. 2015 Mar 27;123(8):806–812. doi: 10.1289/ehp.1409004

Table 1.

Baseline and follow-up characteristics of HEALS participants (N = 10,853).

Characteristic	Q1 (≤ 12 μg/L)		Q2 (12–62 μg/L)		Q3 (62–148 μg/L)		Q4 (> 148 μg/L)		p-Value^a
Characteristic	No.	Mean ± SD or %	No.	Mean ± SD or %	No.	Mean ± SD or %	No.	Mean ± SD or %	p-Value^a
Age (years)	2,752	36.9 ± 10.0	2,711	36.6 ± 10.0	2,688	36.6 ± 9.9	2,702	37.0 ± 10.0	0.234
Male (%)	1,170	42.5	1,143	42.2	1,124	41.8	1,151	42.6	0.935
Current smoker (%)	813	29.6	792	29.2	747	27.8	751	27.8	0.334
Diabetes history (%)	55	2.0	59	2.2	46	1.7	43	1.6	0.370
Education (years)	2,750	3.6 ± 3.9	2,710	3.2 ± 3.7	2,687	3.5 ± 3.9	2,700	3.3 ± 3.7	0.002
BMI baseline (kg/m²)	2,730	19.9 ± 3.3	2,701	19.7 ± 3.1	2,670	19.7 ± 3.0	2,690	19.4 ± 3.0	< 0.001
Systolic blood pressure (mmHg)
Baseline	2,752	113.6 ± 16.6	2,711	114.7 ± 17.2	2,688	113.6 ± 16.5	2,702	113.5 ± 16.6	0.391
Follow up 1	2,676	113.9 ± 16.8	2,639	113.7 ± 17.0	2,623	113.5 ± 17.1	2,639	114.2 ± 17.4	0.442
Follow up 2	2,557	118.4 ± 15.6	2,475	117.8 ± 15.3	2,492	117.8 ± 15.5	2,489	117.4 ± 15.2	0.175
Follow up 3	2,432	108.5 ± 14.9	2,399	112.6 ± 14.8	2,366	112.6 ± 15.7	2,356	112.0 ± 15.6	< 0.001
Diastolic blood pressure (mmHg)
Baseline	2,750	73.8 ± 11.5	2,711	73.6 ± 11.3	2,685	73.4 ± 11.1	2,700	73.1 ± 11.5	0.132
Follow up 1	2,677	73.0 ± 10.2	2,638	72.8 ± 10.3	2,623	72.6 ± 10.2	2,639	72.9 ± 10.3	0.557
Follow up 2	2,557	76.3 ± 10.3	2,475	76.2 ± 10.0	2,492	76.1 ± 10.0	2,489	76.0 ± 10.1	0.683
Follow up 3	2,432	71.1 ± 9.9	2,399	73.9 ± 10.0	2,366	73.8 ± 10.2	2,356	73.4 ± 10.1	< 0.001
Urinary arsenic (μg/L)
Baseline	2,711	51.0 ± 47.7	2,662	99.2 ± 79.3	2,576	150.9 ± 120.4	2,600	258.2 ± 233.8	< 0.001
Follow up 1	2,671	54.3 ± 57.7	2,633	106.9 ± 87.5	2,625	145.3 ± 133.8	2,629	185.7 ± 199.1	< 0.001
Follow up 2	2,621	54.7 ± 55.6	2,534	105.7 ± 85.5	2,547	139.1 ± 125.6	2,542	178.5 ± 191.4	< 0.001
Follow up 3	2,564	51.6 ± 57.5	2,510	92.8 ± 77.7	2,499	118.6 ± 108.8	2,484	149.2 ± 169.5	< 0.001
Urinary creatinine-adjusted arsenic (μg/g creatinine)
Baseline	2,711	99.8 ± 83.5	2,662	209.1 ± 151.7	2,576	316.8 ± 200.5	2,600	525.8 ± 488.1	< 0.001
Follow up 1	2,671	96.7 ± 74.4	2,633	193.1 ± 121.8	2,625	264.2 ± 213.6	2,629	344.9 ± 326.7	< 0.001
Follow up 2	2,621	98.5 ± 79.4	2,534	198.0 ± 120.6	2,547	259.2 ± 201.1	2,542	333.1 ± 323.1	< 0.001
Follow up 3	2,564	99.0 ± 89.5	2,510	190.2 ± 153.6	2,499	247.8 ± 191.2	2,484	305.1 ± 309.7	< 0.001
Abbreviations: Q1, quartile 1; Q2, quartile 2; Q3, quartile 3; Q4, quartile 4. Q1: median = 2.3, SD = 3.3, range = 11.9; Q2: median = 34.0, SD = 14.4, range = 49.7; Q3: median = 101.0, SD = 25.2, range = 86.0; Q4: median = 239.0, SD = 107.4, range = 714.0.^aRepresents the global difference and is based on the chi-square test for categorical variables and analysis of variance for continuous variables.