A 37-yr-old man in DKA has yellowish papules scattered over his trunk and extremities. A tube of plasma that is collected from the patient develops a turbid supernate. This is consistent with which type of hyperlipoproteinemia?
The patient most likely has a type V hyperlipoproteinemia, which is associated with eruptive xanthomas secondary to increased triacylglycerol. Type V hyperlipoproteinemia is a combination of type I, characterized by elevated chylomicrons, and type IV, characterized by increased very-low-density lipoproteins (VLDL). Diabetic ketoacidosis and alcoholism are two of the most common factors that promote type V hyperlipoproteinemia. The absence of insulin characteristic of diabetic ketoacidosis decreases capillary lipoprotein lipase activity, so neither chylomicrons nor VLDL are properly metabolized in the liver. The increased triacylglycerol concentration that results from the accumulation of chylomicrons and VLDL in the blood produces a turbid specimen. Because chylomicrons have the lowest density, they form a turbid supranate in plasma left at 4degC overnight. The density of VLDL is slightly higher than that of chylomicrons, so it forms a turbid infranate. Presence of a supranate and infranate, as in this case, indicates type V hyperlipoproteinemia. A supranate without an infranate occurs in type I hyperlipoproteinemia, and an infranate without a supranate occurs in type IV hyperlipoproteinemia. Another feature of type V disease is hyperchylomicronemia. Clinical features include eruptive xanthomas caused by the deposition of triacylglycerol in the subcutaneous tissue. Once the triacylglycerol concentration is reduced, the xanthomas disappear. Ref : 320
Type I
Type IIa
Type III
Type V
Metabolism of lipid