ABSTRACT
It has already been a decade and a half since the discovery of adiponectin and its role as an insulin sensitizer and only 7 years since its receptors, AdipoR1 and AdipoR2, were described. A single-nucleotide polymorphism (SNP) is a DNA sequence variation that affects only one nucleotide; it may vary from one population to another with different predisposing factors to diseases and other ailments. Once some of the effects of adiponectin and its receptors were known, it was not long until an effort was made to find the associations between specific SNPs of the genes of this hormone and its receptors as genetic risk factors for insulin resistance, type 2 diabetes mellitus, and metabolic syndrome, although these genes were investigated as possible candidates related to the development of these metabolic disorders. All of these possible associations were studied in different populations from France, Finland, the United Kingdom, North America, and Japan, showing hardly concluding results, and because of that it is highly controversial to directly associate one of the genes mentioned above to insulin resistance, type 2 diabetes mellitus, and metabolic syndrome. All of these inconsistencies lead to a review that summarizes the SNPs of the genes of adiponectin, AdipoR1, and AdipoR2 that are mostly related to insulin resistance syndrome, type 2 diabetes mellitus, and metabolic syndrome, although presenting the possible factors that should be taken into account to homogenize the results obtained until now.
Subject(s)
Diabetes Mellitus, Type 2/genetics , Insulin Resistance/genetics , Metabolic Syndrome/genetics , Adiponectin/genetics , Animals , Genetic Predisposition to Disease , Humans , Polymorphism, Single Nucleotide , Receptors, Adiponectin/genetics , Risk FactorsABSTRACT
Lipoprotein (a) [Lp(a)] was discovered by Kare Berg in 1963 from the study of low-density lipoprotein genetic variants. Lp(a) contains a unique protein, apolipoprotein(a), which is linked to the Apo B-100 through a disulfide bond that gives it a great structural homology with plasminogen, and confers it atherogenic and atherothrombotic properties. Interest in Lp(a) has increased because an important association between high plasma levels of Lp(a) and coronary artery disease and cerebral vascular disorders has been demonstrated. Numerous case control studies have confirmed that hyper-Lp(a) is a risk factor for premature cardiovascular disease. Lp(a) is identified as a genetic trait with autosomal transmission, codified by one of the most studied polymorphic genes in humans. It has been demonstrated that variations in this gene are a major factor in the serum levels of Lp(a). Variations differ considerably between individuals and sex across populations. Various approaches to drug treatment using fibric acid derivatives, growth hormone, insulin-like growth factor-1, alcohol extracted soy protein, niacin, and exercise have been proven to decrease Lp(a) in high risk patients, but none has really been an effective therapeutic option for successfully reducing Lp(a) plasma levels.
Subject(s)
Cardiovascular Diseases/prevention & control , Hyperlipoproteinemias/complications , Lipoprotein(a)/blood , Cardiovascular Diseases/etiology , Cerebrovascular Disorders/etiology , Cerebrovascular Disorders/prevention & control , Coronary Artery Disease/etiology , Coronary Artery Disease/prevention & control , Female , Humans , Hyperlipoproteinemias/drug therapy , Lipoprotein(a)/drug effects , Lipoprotein(a)/genetics , Male , Polymorphism, Genetic , Risk FactorsABSTRACT
La Insulinoresistencia se define como un estado metabólico en el cual los efectos periféricos titulares de la insulina se encuentran disminuidos. La resistencia a la acción de esta hormona se compensa mediante un aumento en su secreción por parte de la célula β, resultando en la llamada hiperinsulinemia compensadora. Desde hace varios años se ha acumulado suficiente evidencia de que la insulinoresistencia y la hiperinsulinemia están involucradas en el desarrollo de hipertensión arterial, obesidad y diabetes. Igualmente, la hiperinsulinemia esta altamente relacionada con el desarrollo de de dislipidemia caracterizada por aumento de las VLDL y TAG y una disminución de las HDL favoreciendo la aparición de ateroesclerosis. Otra de las patologías que se ha encontrado fuertemente relacionada con la hiperinsulinemia y la insulinoresistencia es la isquemia miocárdica, tanto en su génesis como en su evolución, ya que se ha demostrado que las posibilidades de supervivencia del miocito se ven reducidas por la disminución de la captación de glucosa durante el período isquémico. La hiperinsulinemia también se relaciona con la hipertrofia miocárdica, probablemente debido al efecto directo de la insulina sobre la elevación de la presión arterial, bien por incremento en la reabsorción de Na+ o por hiperactividad simpática. Finalmente, la resistencia a la insulina es muy prevalente en pacientes no diabéticos que han padecido TIA o ACV sin secuelas. Este hallazgo tiene importantes implicaciones terapéuticas si el tratamiento de esta condición es capaz de reducir la prevalencia de enfermedad cerebro-vascular y enfermedad coronaria.
