Relación entre leptina e insulina sanguíneas en mujeres chilenas obesas y no obesas / Relationship between leptin and insulin blood levels in obese and lean chilean women

Background: Leptin, a product of ob gene and insulin blood levels, are proportional to the amount of adipose tissue. Insulin could have an independent regulatory effect on leptin secretion. Aim: To assess the relationship between serum leptin and plasma insulin levels in obese and lean Chilean women. Material and methods: One hundred forty five women, aged 20 to 60 years old, were studied. Weight, height, waist and hip circumference, fasting blood glucose, insulin and leptin levels were measured. Insulin resistance was assessed using the homeostasis model assessment. The relationship between different variables was determined using multiple linear regression, variance analysis and non parametric correlation. Results: Leptin serum concentrations were positively correlated with body mass index, insulin plasma levels and degree of insulin resistance. The association of leptin with insulin was independent of body mass index and persisted after adjustments by body fat distribution and age. Conclusions: Insulin and insulin resistance are associated to high blood leptin levels and this association is independent of the degree of adiposity and body fat distribution

Transición epidemiológica en América Latina: comparación de cuatro países / Epidemiological transition in Latin America: comparison of 4 countries

Material and methods: Data was obtained from official informational organizations such as Pan American Health Organization, United Nations, Latin American Center for Demography (CELADE) and World Bank. Results: Guatemala is in a pre-transition stage with a high proportion of communicable diseases as causes of death (61 percent) as compared with Mexico (22 porcent), Chile (13 percent) and Uruguay (7 percent). Mexico is in a prolonged transition situation and Chile is close to Uruguay in a post-transitional stage. Despite decreasing rates of mortality, the proportion of deaths represented by chronic diseases and injuries has increased to over 30 percent in all countries,except Uruguay. Adjusted mortality rates for cadiovascular diseases are lower in Latin American countries, as compared to Canada. However, excepting Guatemala, there are differences in the pattern of cardiovascular disease, with a higher mortality due to cerebrovascular and a lower mortality due to coronary artery diseases. Conclusions: An increment in non communicable diseases is expected for the next decades in Latin America. Analysis of demographic and epidemiological transition is crucial to define health policies and to adequate health systems to the new situations

Métodos de estimación de la composición corporal de ancianos: análisis crítico / Body composition estimation methods in elderly: critical analysis

The objective of this study was to compare the values obtained for total body fat obtained with deuterium dilution, anthropometry and bioimpedance in 41 institutionalized elderly individuals (65-90 years old). The values obtained with each technique were compared using the graphic analysis proposed by Bland and Altman, that plots the difference between measurements with both methods against their average. In men (n=20) and women (n=21), the best degree of agreements was obtained between the values measured by deuterium dilution and those calculated from skinfolds (mean difference=1.4 percent and 6.9 percent respectively). The limits of agreement (ñ2SD) for skinfolds reached a maximun of 14.8 percent in men, and 16.8 percent in women. These values tend to underestimate fat in the obese and overestimate it in thinner subjects. For bioimpedance and deuterium dilution, the inter-method difference is significantly greater: 9.3 percent in men and 14.7 percent in women. This lack of agreement is attributed to the fact that the bioimpedance equipment utilizes equations validated for younger adults. In conclusion, estimation of body composition using skinfolds has the smallest difference compared with deuterium dilution, eventhougt individual measurements are not clinically acceptable. Caution is recommended when using individual measurements of body composition in the elderly, due to large errors in the determinations

Influencia del consumo de huevos sobre el perfil lipído en hombres adultos sanos / Lipidic profile and shell egg consumption in healthy male adults

Se estudió el efecto del consumo moderado de huevos ( 1 a 2 por día) durante 6 semanas en voluntarios de sexo masculino, que consumían dietas habituales del nivel sociéconomico medio alto chileno. El grupo control no consumió huevos durante el mismo período. Se realizaron mediciones de colesterol total, LDL y HDL y triglicéridos. Los valores basales de los tres grupos no difirieron estadísticamente, como así tampoco los valores finales. Al comparar los valores basales y finales de cada grupo, no hubo diferencias estadísticamente significativas en los grupos de 1 y 2 huevos, en el control el colesterol total y de LDL aumentaron significativamente, mientras el colesterol de HDL disminuyó. Si bien las respuestas de los sujetos fueron muy variadas, los valores individuales y promedios grupales se mantuvieron dentro de los rangos normales para cada variable. Se concluye que en hombres adultos sanos, el consumo moderado de huevos durante seis semanas no afecta el perfil lipídico

Distribución de grasa corporal: indicadores antropométricos / Body fat distribution: anthropometric indexes

There are two types of fat distribution in obese subjects. The abdominal superior, android or apple shaped and the gluteo-femoral, gynecoid, inferior or pear shaped. In the former, fat ios accumulated in the abdomen and in the latter, in the gluteal region. The superior distribution is associated with a higher risk of cardiovascular diseases. Among anthropometric measurements of fat distribution, the ratio between waist circumference measured at the level of the navel and hip circumference, measured at the level of greater trochanters, is the best indicator. Using the cutoff points of 0.8 for women and 1 for men, it has a good correlation with visceral fat