The historical observation that individuals with uncontrolled diabetes may have high concentrations of serum lipids and may also have an increased incidence of arteriosclerosis has much to do with the present-day theories relating serum lipids and arteriosclerosis. The fact that the lipemia of diabetes is related to defective carbohydrate metabolism rather than to fat in the diet is often overlooked in incrimination of dietary fat. This Symposium offers an opportunity to discuss factors other than dietary fat which may influence serum lipids.
The purpose of this report is to describe variations in serum lipids occurring with fluctuations of carbohydrate metabolism and to focus attention on the significance of serum triglycerides in relation to other serum lipids.
Before the insulin era, lactescence of blood due to accumulation of fat in plasma was reported for certain diabetic patients. While this was thought to be a bad prognostic sign, its relationship to the metabolism of carbohydrate could not be evaluated until the advent of insulin. In 1934 Man and Peters, using accurate quantitative methods, observed the precipitous descent often in twenty-four hours of serum lipids of patients in diabetic acidosis. Initial high concentrations of lipids dropped to normal or even low concentrations in response to administration of insulin, glucose and fluids. As insulin came into general use the serum lipids of controlled diabetics were usually in the normal range, regardless of the amount of dietary fat ingested. In the early days of insulin when high fat diets were still in vogue it was not uncommon to find normal serum lipids even when the diet contained as much as 200 gm. of fat daily.