Table 2.

Factor loading matrix from exploratory factor analysis of kidney tubule biomarkers

Biomarkers	Factor 1: Tubule Injury/Repair	Factor 2: Tubule Injury/Fibrosis	Factor 3: Tubule Reabsorption	Factor 4: Tubular Reserve/Mineral Metabolism	Uniqueness
Alpha-1	−0.085	0.072	0.873	0.117	0.235
Beta-2	0.083	−0.011	0.858	−0.126	0.223
Umod	0.089	−0.071	0.258	−0.683	0.456
IL-18	0.596	0.253	−0.061	0.114	0.485
KIM-1	−0.020	0.894	0.026	0.036	0.200
MCP-1	−0.035	0.912	0.035	−0.073	0.200
YKL-40	0.838	−0.001	−0.016	−0.025	0.304
NGAL	0.877	−0.110	0.033	−0.016	0.259
iFGF-23	−0.043	−0.059	0.157	0.587	0.628
iPTH	0.105	−0.067	0.121	0.707	0.470

Bold indicates factor loading >0.5. Uniqueness is defined as the proportion of each biomarker’s variance not explained by the factors.