Evaluation of Paraoxonase-1 Activity of Arylesterase and Lactonase and Their Correlation with Oxidative Stress in Children with Type 1 Diabetes Mellitus.

BACKGROUND

Type 1 diabetes mellitus (T1DM) is a chronic autoimmune condition that can lead to long-term complications due to oxidative stress and metabolic dysregulation. Paraoxonase-1 (PON-1), an enzyme associated with high-density lipoprotein (HDL), has dual activities: arylesterase and lactonase. These activities protect lipids from oxidative damage. The functional status of PON-1 in children with T1DM may provide insights into the relationship between oxidative stress and the enzyme's protective role. This study aims to assess the arylesterase and lactonase activities of PON-1 in Iraqi children with T1DM.

METHODS

Sixty-seven children with T1DM were enrolled and compared with 57 age-matched healthy controls. The enzymatic activities of arylesterase and lactonase were measured to evaluate PON-1's functional status. The Paraoxonase-1/HDL (PON/HDL) ratio was calculated to assess lipid protection and antioxidant capacity. Oxidative status was assessed by measuring total oxidative status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI).

RESULTS

PON-1 activity analysis showed a significant reduction in arylesterase (2.36 ± 1.17) and lactonase (21.9 ± 7.31) in the patients group compared to controls (arylesterase=4.54 ± 1.84, lactonase =29.51 ± 9.92). TOS and OSI were significantly higher, while TAS was significantly lower in the patients group. Pearson correlation revealed a positive correlation between HDL-C and arylesterase (P = 0.002, r = 0.379), and HDL-C and lactonase (P = 0.040, r = 0.366).

CONCLUSIONS

Reduced PON-1 activity is associated with T1DM, suggesting that enhancing PON-1 or reducing oxidative stress may help prevent diabetic complications and improve cardiovascular health.