LIPOPROTEIN ASSOCIATED PHOSPHOLIPASE A2 ACTIVITY IS NEGATIVELY ASSOCIATED WITH DECREASED BAROREFLEX SENSITIVITY IN HIGH NORMAL BLOOD PRESSURE

Abstract

Objective: The relationship between baroreflex sensitivity (BRS) and inflammatory vascular biomarker Lipoprotein associated phospholipase A2 (Lp-PLA2) in subjects with high normal blood pressure (HNBP, prehypertensives) with a positive family history of hypertension (FHH+) to hypertension history free control subjects (FHH-) was evaluated. Design and method: A total of 24 HNBP participants (age 39.5 ± 2.5 years, 18 male/ 6 female) were studied. 14 HNBP subjects FHH+ were compared to 10 HNBP participants FHH-, being of similar age and body mass index. BRS (ms/mmHg) and BRSf (Hz/mmHg) were determined by the sequence and spectral methods (five-minute non-invasive beat-to-beat recording of blood pressure and inter-beat interval, controlled breathing at a frequency of 0.1 Hz). Venous blood was analysed for Lp-PLA2 biomarker of vascular inflammation and atherothrombotic activity. Results: A significant negative correlation between spontaneous BRS obtained by both methods and blood pressure (BP) was present (BRS spect r = –0.54, p<0.001, BRS seq r = –0.59, p<0.001). BRS obtained by sequence and spectral methods were reduced in HNBP FHH+ compared to group of HNBP without history of hypertension (P= 0.0317 BRS seq, P = 0.0395 BRS spect). There was no difference between both groups of HNBP subjects in BRSf values. Lp-PLA2 was significantly higher in HNBP FHH+ compared to FHH- controls (P = 0.025). Lp-PLA2 was negatively correlated with BRS obtained by sequence method (r = - 0.6758, P = 0.00028) and BRS obtained by spectral method (r = - 0.5935, P = 0.00031). Conclusions: Lipoprotein associated phospholipase A2 is negatively associated with decreased baroreflex sensitivity in subjects with high normal blood pressure and positive family history of hypertension. These findings demonstrate that reduced baroreflex sensitivity as marker of autonomic dysfunction is linked with vascular inflammation predominantly in otherwise healthy participants with positive history of hypertension that could predispose to increased risk of hypertension. Further research is needed.