Eder Carlos Rocha Quintão* Pages 1 - 11 ( 11 )
Plasma concentrations of phytosterols, and of non-cholesterol sterol precursors of cholesterol synthesis have been used as markers, respectively, of intestinal cholesterol absorption and synthesis in inherited and secondary dyslipidemias and in population-based investigations to evaluate the risk for cardiovascular disease. The method aims at replacing initial research tecniques such as use of stable isotopes associated with fecal steroid balance that are limited by high cost and tedious procedures. However, we show in this review that several results obtained with serum sterol measurements are contradictory. In this regard, the following points are discussed: 1) how phytosterols relate to atherosclerosis considering that defects in biliary output or in the transport of phytosterols from the intestinal mucosa back into the intestinal lumen provide increased content of phytosterols and other sterols in plasma and tissues not allowing to conclude that their presence in arteries and atheromas represents the etiology of atherosclerosis; 2) serum non cholesterol sterols as markers of cholesterol synthesis and absorption, such as cholestanol, present discrepant results rendering them often inadequate to identify cases of coronary artery disease as well as alterations in the whole body cholesterol metabolism; 3) such methods of measurement of cholesterol metabolism are confounded by factors like diabetes mellitus, body weight and other pathologies including considerable hereditary hyperlipidemias biological variabilities that influence the efficiency of synthesis and intestinal absorption of cholesterol.
cholesterol metabolism, phytosterols, cholesterol synthesis markers
Lipids Lab (LIM-10), University of São Paulo Medical School, São Paulo