TABLE 3.

Association among CSI, Se and Zn Intake, and toenail concentrations among individuals with low Se and Zn intake (less than or equal to the median).

Predictors	Model 1 (n = 97)			Model 2 (n = 97)			Model 3 (n = 34)			Model 4 (n = 34)
	Estimates	CI	P	Estimates	CI	P	Estimates	CI	P	Estimates	CI	P
(Intercept)	14.64	−16.61 to 45.88	0.354	16.15	2.76–29.53	0.019∗	34.71	−43.14 to 112.55	0.367	59.14	34.55–83.73	<0.001∗
Age (y)	0.61	0.13–1.09	0.013∗	0.61	0.16–1.06	0.008∗	0.69	−0.47 to 1.85	0.229
Sex
Female	RG			RG			RG			RG
Male	−10.43	−21.42 to 0.55	0.062∗	−11.76	−22.00 to −1.53	0.025∗	−9.54	−31.33 to 12.26	0.376
Ethnicity
Non-Hispanic White	RG			RG			RG			RG
Hispanic	16.09	−6.46 to 38.64	0.160				49.13	−5.88 to 104.15	0.078
Non-Hispanic Black	0.20	−13.13 to 13.52	0.977				5.66	−27.06 to 38.37	0.724
Others1	1.71	−12.51 to 15.94	0.811				2.31	−23.88 to 28.50	0.857
Zn intake (mg)	0.01	−0.53 to 0.55	0.974				1.13	−8.37 to 10.63	0.808
Se intake (μg)	−0.02	−0.07 to 0.03	0.448				−0.53	−1.31 to 0.26	0.182	−0.66	−1.21 to −0.11	0.021∗
Zn concentration (μg/g)	0.03	−0.10 to 0.16	0.619				0.01	−0.46 to 0.48	0.955
Se concentration (μg/g)	−2.72	−28.63 to 23.20	0.836				−4.24	−79.76 to 71.29	0.909
R2	0.145			0.116			0.327			0.156

P values are based on results from the multiple regression analysis (p ≤ 0.05∗). ¹ Others include multiracial, Asian, and Middle Eastern. Model 1: adjusted for age, sex, ethnicity, Zn intake, Se intake, Zn concentration, and Se concentration; model 2: adjusted for age, sex, ethnicity, Zn intake, Se intake, Zn concentration, and Se concentration in a stepwise regression analysis; model 3: adjusted for age, sex, ethnicity, Zn intake, Se intake, Zn concentration, and Se concentration among individuals with low Se and Zn intake (below the median); and model 4: adjusted for age, sex, ethnicity, Zn intake, Se intake, Zn concentration, and Se concentration in stepwise regression analysis among individuals with low Se and Zn intake (below the median).

RG, reference group.