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摘要
Objectives. Modifications of cholesterol metabolism with aging are ill-defined. The objective of this study was to define aging-associated alterations of the different metabolic pathways controlling cholesterol homeostasis by analysis of circulating levels of hydroxylated sterols.
Methods. We analyzed serum samples from 123 adult subjects (45 male, 78 female, age range 38-78 years) from the epidemiological M. I. COL. study (Multicentrica Italiana Colelitiasi). The plasma levels of the different hydroxysterols, recognized as markers of the main metabolic pathways of cholesterol homeostasis, were determined: synthesis (lathosterol), absorption (campesterol and sitosterol), degradation to bile acids (7alpha-hydroxy-4-cholesten-3-one). Analysis was performed by gas-chromatography -mass spectrometry.
Results. A significant correlation was detected between age and cholesterol levels. The lathosterol/cholesterol ratio (an index of cholesterol synthesis) was lower in older (age > 65), compared to younger subjects (102 +/- 39 vs. 126 +/- 62 microg/100 microg cholesterol; p < 0.05, t test for independent data). A significant inverse correlation was present between the lathosterol/cholesterol ratio and age. The remaining markers did not show significant modifications with aging, even if a trend toward a reduction of cholesterol markers was present.
Conclusions. These data, although preliminary, show a reduction of cholesterol synthesis with aging. The finding might be related to a reduced metabolic need for cholesterol in advancing age, leading to a down-regulation of the main mechanisms for cholesterol uptake by the liver. The possible implications in terms of pharmacological management of hypercholesterolemia remain to be defined.
- 出版日期2011-8
