Plasma lipids and lipoproteins in Down's syndrome.

Since mongoloids have been reported to differ from other patients with mental retardation by being virtually free of atheromatosis, we analysed plasma lipids and lipoproteins in twenty mongoloid and in twenty age-matched non-mongoloid mentally retarded patients living in the same institution. Plasma total cholesterol in the mongoloids did not differ significantly from that of the control group, but it was low in both groups in comparison with the Finnish population in general. Plasma total triglyceride concentration was higher (P less than 0.01) in the mongoloids than in the controls. This was reflected in higher VLDL-triglyceride and-cholesterol concentrations in the mongoloids. Plasma apolipoprotein B levels were higher (P less than 0.05) and the ratio of apolipoprotein A-1 to apolipoprotein B was lower (less than 0.05) in the mongoloids. The plasma lipid concentrations were in accordance with the significantly higher relative body weights in the mongoloid group. Blood pressure was slightly but significantly lower and cigarette smoking was less common in patients with Down's syndrome. Our results did not explain the reported lower frequency of atheromatosis in Down's syndrome.