Relation between serum progranulin, inflammatory markers and visceral fat in childhood obesity

Aim: To study serum progranulin (PGRN) level in children with obesity and its relationship to inflamamatory markers and visceral fat. Methods: Fifty obese children and 50 controls aged 10 - 18 years were recruited. Demographic, anthropometric and biochemical features were collected according to a standard protocol. Serum progranulin levels, serum IL-6 and hsCRP were measured using ELISA. Insulin resistance was calculated by the homeostasis model (HOMA-IR) using the following formula: HOMA-IR = fasting insulin (mU/L) fasting glucose (mmoL/L)/ 22.5. The maximum visceral fat thickness (VFT) and the minimum subcutaneous fat thickness (SFT) were measured by ultrasonography. Results: In the obese group, a significant increase was found in serum PGRN (48.87 plus or minus 42.33 ng/mL) compared to control group (30.18 plus or minus 23.82 ng/mL). Progranulin correlated significantly with VFT (r = 0.475), IL6 (r = 0.368), Insulin(r = 0.440) and HOMA-IR (r = 0.379). The mean serum progranulin in the high tertile VFT group was significantly higher than those in the low tertile and middle tertile groups (P = 0.030 and P = 0.039 respectively). VFT was highly positively correlated to progranulin, SFT, IL6, insulin, HOMA-IR and hsCRP (P = 0.001, 0.000, 0.001, 0.001, 0.003 and 0.003). However, the correlation coefficient between SFT and progranulin was insignificant. Summary: we demonstrated for the first time that serum PGRN concentrations increased in Egyptian obese children. The concentrations of serum PGRN correlated closely with visceral fat and IL6. Conclusion: PGRN may contribute to the pathogenesis of chronic inflammation in obesity. It could be a novel marker of visceral fat in obesity. Thus PGRN could be a potential therapeutic target for management of chronic inflammation in obesity.