Determinación del índice de resistencia insulínica mediante HOMA en una población de la Región Metropolitana de Chile / Measurement of insulin resistance using the homeostasis model

Background: Insulin resistance is defined as an inappropriate high level of plasma insulin required to maintain metabolic homeostasis. It is associated with type 2 diabetes and cardiovascular diseases. The glucose clamp technique is the standard method for the measurement of insulin resistance. However, this method is laborious, expensive and impractical to perform in epidemiological investigations. The homeostasis model assessment (HOMA) has been proposed to assess insulin resistance and secretion, using fasting glucose and insulin concentrations. Aim: To measure insulin resistance using HOMA (HOMAir) in a population sample from the Metropolitan Region in Chile. Material and Methods: One hundred twenty subjects (59 female) with a normal body mass index and fasting blood glucose were studied. Fasting plasma glucose was measured by a glucose oxidase method and serum insulin was measured by radio immunoassay. Results: Fasting blood glucose was 81.6ñ9.4 mg/dl and serum insulin was 9.7ñ2.4 µU/ml. Mean HOMA insulin resistance was 1.96ñ0.57 (range 0.5 and 3.0). Conclusions: These HOMA values can be used as reference for Chilean non obese individuals

Mecanismos de contaminación de las fórmulas para nutrición enteral / Mechanisms of contamination of formulas for enteral nutrition

Una de las complicaciones más frecuentes de la nutrición enteral es la contaminación de las fórmulas. El objetivo de este trabajo fue evaluar la frecuencia y los mecanismo por los cuales se produce la contaminación en las fórmulas enterales. Se evaluaron dos tipos de fórmulas, una en polvo y la otra líquida estéril, con contenedores reutilizados y estériles. Los resultados demuestran que el mecanismo más importante de contaminación se produce en la central de fórmulas por la manipulación o por el uso de utensilios contaminados. La utilización de contenedores reutilizados contribuye a la contaminación, pero en un menor grado. Las bajadas de los contenedores tienen altos porcentajes de contaminación, superiores al 85 por ciento y no se modifican con el uso de material estéril. Probablemente exista también un mecanismo de contaminación retrógrado

Antipsicóticos, diabetes y control de peso / Antipsychotics, diabetes and body weight control

Los pacientes con esquizofrenia tienen una mayor prevalencia de obesidad, la que se puede acentuar con el uso de nuevos antipsicóticos. Esto puede disminuir la aceptación del tratamiento y favorecer el desarrollo de patologías relacionadas al síndrome de resistencia insulínica, como diabetes tipo 2, la hipertensión arterial y las dislipidemias, aumentando el riesgo de enfermedades cardiovasculares. Entre los fármacos antipsicóticos aquellos que más se relacionan al incremento de peso son la clozapina y la olanzapina, en menor grado la risperidona, la zotepina, sertindole y quetiapina, mientras la ziprasidona no lo modifica. Esta respuesta estaría relacionada al perfil farmacológico de las drogas. En consecuencia, es recomendable evaluar en estos pacientes el peso, la presión arterial, controlando también glicemias y perfiles de lípidos. para un diagnóstico y tratamiento precoz. En estos casos se debe indicar un consejo dietético y hábitos de vida saludables y, eventualmente, un cambio en el antipsicótico indicado

Diferencias en antioxidantes plasmáticos según nivel socioeconómico en mujeres chilenas / Differences in plasma antioxidants according to socioeconomic level in chilean women

Background: Free radical-mediated oxidative damage is a known initial event in atherogenesis. Cardiovascular disease is frequent in the Chilean population showing differences in the prevalence of risk factors of the disease according to socioeconomic level (SEL). Aim: To determine levels of antioxidants and lipid peroxides in Chilean women from different SEL. Patients and methods: Blood samples were taken from 81 women for measurements of plasma ascorbic acid, ß-carotene, a-tocopherol, licopene, ubiquinol, glutathione, total plasma antioxidant capacity, and lipid peroxides (TBARS). Results:Individuals in the lower SEL showed reduced levels of plasma ß-carotene, ascorbic acid, a-tocopherol, and ubiquinol compared to women in the higher SEL. There were no differences between groups in the plasma levels of glutathione, total antioxidant capacity, or TBARS. Conclusions: The results could be explained in part by the higher consumption of fruits and vegetables in women from the upper SEL

Cambios en los factores de riesgo metabólicos en pacientes obesos en tratamiento / The effect of treatment on metabolic risk factors in obese patients

Background: Obesity is a threaten to health due to its association with cardiovascular risk factors. Aim: To assess the change in metabolic risk factors after weight reduction in obese patients. Patients and methods: A retrospective analysis of 277 obese patients (198 female) aged 39.5ñ12 years old, that completed a six month treatment period, consisting in a calori restricted diet (800-1200 Kcal/day), physical activity, education and group psychological counseling. At the beginning and at the end of the program, weight, waist circumference, resting energy expenditure (REE), serum lipid profile, plasma glucose and plasma insulin levels were measured. Results: During the treatment period, body mass index decreased from 38ñ7 to 33.2ñ6.4 kg/m2 with a weight loss of 11.7 kg, waist circumference decreased from 106.6ñ14.6 to 93.9ñ13.5 cm, REE decreased from 1774ñ383 to 1585ñ267 Kcal/day, blood glucose fell by 5.8 percent, plasma insulin fell by 40.4 percent, total cholesterol fell by 7.5 percent, LDL cholesterol fell by 8.7 percent, triglycerides fell by 26.6 percent, and total cholesterol/HDL ratio fell by 12.2 percent. Conclusions: Weight loss was associated with improvement in metabolic cardiovascular risk factors in obese patients

Prevalencia de anticuerpos anti islotes pancreáticos en 1.021 parientes de diabéticos tipo 1 / Prevalence of anti pancreatic islet antibodies among 1.021 relatives of type 1 diabetic patients

Background: An immunological damage of beta cells in the islets of Langerhans, plays a role in the pathogenesis of type 1 diabetes. Recently, the identification of individuals in pre clinical phase and with high risk of developing type 1 diabetes, has become possible by means of the detection of immune markers such as islet cell antibodies (ICA) and the measurement of first phase response of insulin (FPRI). Subjects and methods: We studied 1,021 first degree relatives of type 1 diabetics, aged 4 to 35 years. ICA were measured using poly-IgG peroxidase in sections of human pancreas. In those subjects with positive ICA and normal oral glucose tolerance test, the FPRI was measured. FPRI was defined as the sum of insulinemias at minutes 1 and 3 after a three minutes 0.5 g/kg glucose load. Results: Thirty subjects were ICA (+), defined as having more than 20 juvenile diabetes foundation units (prevalence of 2.9 percent). No differences in age, sex and closeness of familial relationship was found between ICA (+) and ICA (-) individuals. FPRI was measured in 24 subjects with normal oral glucose tolerance test and was normal in five. Seventeen subjects had a decreased response (between percentiles 1 and 5) and two had a response below percentile 1. No relationship between ICA levels and FPRI was found. Conclusions: The early detection of populations at risk of developing type 1 diabetes should be regarded as an important tool to better understand the natural history of the disease and to develop preventive programs in the future

Ingesta de nutrientes en vegetarianos chilenos / Nutrient intake in chilean vegetarians

El consumo de alimentos en vegetarianos ha sido estudiado en forma muy limitada en Chile. En este estudio se midió la ingesta alimentaria en 27 vegetarianos (VT) comparándola con 27 omnívoros (OM), pareados por índice de masa corporal, sexo y edad. El consumo diario fue determinado con encuestas por recordatorio de 24 horas tomando el promedio de 3 días. La ingesta promedio de calorías en VT fue de 1.613 cal/día, que no fue significativamente diferente de OM. El consumo de grasas en VT fue significativamente menor que en OM (37,7 ñ 13.2 g en VT y 46,6 ñ 22,0 g en OM, p<0,01), al igual que el consumo de colesterol (72,5 ñ 52,0 y 192 ñ 111, p<0,001). La ingesta de fibra fue significativamente mayor en VT que en OM (26,7 ñ 12,7 g y 14,4 ñ 6,6 g, p<0,01). Los VT consumen significativamente más caroteno y vitamina C y menos vitamina B12 que los OM. El consumo promedio de calcio fue similar y muy bajo en VT y OM (635 y 655 mg, respectivamente)

Nutrición enteral en crisis grave de colitis ulcerosa: efectividad nutricional y tolerancia digestiva / Enteral nutrition in severe ulcerative colitis: safety, tolerance and nutritional efficiency

Backgrounds and aims: Total parenteral nutrition (TPN) has been traditionally used as an adjunctive therapy in severe ulcerative colitis patients. We performed a prospective study to ascertain the safety, nutritional efficiency, tolerance and costs of total enteral nutrition in this situation. Methods: After 48 hours of intensive medical treatment, severe ulcerative colitis patients initiated enteral feeding with a polymeric formula. The formula concentration and volume were increased daily. Results: 17 patients (7 women, 10 men; age 36,8ñ12,8 years) with a mean clinical activity score of 15,6ñ1,5 were included. In 14 patients (82,4percent) enteral nutrition was well tolerated, attaining in 11 of them more than 80percent of the caloric requirements by day 4. In 3 cases we observed vomiting and bloating. Prealbumin levels improved significantly from 11,1ñ3,4 mg/dl to 22,7ñ6,8 mg/dl (p= 0.002) at the end of enteral nutrition (11,8ñ4,7 days). Albumin and other nutritional parameters did not change. Conclusions: Total enteral nutrition could be considered a safe and well tolerated nutritional support in these patients. Although albumin and other nutritional parameters did not change during the study period, the increase in prealbumin levels suggests a favourable anabolic effect of total enteral nutrition

Dislipidemias en enfermedades renales: etiopatogenia y tratamiento / Dyslipidemias in renal diseases: pathogenesis and treatment

Patients with renal diseases like nephorotic syndrome, chronic renal failure (uremia) and renal transplantation frequently present disturbances of lipid metabolisms, howerer their pathogenesis is partially understood. Moreover, cardiovascular diseases are responsible for many deaths in these patients. Although the effect of the dyslipidemias in the development of atherosclerosis in renal diseases is not clear, they probably play a role. Since actually the survival of these patients is substantial, it is important to manage them appropriately with regard to their dyslipidemias. this review will examine the pathogenesis and treatment of dyslipidemias in patients with nephrotic syndrome, chronic renal failure and renal transplantation

Neuropatía diabética: sensibilidad térmica y control metabólico en diabéticos no insulinodependientes / Diabetic neuropathy: thermal sensation and metabolic control in non insulin dependent diabetics

Background: The early detection of peripheral neuropathy in diabetics is important since it is the main riskfactor for lower limb trophic lesions in diabetics. Aim: To assess the relationship between feet thermal sensation threshold and metabolic control in ambulatory non-insulin-dependent diabetics. Pattients and methods: A random sample of 34 non-insulin-dependent diabetic followed for more than five years in a special clinic, out of 368 patients, was selected. Warmth sensation thresbolds were measured in the dorsum of booth feet using a MSTP-III thermostimulator The average value of all glycosylated hemoglobins obtained during the 9.7 ñ 5.3 years of follow up for each patient was calculated. A multiple stepwise regression analysis was performed between thermal sensation as the dependent variable and glycosylated hemoglobin, fasting blood glucose, age and diabetes duration. Results: The regression model disclosed glycosylated hemoglobin as the only independent predictor of warmth sensation threshold (partial r= 0.385; p= 0.043). Fifteen diabetic patients with metabolic control, defined as those with a mean glycosylated hemoglobin of less than 9.5 percent, had a warmth sensation threhold of 35.6 ñ 3.7 ºC, whereas 19 diabetics with a bad control (glycosylated hemoglobin 9.5 percent) had a threshold of 39 ñ 3.8 ºC(p= 0.017). Conclusions: In this group of diabetics there is a relationship between the severity of distal polyneuropathy and the metabolic contrl, assessed with glycosylated hemoglobin levels

Drogas anorexígenas en el tratamiento de la obesidad / Anorexigenic drugs in the treatment of obesity

Obesity is highly prevalent and has several adverse effects on health. Its treatment is thus warranted and must aim to modify dietary and physical activity habits. The opinion of this association is that anorexigenic drugs with cathecolaminergic action (diethylpropion, phentermine, mazindol and phenylpropanolamine) or serotoninergic action (fenfluoramine and fluoxetine) may be used in moderate or severe obesity (BMI >30 kg/m2) after a complete clinical assessment and in the context of an integral medical treatment. This association recommends a close surveillance of the use of these drugs, specially when formulated as non-propietary prescriptions

Ciprofibrato: nueva terapia farmacológica en la hipertrigliceridemia / Ciprofibrate: a new pharmacologic agent for treatment of hypertriglyceridemia

En 16 hombres portadores de dislipidemia IIb, excluyendodiabéticos y otras patologías graves, evaluamos prospectivamente el efecto en colesterol total, colesterol LDL, colesterol HDL y triglicéridos del ciprofibrato. Después de cuatro semanas con régimen adecuado y sin hipolipemiantes, se les indicaron 100 mg/día en dosis única si mantenían colesterol total o triglicéridos superiores a 200 mg/dL. Se reevaluaron a los 30 y 60 días, duplicando la dosis de ciprofibrato si persistía el colesterol total o los triglicéridos mayores a 200 mg/dL. Con 100 mg de ciprofibrato observamos disminución significativa de colesterol total (promedio ñ D.S. 258 ñ 36 a 228 ñ 28 mg/dL, p<0,002); colesterol LDL (192 ñ 47 a 156 ñ 26 mg/dL, p<0,005); triglicéridos (219 ñ 89 a 142 ñ 50 mg/dL, p<0,001) y elevación de colesterol HDL (35 ñ 7 a 43 ñ 6 mg/dL, p<0,001). Al duplicar la dosis de ciprofibrato en 12 pacientes, no se observó un efecto mayor. Ningún pacinete presentó efctos adversos que pudieran ser atribuidos al medicamento