Hypertriglyceridaemia and diabetes mellitus: cause or effect?

Two patients with hypertriglyceridaemia which was diagnosed several years before the onset of diabetes are described. In the first case a 54-year-old man presented with hypertriglyceridaemia and normal glucose tolerance. After 4 years he developed severe hypertriglyceridaemia (22 mmol/l) which was first ascribed to poor compliance but soon afterwards diabetes was diagnosed and good blood glucose control minimized the hypertriglyceridaemia. The second patient, a female, aged 27 years, with the polycystic ovarian syndrome, presented with eruptive xanthoma after several years of mild hyperlipidaemia. There was severe hyperlipidaemia (triglyceride 140 mmol/l, cholesterol 42 mmol/l) which required urgent plasmapheresis. Diabetes was diagnosed and treated with insulin at this time but the patient was taking the oral contraceptive pill and also had a deficiency of apolipoprotein CII.