Hypertriglyceridaemia associated with an abnormal triglyceride-rich lipoprotein carrying excess apolipoprotein C-III-2.

Two men aged 48 and 35 years with severe hypertriglyceridaemia, glucose intolerance, and a secondary anaemia had more apolipoprotein C-III-2 and less apo C-III-1 on their triglyceride-rich lipoproteins (d less than 1.006) than did types IV or V lipaemic controls. Although the patients' abnormal lipoproteins seemed to produce normal activation of lipoprotein lipase, they did not serve as an efficient substrate for purified lipoprotein lipase. Adipose tissue of case 1 had considerable lipoprotein-lipase activity and the hypertriglyceridaemia responded to dietary therapy (carbohydrate 180 g, fat 80 g, protein 60 g per day, and no alcohol). The haemolytic anaemia improved, but the patient remained glucose intolerant. The abnormal content of apo C-III-2 on the triglyceride-rich lipoproteins, rendering them resistant to clearance by lipoprotein lipase, is believed to have contributed to the patients' severe hypertriglyceridaemia.