Metabolic Basis of Responses to Dietary Fat and Cholesterol
This protocol is designed to conduct simple metabolic tests that will help to establish a defect in sterol metabolism in subjects who present with rare response to dietary fat and cholesterol. Two tests will be carried out in adult subjects referred to the investigators: a dietary challenge to determine responses of LDL cholesterol and a sterol balance test to quantify intestinal sterol absorption and cholesterol synthesis. Pediatric subjects will participate only in the dietary challenge studies.
Adult subjects with rare responses to dietary fat and cholesterol and adult control subjects matched for age, gender and body mass index will be recruited into the study. Members of the proband’s nuclear family (≥ 6yrs) also may be recruited. Subjects with atypical responses to standard of care treatment for hypercholesterolemia will be included for evaluation. An atypical response is defined as a marked change in LDL-cholesterol from baseline upon institution of treatment that includes either dietary modification alone or in combination with hypolipidemic agents. Each referred case will be evaluated on an individual basis.