Abstract
1. In a pathological investigation of 53 cases of sudden death (age range 34 to 87 years), plasma cholesterol concentrations measured at autopsy were correlated negatively with age. There was a high incidence of thrombotic occlusion of the coronary arteries in cases under 60 years of age. In men of all ages, hut not in women, cholesterol concentrations were significantly greater in cases with coronary arterial occlusion than in cases without. 2. In a clinical investigation, the serum concentrations of cholesterol and triglyceride observed in the majority of aged men were within the normal range for younger people. The mean concentrations of both lipids, however, were elevated in aged men with IHD compared with aged controls. In aged women with IHD concentrations of triglyceride, but not cholesterol, were elevated. 3. Preparative ultracentrifugation of serum lipoproteins showed that HDL-cholesterol concentrations were greater in aged women than in aged men. HDL-cholesterol was significantly lower in aged men and women with IHD than in aged controls. The majority of patients whose myocardial ischaemia was associated with supraventricular dysrhythmias did not have abnormalities of lipid metabolism. 4. Blood ascorbic acid concentrations in aged patients were low. In men, WBC-ascorbie acid concentrations were significantly correlated with levels of HDL-cholesterol. Six weeks treatment with daily gram doses of ascorbic acid resulted in significant increases of mean HDL-cholesterol in the men, and in those women with IHD. 5. The participation of ascorbic acid in lipid metabolism was not observed to be by any direct effect on LCAT activity. 6. Rheological studies showed that the elevated blood viscosity found in aged patients with IHD was associated with the haematocrit, but not with plasma fibrinogen concentration. Viscosity was not elevated in patients with dysrhythmia-ischaemia. Treatment with ascorbic acid reduced fibrinogen concentration in nine patients whose initial levels had been elevated. 7. By integrating the pathological, clinical, metabolic, and rheological findings these studies have sought to show that IHD in old age is not simply a consequence of ageing. Some metabolic abnormalities associated with IHD in aged patients responded to treatment with ascorbic acid and, in susceptible people, earlier long-term nutritional measures may aid in protecting against IHD in old age.