Sitosterolemia

Sitosterolemia, also known as phytosterolemia, is a rare lipid metabolic disorder inherited in an autosomal recessive pattern. It is characterized by hyperabsorption of dietary sterols, including the plant sterol beta-sitosterol, together with decreased excretion of those sterols into the bile. Healthy people absorb only about 5 percent of dietary plant sterols, whereas people with sitosterolemia absorb 15 to 60 percent of the sitosterol they eat without excreting much of it into the bile. The condition is named after sitosterol, the most abundant phytosterol in the diet, although other phytosterols are involved, and campesterol is absorbed more readily than sitosterol. Affected people develop high cholesterol, xanthomas of the tendons and skin, premature atherosclerosis, and abnormal blood and liver test results.