DIETARY-CHOLESTEROL FEEDING SUPPRESSES HUMAN CHOLESTEROL-SYNTHESIS MEASURED BY DEUTERIUM INCORPORATION AND URINARY MEVALONIC ACID LEVELS

Citation
Pjh. Jones et al., DIETARY-CHOLESTEROL FEEDING SUPPRESSES HUMAN CHOLESTEROL-SYNTHESIS MEASURED BY DEUTERIUM INCORPORATION AND URINARY MEVALONIC ACID LEVELS, Arteriosclerosis, thrombosis, and vascular biology, 16(10), 1996, pp. 1222-1228
Citations number
46
Categorie Soggetti
Cardiac & Cardiovascular System","Peripheal Vascular Diseas
ISSN journal
10795642
Volume
16
Issue
10
Year of publication
1996
Pages
1222 - 1228
Database
ISI
SICI code
1079-5642(1996)16:10<1222:DFSHCM>2.0.ZU;2-X
Abstract
The objective of this study was to measure the response of cholesterol biosynthesis in subjects to three different amounts of dietary choles terol: 50 (low), 350 (medium), and 650 (high) mg cholesterol per 2800 kcal. Individuals with low (n=7), normal (n=12), and elevated (n=11) p lasma cholesterol concentrations consumed in random order solid-food t est diets (15%, 55%, and 30% of energy as protein, carbohydrate, and f at, re spectively) at each dietary cholesterol level. The three diets were consumed for 4 weeks each, and each dietary phase was separated b y a 4-week washout period. During the final week of each diet, 0.7 g D 2O was given per kilogram of body water and deuterium incorporation in to the erythrocyte cholesterol pool was measured for 24 hours. Urinary mevalonate levels were also determined in samples obtained during two consecutive 24-hour periods. Both techniques provided measurements of whole-body cholesterol biosynthesis. In all subjects the cholesterol synthesis rate as measured by deuterium incorporation was significantl y lower (P<.05) after the transition from low- to medium- and low- to high-cholesterol diets. Urinary mevalonate excretion decreased after t he change from the medium- to high- (P<.05) and low- to high- (P<.01) cholesterol diets. Although correspondence between the two methods was poor, they bath indicated some suppression of cholesterol synthesis b y dietary cholesterol. The response of cholesterogenesis to different amounts of dietary cholesterol was related to the rate of synthesis un der depressed conditions of the low-cholesterol diet. These findings i ndicate modest downregulation of synthesis in response to dietary chol esterol in humans, independent of plasma cholesterol levels.