Serum lipid and lipoprotein levels were studied in 17 normal subjects, and in 40 heterozygous and 4 homozygous patients with familial hypercholesterolemia (FH) in Japan. The serum cholesterol (Chol) levels (mean ± SD) in normal subjects, heterozygotes and homozygotes were 173 ± 22, 358 ± 70 and 532 ± 44 mg/dl, respectively. LDL-Chol levels in heterozygotes (254 ± 59 mg/dl) were significantly higher than in normal subjects (94 ± 21 mg/dl) and lower than in homozygotes (432 ± 66 mg/dl). IDL-Chol levels in heterozygotes and homozygotes were significantly higher than normal; serum triglyceride (TG) levels in heterozygotes were significantly higher than normal; LDL-TG levels in patients with FH were significantly higher than normal, as were serum phospholipid (PL) levels. LDL-PL levels in heterozygotes were significantly higher than in normal subjects (P < 0.001) and lower than in homozygotes (P < 0.001). IDL-PL levels in patients with FH were significantly higher than normal. Serum Chol levels correlated highly with the LDL-Chol levels. The regression equation was Y(LDL-Chol in mg/dl)= 0.873X(serum Chol in mg/dl)-58.132 (r : 0.977, P < 0.01). Serum Chol levels weakly correlated with IDL-Chol. Serum PL highly correlated with serum LDL-PL levels, regression equation being Y(LDL-PL in mg/dl)= 0.772X(serum PL in mg/dl)-71.316 (r : 0.913,v P < 0.01). LDL-Chol/LDL-PL ratios in normal, heterozygous, and homozygous subjects were 1.69 ± 0.11, 1.78 ± 0.03 and 1.95 ± 0.13, respectively. LDL-Chol/LDL-TG ratios in normal, heterozygous, and homozygous subjects were 5.46 ± 2.44, 7.30 ± 2.03 and 9.37 ± 4.80, respectively. Thus, FH is a disease characterized by high concentrations of LDL with an increased proportion of Chol and a decreased proportion of TG and PL. © 1979.
