Optimal partitioning method for evaluating of effect of hemoglobin oxygenation levels of vessel endothelial growth factor

The work is aimed to study relationship between vessel endothelial growth factor (VEGF) serum levels and hypoxia in patients with severe neurological disorders. Overviewed literature sources indicate activation of VEGF synthesis during hypoxia. But standard correlation analysis does not reveal a statistically significant association between VEGF levels and pulse oxymetry parameters objectively assessing oxygen supply. Due to a proposed in the paper technique it became possible to reveal valid relationship between VEGF levels and oxygenation. This relationship can be described as increase of correlation between VEGF and immunological complement C4 when oxygenation level is below a certain threshold. Developed method includes searching of such boundaries for oxymetry parameters that correlation coefficients between VEGF and some additional factor Z in formed group are maximally different. ranges. The original technique based on permutation test was used not only to asses validity of effects associated with each oxymetry parameter but also to evaluate joint effect by full group of such factors. Great number of variable from database were tested as additional factors/ So additional correction of validity was made to take into account multiple testing.