Serum Cytokines are regulated in African Americans with High HbA1c

Abstract

Abstract Background Low grade inflammation is associated with T2D resulting from a cadre of serum cytokines. IL3, IL4, IL7, IL-17A, GM-CSF, and GM-CSF play a coordinated pathogenic role in many inflammatory diseases. It has been previously reported high circulating HbA1c influences serum cytokine levels and cholesterol metabolism. Methods A total of 120 serum samples were collected from African Americans: 68 women and 52 men. This group consists of 45 normal HbA1c and 71 high HbA1c participants. Clinical metabolic parameters were measured. Cytokines were measured using Luminex X-MAP® technology. A series of unpaired t-test were computed to determine if there were significant differences between participants with and without elevated HbA1c. Pairwise Pearson Correlation (r) test was computed for each variable. Results In women, IL-3 expression was upregulated 1.7-fold in the presence of high circulating glucose. In men, IL-3 expression was downregulated 1.5-fold. Individuals with high HbA1c exhibit a negative correlation between IL-3 and BMI in men and women. Male serum IL-7 levels decrease in presence of circulating high glucose while female serum IL-7 levels increase. Normal HbA1c men have a 2.7-fold higher serum IL-7 level than women with normal HbA1c. Women participants have a positive correlation with serum IL-7 and HbA1c, as well as BMI. These correlations are lost in men. In the presence of high HbA1c, there is an increase in serum levels of IL-17A, G-CSF, and GM-CSF in women with high HbA1c. Conclusion An increase in HbA1c increases the expression of inflammatory cytokines and the risk of metabolic disease. Our data suggests that, in a sex specific manner, several cytokines may regulate cholesterol and lipid management in T2D.