Correlation of plasma lipid fractions with colorimetrically determined glycated hemoglobin in a nondiabetic population.

To evaluate the incidence of protein glycation (measured as glycated hemoglobin) on plasma lipid levels in a free-living population, a colorimetric method has been used to detect 5-hydroxymethylforfural (HMF) released from glycated hemoglobin (GHb) and enzymatic methods have been used to evaluate total cholesterol, high-density lipoprotein (HDL) cholesterol, fasting glycemia, and total plasma triacylglycerides. These results have been used to calculate low-density lipoprotein-(LDL) cholesterol levels with the Friedewald formula. Results show that a positive correlation exists in men, but not in premenopausal women, between GHb and fasting glycemia (P less than 10(-14], GHb and total plasma cholesterol (P less than .001), GHb and LDL cholesterol (P less than .0001), and GHb with the atherogenic index total/HDL cholesterol (P less than .0001), whereas a negative correlation was shown between GHb and HDL cholesterol (P less than .05). Fasting glycemia does not correlate with cholesterol lipoprotein fractions, but correlates well with total triacylglycerides. These correlations are significant when they are adjusted by age and body mass index. It has also been observed that the positive correlation between glycation of hemoglobin and total cholesterol occurs constantly at all glycohemoglobin levels, and affects all cholesterol fractions analyzed. This suggests an increased atherogenicity with increasing glycohemoglobin levels. Comparisons between groups with high and low GHb levels show variations in the order of 6.5% of total cholesterol levels and a major proportion in the different cholesterol fractions. The higher-range "glycated" populations show total cholesterol, LDL cholesterol and HDL cholesterol values significantly different from the lower-range "glycated" population.(ABSTRACT TRUNCATED AT 250 WORDS)