The changes of serum glypican4 in obese patients with different glucose metabolism status.

ABSTRACT

CONTEXT AND OBJECTIVE: Glypican 4 (Gpc4) was identified as a novel adipokine capable of intensifying insulin signaling and regulating adipocyte differentiation. This study was performed to investigate the changes of serum Gpc4 levels in obese patients with different glucose metabolism status and its association with metabolic-related parameters. DESIGN AND PARTICIPANTS: A total of 170 obese patients with different glucose metabolism status and 38 normal controls were recruited, and obese patients were divided into 4 groups OB1, obese patients with normal glucose tolerance (NGT) and normal insulin levels; OB2, obese patients with normal glucose tolerance and hyperinsulinemia; OB3, obese patients with impaired glucose tolerance; and OB4, obese patients with type 2 diabetes mellitus. Serum Gpc4 was determined by commercially available ELISA kits. RESULTS: Serum Gpc4 levels in the OB2, -3, and -4 groups were significantly increased in comparison with that in the OB1 group (3.5 [2.0-5.3] ng/mL, 3.0 [1.5-6.1] ng/mL, and 3.4 [1.8-5.4] ng/mL vs 1.9 [1.3-4.3] ng/mL, P < .05). The levels were positively correlated with body mass index (BMI), systolic blood pressure (SBP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), fasting insulin (FINS), and homeostasis model assessment of insulin resistance (HOMA-IR) in all subjects. Multiple linear regression showed that SBP, AST, HOMA-IR, and FINS were independent contributors to circulating Gpc4 levels after adjusting for age, gender, and BMI in all subjects (P < .05). Additionally, serum Gpc4 levels in males of the normal group and the OB3 group were higher than those in females (2.9 [2.1-4.9] ng/mL vs 1.6 [1.2-3.1] ng/mL; 4.8 [2.5-6.3] ng/mL vs 2.7 [1.1-4.4] ng/mL, P < .05). CONCLUSIONS: Serum Gpc4 levels were significantly elevated in obese patients with insulin resistance and positively correlated with BMI, SBP, ALT, AST, FINS, and HOMA-IR, suggesting Gpc4 is a novel adipokine associated with obesity and insulin resistance-related metabolic disorders.