Imaging-based clusters in former smokers of the COPD cohort associate with clinical characteristics: the SubPopulations and intermediate outcome measures in COPD study (SPIROMICS)

Table 6 Characteristics of biomarkers in four imaging-based clusters

	Cluster 1	Cluster 2	Cluster 3	Cluster 4	P value
	N = 100	N = 80	N = 141	N = 85	P value
Blood/serum biomarkers
RBC distribution width (%)	13.69 (1.49)	13.66 (1.62)	13.77 (1.54)	13.78 (1.57)	0.953
Total WBC count (N/μl)	6203.8 (1595.18)	6773.08 (1954.3)	6907.27 (1721.5)	7330.24 (2155.13)	0.0005
Neutrophils% (%)	59.74 (8.48)	61.17 (9.35)	62.12 (8.32)	63.5 (11.2)	0.044
Lymphocyte% (%)	28.38 (7.98)	27.28 (8.74)	25.97 (7.14)	23.9 (9.47)	0.002
Monocyte% (%)	7.97 (2.43)	7.72 (2.44)	8.3 (2.55)	8.06 (2.71)	0.432
Eosinophils% (%)	3.29 (2.12)	3.18 (1.98)	2.85 (1.62)	2.64 (1.73)	0.071
Basophils% (%)	0.68 (0.41)	0.59 (0.41)	0.65 (0.52)	0.57 (0.56)	0.321
Matrix metalloproteinase (MMP-3) (pg/mL)	10.17 (8.1)	8.41 (4.65)	11.07 (6.12)	12.43 (10.57)	0.0082
Baseline CAT score ^a
	9.36 (6.19)	10.73 (6.61)	10.96 (6.38)	17.06 (7.34)	< 0.0001
Exacerbations
Severe^b	0.08 (0.34)	0.25 (1.11)	0.23 (0.7)	0.84 (1.61)	< 0.0001
Total^c	0.44 (0.96)	0.81 (1.78)	0.94 (1.52)	2.56 (3.09)	< 0.0001
Total at baseline^d	0.16 (0.44)	0.32 (0.87)	0.21 (0.53)	0.66 (0.92)	< 0.0001
Activity limitation
6-min walk distance (m)	459.23 (84.5)	431.4 (91.71)	412.76 (113.09)	338.5 (114.57)	< 0.0001
Oxygen desaturation with 6-min walk (%)	18	17	36	76	< 0.0001

Kruskal-Wallis and chi-square tests were performed for continuous and categorical variables, respectively, and their P values were reported
^aCAT score range from 0 to 40, with higher scores indicating greater severity symptoms
^bTotal count of exacerbations requiring ED visit or hospitalization since entering the study
^cTotal count of exacerbations since entering the study
^dTotal Exacerbations for baseline

ISSN: 1465-993X