL activity (ratio of activity over mass) was approximately twofold greater in OAT compared with SAT. There was correlation between LPL mRNA and LPL activity in SAT (P < 0.05) and a similar tendency in OAT (P = 0.08). There were strong correlations (P < 0.01) for mRNA abundance as well as for LPL activity between the two depots. In contrast there was no correlation between the LPL mass and LPL mRNA or activity in any of the depots. CONCLUSIONS: These results indicate that long-term regulation, as reflected in the mRNA abundance, is similar in the two types of adipose tissue. The displayed activity reflects the mRNA abundance and the fraction of newly synthesized LPL molecules which the post-translational mechanism allows to become/remain active. This fraction was on average twofold greater in OAT compared with SAT.
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Tejido Adiposo/enzimología , Lipoproteína Lipasa/metabolismo , Epiplón/enzimología , Abdomen/cirugía , Antropometría , Biopsia , Femenino , Expresión Génica , Humanos , Lípidos/sangre , Lipoproteína Lipasa/biosíntesis , Lipoproteína Lipasa/genética , Masculino , Persona de Mediana Edad , ARN Mensajero/genética , Grasa Subcutánea/enzimologíaRESUMEN
BACKGROUND: We have previously reported that the activity of lipoprotein lipase (LPL) measured in postheparin plasma from humans fasted for 30 h is increased relative to the fed state. This is in contrast to laboratory animals, where the strong down-regulation of LPL in their adipose tissue on fasting is reflected in decreased levels of LPL activity in postheparin plasma. MATERIALS AND METHODS: To search for the tissue source of the increase in LPL activity on fasting of humans, young, healthy subjects were fasted for 10, 20 or 30 h, and LPL was measured in plasma (pre- and postheparin) and in biopsies from subcutaneous adipose tissue (abdominal) and from a skeletal muscle (tibialis anterior). Both LPL activity and LPL protein mass were measured in the tissue homogenates. Values after fasting were compared with values from postprandial samples obtained 2 h after a meal. RESULTS: Fasting for up to 30 h did not alter LPL activity in basal plasma (preheparin). LPL activity in postheparin plasma remained unchanged after 10 and 20 h of fasting, but was increased by 50% after 30 h (P < 0.05). Ten hours of fasting caused a 25% (P < 0.05) decrease in LPL activity in subcutaneous adipose tissue, while LPL activity in skeletal muscle remained unchanged. After 30 h of fasting, both LPL activity and mass had decreased by approximately 50% (P < 0.05) in adipose tissue, but had increased by approximately 100% (P < 0.05) in muscle. CONCLUSIONS: The increase in postheparin plasma LPL activity after 30 h of total food deprivation of healthy human subjects seemed to reflect an increased activity and mass of LPL in skeletal muscle.
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Ayuno/metabolismo , Lipoproteína Lipasa/metabolismo , Tejido Adiposo/enzimología , Adulto , Anticoagulantes , Ayuno/sangre , Femenino , Heparina , Humanos , Lipoproteína Lipasa/sangre , Masculino , Músculo Esquelético/enzimología , Periodo Posprandial/fisiologíaRESUMEN
Visceral adiposity is associated with insulin resistance and type 2 diabetes. This study explores the metabolic differences between s.c. and visceral fat depots with respect to effects in vitro of glucocorticoids and insulin on glucose uptake. Adipocytes from human s.c. and omental fat depots were obtained during abdominal surgery in 18 nondiabetic subjects. Cells were isolated, and metabolic studies were performed directly after the biopsies and after a culture period of 24 h with or without dexamethasone. After washing, basal and insulin-stimulated [14C]glucose uptake as well as cellular content of insulin signaling proteins and glucose transporter 4 (GLUT4) was assessed. Omental adipocytes had an approximately 2-fold higher rate of insulin-stimulated glucose uptake compared with s.c. adipocytes (P < 0.01). Dexamethasone treatment markedly inhibited (by approximately 50%; P < 0.05) both basal and insulin-stimulated glucose uptake in omental adipocytes but had no consistent effect in s.c. adipocytes. The cellular content of insulin receptor substrate 1 and phosphatidylinositol 3-kinase did not differ significantly between the depots, but the expression of protein kinase B (PKB) tended to be increased in omental compared with s.c. adipocytes (P = 0.09). Dexamethasone treatment decreased the expression of insulin receptor substrate 1 (by approximately 40%; P < 0.05) and PKB (by approximately 20%; P < 0.05) in omental but not in s.c. adipocytes. In contrast, dexamethasone pretreatment had no effect on insulin-stimulated Ser473 phosphorylation of PKB. GLUT4 expression was approximately 4-fold higher in omental than s.c. adipocytes (P < 0.05). Dexamethasone treatment did not alter the expression of GLUT4. In conclusion, human omental adipocytes display approximately 2-fold higher glucose uptake rate compared with s.c. adipocytes, and this could be explained by a higher GLUT4 expression. A marked suppression is exerted by glucocorticoids on glucose uptake and on the expression of insulin signaling proteins in omental but not in s.c. adipocytes. These findings may be of relevance for the interaction between endogenous glucocorticoids and visceral fat in the development of insulin resistance.
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Adipocitos/efectos de los fármacos , Adipocitos/metabolismo , Dexametasona/farmacología , Glucocorticoides/farmacología , Proteínas Musculares , Epiplón/citología , Adipocitos/citología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Transporte Biológico/efectos de los fármacos , Radioisótopos de Carbono , Células Cultivadas , Femenino , Glucosa/farmacocinética , Transportador de Glucosa de Tipo 4 , Humanos , Insulina/metabolismo , Masculino , Persona de Mediana Edad , Proteínas de Transporte de Monosacáridos/metabolismo , Epiplón/metabolismo , Transducción de Señal/efectos de los fármacos , Tejido Subcutáneo/metabolismoRESUMEN
Lipoprotein lipase (LPL) has high affinity for heparin and heparin-like compounds. In vivo the enzyme is attached to heparan sulfate proteoglycans on the endothelium of capillaries and larger blood vessels. The enzyme is released from these sites after intravenous injection of heparin. One has here investigated the effects of RG-13577 on LPL, both after intravenous injection to rats and under cell culture conditions. RG-13577 is a heparin-mimicking compound known to prevent angiogenesis by interference with binding of growth factors to cells. It has therefore been considered for use in cancer therapy as well as for prevention of atherosclerosis and restenosis. It was found that intravenously injected RG-13577 released both LPL and hepatic lipase (HL) to the blood. Binding of LPL in extrahepatic tissues was prevented and clearance of radiolabeled LPL from the circulation was delayed. Furthermore, RG-13577 released LPL from extracellular matrix (ECM) produced by endothelial cells and from THP-1 monocyte-derived macrophages. Lipase-mediated binding and uptake of human LDL in these cells was also prevented by RG-13577. Thus, in the test systems RG-13577 had the same effects as heparin, but on a molar basis RG-13577 was in all cases less effective.
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Endotelio Vascular/metabolismo , Lipoproteína Lipasa/metabolismo , Lipoproteínas LDL/metabolismo , Macrófagos/metabolismo , Fenoxiacetatos/farmacología , Polímeros/farmacología , Animales , Bovinos , Células Cultivadas , Endotelio Vascular/efectos de los fármacos , Fibrinolíticos/química , Fibrinolíticos/farmacología , Heparina/química , Heparina/farmacología , Humanos , Macrófagos/efectos de los fármacos , Masculino , Fenoxiacetatos/química , Polímeros/química , Unión Proteica/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Receptores de LDL/metabolismoRESUMEN
OBJECTIVE: To study the effect of fasting on lipoprotein lipase (LPL) activity in human post-heparin plasma, representing the functional pool of LPL. DESIGN: Fourteen healthy volunteers were recruited for the study. The subjects were fasted for 30 h. Activities of LPL and hepatic lipase (HL), and LPL mass, were measured in pre- and post-heparin plasma in the fed and in the fasted states, respectively. For comparison, LPL and HL activities were measured in pre- and post-heparin plasma from fed and 24-h-fasted guinea pigs. RESULTS: Fasting caused a significant drop in the levels of serum insulin, triglycerides and glucose in the human subjects. Post-heparin LPL activity increased from 79 +/- 6.4 mU mL-1 in the fed state to 112 +/- 10 mU mL-1 in the fasted state (P < 0.01), while LPL mass was 361 +/- 29 in the fed state and 383 +/- 28 in the fasted state, respectively (P = 0.6). In contrast, fasting of guinea pigs caused an 80% drop in post-heparin LPL activity. The effect of fasting on human and guinea pig post-heparin HL activity were moderate and statistically not significant. CONCLUSIONS: In animal models such as rats and guinea pigs, post-heparin LPL activity decreases on fasting, presumably due to down-regulation of adipose tissue LPL. In humans, fasting caused increased post-heparin LPL activity.
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Anticoagulantes/administración & dosificación , Privación de Alimentos/fisiología , Heparina/administración & dosificación , Lipoproteína Lipasa/metabolismo , Tejido Adiposo/enzimología , Adulto , Animales , Glucemia , Activación Enzimática/efectos de los fármacos , Activación Enzimática/fisiología , Femenino , Cobayas , Humanos , Insulina/sangre , Masculino , Músculo Esquelético/enzimología , Miocardio/enzimología , Triglicéridos/sangreRESUMEN
Several laboratories have shown that when rats are fasted, the amount of lipoprotein lipase (LPL) at the vascular endothelium in heart (monitored as the amount released by heparin) increases severalfold without corresponding changes in the production of LPL. This suggests that there is a change in endothelial binding of LPL. To study this, (125)I-labeled bovine LPL was injected. The fraction that bound in the heart was more than twice as high in fasted than in fed rats, 4.3% compared with 1.9% of the injected dose. Refeeding reversed this in 5 h. When unlabeled LPL was injected before the tracer, the fraction of (125)I-LPL that bound in heart decreased, indicating that the binding was saturable. When isolated hearts were perfused at 4 degrees C with a single pass of labeled LPL, twice as much bound in hearts of fasted rats. We conclude that fasting causes a change in the vascular endothelium in heart such that its ability to bind LPL increases.