We have shown that serum total sialic acid is elevated in hypertriglyceridaemic patients showing the Frederickson's type IIB phenotype in comparison with normal subjects (2.30 +/- 0.34 versus 1.92 +/- 0.32 mmol/l, P < 0.02). Lipid-associated sialic acid was also elevated in the hypertriglyceridaemic group in comparison with the normal subjects (0.60 +/- 0.09 versus 0.35 +/- 0.04 mmol/l, P < 0.001). 2. We measured five serum acute-phase proteins in the hypertriglyceridaemic patients and the normal subjects, namely alpha 1-antichymotrypsin, alpha 1-acid glycoprotein, alpha 2-macroglobulin, C-reactive protein and haptoglobin. Serum alpha 2-macroglobulin was significantly elevated in the hypertriglyceridaemic patients compared with the normal subjects (2.1 +/- 1.0 versus 1.5 +/- 0.55 g/l, P < 0.05) as was serum C-reactive protein (5.9 +/- 3.5 versus 3.5 +/- 1.9 mg/l, P < 0.05). There were, however, no significant differences in the serum concentrations of alpha 1-antichymotrypsin, alpha 1-acid glycoprotein or haptoglobin between the two groups. 3. There was a significant correlation between serum total sialic acid and serum alpha 1-antichymotrypsin, alpha 1-acid glycoprotein and haptoglobin (Spearman correlation coefficients 0.74, 0.50 and 0.76, respectively) in the normal subjects, and there was a significant correlation between serum total sialic acid and serum alpha 1-antichymotrypsin and alpha 1-acid glycoprotein (Spearman correlation coefficients 0.72 and 0.84, respectively) in the hypertriglyceridaemic patients.
