Paraoxonase 1 Activity is Associated with Interleukin-6 Levels in Type 2 Diabetes: Effects of Age and Gender

Background: A further understanding of the mechanisms linking inflammation to T2D and related complications can help prevent or control this silent but dangerous disease. This study was conducted to determine the association between paraoxonase 1 (PON1) activity and interleukin-6 (IL-6) in type 2 diabetes (T2D). Furthermore, we have evaluated the role of age and gender in the relationship between the PON1 activity and IL-6.

Methods: A total of 105 people with T2D were enrolled in this study. IL-6 levels were determined using ELISA. For the PON1 activity assay, the hydrolysis rate of the substrate phenylacetate was spectrophotometrically assayed in serum at 270 nm. The determined velocities were the initial velocities of substrate hydrolysis.

Results: PON1 activity was negatively correlated with IL-6 in total data (r = -0.34, P = 0.001). In both groups with age ≥50 and <50 years, PON1 activity was negatively correlated with IL-6, but the correlation was significant in patients aged 50 years and above (r = -0.358, P = 0.005) compared with patients with age <50 years. In both women and men, PON1 activity was negatively correlated with IL-6, but the correlation was significant in women (r = -0.318, P = 0.006) in comparison with men.

Conclusions: Inverse association between PON1 activity and IL-6 in T2D may represent the oxidative-inflammatory interaction in this disease. Our findings highlight that at older ages and in women, the associations between lower PON1 activity and higher IL-6 concentrations are more evident, and this should be considered in patients with T2D.