Biochemical and hemodynamic determinants of c-reactive protein as an inflammatory marker of endothelial dysfunction. the impact of systolic hypertension

Abstract

C-reactive protein (CRP) is a known factor of systemic inflammation and is currently conceived as a cardiovascular risk factor in the short and long term. To know the biochemical and hemodynamic determinants of CRP. To assess its correlation with Endothelial Dysfunction (ED). Study Population: N=131 patients from a cardiovascular risk population, 70 female, 61 male, aged 21-82 years (57 +/- 14), 52 dyslipemic (LDLc > 160mg/dl), 84 hypertensive (WHO Criteria), 50 type 2 diabetics (WHO Criteria) and 31 active smokers. Biochemical parameters: basal glycemia, HbAlc, total cholesterol, cLDL, cHDL, triglycerides, and lipoprotein a (Lpa). Hemodynamic parameters: Blood Pressure Holter (Spacelabs 90210): Four periods were assessed: 1) Global 24h Period; 2) Daytime Period (9-22h); 3) Nighttime period (22-6h); and 4) Critical Period (6-9h). ENDOTHELIAL DYSFUNCTION: endothelium-dependent vasodilatation (EDV), by Flow Mediated Vasodilatation (FMV) and endothelium-independent vasodilatation (EIV), by sublingual nitroglycerin, were assessed by brachial artery Doppler Ultrasonography (DUS) in N=58. CRP: Behring Nephelometer II. T-Student, Chi-square. 1- 18% of patients had CRP serum levels higher or equal to 5 mg/l. 2- Such levels were positively correlated with : basal glycemia (143.22 +/-17.71 vs 122.07 +/- 5.93;p<0.02), HbAlc (6.66 +/- 0.44 vs 5.76 +/- 0.16; p<0.039), Lp(a) (35.57 +/- 8.92 vs 24.75 +/- 2.55; (Mean +/- SEM); p<0.015) 75% of patients with high levels of CRP had average systolic arterial blood pressure levels higher or equal to 125 mmHg versus 47 % with systolic blood pressure levels <125 (p<0.040). 3- A statistically significant association was found between high levels of CRP and endothelial dysfunction (22.8% ED and CRP>5 vs 4.34% no ED and CRP>5; p<0.05). 1- Basal glycemia, HbA1c and Lpa, but not total cholesterol, cLDL nor triglycerides are biochemical factors of CRP levels elevation. 2- The degree of systolic arterial blood pressure levels could be the determinant hemodynamic factor. 3- ED associated with high CRP levels justifies by itself the high risk for acute events.