Intersubject Variability of Blood Analysis Reference Values: Assessment of Age and Locality Influence by Means of a Linear Discriminant Analysis Model

Glycemic and lipidic profiles might be influenced by several factors. The influence of the age group in the most extensively evaluated lipidic and glycemic parameters is more or less well-accepted. To verify this empirical notion, 996 human subjects aged between 21 and 90 years from different localities were characterized according to age. To assess lipid profile, total cholesterol and cholesterol associated with lipoprotein fractions (low-density lipoprotein cholesterol and high-density lipoprotein cholesterol) and triglycerides were determined. Regarding glycemic profile, glucose, and glycated hemoglobin were measured. The majority of the population had values of lipidic parameters fit into the reference values, presenting low or moderate risk for developing cardiovascular disease. Blood glucose was often far above the desirable, but this can be devalued due to the HbA1c values, which were overwhelmingly located in the normal range. The categorization of data in different age groups did not allow defining statistically significant differences. Despite the discriminant linear model was presented, the results indicate that age group did not act as a strong discriminant factor. Somehow unexpectedly, the most significant differences were found among the different localities, which tended to show a similarity according with their latitude. Furthermore, there were no significant correlations in the parameters associated with lipidic profile, but there was a direct correlation between glucose levels and HbA1c (glycemic parameters).