The prevalence of hypercholesterolaemia is similar in non-
insulin-dependent diabetic (
NIDDM) patients and in non-diabetic subjects. The prevalence of hypertriglyceridaemia and of low
high-density-lipoprotein (
HDL) cholesterol is roughly double the norm in
NIDDM, but the exact prevalence varies greatly from study to study.
Obesity and a familial form of hypertriglyceridaemia (conditions that may alter plasma
lipoprotein levels) are frequently observed in
NIDDM patients. In carefully controlled
NIDDM patients without concomitant primary hyperlipoproteinaemia,
body weight may be more important than glycaemic control or the type of treatment plan adopted in determining
lipoprotein levels. Hypertriglyceridaemia in
NIDDM is a result of both increased
very-low-density-lipoprotein (VLDL) synthesis and impaired VLDL catabolism. Whilst
low-density-lipoprotein (
LDL) levels are normal, the
LDL synthesis and removal rates may be increased. Low
high-density-lipoprotein (HDL) levels may be due to increased catabolism. In addition to quantitative changes in plasma
lipids and
lipoproteins.
NIDDM patients demonstrate qualitative
lipoprotein alterations. The size and density of
LDL particles in
NIDDM patients are greatly affected by
triglyceride levels. Smaller, denser
LDL particles have been observed in hypertriglyceridaemic subjects. Glycosylation of
apolipoproteins may alter the metabolic properties of
lipoproteins. Glycosylated and small, dense
LDL have an increased susceptibility to oxidation.