Plant Sterols in Serum and in Atherosclerotic Plaques of Patients Undergoing Carotid Endarterectomy

• Published in: Journal of the American College of Cardiology 2005-06, Vol.45 (11), p.1794-1801
• Main Authors: Miettinen, Tatu A., Railo, Mikael, Lepäntalo, Mauri, Gylling, Helena
• Format: Article
• Language: English
• Subjects: Absorption; Aged; Aged, 80 and over; Atherosclerosis (general aspects, experimental research); Biological and medical sciences; Blood and lymphatic vessels; Cardiology; Cardiology. Vascular system; Cardiovascular disease; Carotid Arteries - chemistry; Carotid Arteries - metabolism; Carotid Artery Diseases - metabolism; Carotid Artery Diseases - surgery; Cholestanol - metabolism; Cholesterol; Cholesterol - analogs & derivatives; Cholesterol - metabolism; Cholesterol, HDL - blood; Chromatography, Gas; Endarterectomy, Carotid; Female; Hospitals; Humans; Low density lipoprotein; Medical sciences; Middle Aged; Mortality; Phytosterols - blood; Phytosterols - metabolism; Population; Sitosterols - metabolism; Sterols; Stroke; Studies; Surgery; Veins & arteries
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/j.jacc.2005.02.063

The purpose of this research was to determine whether serum plant sterol levels are associated with those in atheromatous plaque. Cholesterol of low-density lipoprotein (LDL) particles contributes to atheromatous plaque formation; LDL also contains most serum non-cholesterol sterols, including plant sterols. The role of plant sterols in atheromatous plaque formation is open. Free, ester, and total cholesterol and the respective non-cholesterol sterols were measured by gas-liquid chromatography in serum and arterial tissue of 25 consecutive patients undergoing carotid endarterectomy. The population was ranked to triads according to tissue cholesterol concentration. Cholesterol concentration increased markedly in tissues but not in serum with triads. The ester percentage was lower in the third than in the first triad (47% vs. 56%; p < 0.01) and lower than in serum triads (70%; p < 0.001). Ratios to cholesterol of non-cholesterol sterols decreased in increasing tissue triads, but were unchanged in serum. A major new observation was that the higher the ratio to cholesterol of the surrogate absorption sterols (cholestanol, campesterol, sitosterol, and avenasterol) in serum, the higher was their ratio also in the carotid artery wall (e.g., r = 0.683 for campesterol). Despite undetectable differences in serum and tissue cholesterol concentrations off and on statins, an additional important novel finding was that statin treatment was associated with increased ratios of the absorption sterols in serum and also in the arterial plaque. The higher the absorption of cholesterol, the higher are the plant sterol contents in serum resulting also in their higher contents in atherosclerotic plaque. However, the role of dietary plant sterols in the development of atherosclerotic plaque is not known.