Serum total sialic acid, a reputed cardiovascular risk factor, and its relationship to lipids, plasma fasting insulin, blood pressure and body mass index in normal individuals.

1. Serum sialic acid is a reputed cardiovascular risk factor, but the reason why this is so is not clear. We therefore studied its relationship with other known cardiovascular risk factors (particularly those associated with insulin resistance) in 100 healthy young subjects (54 females and 46 males, age 20.7+/-0.89 years). 2. There was a significant univariate correlation between serum total sialic acid and fasting plasma insulin. Serum total sialic acid also correlated with fasting plasma glucose concentration and serum cholesterol and triacylglycerol. 3. In females there was a strong univariate correlation between serum total sialic acid and plasma fasting insulin and glucose concentrations, although in males there was a weaker univariate correlation between serum total sialic acid and fasting plasma glucose and the insulin resistance index. In addition, serum total sialic acid significantly correlated with systolic blood pressure, fasting serum cholesterol and triacylglycerol concentrations and body mass index in the females. In males serum total sialic acid significantly positively correlated with fasting serum cholesterol and triacylglycerol concentrations, and correlated inversely with the hip/waist ratio. 4. In multiple regression analysis of the 100 subjects serum total sialic acid correlated independently with fasting serum cholesterol, glucose and also plasma insulin concentrations. In females serum total sialic acid independently correlated with systolic and diastolic blood pressure, and serum cholesterol and fasting plasma glucose concentrations, although there was no significant independent correlation between serum total sialic acid and any of the other variables in the males.