Preoperative factors correlated with post-bariatric surgery weight loss.

Whether preoperative parameters can predict weight loss following bariatric surgery is a matter of debate. We conducted a longitudinal and prospective pilot study on 35 patients that underwent bariatric surgery, with a 12-month follow-up. In the preoperative period, a high HOMA-beta index, lower fasting blood glucose, and lower HbA1c were correlated with a lower BMI at 12 months. Traditional preoperative factors, such as weight and BMI, were correlated with the postoperative BMI values. The presence of well-controlled diabetes may influence weight loss after surgery.

The Relationship between 25-hydroxyvitamin D Levels, Insulin Sensitivity and Insulin Secretion in Women 3 Years after Delivery.

OBJECTIVES: There is a direct correlation between 25-hydroxyvitamin D (25[OH]D) levels and insulin sensitivity. Furthermore, women with gestational diabetes (GDM) may have lower levels of 25(OH)D compared to controls. The present study intended to investigate 25(OH)D levels and their association with insulin sensitivity and insulin secretion in women with prior GDM and in controls 3.2 years after delivery. METHODS: A total of 87 patients with prior GDM and 45 randomly selected controls (age range, 22 to 44 years) with normal glucose tolerance during pregnancy nested within a cohort of all deliveries at Saint Margit Hospital, Budapest, between January 1 2005, and December 31 2006, were examined. Their 25(OH) D levels were measured by radioimmunoassay. Insulin sensitivity and fasting insulin secretion were estimated using the homeostasis model asssessment (HOMA) calculator and early insulin secretion by the insulinogenic index based on a 75 g oral glucose tolerance test. RESULTS: There was no significant difference in 25(OH)D levels between cases and controls (27.2±13.1 [±SD] vs. 26.9±9.8 ng/L). There was a positive association between HOMA insulin sensitivity and 25(OH)D levels (beta = 0.017; 95% CI 0.001 to 0.034/1 ng/mL) that was robust to adjustment for age and body mass index. There was a nonsignificant association between HOMA insulin secretion and 25(OH)D (p=0.099), while no association was found with the insulinogenic index. CONCLUSIONS: Prior GDM status was not associated with 25(OH)D levels; however, 25(OH) D levels were associated with HOMA insulin sensitivity. It is hypothesized that the association between HOMA insulin secretion and 25(OH)D levels is related to the autoregulation of fasting glucose levels because no association between 25(OH)D and insulinogenic index was found.

Efecto del consumo de bebidas dietéticas sobre los niveles de glucosa e insulina plasmática en jóvenes estudiantes de la Universidad del Norte / Effect of the consumption of diet sodas in plasmatic levels of glucose and insulin in young students at Universidad del Norte

Objetivo: Determinar el efecto de las bebidas dietéticas en los niveles de glucosa e insulina en jóvenes estudiantes de medicina de la Universidad del Norte. Materiales y métodos: Se realizó un estudio experimental aleatorizado con una muestra de 16 estudiantes de sexo femenino de tercer semestre del programa de Medicina de la Universidad del Norte. Su participación fue voluntaria, previa firma del consentimiento informado. Se determinaron las variables antropométricas: peso, talla e índice cintura/ cadera. Se extrajo muestras para la determinación de la glucosa e insulina en ayunas. Posteriormente se distribuyeron aleatoriamente en dos grupos. Al grupo control se le suministró una gaseosa normal de 600cc y al grupo experimental, una gaseosa dietética de igual volumen. Al término de 2 horas se extrajeron nuevas muestras para determinar niveles de glucosa e insulina postprandiales. Se recolectaron los datos y se realizó el análisis estadístico utilizando el software IBM SPSS v22.0. Resultados: Se encontró una relación lineal positiva estadísticamente significativa entre los niveles de insulina (r = 0,908; p=0,002) y entre los índices HOMA (r= 0,913; p=0,002), HOMAR (r= 0,920;p=0,001), HOMA beta (r= 0,838;p=0,009)y OUICKI (r= 0,996;p=0,001) pre- y postprandial en el grupo que recibió la bebida dietética. Conclusiones: Los datos demuestran que los niveles de glucosa, insulina y el índice HOMA se comportan de forma lineal según el tipo de gaseosa consumido. No obstante se necesitan más estudios para determinar la interrelación entre dichas variables.

Objective: To determine the effect of diet sodas in glucose and insulin levels in young medical students from the Universidad del Norte. Materials and methods: A randomized experimental study with a sample of 16 female students with an average age of 18 years, belonging to the third semester of Medicine pro-gram at Universidad del Norte. The subject's participation was voluntary prior signature of informed consent. We assed the following anthropometric variables: weight, height, waist / hip ratio. Blood samples were obtainedfor determination of fasting glucose. We randomly divided the sample into two groups. The control group was provided a 600 cc of a regular soda, and the group experimental, an equal volume of diet soda. After 2 hours, new blood samples were taken in order to determine postprandial glucose and insulin levels. Data was collected and statistical analysis was performed using SPSS v22.0 software. Results: A statistically significant positive linear relationship between the levels of basal and postprandial insulin (r = 0.908; p = 0.002) and between pre and post-prandial HOMA index (r = 0.913;p = 0.002), HOMAR (r= 0,920;p=0,001), HOMA beta (r= 0,838;p=0,009), y OUICKI (r= 0,996; p=0,001) was found in the group receiving dietary drink. Conclusions: Data from this study show that the levels of glucose, insulin and HOMA index behave in lineal ways according to the type of soda consumed, however further studies are needed to determine the inter-relationship between these variables.

Puntos de corte del perímetro de la cintura para identificar sujetos con resistencia a la insulina en una población colombiana / Cut points of waist circumference to identify subjects with insulin resistance in a colombian population

Resumen Introducción: el síndrome metabólico (SM) es una condición clínica que aumenta el riesgo de enfermedad cardiovascular y se relaciona con resistencia a la insulina (RI). Aunque los consensos establecen la necesidad de puntos de corte específicos del perímetro de la cintura (PC) para cada país, con el fin de identificar sujetos con SM, en Colombia no han sido definidos. Objetivo: definir los puntos de corte del PC en hombres y en mujeres que mejor discriminan la presencia de RI, establecer la prevalencia de SM y verificar la relación entre el PC y RI. Material y métodos: en el contexto del estudio Diagnóstico del Riesgo Cardiovascular Global, Medellín 2007-2008, se realizó una evaluación clínica, antropométrica y de laboratorio. Con el índice de resistencia a la insulina HOMA (IR-HOMA) se definió la presencia de RI a partir del percentil 75. Se construyeron curvas de las características operativas del receptor (COR), se obtuvo el área bajo la curva (AUC) para cada sexo y se usó el índice de Youden para establecer el PC que mejor discriminaba la presencia de RI. Resultados: se incluyeron 800 sujetos, de los cuales 44.8% fueron hombres, con un promedio de edad de 50.3±12.1 e índice de masa corporal (IMC) de 26.1±4.7. Los sujetos con RI tuvieron mayor PC, triglicéridos y presión arterial, además, menor colesterol HDL que aquellos sin RI. Los valores que mejor discriminan la presencia de RI fueron 92 cm en hombres (sensibilidad 82.28%; especificidad 70.14%) y 84 cm en mujeres (sensibilidad 78.15%; especificidad 73.98%) (índice de Youden de 0.52 en ambos sexos). Para los hombres y mujeres el AUC fue 0.828 (IC 95% 0.780-0.876) y 0.815 (IC 95% 0.770-0.859), respectivamente, valor de p< 0.001. Se encontró correlación entre el PC e IR-HOMA (ρ=0.65 en los hombres y ρ=0.62 en las mujeres) y una prevalencia del SM del 44.9%. Conclusión: los valores de PC que mejor discriminaron la presencia de RI son 92 cm para hombres y 84 cm para mujeres. Este criterio podría ser utilizado para identificar sujetos con SM a nivel poblacional. (Acta Med Colomb 2013; 38: 118-126).

Abstract Introduction: the metabolic syndrome (MS) is a clinical condition that increases the risk of cardiovascular disease and is associated with insulin resistance (IR). Although consensus establish the need of specific cut points of waist circumference (WC) for each country in order to identify subjects with MS, these have not been defined in Colombia. Objective: to define the WC cut points in men and women that best discriminate the presence of IR, to establish the prevalence of MS and verify the relation between WC and IR. Material and methods: in the context of the Diagnosis of the Global Cardiovascular Risk study, Medellin 2007-2008, we conducted an anthropometric and laboratory clinical evaluation. With the HOMA insulin resistance (HOMA-IR) index, we defined the presence of IR starting from the 75th percentile. Curves of the receiver operating characteristics (ROC) were made and the area under the curve (AUC) for each sex was obtained and the Youden index was used to establish the WC that best discriminated the presence of IR. Results: 800 subjects were included, of whom 44.8% were male, with a mean age of 50.3 ± 12.1 years and body mass index (BMI) of 26.1 ± 4.7. Subjects with IR had higher WC, triglycerides and blood pressure and also lower HDL cholesterol than those without IR. The values that best discriminate the presence of IR were 92 cm in men (sensitivity 82.28%, specificity 70.14%) and 84 cm in women (sensitivity 78.15%, specificity 73.98%) (Youden index of 0, 52 in both sexes). For men and women, the AUC was 0.828 (95% CI 0.780-0.876) and 0.815 (95% CI 0.770 to 0.859), respectively, p <0.001. A correlation between the WC and IR-HOMA ( ρ= 0.65 in men and ρ= 0.62 in women) as well as MS prevalence of 44.9% was found. Conclusion: WC values that best discriminated the presence of IR are 92 cm for men and 84 cm for women. This criterion could be used to identify subjects with MS at the population level. (ActaMed Colomb 2013; 38: 118-126).

Análise crítica do uso dos índices do Homeostasis Model Assessment (HOMA) na avaliação da resistência à insulina e capacidade funcional das células-beta pancreáticas: [revisão] / Critical analysis on the use of the homeostasis hodel assessment (HOMA) indexes in the evaluation of the insulin resistance and the pancreatic beta cells functional capacity: [review]

A disfunção das células-beta e a resistência insulínica são anormalidades metabólicas inter-relacionadas na etiologia do diabetes tipo 2. Em diversos países, tem sido observado o aumento da prevalência de obesidade e diabetes em associação com a presença da resistência insulínica. Nesse contexto, é útil a mensuração da resistência insulínica e da capacidade funcional das células-beta nos indivíduos. Os índices Homeostasis Model Assessment (HOMA) têm sido amplamente utilizados, representando uma das alternativas para avaliação desses parâmetros, principalmente por figurarem um método rápido, de fácil aplicação e de menor custo. Esta revisão discute sobre a origem e a evolução dos índices HOMA, bem como as particularidades do método, abordando aspectos relacionados à sua validação e aos pontos de corte existentes para sua interpretação.

Beta-cell dysfunction and insulin resistance are interrelated metabolic abnormalities in the aetiology of Type 2 Diabetes. In several countries, increases in the prevalence of obesity and diabetes have been observed in association with the presence of insulin resistance. In this context, measurement of insulin resistance and beta-cell function is useful. The HOMA indexes (Homeostasis Model Assessment) have been widely used, representing an alternative for the evaluation of these parameters, particularly as a fast, easy and cheap method. This review discusses the origin and evolution of the HOMA index, as well as details of the method, analyzing features related to its validation and the cutoff limits for its interpretation.