The Relationship of the Concentration of Lipoprotein(a) and Markers of Inflammation with Multifocal Atherosclerosis in Women

Abstract

Purpose: to study relationship of lipoprotein(a) [Lp(a)], indicators of systemic inflammation and humoral immunity with severity of atherosclerotic involvement of various vascular beds in women.Materials and methods. We included in this study 148 women aged 69±11 years with results of instrumental investigation of coronary, carotid arteries, and arteries of lower extremities. According to results of coronary angiography and ultrasound study patients were distributed into two groups: with stenosing atherosclerosis (those with hemodynamically significant [>50%] atherosclerotic lesions in any of these vascular beds, n=108), and control (those without hemodynamically significant stenoses, n=40). In dependence of extent of atherosclerotic involvement patients with stenosing atherosclerosis were divided into subgroups: with lesions in one vascular bed (subgroup 1, n=44) and with lesions in two and more vascular beds (subgroup 2, n=64). All patients with stenosing atherosclerosis and 78% of control patients took statins. In all patients we measured lipid spectrum, Lp(a) concentration, C-reactive protein (CRP). Preparations of oxidized lipoproteins [oxLp(a)] were obtained by Cu2+-induced free radical oxidation at 37 °С for 3 hours. Titer of autoantibodies to Lp(a), LDL and their oxidized modifications was determined by enzyme-linked immunosorbent assay (ELISA). Concentration of low-density lipoprotein cholesterol corrected on cholesterol in Lp(a) (LDLCh corr) was calculated by Dahlen modification of Friedewald formula.Results. Stenosing atherosclerosis was diagnosed in 60 of 74 women (80%) with Lp(a) concentration above median - 33 mg/dl (in 38 multifical). Increase of blood serum Lp(a) concentration was associated with presence of isolated as well as multifocal atherosclerosis according to unifactorial, multifactorial, and logistic analysis, irrespective of other factors of risk and indicators of inflammation. According to results of logistic regression analysis increase of Lp(a) concentration by 1 mg/dl was associated with 1 % elevation of probability of appearance and development of multifocal atherosclerosis in women. Low level of class IgM autoantibodies to Lp(a) was linked with detection of stenosing atherosclerosis in any of 3 vascular beds (1st vs. 4th quartile of IgM autoantibodies concentration - OR 7.6., 95%CI 1.9-29.4; р=0.004) and had diagnostic significance. Indicators of systemic inflammation such as CRP and circulating immune complexes were high and had diagnostic significance for detection of multifocal atherosclerosis in studied women. However none of indicators was predictor of appearance of stenosing atherosclerosis according to data of logistic regression analysis.Conclusion. Elevated concentration of Lp(a) is an independent predictor of risk of development stenosing atherosclerosis in various vascular beds and appearance of multifocal irrespective of other risk factors, indicators of systemic inflammation, and factors of humoral immunity in women. Markers of inflammation, as well as IgM autoantibodies against Lp(a) have diagnostic value for detection of patients stenosing lesions ib one or several vascular beds.