Low Density Lipoprotein (LDL) Cholesterol Metabolism in Impaired Glucose Tolerance

Plasma Kinetics Study the of Free Cholesterol and Cholesterol Ester in Subjects With Impaired Glucose Tolerance

Impaired glucose tolerance is associated with an increased risk of developing cardiovascular disease and atherosclerosis for reasons not yet totally understood. Previous studies evaluated the kinetics of plasma LDL and a faster removal rate of free cholesterol in normolipidemic patients with diagnosed arterial coronary disease and deposits of this cholesterol on the blood vessel walls. This disassociation of the cholesterol may suggest a new mechanism for not only the genesis but for the progression of arterial coronary disease. The objective of this research was to study the plasma kinetics of free cholesterol and cholesterol ester in impaired glucose tolerance patient, asymptomatic for coronary artery disease (CAD), to elucidate mechanisms involved in atherogenesis in these patients.

Along with hyperglycemia, the presence of obesity and dyslipidemia, risk factors associated with the natural onset of diabetes mellitus type 2, could possibly explain the high susceptibility of the glucose intolerance to cardiovascular disease. Dyslipidemia commonly linked to glucose intolerance is characterized by hypertriglyceridemia, low HDL-C and in spite of the LDL-C being apparently normal or slightly elevated, there is presence of small dense LDL. Formulated in the laboratory, an artificial lipid nanoemulsion marked with both 14C-cholesterol ester and 3H-cholesterol with lipid composition similar to LDL allows study the plasma kinetics of the two forms of cholesterol (free and esterified. The nanoemulsion mimics the natural LDL, but is prepared without protein. In contact with the bloodstream, the nanoemulsion acquires apolipoproteins, apo E preferentially, allowing it to be recognized and removed from plasma by LDL receptor. The application of this nanoemulsion was shown to be technically safe, appropriate and simple to be used in humans in order to understand the role of dyslipidemia in the atherogenic process.

Inclusion Criteria:

• total cholesterol < 6mmol/L
• LDL-C < 4mmol/L
• triacylglycerides < 2.2mmol/L
• with normal blood pressure or hypertension until 130/85 mmHg

Exclusion Criteria:

• presence of previous cardiovascular disease: macrovascular, peripheral arterial disease and cerebral stroke.
• presence of chronic disease: chronic renal failure (creatinin >30 ug/mg), hepatic failure, asthma, chronic obstructive pulmonary disease, inflammatory disease, oncology and thyropathy compensated.
• use of drugs: statins, fibrates, glucocorticoids and metformin