Antonia Priego

Cuantificación de insulinorresistencia con los valores de insulina basal e índice HOMA en una población no diabética

Fundamento Calcular la prevalencia y definir el sindrome de insulinorresistencia mediante la determinacion de insulinemia basal y el indice HOMA, y estudiar su relacion con otros componentes del sindrome metabolico. Sujetos y metodo Estudiamos una poblacion de 292 sujetos no diabeticos, de ambos sexos y edades entre 20 y 65 anos, seleccionados por un metodo de muestreo simple aleatorio entre los que consultaron durante un ano en un centro de salud (en el area metropolitana de Valencia), mediante un metodo de busqueda oportunista. De ellos se selecciono a un subgrupo formado por 96 sujetos que no tenian caracteristicas clinicas ni analiticas del sindrome de insulinorresistencia, y se estudiaron los lipidos plasmaticos, parametros antropometricos, glucosa e insulina plasmatica y el valor del indice HOMA. Resultados El diagnostico de insulinorresistencia se ha establecido por los cortes del percentil 90 de la subpoblacion sin parametros clinicos ni analiticos del sindrome de insulinorresistencia, considerando una insulina plasmatica basal de 16,7 mU/l o superior, o indice HOMA de 3,8 o mayor. El indice HOMA es mas sensible que la insulina plasmatica para el diagnostico de insulinorresistencia. La prevalencia de insulinorresistencia (HOMA ≥ 3,8) en la poblacion estudiada por nosotros es elevada, 31,8%, siendo mas frecuente en hombres que en mujeres. Conclusion Ademas de los valores plasmaticos de insulina e indice HOMA, los mejores indicadores clinicobioquimicos de insulinorresistencia son los valores de glucemia en ayunas, el indice de masa corporal (IMC) y los trigliceridos plasmaticos. Asi, la razon de probabilidad de tener insulinorresistencia es de 5,9, 2,6 y 2,2, respectivamente para glucemia ≥ 110 mg/dl, IMC ≥ 25 kg/m2 y trigliceridos ≥ 150 mg/dl.

Misclassification of subjects with insulin resistance and associated cardiovascular risk factors by homeostasis model assessment index. Utility of a postprandial method based on oral glucose tolerance test.

Different methods are available for assessing insulin sensitivity in the fasting state. However, insulin resistance (IR) is initially a postprandial disturbance; and usually, when basal (fasting) disturbance appears, the process has been in progress for some time. Our aim was to investigate if a postprandial measurement, performing an oral glucose tolerance test (OGTT), is more sensitive than fasting values. We wished to identify early IR states in healthy, nonobese individuals and ascertain if this situation was associated with other cardiovascular risk factors. A total of 90 nonobese, nondiabetic, and nonsmoker individuals were studied. They were divided into 3 groups according to IR state--group 1: non-IR--homeostasis model assessment of IR (HOMA(IR)) and insulin sensitivity index of Matsuda-De Fronzo (ISI-Mat) were normal (HOMA(IR) <3.2 and ISI-Mat >4.0); group 2: with IR post-OGTT (ISI-Mat ≤4.0 and HOMA(IR) <3.2); and group 3: subjects with IR in basal conditions (HOMA(IR) ≥3.2). An intravenous glucose tolerance test to compare both indices was also performed. In 14.4% of subjects, the fasting HOMA(IR) values failed to identify IR (false-negative results). The ISI-Mat values were better correlated than HOMA(IR) (r = 0.875, P = .0001 and r = -0.631, P = .0001, respectively) with insulin sensitivity index obtained with intravenous glucose tolerance test. Subjects with IR had higher prevalence of a cluster of cardiovascular risk factors than non-IR subjects. These data show that that a significant percentage of subjects were misclassified with HOMA(IR). Early identification of IR by OGTT was associated with other cardiovascular risk factors. The OGTT is a simple method that could be applied to accurately identify IR subjects in the general population.

Insulin Resistance in Patients With Familial Combined Hyperlipidemia and Coronary Artery Disease

The minimum model modified by the administration of insulin provides an objective and relatively easily measured index of peripheral sensitivity to insulin which was significantly lower (p <0.02) in familial combined hyperlipidemia (FCH) with ischemic heart disease (IHD) than in FCH without IHD and in control subjects (1.2 +/- 0.6, 1.9 +/- 1.0, 2.9 +/- 1.2 x 10(-4) mU/L/ min, respectively). In patients with FCH, insulin resistance explains, at least in part, their metabolic alterations (hypertension, abnormal glucose tolerance, hyperinsulinemia) and elevated IHD.

Plasma homocysteine levels are associated with ulceration of the foot in patients with type 2 diabetes mellitus

To examine the association of biochemical markers of risk (plasma Hcy, microalbuminuria, lipoprotein (a)(Lp(a)) and diabetic dyslipidaemia) with the prevalence of diabetic foot ulceration in type 2 diabetic patients.

Classical cardiovascular risk factors according to fasting plasma glucose levels

BACKGROUND To compare the prevalence of classical cardiovascular risk factors (CVRF) and metabolic syndrome (MetS) in our population according to fasting plasma glucose levels (FPG). METHODS We have studied 344 subjects between 20-70 years of age, recruited in a Primary Care Clinic. Subjects were divided into four groups according to their fasting plasma glucose (FPG) values: normal plasma glucose (NG) when FPG < 5.6 mmol/L; FPG between 5.6 and 6.0 mmol/L (FPG1); FPG between 6.1-6.9 mmol/L (FPG2); and diabetes (DM) FPG > or = 7 mmol/L or previous diagnosis of diabetes. Cardiovascular risk factors (hypertension, TC/HDL-C index and Apo B values), presence of the MetS and indirect measure of insulin resistance (HOMA) were analyzed. RESULTS Subjects with FPG2 have a prevalence of classic CVRF and MetS similar to that observed in subjects with type 2 diabetes mellitus (T2DM). The TC:HDL-C index > or = 5 in 56% and 57%, Apo B > or = 1.2 g/L in 59% and 57%, hypertension in 60% and 54% of FPG2 and T2DM subjects, respectively. MetS was diagnosed in 79% of FPG2 and 80% of T2DM. We found significant differences with FPG1 group who presented low CVRF and MetS proportion. CONCLUSION In our population FPG2 and T2DM subjects show a similar cardiovascular risk profile. On the other hand, such risk is significantly lower in subjects with FPG between 5.6-6.0 mmol/L. These results might have practical implications.

Arteriosclerosis carotídea subclínica en pacientes con hiperlipidemia familiar combinada. Evolución tras dos años de tratamiento con dosis altas de atorvastatina

BACKGROUND AND OBJECTIVE Familial combined hyperlipidemia (FCH) is a genetic model of atherogenic dyslipidemia with insulin resistance and early coronary disease. Our objective was to evaluate the presence of carotid alterations as a marker of systemic atherosclerosis in subjects with FCH and assess the effect of 80 mg of atorvastatin per day in carotid plaque thickness after 2 years. SUBJECTS AND METHODS 100 non diabetic subjects with FCH in primary prevention were consecutively included. Clinical and biochemical parameters and carotid ultrasonography were performed. Subjects with carotid plaque started treatment with 80 mg of atorvastatin per day for 2 years. RESULTS 29% of subjects had carotid plaques. We did not find significant differences in any of the parameters between subjects with presence or absence of carotid plaques. Twenty subjects with carotid plaques accepted/agreed to participate in the interventional study. Two years follow-up showed a significant reduction in LDLc (30%) and carotid plaque thickness (10%). CONCLUSION Carotid ultrasonography is useful to detect subclinical atherosclerosis in high risk cardiovascular patients such as subjects with FCH. Treatment with high doses of atorvastatin induces the regression of carotid plaque thickness after 2 years follow-up. Our results suggest that intensive treatment with atorvastatin could be useful to reduce the development of cardiovascular disease in this group of patients.

Familial Combined Hyperlipidemia, Metabolic Syndrome and Cardiovascular Disease

Our aim was to investigate the relationship between metabolic syndrome and cardiovascular disease (i.e., survivors of myocardial infarction) in patients with familial combined hyperlipidemia (FCH). We compared a group of 20 male patients with FCH who had survived a myocardial infarction with two other groups matched for age and body mass index, comprising 20 individuals with FCH who had not had a myocardial infraction and 20 control subjects. Plasma lipid, glucose, and insulin levels were determined. Metabolic syndrome was judged to present on the basis of World Health Organization (WHO) and National Cholesterol Education Program-Adult treatment panel (NCEP-ATPIII) criteria. Differences between the groups were evaluated using non-parametric tests and the association between ischemic coronary disease and other parameters was assessed by logistic regression analysis. According to WHO criteria, the metabolic syndrome was present in 19 FCH patients who had survived a myocardial infarction, in 11 individuals with FCH who had not had a myocardial infraction, and in six control subject (P<.001); the difference between FCH patients with and without myocardial infarction was significant (P<.01). Presence of the metabolic syndrome, as defined by WHO criteria, is a marker of cardiovascular risk in individuals with FCH.

Increased thioredoxin levels are related to insulin resistance in familial combined hyperlipidaemia

Thioredoxins (TRX) are major cellular protein disulphide reductases that are critical for redox regulation. Oxidative stress and inflammation play promoting roles in the genesis and progression of atherosclerosis, but until now scarce data are available considering the influence of TRX activity in familial combined hyperlipidaemia (FCH). Since FCH is associated with high risk of cardiovascular disease, the objective of the present study was to assess oxidative stress status in FCH patients, and evaluate the influence of insulin resistance (IR).

Hiperlipidemia familiar combinada, síndrome metabólico y enfermedad cardiovascular

Se estudia la relacion entre sindrome metabolico (SM) e infarto agudo de miocardio (IAM) en la hiperlipidemia familiar combinada (HFC). Se comparan 20 sujetos varones con HFC supervivientes a IAM con otras 2 series de sujetos emparejados por edad e indice de masa corporal (IMC): 20 individuos con HFC que no han presentado IAM y 20 controles sanos. Se determinaron los lipidos, la glucosa y la insulina en plasma y la presencia de SM definido por criterios de la Organizacion Mundial de la Salud (OMS) y National Cholesterol Education Program-Adults Treatment Panel (NCEP-ATP-III). El SM definido por criterios OMS se encontro en 19 sujetos con HFC e IAM, en 11 sujetos con HFC sin IAM y en 6 controles (p