Chronic exposure to arsenic, LINE-1 hypomethylation, and blood pressure: a cross-sectional study in Bangladesh

Khaled Hossain; Takehiro Suzuki; M. M. Hasibuzzaman; Md. Shofikul Islam; Atiqur Rahman; Sudip Kumar Paul; Tanzina Tanu; Shakhawoat Hossain; Zahangir Alam Saud; Mashiur Rahman; Farjana Nikkon; Hideki Miyataka; Seiichiro Himeno; Keiko Nohara

doi:10.1186/s12940-017-0231-7

Table 2

Arsenic exposure levels and other characteristics of the subjects in the arsenic-endemic and non-endemic areas

Parameter	All	Non-endemic	Arsenic-endemic	p-value
Subjects (n)	236	61	175
Drinking water As (μg/L)^b
Total subjects	17.76 (15.16)	0.76 (5.49)	53.39 (7.90)	<0.001^*
Males	13.28 (19.90)	0.60 (4.96)	40.22 (9.02)	<0.001^*
Females	24.66 (13.97)	0.98 (6.10)	73.09 (6.52)	<0.001^*
p-value (between male & female groups)	0.081^*	0.269^*	0.056^*
Hair As (μg/g)^b
Total subjects	1.28 (4.43)	0.25 (2.38)	2.08 (3.54)	<0.001^*
Males	1.08 (4.80)	0.19 (2.15)	1.99 (3.70)	<0.001^*
Females	1.39 (3.99)	0.36 (2.40)	2.20 (3.38)	<0.001^*
p-value (between male & female groups)	0.191^*	<0.01^*	0.604^*
Nail As (μg/g)^b
Total subjects	3.40 (3.53)	0.96 (2.43)	5.29 (2.96)	<0.001^*
Males	3.19 (3.41)	1.05 (2.32)	4.73 (3.00)	<0.001^*
Females	3.67 (3.78)	0.85 (2.58)	5.98 (2.98)	<0.001^*
p-value (between male & female groups)	0.403^*	0.367^*	0.155^*
Skin symptoms [n, (%)]
(+) symptom	132 (55.90)	0 (0.0)	132 (75.40)	<0.001^†
(−) symptom	104 (44.10)	61 (100.0)	43 (24.60)	<0.001^†
DBP (mm Hg)^a
Total subjects	77.11 ± 11.84	71.97 ± 9.89	78.90 ± 11.96	<0.001^*
Males	76.73 ± 10.51	73.33 ± 8.26	77.95 ± 10.99	<0.05^*
Females	77.54 ± 13.21	70.36 ± 11.46	79.96 ± 12.93	<0.01^*
p-value (between male & female groups)	0.608^*	0.245^*	0.269^*
SBP (mm Hg)^a
Total subjects	118.72 ± 18.01	111.18 ± 14.22	121.35 ± 18.48	<0.001^*
Males	116.56 ± 14.83	112.88 ± 10.91	117.88 ± 15.83	0.097^*
Females	121.16 ± 20.83	109.18 ± 17.30	125.20 ± 20.45	<0.001^*
p-value (between male & female groups)	0.055^*	0.334^*	<0.01^*
Hypertension [n, (%)]
Total subjects
Yes	32 (13.60)	3 (4.90)	29 (16.60)	<0.05^†
No	204 (86.40)	58 (95.10)	146 (83.40)	<0.05^†
Males
Yes	10 (8.00)	0 (0.0)	10 (10.90)	<0.05^†
No	115 (92.00)	33 (100.0)	82 (89.10)	<0.05^†
Females
Yes	22 (19.80)	3 (10.70)	19 (22.90)	0.162^†
No	89 (80.20)	25 (89.30)	64 (77.10)
p-value (between male & female groups)	<0.01^†	0.054^†	<0.05^†
LINE-1 Methylation level (%)^a
Total subjects	64.94 ± 2.12	65.67 ± 1.99	64.69 ± 2.12	<0.01^*
Males	65.21 ± 1.91	65.46 ± 2.24	65.12 ± 1.78	0.430^*
Females	64.65 ± 2.33	65.92 ± 1.66	64.23 ± 2.38	<0.01^*
p-value (between male & female groups)	<0.05^*	0.372^*	<0.01^*

^aMean ± SD. ^bGeometric mean (GSD) for log-transformed value

^* p- and ^† p-values were obtained by independent sample t-test and Chi-square test, respectively