Reference Intervals of Spot Urine Creatinine-to-Osmolality Ratio as a Surrogate of Urinary Creatinine Excretion Rate

Table 6

Standardized () coefficients of univariable linear regression models^a for spot urine profile.

	sUCr		sUOsm		sUCr/Osm
Age	-0.152	<0.001	-0.158	<0.001	-0.067	<0.001
Body weight	0.267	<0.001	0.173	<0.001	0.247	<0.001
Body mass index	0.151	<0.001	0.122	<0.001	0.109	<0.001
Blood biochemistry
Urea nitrogen	0.084	<0.001	0.193	<0.001	-0.092	<0.001
Creatinine	0.259	<0.001	0.062	<0.001	0.365	<0.001
MDRD eGFR	-0.043	0.013	0.088	<0.001	-0.180	<0.001
Albumin	-0.045	0.009	-0.052	0.003	-0.014	0.428
GOT	0.027	0.121	-0.006	0.724	0.053	0.002
GPT	0.041	0.017	0.040	0.022	0.022	0.201
Total bilirubin	0.084	<0.001	0.028	0.111	0.109	<0.001
Uric acid	0.185	<0.001	0.070	<0.001	0.230	<0.001
CPK	0.200	<0.001	0.121	<0.001	0.193	<0.001
Glucose	0.029	0.097	0.066	<0.001	-0.031	0.070
Osmolality	0.090	<0.001	0.134	<0.001	-0.011	0.540
Na	0.069	<0.001	0.057	0.001	0.048	0.005
K	0.006	0.738	0.017	0.322	-0.011	0.527
Ca	-0.025	0.153	-0.050	0.004	0.018	0.295
P	-0.054	0.002	-0.038	0.031	-0.047	0.007
Urine profile
sUCr	NA	NA-	0.815	<0.001	0.712	<0.001
sUOsm	0.815	<0.001	NA	NA	0.173	<0.001
sUCr/Osm	0.712	<0.001	0.173	<0.001	NA	NA
UACR	-0.056	0.001	-0.046	0.008	-0.039	0.024

Abbreviations: CPK: creatine phosphokinase; MDRD eGFR: estimated glomerular filtration rate derived with Modification of Diet in Renal Disease (MDRD) Study equation; GOT: glutamic oxaloacetic transaminase; GPT: glutamic pyruvic transaminase; NA: nonapplicable; sUCr: spot urine creatinine; sUCr/Osm: spot urine creatinine-to-osmolality ratio; sUOsm: spot urine osmolality; UACR: urine albumin-to-creatinine ratio. ^aPerformed with natural logarithm-transformed data of all variables.