Lipoprotein associated phospholipase A2 activity & its correlation with oxidized LDL & glycaemic status in early stages of type-2 diabetes mellitus

Abstract

Background & objectives:Lipoprotein associated phospholipase A2 (Lp-PLA2) is an important risk predictor of coronary artery disease (CAD). This study was aimed to evaluate Lp-PLA2 activity and oxidized low density lipoprotein (oxLDL) in newly diagnosed patients of type 2 diabetes mellitus and to determine the correlation of Lp-PLA2 activity with oxLDL and plasma glucose levels.Methods:Blood samples were collected in patients with newly diagnosed type 2 diabetes (n=40) before any treatment was started and healthy controls (n=40). These were processed for estimating plasma glucose: fasting and post prandial, ox LDL, and Lp-PLA2 activity. The parameters in the two groups were compared. Correlation between different parameters was calculated by Pearson correlation analysis in both groups.Results:Lp-PLA2 activity (24.48 ± 4.91 vs 18.63 ± 5.29 nmol/min/ml, P<0.001) and oxLDL levels (52.46 ± 40.19 vs 33.26 ± 12.54 μmol/l, P<0.01) were significantly higher in patients as compared to those in controls. Lp-PLA2 activity correlated positively with oxLDL in both controls (r=0.414, P<0.01), as well in patients (r=0.542, P<0.01). A positive correlation between Lp-PLA2 activity and fasting plasma glucose levels was observed only in patients (r=0.348, P<0.05).Interpretation & conclusions:Result of this study implies that higher risk of CAD in patients with diabetes may be due to increase in Lp-PLA2 activity during the early course of the disease. A positive correlation between enzyme activity and fasting plasma glucose indicates an association between hyperglycaemia and increased activity of Lp-PLA2. This may explain a higher occurrence of CAD in patients with diabetes. A positive correlation between oxLDL and Lp-PLA2 activity suggests that Lp-PLA2 activity may be affected by oxLDL also.

The role of Lp-PLA2 and biochemistry parameters as potential biomarkers of coronary artery disease in Asian South-Indians: a case-control study

“…In a north Indian population with type II diabetes mellitus, Lp-PLA 2 activity was associated with oxidized LDL levels, with higher Lp-PLA 2 activity among subjects with newly diagnosed diabetes. Although this study did not evaluate CAD prevalence, it was speculated that the increased Lp-PLA 2 activity could lead to greater risk of CAD among subjects with type II diabetes mellitus (18). Taken together, these disparate population studies suggest that Lp-PLA 2 concentration is associated with CAD, whereas the data on Lp-PLA 2 activity is less strong.…”

The role of dyslipidemia in diabetic retinopathy

“…Namely, there is a decrease in the ratio of anti-inflammatory omega3 vs. pro-inflammatory omega6 PUFA in the diabetic retina (14, 90, 91). Combined with an increase in phospholipase A2 (PLA2) activity, this leads to an increase in free omega 6 PUFA, these omega-6 PUFA are then rapidly metabolized through different enzymatic pathways which include lipoxygenase (LOX), cytochrome P450 and cyclooxygenase and converted to pro-inflammatory bioactive lipid mediators including prostaglandins, HETEs and leukotrienes (22, 92). …”

A red yeast rice-olive extract supplement reduces biomarkers of oxidative stress, OxLDL and Lp-PLA2, in subjects with metabolic syndrome: a randomised, double-blind, placebo-controlled trial

“…Therefore, assessment of this biomarker is important in risk assessment of MetS as well as in the evaluation of a potential treatment. In early stages of type 2 diabetes mellitus, a positive correlation is observed between OxLDL and Lp-PLA 2 [16]. …”