Variations in levels of interleukins and adiponectin in normal and obese adults; a case-control study

Background: Changes in secretion of cytokines can cause various physiological alterations in the body and might be involved in pathogenesis of metabolic disorders such as diabetes and metabolic syndrome. However, our knowledge in this field is still limited and further investigations are required. Accordingly, the present study aimed to provide evidence on the levels of adiponectin and interleukins in obese and normal subjects.Methods: In this case-control study, 70 healthy subjects with body mass indices (BMI) ranging from 18.0 to 24.9 kg/m2 and 70 healthy obese subjects with BMIs equal or greater than 25 kg/m2 were recruited from the students of Tehran University of Medical Sciences as the control and case groups, respectively. Included subjects underwent anthropometric measurements and then the concentrations of tumour necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), interleukin 8 (IL-8), interleukin 10 (IL-10), interleukin 12 (IL-12), interleukin 18 (IL-18) and adiponectin were measured in their sera.Results: Analyses showed positive significant linear correlations between BMI and the levels of TNF-alpha (r=0.58; p<0.0001), IL-6 (r=0.72; p<0.0001), IL-8 (r=0.57; p<0.0001), IL-12 (r=0.60; p<0.0001) and IL-18 (r=0.52; p<0.0001). On the other hand, serum concentrations of IL-10 (r= -0.59; p<0.0001) and adiponectin (r= -0.48; p<0.0001) were found to be negatively correlated with BMI.Conclusion: The findings of the present study showed significant correlations between serum levels of inflammatory markers and BMI. Increasing BMI was found to be associated with rises in the levels of TNF-alpha, IL-6, IL-8, IL-12 and IL-18 and decreases in the concentrations of IL-10 and adiponectin. These results further emphasize the importance of addressing inflammatory markers in obesity.