Inflammatory cytokines in insulin-treated patients with type 2 diabetes

The mean serum cytokine levels in group A vs. group B were: IL-6, 8.54 ± 11 vs. 2.71 ± 1.9 pg/ml (p = 0.000); TNF-α, 14.33 ± 24 vs. 5.12 ± 15 pg/ml (p = 0.016); sTNFR60, 3.9 ± 2.8 vs. 2.36 ± 1.4 ng/ml (p = 0.000); and sTNFR80, 11.9 ± 7 vs. 9.4 ± 6 ng/ml (p = 0.080). The mean serum cytokine levels in group A vs. group C were: IL-6, 8.54 ± 11 vs. 4.74 ± 7 pg/ml (p = 0.017); TNF-α, 14.33 ± 24 vs. 5.94 ± 3.4 pg/ml (p = 0.003); sTNFR60, 3.9 ± 2.8 vs. 2.54 ± 1.4 ng/ml (p = 0.000); and sTNFR80, 11.9 ± 7 vs. 10.85 ± 8 ng/ml (p = 0.470). A positive association between waist circumference and IL-6 (r = 0.165, p = 0.030) and sTNFR-60 (r = 0.276, p = 0.000) was detected. A significant correlation coefficient was observed between haemoglobin A1c (HbA1c) and both IL-6 (r = 0.278, p = 0.000) and sTNFR-60 (r = 0.293, p = 0.000), when the groups were studied as one. No correlation between inflammation and units of insulin/kg BW was found. In conclusion, low-grade chronic inflammation, as estimated by the relative levels of inflammatory cytokines, was present in patients with type 2 diabetes that were receiving insulin treatment, with significantly higher cytokine levels recorded compared to sulfonylurea-treated patients. In addition, an association between inflammation and both obesity and glucose homeostasis was detected.