Increased circulating and visceral adipose tissue expression levels of YKL-40 in obesity-associated type 2 diabetes are related to inflammation: impact of conventional weight loss and gastric bypass
Catalán V [SP], Gómez-Ambrosi J [SP], Rodríguez A, Ramírez B, Rotellar F, Valentí V, Silva C [SP], Gil MJ [SP], Salvador J, Frühbeck G [SP].
Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain
Magazine: The Journal of Clinical Endocrinology and Metabolism
Date: Jan 1, 2011General and Digestive Surgery Biochemistry [SP] Endocrinology and Nutrition [SP] Obesity Unit
Plasma YKL-40 is elevated in patients with type 2 diabetes. The potential role of visceral adipose tissue (VAT) as a significant source of YKL-40 is unknown.
In the study circulating and expression levels of YKL-40 were examined in VAT analyzing the contribution of adipocytes and stromovascular fraction cells (SVFCs). We also explored YKL-40's implication in insulin resistance and inflammation and the effect of weight loss on plasma YKL-40 concentrations.
PATIENTS AND METHODS
Samples obtained from 53 subjects were used in the study. Gene and protein expression levels of YKL-40 were analyzed in VAT as well as in both adipocytes and SVFCs. In addition, circulating YKL-40 concentrations were measured before and after weight loss achieved either by Roux-en-Y gastric bypass (n = 26) or after a conventional dietetic program (n = 20).
Circulating concentrations and VAT expression of YKL-40 were increased in obese patients with type 2 diabetes (P < 0.01) as well as associated with variables of insulin resistance and inflammation. No differences in YKL-40 expression levels between adipocytes and SVFCs were detected. Monocyte chemoattractant protein-1 and homeostasis model assessment emerged (P < 0.01) as independent factors predicting circulating YKL-40. Elevated levels of YKL-40 in obese patients decreased after weight loss following a conventional hypocaloric diet (P < 0.05) but not via a surgery-induced negative energy balance mediated by the Roux-en-Y gastric bypass.
The association of increased YKL-40 mRNA and protein levels in VAT with its circulating concentrations indicates an important contribution of VAT in YKL-40 regulation. Furthermore, our data suggest a relevant role of glucose metabolism and inflammation on YKL-40 regulation.
CITATION J Clin Endocrinol Metab. 2011 Jan;96(1):200-9
you maybe interested
The Clínica is the greater private hospital with technological equipment of Spain, all in a single center.
The professionals of the Clínica perform continuous research and training, always to the benefit of the patient.
Learn why we are different from other healthcare centers. Quality, speed, comfort and results.