Adipokines and soluble cell adhesion molecules in insulin resistant and non-insulin resistant women with polycystic ovary syndrome.

INTRODUCTION: Insulin resistance (IR) is closely associated with increased atherogenic risk. OBJECTIVE: To investigate leptin, adiponectin, soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1) levels and their relationship with each other and metabolic parameters in women with polycystic ovary syndrome (PCOS). METHODS: The study included 76 PCOS women divided into insulin resistant and non-insulin resistant. Anthropometric parameters, glucose and lipid parameters, leptin, adiponectin, sICAM-1 and sVCAM-1 were determined. Homeostasis model of IR index(HOMA-IR), atherogenic index of plasma(AIP) and leptin/adiponectin ratio were calculated. HOMA-IR > 2.5 and/or fasting plasma glucose/immunoreactive insulin ratio < 0.333 were used as markers for IR. RESULTS: Non-insulin resistant PCOS had significantly higher adiponectin and sVCAM-1 levels. AIP was significantly higher in insulin resistant PCOS. Adiponectin showed a positive correlation with sVCAM-1 and sICAM-1. CONCLUSION: Insulin resistant PCOS women were at higher atherogenic risk compared to non-insulin resistant group. sVCAM-1 data confirms the necessity of further investigations for clarifying its role in IR.

Pathophysiological Role of Adiponectin, Leptin and Asymmetric Dimethylarginine in the Process of Atherosclerosis.

Adipose tissue is recognized as a rich source of proinflammatory mediators that may directly contribute to vascular injury, insulin resistance, and atherogenesis. Many studies have shown that adiponectin has antiatherogenic and anti-inflammatory properties. Adiponectin acts not only as a factor increasing insulin sensitivity, and the protective effect may result from its ability to suppress production of proinflammatory cytokines. It negatively regulates the expression of TNF-alpha and C-reactive protein (CRP) in adipose tissue; reduces expression of vascular and intracellular adhesion molecules (VCAM-1, ICAM-1), E-selectin, interleukin-8 (IL-8). Hyperleptinemia has been linked with the development of hypertension and endothelial dysfunction/atherosclerosis, two main pathophysiological conditions associated with cardiovascular disease development. Leptin-mediated increases in sympathetic nervous system activity may be among the principal mechanisms evoking obesity related hypertension. Leptin stimulates the secretion of proinflammatory cytokines, and increases the release of endothelin-1 (ET-1), which may promote hypertension. Increased serum levels of asymmetric dimethylarginine (ADMA), a physiological regulator of the biosynthesis of nitric oxide (NO), promote the process of atherosclerosis, leading to the occurrence of endothelial dysfunction and cardiovascular disease.

Adipose tissue hormones and appetite and body weight regulators in insulin resistance.

Impaired sensitivity to insulin (the so called insulin resistance, IR) occurs in a number of genetic and acquired conditions, including obesity, non-insulin dependent diabetes mellitus, polycystic ovary syndrome (PCOS) and metabolic syndrome (MS). In this review we discuss the correlation between IR, the adipose tissue hormones and appetite and body weight regulators. Leptin acts as a major adipostat: it suppresses food intake and activates catabolic pathways associated with increased energy production. It improves the peripheral insulin sensitivity and affects beta-cell function. Adiponectin is the only adipocytokine discovered so far that has anti-atherogenic properties. There is a reverse correlation between the serum adiponectin levels and the degree of obesity, IR, impaired glucose tolerance, dyslipidemia and atherosclerosis. Ghrelin stimulates food intake; of all circulating orexigenic hormones ghrelin is the most thoroughly studied. Ghrelin levels are decreased in MS and PCOS patients as this hormone is negatively correlated with body mass. Resistin is a hormone secreted by adipose tissues; a growing body of evidence suggests that it might be implicated in the link between obesity and diabetes. It has been found that the hormone's levels are significantly higher in obese people than those in normal body mass people. The recently discovered adipose tissue hormones, vaspin, visfatin, omentin-1 and their effect on IR development, have been increasingly researched.