Table 3.

Association of demographic and lifestyle factors in adults (N = 3,522) from NHANES 2011–2014 with urinary tin concentrations (creatinine was adjusted in the model).

Variables	Urinary tin concentrations
	β coefficient	P
Age
20–39	[ref]
40–59	0.19	<0.0001
≥60	0.77	<0.0001
Gender
Male	[ref]
Female	0.31	<0.0001
Race/ethnicitya
Non-Hispanic white	[ref]
Hispanic	−0.05	0.49
Non-Hispanic black	0.09	0.13
Other	−0.07	0.25
Educationb
Less than high school	[ref]
High school	0.02	0.70
College or higher	−0.11	0.09
Family income to poverty ratioc
≤1.30	[ref]
1.30–3.50	−0.09	0.055
>3.50	−0.18	0.02
Missing	−0.09	0.26
Smokingd
Never smoker	[ref]
Current smoker	0.05	0.36
Ever smoker	−0.03	0.68
Physical activity, MET-min/weeke
<600	[ref]
600–1200	−0.10	0.13
>1200	−0.17	0.01
Alcohol
0 g/d	[ref]
0-14g/d in women or 1-28g/d in men	−0.13	0.11
≥14g/d in women or ≥28g/d in men	−0.05	0.43
Missing	−0.07	0.33
BMI, kg/m2f
<25	[ref]
25–29.9	−0.01	0.88
≥30	−0.04	0.44
Missing	0.82	0.02

^aRace/ethnicity was categorized based on self-reported data into Hispanic (including Mexican and non-Mexican Hispanic), non-Hispanic white, non-Hispanic black and other race/ethnicity (Liu et al., 2017).

^bSelf-reported education was grouped as less than high school, high school, and college or higher (Liu et al., 2017).

^cFamily income to poverty ratios were categorized as ≤ 1.30, 1.30–3.50, and > 3.50 (Johnson et al., 2013; Liu et al., 2017)

^dSelf-reported smoking was classified as never smokers who smoked less than 100 cigarettes in their lifetime; current smokers who currently smoke cigarettes; and ever smokers who smoked more than 100 cigarettes in their lifetime but don’t smoke currently (Liu et al., 2017).

^eSelf-reported physical activity was used to derive metabolic equivalent of task (MET) minutes per week according to the Global Physical Activity Questionnaire Analysis Guide (WHO, n.d.-b) and categorized as <600, 600-1,200 and >1,200 MET-min/week (Liu et al., 2017).

^fBMI was calculated as weight in kilograms divided by the square of height in meters and classified as normal weight (BMI < 25), overweight (25–29.9), and obese (≥ 30). Weight and height were determined by trained health technicians according to the NHANES Anthropometry Procedures Manual (WHO, n.d.-b).

BMI, body mass index.