Читать книгу Gestational Diabetes - Группа авторов - Страница 24

Adiponectin is produced in large quantities by adipose tissue and is associated with increased insulin sensitivity. Levels of circulating adiponectin are inversely related to insulin resistance in obesity and diabetes [35] and are negatively correlated with adiposity [36]. Adiponectin is considered to be an anti-diabetes cytokine, downregulating the production and release of other proinflammatory cytokines from adipocytes [37]. Three forms of adiponectin appear in the circulation: low, mid, and high molecular weight. High-molecular weight adiponectin has been postulated to be the form that has insulin-sensitizing anti-diabetic effects. Adiponectin is increased during adipogenesis, presumably leading to increased insulin sensitivity and favoring energy storage in fat. Low levels of circulating adiponectin prior to pregnancy have been associated with the subsequent development of gestational diabetes [38]. Women destined to develop gestational diabetes had lower adiponectin levels at 16 weeks’ gestation than did controls who did not develop gestational diabetes [30]. Adiponectin decreases by about one-third during pregnancy [32], despite an approximately 25% increase in fat mass [39]. Adiponectin appears not to be produced by the placenta [40, 41], and its downregulation in pregnancy may be mediated by methylation of the adpN gene DNA [41]. Whether the fall in adiponectin during pregnancy is a cause or an effect of insulin resistance is debated.