RESUMEN
The aim of the present study was to determine in adolescents the relationship between insulin levels and body mass index (BMI), body fat distribution, diet, life style and lipid profile. We studied 167 adolescents (68 boys and 99 girls) whose ages ranged from 14 to 17 years. A detailed medical (including pubertal stage) and nutritional record was obtained from each subject. Biochemical measurements included fasting serum insulin, glucose, total cholesterol (TC), triglycerides (Tg), HDL-C, LDL-C and VLDL-C. HOMA insulin resistance (IR) and HOMA beta-cell function (beta-cell) were calculated. Insulin levels were over 84 pmol/L (cut off normal value in our lab) in 56 per cent of the boys and 43 per cent of the girls. Thirty-seven percent of lean adolescents whose BMI was 21.5 +/- 1.9 kg/m2 presented higher fasting insulin levels. HOMA IR, Tg, systolic (SBP) and diastolic blood pressure (DBP) values when compared to a lean normoinsulinemic group. Insulin levels were correlated (p < 0.01) with body mass index. Both boys and girls in the highest BMI quartile (BMI > 24 kg/m2) had significantly higher serum insulin, HOMA beta-cell, and Tg levels, and the lowest HDL-C levels. A high-energy intake rich in saturated fat and low physical activity were found in this lean but metabolically altered adolescents. We conclude that even with a BMI as low as 21 kg/m2 an inappropriate diet and low physical activity might be responsible for the high insulin levels and dislipidemias in adolescents.
Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Delgadez/metabolismo , Síndrome Metabólico/etiología , Presión Arterial , Índice de Masa Corporal , Dieta , Ejercicio Físico , Insulina/sangre , Insulina/metabolismo , Estilo de Vida , Lípidos/sangre , Lípidos/metabolismo , Factores de Riesgo , Síndrome Metabólico/sangreRESUMEN
With the purpose of determining how certain risk factors for type 2 diabetes such as family history of diabetes, obesity and dyslipidemia, affect the glucose-insulin response to a glucose challenge, 135 individuals (77 women and 58) men were studied. Their ages ranged from 20-68 years, their basal glycemic values were less than 110 mg/dL but they were considered at risk for diabetes due to the presence of one or more of those factors. We found that the presence of those risk factors did not affect the glycemic response in any case. However, the basal insulin levels as well as the post-challenge values were increased significantly (p < 0.0001) by the presence of obesity in men as well as in women. Dyslipidemia increased the basal and post challenge glucose insulin values only in men (p < 0.002). The coexistence of obesity and family history of diabetes provoked a decrease in the basal insulin levels as well as in the insulin response to glucose. We conclude that, without alteration of the glycemic response, the presence of risk factors as obesity, dyslipidemia or family history of diabetes leads to basal hyperinsulinemia, as well as glucose stimulated hyperinsulinemia, however the coexistence of obesity and family history of diabetes, is responsible for a deficit in the insulin secretion by the pancreas.
Asunto(s)
Glucemia/análisis , Diabetes Mellitus Tipo 2/epidemiología , Prueba de Tolerancia a la Glucosa , Hiperinsulinismo/epidemiología , Insulina/análisis , Estado Prediabético/epidemiología , Adulto , Anciano , Índice de Masa Corporal , Comorbilidad , Diabetes Mellitus Tipo 2/genética , Susceptibilidad a Enfermedades , Ayuno/sangre , Femenino , Predisposición Genética a la Enfermedad , Glucosa , Humanos , Hiperinsulinismo/diagnóstico , Hiperinsulinismo/genética , Hiperlipidemias/epidemiología , Hipertensión/epidemiología , Resistencia a la Insulina , Masculino , Persona de Mediana Edad , Obesidad/sangre , Obesidad/epidemiología , Estado Prediabético/sangre , Estado Prediabético/diagnóstico , Estado Prediabético/genética , Factores de RiesgoRESUMEN
Hyperinsulinemia and impaired insulin action are familial and predictive of Type 2 diabetes onset. Since high levels of insulin are characteristic of our general (venezuelan)hispanic population, the purpose of this investigation was to identify early metabolic defects in a group of healthy first degree relatives of Type 2 diabetic patients. We studied 46 (29 women and 17 men; ages ranging 18-66 y) first degree relatives of Type 2 diabetic patients comparing them with 22 (12 women and 10 men; ages ranging 22-60 y) subjects who had no family history of diabetes. All subjects underwent resting blood pressure and anthropometric measurements; a 75 g oral glucose tolerance test with determination of glucose and insulin and a fasting lipid profile. The relatives of Type 2 diabetic patients had higher tricipital (TC) and subscapular (SC) skinfolds, and elevated DBP in relation to the control group. The skinfolds elevation was more evident in women, while in men the elevation in DBP predominates. None of the relatives had glucose intolerance, however, the glucose-stimulated insulin response was elevated at all points in men as well as in women. No difference was observed in the HOMA values for IR and beta cell function, or in the delta I30/delta G30 ratio. The lipid profile showed a marked elevation in TG levels in men as well as in women, with low HDL-C values in men. No other lipid abnormalities were observed. Correlation analysis revealed strong association between BMI and WHR with skinfolds and several parameters of the carbohydrate metabolism in women, but not in men. IR in women was possitively associated with skinfolds, SBP and lipid parameters and beta cell function with VLDL-C. Adult relatives of Type 2 diabetic venezuelan patients from hispanic origin had, early in their lives, several parameters of the metabolic syndrome as hyperinsulinemia, obesity, dyslipidemia and high blood pressure. These alterations were more prominent in women, group in which the association among BMI, WHR and IR were statistically significant respect to SBP, DBP, basal insulin, insulin/glucose ratio, TG and HDL-C.
Asunto(s)
Diabetes Mellitus Tipo 2/genética , Salud de la Familia , Hiperinsulinismo/genética , Resistencia a la Insulina/genética , Estado Prediabético/genética , Adulto , Edad de Inicio , Antropometría , Glucemia/análisis , Metabolismo de los Hidratos de Carbono , HDL-Colesterol/sangre , Comorbilidad , Diabetes Mellitus Tipo 2/metabolismo , Femenino , Predisposición Genética a la Enfermedad , Prueba de Tolerancia a la Glucosa , Humanos , Hiperinsulinismo/epidemiología , Hiperinsulinismo/etnología , Hipertensión/epidemiología , Hipertensión/etnología , Hipertensión/genética , Hipertrigliceridemia/epidemiología , Hipertrigliceridemia/etnología , Hipertrigliceridemia/genética , Incidencia , Insulina/sangre , Insulina/metabolismo , Secreción de Insulina , Islotes Pancreáticos/metabolismo , Masculino , Persona de Mediana Edad , Obesidad/epidemiología , Obesidad/etnología , Obesidad/genética , Estado Prediabético/epidemiología , Estado Prediabético/etnología , Factores de Riesgo , Factores Sexuales , España/etnología , Venezuela/epidemiologíaRESUMEN
This study reports a 7-y-old boy with severe hypertriglyceridaemia who was successfully treated for 6 y with a low glycaemic index-high carbohydrate modified-lipid diet that produced beneficial changes in triglyceride and total cholesterol levels. It is suggested that a selection of a complex digestible carbohydrate and an adequate ratio between polyunsaturated and monounsaturated fat may, in the long term, favourably improve the lipid profile.
Asunto(s)
Carbohidratos de la Dieta/uso terapéutico , Hipertrigliceridemia/dietoterapia , Niño , Dieta Aterogénica , Dieta con Restricción de Grasas , Humanos , Hipertrigliceridemia/diagnóstico , Hipertrigliceridemia/fisiopatología , Masculino , Triglicéridos/sangreRESUMEN
Phosphofructokinase (PFK) from human polymorphonuclear leukocytes (PMN) was characterized by immunological titration with subunit specific antibodies and column chromatography on QAE-Sephadex in three different groups: control, type II diabetic, and obese individuals. It was found that PMN phosphofructokinase in the three groups consists mainly of a mixture of L4 and M4 homotetramers with possibly some hybrid forms. The predominant subunit was the L-type. A 24% decrease in the specific activity of the L-type isozyme was observed and an intermediate form (I-isozyme) having 23% of the total activity in diabetic individuals appeared. In obese individuals a 30% decrease was observed in the activity of M-type isozyme and 9% of the total activity corresponded to the intermediate form. Kinetic studies showed different regulatory properties among the isozymes from the three groups. The lower PFK activity found in diabetic and obese individuals can be associated with the decreased activity in the L-type isozyme (for diabetic individuals) and in the M-type isozyme (for obese individuals); the lower activity can also be associated with the four times lower affinity for F-6-P showed by the M-type isozyme, the decreased sensitivity to ATP inhibition (for both isozymes), and the appearance of an intermediate form with a different kinetic behaviour.
Asunto(s)
Resistencia a la Insulina/fisiología , Isoenzimas/sangre , Neutrófilos/enzimología , Fosfofructoquinasa-1/sangre , Adenosina Trifosfato/metabolismo , Adenosina Trifosfato/farmacología , Estudios de Casos y Controles , Citratos/farmacología , Ácido Cítrico , Diabetes Mellitus Tipo 2/enzimología , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Fructosadifosfatos/farmacología , Fructosafosfatos/metabolismo , Fructosafosfatos/farmacología , Humanos , Isoenzimas/antagonistas & inhibidores , Cinética , Obesidad/enzimología , Fosfofructoquinasa-1/antagonistas & inhibidores , Especificidad por SustratoRESUMEN
The aim of this study was to evaluate the alterations of the lipoprotein composition and their relation with the insulin-resistance and/or hyperinsulinemia in non diabetic obese patients. Twenty-two no obese(13 women and 9 men) and 30 obese patients (BMI > 30) were studied, who were divided into two groups according to the total lipid levels. The first group was formed by 18 obese patients (10 women and 8 men) with normal serum cholesterol (Chol) concentration < 200 mg/dL and triglycerides (TG) < 150mg/dL (NO), while the second group were formed by 12 obese patients (3 women and 9 men) with elevated Chol level > 200mg/dL and/or TG > 150 mg/dL (HO). A clinical and anthropometric examination was performed to each patient, as well as a glucose tolerance test, including serum glucose and insulin determinations. Likewise, the plasma lipoproteins (VLDL, LDL, HDL2 and HDL3) were isolated by ultracentrifugation and their cholesterol and triglycerides content were determined by enzymatic methods. In this report, we demonstrate the existence of compensatory basal hyperinsulinemia in men and women on both obese patients populations as well as alterations in the lipoprotein composition, mostly a TG overload even on NO. On the other hand, the presence of lipids and lipoproteins modification were obvious in those patients with abdominal obesity, on whom the hyperinsulinemia was more evident, which could be related with the high risk of cardiovascular disease in this kind of patients.
Asunto(s)
Hiperlipidemias/sangre , Lipoproteínas/sangre , Obesidad/sangre , Adulto , Antropometría , Glucemia/análisis , Enfermedades Cardiovasculares/epidemiología , Colesterol/sangre , Femenino , Prueba de Tolerancia a la Glucosa , Humanos , Insulina/sangre , Resistencia a la Insulina , Masculino , Persona de Mediana Edad , Factores de Riesgo , Triglicéridos/sangreRESUMEN
Phosphofructokinase (PFK) from human polymorphonuclear leukocytes (PMN) was characterized by immunological titration with subunit specific antibodies, column chromatography on QAE-Sephadex and SDS-polyacrylamide gel electrophoresis. Two different isozymes, M-type and L-type, were found. The M(r) values of the M and L subunits were 79,500 +/- 1,914 and 74,250 +/- 1,258, respectively. The two isozymes presented different kinetic and regulatory properties. The results suggest that PFK from human normal PMN is a mixture of M-type and L-type homotetramers, mainly, with possible minor heterotetrameric forms.
Asunto(s)
Isoenzimas/análisis , Neutrófilos/enzimología , Fosfofructoquinasa-1/análisis , Adenosina Trifosfato/metabolismo , Adenosina Trifosfato/farmacología , Cromatografía por Intercambio Iónico , Citratos/farmacología , Ácido Cítrico , Electroforesis en Gel de Poliacrilamida , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Fructosadifosfatos/farmacología , Humanos , Técnicas de Inmunoadsorción , Isoenzimas/antagonistas & inhibidores , Isoenzimas/metabolismo , Cinética , Sustancias Macromoleculares , Fosfofructoquinasa-1/antagonistas & inhibidores , Fosfofructoquinasa-1/metabolismoRESUMEN
To determine the most frequent dyslipidemias among first-degree relatives of NIDDM patients, and its association with their glucose-tolerance status and hyperinsulinemia, we have started to examine members of NIDDM pedigrees, according to American Diabetes Association guidelines for nuclear family studies. In a large family with 2 NIDDM siblings in the 2nd generation, and 4 siblings with NIDDM in the 3rd generation, we have evaluated 14 first degree relatives and also 15 sex and aged matched healthy control subjects without family history of diabetes. The NIDDM relative group presented BMI = 31.8 +/- 3.9 kg/m2, SBP = 128 +/- 18.2 mmHg, DBP = 84 +/- 12.7 mmHg. Both relatives and controls were subjected to a 2h 75g OGTT for glucose and insulin determinations. Although none of NIDDM relatives has IGT, both Glycemic Area (GA) and Insulin Area (IA) were greater (p < 0.01) in the NIDDM relative group. The Insulin/Glucose ratio was also higher (p < 0.01) at 0 and 120 min of OGTT, this might be indirect evidence of Insulin- Resistance. Fasting serum lipids in the NIDDM relatives were TG = 148 +/- 24mg/dl, T-Chol = 244 +/- 10.7mg/dl, HDL-C = 34.2 +/- 2.5mg/dl; lipids in the control group were TG = 84.8 +/- 10.1mg/dl, T-Chol = 167 +/- 10.2mg/dl, HDL-C = 44.4 +/- 2.6mg/dl. Electrophoretic pattern showed type IIa (30.7%) and IIb (61.5%) hyperlipidemias in the NIDDM relatives. In this group, there was a positive and significant association between basal insulin and DBP (r = 0.67; p < 0.01), and between DBP and both TG (r = 0.74; p < 0.01)) and VLDL-C (r = 0.58; p < 0.05). It was also obtained a negative association between basal insulin and HDL-C (r = -0.89; p < 0.001). These data suggest that hyperinsulinemia in association with lipid abnormalities could appear early (before the development of Impaired Glucose Tolerance and Diabetes) in first degree relatives of NIDDM patients.
Asunto(s)
Diabetes Mellitus Tipo 2/genética , Hiperinsulinismo/epidemiología , Hiperlipidemias/epidemiología , Obesidad/epidemiología , Adulto , Glucemia , Femenino , Humanos , Hiperinsulinismo/genética , Hiperlipidemias/genética , Masculino , Persona de Mediana Edad , Obesidad/genética , Linaje , Análisis de RegresiónRESUMEN
In view of the controversy surrounding the role of environmental factors, such as the presence of bovine albumin in milk, or viral infections, in the etiology of IDDM, a study was undertaken to determine the relationship between these events and the subsequent risk of developing IDDM. On 40 venezuelan diabetic children (< 18 y) and forty, age, sex and race-matched controls were studied at the same time. Parents of children completed a questionnaire on the infant's feeding habits, its environment and family history. The X2 method and the Fischer's exact test were used to analyze the results. We found that 20% of the controls, and 10% of IDDM (NS), were never breast-fed. In 95% of controls vs 65% of IDDM (p < 0.001), cow's milk was given exclusively from birth, or combined with breast-feeding, 65% of IDDM and 60% of controls (NS) were breast-fed (alone or combined with milk substitutes) for more than three months. These results do not support the hypothesis that early exposure to breast milk substitutes increases the risk of IDDM in venezuelan children. The study revealed, however, that a family history of diabetes mellitus was present in 55% of IDDM vs 30% of controls (p < 0.05) and mumps infection before the onset of diabetes was recorded in 42.5% of IDDM in comparison with 12.5% of controls (p = 0.005). Other viral infections (rubella, chicken pox) had no statistical significance. The latter results suggest an association between a family history of diabetes mellitus and viral infections with the development of IDDM among this group of children.
Asunto(s)
Diabetes Mellitus Tipo 1/etiología , Adolescente , Niño , Preescolar , Ambiente , Femenino , Humanos , Lactante , Masculino , VenezuelaRESUMEN
With the purpose of exploring the glucose and insulin responses to a breakfast composed of a complex carbohydrate (CC) in the form of a "arepa" prepared with precooked corn flour, with or without the addition of protein and fat (CC + P + F), we studied 6 healthy volunteers, ages ranging from 26-50 years and body mass index of 24.5 +/- 1.32. Three tests were performed on each individual: 1) 75 g OGTT, 2) Ingestion of 75 g of CC ("arepa") and 3) Ingestion of 75 g of CC + 6.7 g protein (low fat cheese) and 4 g fat (margarine). Glycemic values (glucose - oxidase method) and insulinemia (radioimmunoassay) were determined at basal, 30, 60, 120, 180 and 240 min. Glucose (GA) and insulin (IA) areas, glycemic index (GI) and insulin/glucose ratio (I/G) were calculated. We found that the "arepa" has a high GI (71.5%) that it is increased, although not significatively to 140% with the addition of protein and fat. Total GA as well as IA obtained for CC and for CC + P + F were similar to OGTT, however the profiles of the glucose and insulin responses during CC and CC + P + F were less abrupt but more prolonged, resulting in a greater I/G ratio for OGTT in comparison with CC or CC + P + F during the initial steps. We conclude that GI of this corn bread ("arepa") is high in comparison to other complex carbohydrates and it is not altered by the addition of protein and fat. This is possibly due to glucose and insulin responses similar to that produced by OGTT.
Asunto(s)
Glucemia , Culinaria , Carbohidratos de la Dieta/administración & dosificación , Glucosa/administración & dosificación , Insulina/sangre , Zea mays , Adulto , Grasas de la Dieta/administración & dosificación , Proteínas en la Dieta/administración & dosificación , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Insulin resistant states are characterized by receptor and post-receptor defects in insulin action. When the insulin resistant state progresses, elevated levels of insulin are accompanied by increasing levels of glucose. In a previous paper we demonstrated that treatment of isolated adipocytes with high levels of insulin led to a decrease in insulin binding as well as a decrease in basal and insulin-stimulated lipid synthesis. The results of the present study establish that the addition of high concentrations of glucose in combination with a high level of insulin, does not modify the decrease in binding of insulin to its receptor. However, the decrease in lipid synthesis previously observed in the presence of high concentrations of insulin was completely overcome by the presence of high glucose.
Asunto(s)
Adipocitos/metabolismo , Glucosa/farmacología , Insulina/farmacología , Lípidos/biosíntesis , Adipocitos/efectos de los fármacos , Animales , Células Cultivadas , Relación Dosis-Respuesta a Droga , Glucosafosfato Deshidrogenasa/metabolismo , Cinética , Malato Deshidrogenasa/metabolismo , Complejos Multienzimáticos/metabolismo , Oxo-Ácido-Liasas/metabolismo , RatasRESUMEN
The effect of hormonal therapy in serum glucose, lipoproteins and the hemostatic system was studied in menopausal women, who were distributed in three groups: Group I (15 patients) received placebo in cycles of 21 days, followed by 7 days of rest; Group II (16 patients), received natural estrogens conjugated with progesterone in a sequential way, also in cycles of 21 days: Group III (16 patients), was treated with triphasic oral contraceptives in the same cyclical fashion. The patients completed 6, 12 or 18 cycles of the treatment. The results were as follows: The glucose levels were decreased by the 18th cycle in group II (P < 0.01). The HDL-cholesterol levels and the cholesterol/HDL cholesterol index were unchanged, however the basal levels of LDL-cholesterol in group III were high, but normal after 12 cycles of treatment. The coagulation factors did not changed significantly with the hormonal treatment, however fibrinogen was increased after 18 cycles under placebo. The von Willebrand factor and antithrombin III remained stable. Platelet aggregation with ADP increased after 12 cycles in group III (p < 0.05), and no changes were found with collagen. The above results suggest that the hormonal treatment in menopausal women, either with natural estrogens and progesterone or with triphasic oral contraceptives, has little effect in the lipidic concentrations of sera in these patients, however it can increase platelet activity, specially with prolonged treatment with semisynthetic estrogens.
Asunto(s)
Terapia de Reemplazo de Estrógeno , Estrógenos/administración & dosificación , Menopausia/sangre , Factores de Coagulación Sanguínea/análisis , Factores de Coagulación Sanguínea/efectos de los fármacos , Glucemia/efectos de los fármacos , Estrógenos/farmacología , Estrógenos/uso terapéutico , Femenino , Humanos , Lípidos/sangre , Persona de Mediana Edad , Agregación Plaquetaria/efectos de los fármacosAsunto(s)
Glucemia/análisis , Diabetes Mellitus Tipo 1/complicaciones , Angiopatías Diabéticas/prevención & control , Neuropatías Diabéticas/prevención & control , Retinopatía Diabética/prevención & control , Adolescente , Adulto , Terapia Combinada , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/terapia , HumanosRESUMEN
The purpose of this study was to evaluate the presence of insulin-resistance in non-obese, non-diabetic patients with mild to moderate essential arterial hypertension of recent diagnosis and without prior pharmacological treatment and its relationship with the lipid alteration found in those patients. Twenty-one controls (9 M/12F) and twenty-nine patients (19 M/10 F) were studied. The control group presented mean age: 29 +/- 1.5 years, BMI: 23.9 +/- 0.46 Kg/m2, SBP: 112.6 +/- 2.9 mm Hg, DBP: 68.0 +/- 2.9 mm Hg. The patient group presented mean age: 35 +/- 1.4 years, BMI: 27.3 +/- 0.45 Kg/m2, SBP: 140 +/- 26 mm Hg, DBP: 95.1 +/- 1.4 mm Hg. The fasting levels of glucose, insulin and lipids were measured in each individual. Both controls and patients were subjected to an oral glucose tolerance test (OGTT) with determination of glucose and insulin at 30, 60, and 120 minutes. The patients had significantly (p < 0.05) increased plasma glucose at 0, 30, 60 and 120 min. and increased (p < 0.05) plasma insulin levels at O and 120 min compared to controls. The G/I ratio was significantly lower (p < 0.005) in the hypertensive group, at 0 h and 120 min. Abnormalities in fasting lipid profile were also observed in the patients including a significant increase in TG, Cholesterol, VLDL-C and LDL-C. These increases were especially evident in men and those with higher BMI. There was a positive and significant association between basal-insulin and TG, VLDL-C and DBP in hypertensive patients. We conclude that hyperinsulinemia is present in the majority of hypertensive patients and that hyperinsulinemia is associated with lipid abnormalities specially in men and the most individuals with higher BMI.
Asunto(s)
Hiperinsulinismo/etiología , Hipertensión/sangre , Resistencia a la Insulina , Lípidos/sangre , Adulto , Glucemia/análisis , Índice de Masa Corporal , Femenino , Prueba de Tolerancia a la Glucosa , Humanos , Hiperlipidemias/etiología , Hipertensión/complicaciones , Masculino , Factores SexualesRESUMEN
To assess the effect of insulin on lipid synthesis in isolated rat adipocytes, cells were preincubated for 3 h with high concentrations (16.6 nM) of the hormone and lipogenesis measured through 14C-acetate incorporation into lipids, analyzing at the same time the activity of some lipogenic enzymes. It was found that insulin induced not only a decrease in the number of insulin receptors but a 30% loss in basal and insulin-stimulated acetate incorporation into total lipids as well as a decrease in the activities of enzymes related to the novo fatty acid synthesis pathway as malic enzyme and glucose-6-phosphate dehydrogenase.