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Table 3 Results of unsupervised k-means clustering in (a) non-Hispanic white and (b) African American subjects with fixed threshold-defined P reserved R atio I mpaired S piro m etry (PRISm)

From: Epidemiology, genetics, and subtyping of preserved ratio impaired spirometry (PRISm) in COPDGene

  (a) Non-Hispanic White subjects (b) African American subjects
Feature Cluster 1 Cluster 2 Cluster 3 Cluster 1 Cluster 2 Cluster 3
n 227 291 137 171 167 142
Age 57.9 (8.2) 62.2 (8.1) 59.2 (9.4) 52.9 (5.8) 54.6 (6.1) 52.6 (5.3)
Sex (% male) 34.8 45.7 51.1 47.4 56.9 45.1
Body Mass Index 30.9 (6.4) 30.4 (6.3) 36.2 (7.1) 32.0 (6.8) 27.3 (6.0) 35.7 (8.4)
Current smoker 53.3 43.6 49.6 84.8 83.8 80.3
Pack-years 42.8 (22.6) 46.6 (24.5) 50.9 (29.7) 35.6 (18.5) 39.6 (24.0) 38.1 (21.4)
FEV1% predicted 74.2 (4.3) 73.4 (5.3) 60.5 (7.8) 73.3 (5.1) 72.7 (6.2) 62.5 (8.9)
FEV1/FVC 0.80 (0.04) 0.74 (0.03) 0.74 (0.04) 0.83 (0.04) 0.74 (0.03) 0.75 (0.03)
FEF 25–75 2.21 (0.65) 1.58 (0.47) 1.41 (0.47) 2.38 (0.71) 1.58 (0.50) 1.42 (0.43)
Resting O2 saturation 96.4(2.3) 96.3 (2.1) 95.2 (2.9) 97.1 (2.2) 97.1 (2.3) 96.6 (2.7)
TLCCT*% predicted 79.4 (9.8) 90.4 (10.7) 74.4 (12.7) 71.0 (11.1) 83.6 (12.3) 71.6 (12.3)
Percent emphysema 0.6 (0.7) 2.6 (2.7) 0.9 (1.1) 0.5 (0.6) 2.7 (4.5) 0.8 (1.0)
Segmental Wall Area% 62.0 (2.5) 60.6 (2.3) 64.7 (2.6) 62.4 (2.8) 61.9 (2.9) 65.7 (2.5)
Percent Gas Trapping 6.5 (6.0) 13.5 (8.6) 9.8 (7.1) 7.2 (7.3) 14.8 (13.5) 9.4 (7.5)
Diabetes Mellitus 18.5 14.4 36.5 22.8 15.6 27.5
Hypertension 36.6 47.4 56.2 53.8 51.5 54.2
Hyperlipidemia 45.4 58.8 59.9 31.0 24.0 29.6
Chronic bronchitis 16.3 15.8 32.9 11.1 19.2 14.8
Bronchodilator Response 11.5 13.5 22.2 11.4 9.2 20.1
MMRC 1.154 (1.32) 1.13 (1.29) 1.95 (1.50) 1.63 (1.53) 1.57 (1.47) 1.96 (1.53)
6 minute walk distance 1386.5 (347.1) 1392.2 (320.4) 1132.6 (390.2) 1219.9 (349.4) 1279.5 (338.1) 1099.2 (342.1)
  1. Results are reported as mean (SD) or percent.
  2. Preserved Ratio Impaired Spirometry (PRISm) defined as: FEV1/FVC ≥ 0.7 & FEV1 < 80% predicted.
  3. *TLCCT = Total Lung Capacity by computed tomography.
  4. Bronchodilator response considered present if the change in FEV1 or FVC was >200 mL and ≥ 12% predicted following administration of short acting inhaled beta-agonist.
  5. MMRC = Modified Medical Research Council.