Vitamin A tolerance test and fat metabolism disorders in angina pectoris

Vitamin A tolerance tests were performed on 54 anginal patients with coronary atherosclerosis. In 26 of them the curves were within normal limits, in 5 they were below normal, and in 23 they were above normal. Normal curves were found in 7 patients with primary hypercholesterolemia (2 of whom had tendon xanthoma) and in 19 other patients of whom 8 had a normal blood lipid pattern and 11 had an atypical one). Flat curves occurred in 2 patients with diabetic hyperlipemia and in 3 with an atypical blood lipid pattern. High curves were found in 1 patient with myxedema and in 8 patients with primary (essential) hyperlipemia, but also in 4 with normal blood lipids and in 10 with an atypical blood lipid pattern. The different responses to the vitamin A tolerance test confirmed the presence of different metabolic disorders underlying the various hyperlipemias associated with coronary atherosclerosis. The high curves found in 22 patients (excluding the one with myxedema) are probably related to a disturbance of the early stages of lipid metabolism (absorption, transport, storage). The variable intensity of this disturbance, essentially limited to the postabsorptive period, probably accounts for the divergent results of the simple dosage of fasting blood fats. Perhaps the majority of these cases are representative of different aspects of essential hyperlipemia of variable severity. It is justifiable therefore to detect among anginal patients those with abnormally high vitamin A tolerance curves, thus allowing for a more specific treatment.