Cholesterol metabolism in a patient with familial Hyper-betalipoproteinaemia during periods of high and low cholesterol intake

Abstract

Listen

Translate article

The metabolism of cholesterol was estimated in a man with familial hyper-betalipoproteinaemia in the heterozygous form during periods of high and low cholesterol intake. [ 14C]Cholesterol of constant specific activity was fed daily for several weeks at the beginning of each period. Faecal excretion of total steroids was estimated by the isotopic balance method during each period when all unabsorbed dietary [ 14C]cholesterol had been excreted. Absorption of dietary cholesterol during each period was estimated from the cumulative total of endogenous 14C excreted in the faeces. Cholesterol synthesis was estimated as the difference between faecal excretion of endogenous steroids and absorption of dietary cholesterol, on the assumption that the amount of cholesterol in the exchangeable pool remained constant during each period. Absorption of dietary cholesterol was about 100 mg/day more on the high than on the low intake. Excretion of bile acids in the faeces was higher on the high than on the low intake, but the difference was not statistically significant. Cholesterol synthesis was not significantly lower on the high than on the low cholesterol intake. It is concluded that increased absorption of dietary cholesterol did not lead to inhibition of cholesterol synthesis in this patient.