  More advanced visualization tools are needed to assist with the analyses and
interpretation of human metabolomics data, which are rapidly increasing in
quantity and complexity. Using a dataset of several hundred bioactive lipid
metabolites profiled in a cohort of over 1400 individuals sampled from a
population-based community study, we performed a comprehensive set of
association analyses relating all metabolites with eight demographic and
cardiometabolic traits and outcomes. We then compared existing graphical
approaches with an adapted rain plot approach to display the results of these
analyses. The rain plot combines the features of a raindrop plot and a parallel
heatmap approach to succinctly convey, in a single visualization, the results
of relating complex metabolomics data with multiple phenotypes. This approach
complements existing tools, particularly by facilitating comparisons between
individual metabolites and across a range of pre-specified clinical outcomes.
We anticipate that this single visualization technique may be further extended
and applied to alternate study designs using different types of molecular
phenotyping data.
