Adiponectin gene expression and adipocyte NF-B transcriptional activity in elderly overweight and obese women: inter-relationships with fat distribution, hs-CRP, leptin and insulin resistance

• Published in: International Journal of Obesity 2007-07, Vol.31 (7), p.1104-1109
• Main Authors: Zamboni, M, Di Francesco, V, Garbin, U, Fratta Pasini, A, Mazzali, G, Stranieri, C, Zoico, E, Fantin, F, Bosello, O, Cominacini, L
• Format: Article
• Language: English
• Subjects: adiponectin; Adipose tissue; Body fat; body fat distribution; Body mass index; C-reactive protein; Cholesterol; elderly; elderly nutrition; gene expression; human genetics; inflammation; Insulin resistance; leptin; nuclear factor kB; Obesity; overweight; transcription (genetics); women
• ISSN: 0307-0565; 1476-5497
• DOI: 10.1038/sj.ijo.0803563

Objective: The regulatory processes that modulate adiponectin production and the mechanisms involved in nuclear factor kB (NF-kB) transcriptional activity in human adipocytes are not yet fully known. The aim of our study was to evaluate the inter-relationships between body fat, fat distribution, systemic inflammation, insulin resistance, leptin and the serum and subcutaneous adipose tissue gene expression levels of tumor necrosis factor-alpha (TNF-α), adiponectin and the inhibitor kappa B-alpha (IkB-α), in subjects with a wide range of body mass index (BMI). We also wanted to determine which of these variables was most closely related to adiponectin gene expression and adipocyte NF-kB transcriptional power. Methods: A total of 27 women aged between 50 and 80 years, with BMI ranging from 22.1 to 53.3 kg/m2, were studied. In all subjects BMI, waist circumference, body composition by dual X-ray absorptometry, triglycerides, cholesterol, high-density lipoprotein cholesterol (HDL-Ch), glucose, insulin, homeostasis model assessment of insulin resistance (HOMA), high-sensitive C-reactive protein (hs-CRP), serum adiponectin, leptin and TNF-α were evaluated. Subcutaneous adipose tissue biopsies were taken from the abdomen of all subjects and the mRNA levels of adiponectin, TNF-α and IkB-α were determined. Results: BMI and waist circumference were associated positively with leptin, HOMA, and hs-CRP, and negatively with HDL-Ch; waist was also associated with adiponectin and IkB-α mRNA. HOMA was negatively associated with serum adiponectin and adiponectin mRNA. Hs-CRP was negatively associated with IkB-α mRNA, and was positively associated with HOMA. Step-down multiple regression analysis was performed to determine the joint effects of BMI, waist circumference, triglycerides, HDL-Ch, HOMA, hs-CRP, leptin, serum and TNF-α mRNA on adiponectin gene expression: waist circumference and leptin were both included in the best fitting regression equation for predicting adiponectin gene expression (R 2=0.403, P=0.006). Stepwise multiple regression analysis was performed, considering IkB-α mRNA as a dependent variable and BMI, waist, HDL-Ch, HOMA, hs-CRP and adiponectin mRNA as independent variables. Adiponectin mRNA was the only variable to enter the regression (R2=0.406, P