Study groups

N

Mean

Std. Error Mean

P value

age in years

Subjects

190

34.78

0.73

0.385

Controls

80

35.95

1.13

duration of occupation (years)

Subjects

190

11.92

0.67

0.001

Controls

80

8.04

0.82

body mass index (kg/m2)

Subjects

190

24.92

0.26

0.028

controls

80

26.14

0.571

mean systolic blood pressure (mmHg)

subjects

190

118.49

1.06

0.008

controls

80

113.62

1.26

mean diastolic blood pressure (mmHg)

subjects

190

74.67

0.79

0.285

controls

80

73.24

0.82

blood lead levels (ug/dl)

subjects

190

50.38

1.78

0.003

controls

80

40.48

2.83