Research

Lipoprotein-associated phospholipase A₂ (Lp-PLA₂) activity, platelet-activating factor acetylhydrolase (PAF-AH) in leukocytes and body composition in healthy adults

Paraskevi Detopoulou¹ , Tzortzis Nomikos¹ , Elizabeth Fragopoulou¹ , Demosthenis B Panagiotakos¹ , Christos Pitsavos² , Christodoulos Stefanadis² and Smaragdi Antonopoulou¹

¹  Department of Nutrition-Dietetics, Harokopio University, Athens, Greece

²  First Cardiology Clinic, School of Medicine, University of Athens, Athens, Greece

author email corresponding author email

Lipids in Health and Disease 2009, 8:19doi:10.1186/1476-511X-8-19

Published:	5 June 2009

Abstract

Background

Lipoprotein-associated phospholipase A₂ (Lp-PLA₂) also known as serum platelet activating factor acetylhydrolase (PAF-AH) activity constitutes a novel risk marker for cardiovascular disease. Leukocytes constitute one main cellular source of circulating Lp-PLA₂. The aim of the present study was to evaluate the association of both serum and leukocyte PAF-AH activities with fat distribution and lean tissue. One hundred healthy volunteers without cardiovascular disease history participated in this study (n = 52 men, 44 ± 13 years and n = 48 women, 43 ± 13 years). Body composition was assessed with dual-energy X-ray absorptiometry, while anthropometrical indices were also measured. The activity of Lp-PLA₂ and levels of lipid and glycemic parameters were determined in fasting samples.

Results

Mean Lp-PLA₂ activity was 24.8 ± 4.5 and 19.6 ± 5.0 nmol/min/mL in men and women, respectively (P < 0.001). Mean activity of PAF-AH in leukocyte homogenates was 386 ± 127 pmol/min/mg and 292 ± 92 pmol/min/mg in men and women, correspondingly (P < 0.001). In multiple regression models upper and total adiposity measures were positively associated with Lp-PLA₂ activity in men after adjusting for LDL-cholesterol, age, smoking, hs-CRP and physical activity, whereas no associations were found with PAF-AH leukocyte homogenates activity. Hierarchical analysis revealed that the variables with the highest explanatory ability of Lp-PLA₂ activity in men, were DXA deriving L1–L4 region of interest and arms fat (increase in R² = 0.136, P = 0.005 and increase in R² = 0.118, P = 0.009, respectively), followed by trunk fat and total fat. In women, no association of body composition variables with Lp-PLA₂ nor PAF-AH leukocyte homogenates activity was found.

Conclusion

Lp-PLA₂ activity is differentiated across levels of adiposity and topology of adipose tissue, whereas no association was found regarding PAF-AH leukocyte homogenates activity. Our findings suggest that Lp-PLA₂ may compensate for the adiposity-associated increases in inflammatory and oxidative burden, in men.