Table 4.

Multiple regression analysis of the determinants of U‑RBP in the general population, stratified by age groups and adult smoking status.

Participants	n	U-RBP (μg/g creatinine)				U-RBP (μg/L)
		Independent variable	Coefficient (95% CI)	p-Value	r2	Independent variable	Coefficient (95% CI)	p-Value	r2
Children	296	U-Cd	0.217 (0.057, 0.376)	0.007	0.177	U-Cd	0.198 (0.025, 0.375)	0.026	0.300
		Age	–0.100 (–0.127, –0.073)	<0.001		U-Creat	0.756 (0.561, 0.944)	<0.001
						Age	–0.098 (–0.126, –0.069)	<0.001
Adolescents	200	U-Cd	0.313 (0.096, 0.529)	0.005	0.093	U-Cd	0.363 (0.139, 0.587)	0.002	0.409
		BMI	–1.07 (–1.66, –0.48)	<0.001		BMI	–1.07 (–1.65, –0.477)	<0.001
						U-Creat	0.808 (0.549, 1.07)	<0.001
Adults (19–70 years)
All	744	U-Cd	0.125 (0.073, 0.177)	<0.001	0.049	U-Cd	0.116 (0.060, 0.173)	<0.001	0.391
		BMI	–0.546 (–0.786, –0.305)	<0.001		BMI	–0.545 (–0.785, –0.304)	<0.001
						U-Creat	0.846 (0.761, 0.932)	<0.001
Never-smokers	284	U-Cd	0.111 (0.029, 0.193)	0.008	0.034	U-Cd	0.103 (0.007, 0.200)	0.035	0.389
		BMI	–0.577 (–0.982, –0.173)	0.005		BMI	–0.580 (–0.986, –0.174)	0.005
						U-Creat	0.872 (0.733, 1.01)	<0.001
Ever-smokers	460	U-Cd	0.138 (0.068, 0.211)	<0.001	0.052	U-Cd	0.127 (0.052, 0.203)	0.001	0.381
		BMI	–0.515 (–0.978, –0.181)	<0.001		BMI	–0.504 (–0.809, –0.198)
						U-Creat	0.822 (0.709, 0.935)
Adults (> 70 years)
All	98	U-Cd	0.013 (–0.391, 0.188)	0.49	0.005	U-Cd	–0.077 (–0.382, 0.227)	0.6	0.197
						U-Creat	1.21 (0.720, 1.69)	<0.001
Never-smokers	62	U-Cd	–0.076 (–0.406, 0.255)	0.65	0.003	U-Cd	–0.053 (–0.392, 0.286)	0.8	0.259
						U-Creat	1.22 (0.673, 1.76)	<0.001
Ever-smokers	36	U-Cd	–0.128 (–0.699, 0.443)	0.65	0.006	U-Cd	–0.114 (–0.731, 0.503)	0.7	0.092
						U-Creat	1.19 (0.156, 2.21)	0.025
CI, confidence interval.