Review of human studies evaluating individual dietary responsiveness in patients with hypercholesterolemia.

Individual variation in the low-density-lipoprotein (LDL)-cholesterol response to a cholesterol-lowering diet has been well documented in inpatient and outpatient diet studies. This variation could be due to both clinical and biological factors. Clinical factors include adherence to dietary changes and changes in body weight. Biological factors include specific changes in dietary composition, initial serum cholesterol concentrations, presence of excess body weight, the fractional catabolic rate of LDL with a diet high in saturated fatty acid, the presence of specific isoforms of apoprotein E and apoprotein A-IV, changes in the gene encoding apoprotein B or the apoprotein A-I promoter region, and the ultracentrifugation pattern of LDL lipoproteins. Work exploring the metabolic basis for individual variation in responsiveness to a cholesterol-lowering diet is in its infancy. Careful studies controlling for the clinical influences of responsiveness are needed so that true biological determinants of response can be uncovered.