Maximal low density lipoprotein receptor activity and the effect of lipid lowering diet on total serum cholesterol

This study was undertaken to test if the effect of lipid lowering diet on total serum cholesterol, is influenced by maximal low density lipoprotein (LDL) receptor activity. LDL receptor activity was determined in cultured skin fibroblasts from hypercholesterolemic, male subjects after lipid lowering diet intervention. The LDL receptor values from 15 subjects (responders) who had responded well to a lipid lowering diet and from 14 subjects (non-responders) who had responded poorly, were compared. The responders had a reduction in total serum cholesterol of 29.4%, and the non-responders had a reduction of 8.2% (p less than 0.0001). The higher values for LDL receptor activity among the responders did not reach statistical significance. For all 29 subjects there were non-significant positive correlations between reductions in total serum cholesterol and values for association or degradation of 125I-LDL at 37 degrees C (r = 0.16, p = 0.40 and r = 0.17, p = 0.38, respectively). Thus, it seems that maximal LDL receptor activity is not a major predictor for the response of lipid lowering diet on total serum cholesterol levels in hypercholesterolemic subjects without autosomal dominant familial hypercholesterolemia.