Table 3.

Relationship of sociodemographic characteristics, arsenic exposure, and lifestyle variables with urinary arsenic metabolites in controls

n*PMI = MMA/InAs
SMI = DMA/MMA
%DMA
%MMA
Adjusted means (SD)P for trendAdjusted means (SD)P for trendAdjusted means (SD)P for trendAdjusted means (SD)P for trend
Sociodemographic and lifestyle variables
    BMI
        <18.23410.91 (0.05)0.206.32 (0.23)0.4069.60 (0.54)0.2213.17 (0.31)0.20
        18.2-20.83400.94 (0.06)6.32 (0.24)69.58 (0.56)13.34 (0.33)
        >20.83500.99 (0.06)6.57 (0.24)70.40 (0.56)12.71 (0.33)
    Age (y)
        17-303440.81 (0.06)<0.016.43 (0.27)0.8069.12 (0.63)0.0212.72 (0.36)0.11
        30-403670.96 (0.05)6.28 (0.24)69.72 (0.55)13.13 (0.32)
        41-653201.09 (0.05)6.49 (0.23)70.75 (0.53)13.38 (0.31)
    Sex
        Women6140.89 (0.06)0.057.63 (0.27)<0.0172.15 (0.63)<0.0111.33 (0.36)<0.01
        Men4171.05 (0.05)5.16 (0.19)67.91 (0.45)14.95 (0.26)
    Cigarette smoking status
        Never6711.00 (0.04)0.616.43 (0.19)0.9070.17 (0.45)0.6813.18 (0.26)0.46
        Past520.97 (0.11)6.12 (0.49)68.60 (1.14)13.77 (0.66)
        Current3080.96 (0.06)6.53 (0.24)70.64 (0.56)12.81 (0.32)
    Betel nut use
        Never6280.99 (0.05)0.406.41 (0.22)0.3969.79 (0.53)0.7013.37 (0.30)0.59
        Ever4030.96 (0.05)6.32 (0.21)69.82 (0.49)13.14 (0.28)
    Well arsenic (μg/L)
        0.1-233441.04 (0.06)0.067.06 (0.25)<0.0172.01 (0.59)<0.0112.43 (0.34)0.01
        24-1013370.90 (0.06)6.13 (0.24)69.43 (0.56)13.25 (0.32)
        102-8643500.91 (0.06)6.01 (0.25)68.13 (0.59)13.54 (0.35)
    Urine arsenic (μg/L)
        5-533410.99 (0.06)0.746.15 (0.27)0.3469.47 (0.64)0.7613.16 (0.37)0.76
        54-1283400.90 (0.05)6.55 (0.24)70.47 (0.55)12.80 (0.32)
        >1293500.95 (0.06)6.51 (0.27)69.64 (0.63)13.26 (0.36)
    Urinary creatinine (g/L)
        4-323390.80 (0.06)<0.015.64 (0.25)<0.0166.41 (0.59)<0.0113.73 (0.34)<0.01
        33-683431.03 (0.06)6.37 (0.24)70.57 (0.55)13.40 (0.32)
        69-3593491.02 (0.06)7.20 (0.25)72.60 (0.59)12.10 (0.35)
Genetic variables of interest
    MTHFR 677 (rs1801133)
        CC7330.96 (0.03)0.466.80 (0.13)0.1570.76 (0.30)0.3912.55 (0.17)0.30
        CT1830.91 (0.06)6.53 (0.26)70.69 (0.61)12.76 (0.34)
        TT110.94 (0.24)5.39 (1.04)66.45 (2.48)14.34 (1.39)
    MTHFR 1298 (rs1801131)
        CC1350.92 (0.07)0.416.83 (0.30)0.4070.50 (0.72)0.8513.10 (0.40)0.57
        CA4320.93 (0.04)6.79 (0.17)70.77 (0.40)12.45 (0.22)
        AA3320.98 (0.04)6.58 (0.19)70.48 (0.46)12.65 (0.25)
    GSTO1 (rs4925)
        CC6280.92 (0.03)0.246.60 (0.14)0.3512.65 (0.18)0.8670.61 (0.33)0.88
        CA2671.01 (0.05)7.07 (0.21)12.46 (0.28)70.83 (0.50)
        AA300.92 (0.14)6.03 (0.64)13.07 (0.84)70.23 (1.50)
    GSTO1 (rs11509437)
        AA7060.94 (0.02)0.176.64 (0.13)0.3612.80 (0.17)0.0770.45 (0.31)0.35
        AT1540.89 (0.04)6.95 (0.27)12.03 (0.36)71.43 (0.64)
        TT150.83 (0.12)6.77 (0.87)12.31 (1.15)69.65 (2.05)
    GSTO1 (rs11509438)
        GG7150.91 (0.13)0.206.41 (0.90)0.3713.12 (1.20)0.0869.41 (2.12)0.32
        GA1640.91 (0.04)6.54 (0.31)12.56 (0.41)70.67 (0.72)
        AA150.96 (0.03)6.25 (0.19)13.32 (2.54)69.80 (0.44)
  • * Analysis excluded 10 participants with unknown status of betel nut use (n = 3) and BMI (n = 7). Among the 1,031 participants with values for all the sociodemographic and lifestyle variables, 926, 899, 925, 875, and 894 have information on carrier status of MTHFR 677 (rs1801133), MTHFR 1298 (rs1801131), GSTO1 (rs4925), GSTO1 (rs11509437), and GSTO1 (rs11509438), respectively.

  • Means according to sociodemographic and lifestyle variables were adjusted for one another. Means according to genetic variables were adjusted for sociodemographic and lifestyle variables.

  • Cut points were determined based on tertiles in the controls.