Developing a Tool to Assess the Effect of Age and Sex Trends of Variations in Human Body Composition During a Long-Term Study

Long-term observations of body composition values are used in extended clinical settings: in case of fat mass reduction, during observations after GIT resection, among patients with cardiovascular and renal insufficiency, etc. In case of long-term observations, an important element of the analysis is to assess the impact of age and sex variability as compared to the effect of treatment or disease development. An objective of this study is to develop a tool for two-dimensional visualizations, which allows to assess whether a patient's trend data can be explained only with the factor of age and sex dependence of body composition values and to which extent. In his paper, the data of 1,083,275 bioimpedance analyses conducted at health centers of Russia in 2010-2015 involving patients who were 5 to 80 years of age were used. Visualization of age and sex trends of BIA onedimensional value medians allows to discover special points. The trends look more flattened in elder patients. Visualization of age and sex trends of two-dimensional modes depicts more obvious trends but clinical judgements can be made with direct reference to dynamic variations in the patient's values. The difficulty is eliminated if age and sex trend is added to the 2D BIA result sheet. In case of significant projection of current change vector on the opposite or perpendicular direction in relation to the vector of age and sex changes it can be assumed that the events in the human body were affected extrinsically: the effect could be therapeutic or caused by some disease factors or something else.