title: Despite higher body fat content, Ecuadorian subjects with Laron syndrome have less insulin resistance and lower incidence of diabetes than their relatives.
abstract: In the present pandemics of obesity and insulin resistant diabetes mellitus (DM), the specific contribution of etiological factors such as shifts in nutritional and exercise patterns, genetic and hormonal, is subject of ongoing research. Among the hormonal factors implicated, we selected obesity-driven insulin resistance for further evaluation. It is known that growth hormone (GH) has profound effects on carbohydrate metabolism. In consequence, we compared the effects of the lack of the counter-regulatory effects of GH, in a group of subjects with GH receptor deficiency (GHRD) due to a mutated GH receptor vs. that of their normal relatives. It was found that, despite their obesity, subjects with GHRD, have diminished incidence of diabetes, lower glucose and insulin concentrations, and lower values of indexes indicative of insulin resistance such as HOMA-IR. The GHRD subjects were also capable of appropriately handling glucose or mixed meal loads despite diminished insulin secretion. These observations allow us to suggest that the association of obesity with increased risk for diabetes appears to be dependent on intact growth hormone signaling.
authors.affiliation: Colegio de Ciencias de la Salud, Universidad San Francisco de Quito, Ecuador; Instituto de Endocrinología, Metabolismo y Reproducción - IEMYR, Quito, Ecuador. Electronic address: guevaraaguirre@yahoo.com.
authors.forename: Jaime
authors.initials: J
authors.lastname: Guevara-Aguirre
authors.affiliation: Instituto de Endocrinología, Metabolismo y Reproducción - IEMYR, Quito, Ecuador.
authors.forename: Patricio
authors.initials: P
authors.lastname: Procel
authors.affiliation: Instituto de Endocrinología, Metabolismo y Reproducción - IEMYR, Quito, Ecuador.
authors.forename: Carolina
authors.initials: C
authors.lastname: Guevara
authors.affiliation: Instituto de Endocrinología, Metabolismo y Reproducción - IEMYR, Quito, Ecuador.
authors.forename: Marco
authors.initials: M
authors.lastname: Guevara-Aguirre
authors.affiliation: Instituto de Endocrinología, Metabolismo y Reproducción - IEMYR, Quito, Ecuador.
authors.forename: Verónica
authors.initials: V
authors.lastname: Rosado
authors.affiliation: Colegio de Ciencias de la Salud, Universidad San Francisco de Quito, Ecuador.
authors.forename: Enrique
authors.initials: E
authors.lastname: Teran
mesh_terms: D000273:Adipose Tissue; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000235:genetics / Q000378:metabolism; D004484:Ecuador / Q000453:epidemiology; D005190:Family; D006801:Humans; D015994:Incidence; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance / Q000235:genetics; D046150:Laron Syndrome / Q000453:epidemiology / Q000235:genetics / Q000378:metabolism*; D011986:Receptors, Somatotropin / Q000235:genetics
chemical_list: D001786:Blood Glucose; D007328:Insulin; D011986:Receptors, Somatotropin
keywords: Growth hormone; Growth hormone receptor; Growth hormone receptor deficiency; Laron syndrome