Blood glucose and
insulin responses to oral
glucose were measured in 33 men: 8 normal, 13 with borderline
carbohydrate-lipid metabolism disturbance (BCLMD) (pre-beta-lipoproteinemia with normal
cholesterol and
triglyceride levels), and 12 with mild
Type IV hyperlipoproteinemia. Average age was 30 years, and the percentage of ideal weight was 101%. Borderline patients exhibited
hyperinsulinemia following oral
glucose, notably at 30 min; they also demonstrated an apparent impairment in homeostatic control of
blood glucose level, with a greater-than-normal decline in
blood glucose in the 3- to 4-h period (by profile analysis). The Type IV patients, though of normal weight and adiposity, exhibited elevated late incremental
insulin area (LIIA) (1-5 h) responses. Combining all data, fasting
triglycerides correlated with LIIA (p = 0.0002); LIIA correlated with the percentage of adipose mass (p = 0.003), suggesting that LIIA reflects
insulin resistance.
Lipoprotein electrophoresis remains useful for detecting pre-beta-lipoproteinemia, which may occur even in persons with normal
cholesterol and
triglyceride levels. When present, it suggests the possibility of
hyperinsulinemia following
glucose ingestion, which in turn has been shown to be an independent predictor for the development of
coronary heart disease. To gain increased understanding of the natural history of
hypertriglyceridemia, persons with BCLMD should be studied separately from those with normal
lipid and carbohydrate metabolism and from those with
hypertriglyceridemia.