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Table 4 Descriptive statistics for outcome variables among 108 study participants

From: Association of pulmonary, cardiovascular, and hematologic metrics with carbon nanotube and nanofiber exposure among U.S. workers: a cross-sectional study

Outcome Variable

N available

Mean

Median

Standard deviation

25th-75th %-ile

Min.-Max.

N (%) outside normal rangea

Spirometry measures

 FVC PP

103

98.6%

99.6%

11.5%

90.7-105%

66.8-133%

5 (5.0%)

 FEV1/FVC ratio PP

103

99.6%

100%

7.56%

93.9-105%

78.6-116%

8 (7.8%)b

 FEF25-75 PP

103

100%

96.7%

31.5%

75.0-125%

35.6-185%

8 (7.8%)

 PEF PP

103

107%

107%

14.6%

96.9-117%

69.8-142%

1 (1.0%)

Cardiovascular measures

 Systolic BP (mmHg)

106

122

122

14.2

112-130

92-164

13 (12.3%)

 Diastolic BP (mmHg)

106

75.1

74.5

10.1

69-82

42.5-106

6 (5.7%)

 Heart rate (BPM)

106

69.9

69.8

11.2

61.5-77

45.5-108

1 (0.9%)

Blood component measures

 Leukocyte count (x103/μL)

98

7.01

6.80

1.70

5.9-8.0

3.5-12.2

2 (2.0%)

  Abs. neutrophils

98

3.99

3.80

1.24

3.2-4.7

1.6-7.3

1 (1.0%)

  Abs. lymphocytes

98

2.33

2.30

0.69

1.8-2.6

1.1-4.8

8 (8.2%)c

  Abs. monocytes

98

0.50

0.50

0.15

0.4-0.6

0.20-0.83

2 (2.0%)

 Platelet (x103/μL)

98

249.8

238.5

53.2

212-279

157-460

1 (1.0%)

 Hemoglobin (g/dL)

98

15.1

15.3

1.18

14.3-16

12.1-17.5

2 (2.0%)

 Hematocrit

98

44.8%

45.1%

2.98%

42.5-47.3%

37.3-49.9%

0

  1. Abbreviations: BP blood pressure, BPM beats per minute, FEV1 forced expiratory volume in one second, FVC forced vital capacity, PP percent predicted, FEF25-75 forced expiratory flow at 25-75-% of the pulmonary volume, PEF peak expiratory flow
  2. aBelow the lower limit of normal for pulmonary function measures (two subjects’ tests were not interpretable with respect to this criterion); above 139 and 89 mm Hg for systolic and diastolic (respectively) BP; above 100 beats per minute for heart rate; above or below the reference range for blood component measures
  3. bIncludes three participants determined clinically to have normal spirometry pattern and one participant with clinically uninterpretable spirometry
  4. cAll were above the reference range