Superiority of partial ileal bypass over cholestyramine reducing cholesterol in familial hypercholesterolaemia.

Low density lipoprotein (LDL) turnover studies were conducted on three occasions in each of six patients with heterozygous familial hypercholesterolaemia (FH)-on diet, after 1 month on cholestyramine 16 g/day, and 2 months after partial ileal bypass. Partial ileal bypass lowered total and LDL cholesterol levels and increased the fractional catabolic rate of LDL to a greater extent than did cholestyramine; this difference presumably reflects the greater increase in bile acid excretion induced by the surgical procedure. Studies in two other heterozygotes showed that partial ileal bypass specifically enhanced receptor-mediated catabolism of LDL. The findings support the concept that therapeutic stimulation of bile acid synthesis increases the rate of receptor-mediated uptake and degradation of LDL by the liver.