Association between prehypertension, metabolic and inflammatory markers, decreased adiponectin and enhanced insulinemia in obese subjects

Background: Obesity is associated with development of the cardiorenal metabolic syndrome, which is a constellation of risk factors, such as insulin resistance, inflammatory response, dyslipidemia, and high blood pressure that predispose affected individuals to well-characterized medical conditions such as diabetes, cardiovascular and kidney chronic disease. The study was designed to establish relationship between metabolic and inflammatory disorder, renal sodium retention and enhanced blood pressure in a group of obese subjects compared with age-matched, lean volunteers. Methods: The study was performed after 14 h overnight fast after and before OGTT in 13 lean (BMI 22.92 +/- 2.03 kg/m(2)) and, 27 obese (BMI 36.15 +/- 3.84 kg/m(2)) volunteers. Assessment of HOMA-IR and QUICKI index were calculated and circulating concentrations of TNF-alpha, IL-6 and C-reactive protein, measured by immunoassay. Results: The study shows that a hyperinsulinemic (HI: 10.85 +/- 4.09 mu g/ml) subgroup of well-characterized metabolic syndrome bearers-obese subjects show higher glycemic and elevated blood pressure levels when compared to lean and normoinsulinemic (NI: 5.51 +/- 1.18 mu g/ml, P < 0.027) subjects. Here, the combination of hyperinsulinemia, higher HOMA-IR (HI: 2.19 +/- 0.70 (n = 12) vs. LS: 0.83 +/- 0.23 (n = 12) and NI: 0.98 +/- 0.22 (n = 15), P < 0.0001) associated with lower QUICKI in HI obese when compared with LS and NI volunteers (P < 0.0001), suggests the occurrence of insulin resistance and a defect in insulin-stimulated peripheral action. Otherwise, the adiponectin measured in basal period was significantly enhanced in NI subjects when compared to HI groups (P < 0.04). The report also showed a similar insulin-mediated reduction of post-proximal urinary sodium excretion in lean (LS: 9.41 +/- 0.68% vs. 6.38 +/- 0.92%, P = 0.086), and normoinsulinemic (NI: 8.41 +/- 0.72% vs. 5.66 +/- 0.53%, P = 0.0025) and hyperinsulinemic obese subjects (HI: 8.82 +/- 0.98% vs. 6.32 +/- 0.67%, P = 0.0264), after oral glucose load, despite elevated insulinemic levels in hyperinsulinemic obeses. Conclusion: In conclusion, this study highlights the importance of adiponectin levels and dysfunctional inflammatory modulation associated with hyperinsulinemia and peripheral insulin resistance, high blood pressure, and renal dysfunction in a particular subgroup of obeses.