Paraoxonase 1 activity in chylomicrons and VLDL: the effect of type 2 diabetes and meals rich in saturated fat and oleic acid

Paraoxonase 1 (PON 1) has antioxidant and cardioprotective properties and is abnormally low in type 2 diabetic serum. This study aimed to determine the effect of type 2 diabetes and meals rich in saturated fat and oleic acid on PON1 activity in chylomicrons and very low density lipoproteins (VLDL). PON1 arylesterase activity was measured in chylomicrons and VLDL that were isolated in serum from 20 patients with type 2 diabetes and 20 age- and gender-matched, overweight controls 3 h after meals rich in cream or olive oil in a randomized, cross-over study. Chylomicron-PON1 activity (45%, P = 0.02), ratio chylomicron-PON1/chylomicron-triacylglycerides (TAG) (42%, P = 0.03) and chylomicron-protein content (46%, P < 0.001) were significantly lower in patients with type 2 diabetes compared with controls after the olive oil meal with comparable findings after the meal rich in cream. After ingestion of olive oil, chylomicron-PON1 activity was significantly higher in controls (P = 0.01) and marginally higher (P = 0.06) in diabetic patients and chylomicron-TAG were significantly (P < 0. 05) higher in both groups of subjects, compared with values after ingestion of cream. VLDL-PON1 increased (two-fold) significantly (P < 0.003) during both meals. Chylomicron-PON1 activity was correlated significantly with chylomicron-protein (P