Flow-Volume Parameters in COPD Related to Extended Measurements of Lung Volume, Diffusion, and Resistance

Table 2

Body plethysmography and single breath helium dilution with CO-diffusion (SB) parameters.

	Controls	GOLD1	GOLD2	GOLD3	GOLD4
Body plethysmography (BP)
𝑅in, cmH2O*s/L	2.0 (1.6–2.4)	2.0 (1.6–2.8)	3.0 (2.1–3.2)**	3.6 (2.8–5.3)^***†††‡‡	35.4 (4.6–6.6)^***††† ‡‡‡##
𝑅ex, cmH2O*s/L	3.2 (2.4–3.7)	2.7 (2.3–4.4)	4.8 (3.2–6.8)^**††	13.2 (5.1–21.0)^***†††‡‡	21.2 (14.1–33.1)^***†††‡‡‡#
IC, L	3.2 (2.7–3.8)	3.0 (2.7–3.7)	2.7 (2.4–3.2)	2.3 (1.9–3.0)^***††	1.4 (1.0–2.6)^***†††‡‡
IC, %p	101 (88–108)	97 (88–108)	85 (73–98)^†	77 (67–91)^***††	52 (31.66)^***†††‡‡##
RVBP, L	2.5 (2.2–2.9)	2.5 (2.3–3.0)	2.8 (2.4–3.1)	3.6 (3.2–4.8)^***†††‡‡‡	4.5 (4.3–5.3)^***†††‡‡‡#
RVBP, %p	111 (98–120)	115 (105–124)	124 (100–144)	174 (148–187)^***†††‡‡‡	217 (193–245)^***†††‡‡‡##
TLCBP, L	6.4 (5.4–7.3)	6.7 (5.7–8.1)	6.2 (5.7–7.1)	7.3 (6.0–7.7)	7.0 (5.7–7.6)
TLCBP, %p	105 (97–111)	108 (107–117)*	104 (88–123)	113 (107–126)**	121 (100–138)^**‡
FRCBP, L	3.1 (2.6–3.4)	3.4 (3.0–4.1)*	3.6 (3.2–4.0)**	4.4 (3.9–5.7)^***†‡‡	5.4 (4.6–5.8)^***†††‡‡‡
FRCBP, %p	94 (88–108)	109 (102–120)**	106 (91–142)*	135 (123–152)^***†††‡‡	172 (161–203)^***†††‡‡‡##
Single breath helium dilution with carbon monoxide diffusion (SB)
DLCOSB, mmol/min/kPa	6.2 (5.3–7.1)	5.6 (4.5–7.7)	5.2 (4.6–6.3)**	3.0 (2.4–4.5)^***†††‡‡‡	1.8 (1.1–2.5)^***†††‡‡‡###
DLCOSB, %p	75 (69–83)	75 (53–87)	63 (53–70)***	40 (32–46)^***†††‡‡‡	22 (15–29)^***†††‡‡‡###
VA, L	5.3 (4.7–5.3)	5.6 (4.9–5.6)	4.8 (4.2–5.7)^†	4.4 (4.0–5.2)^*††	3.7 (3.1–4.5)^***†††‡‡‡
VA, %p	90 (83–97)	96 (93–103)*	84 (74–89)^*†††	78 (64–83)^***†††	67 (58–77)^***†††‡‡‡
DLCOSB/VA, mmol/min/kPa/L	1.2 (1.1–1.3)	1.1 (0.9–1.2)*	1.1 (0.9–1.3)*	0.71 (0.64–0.83)^***†††‡‡‡	0.46 (0.35–0.56)^***†††‡‡‡###
DLCOSB/VA, %p	89 (78–95)	73 (61–90)*	76 (64–93)*	50 (45–60)^***††‡‡‡	35 (23–41)^***†††‡‡‡###
RVSB, L	1.9 (1.7–2.0)	2.0 (1.6–2.3)	1.7 (1.5–2.0)^†	1.5 (1.3–1.9)^**†	1.6 (1.3–1.8)*
RVSB, %p	81 (72–87)	90 (77–96)	77 (64–89)	67 (59–79)^*†	69 (58–95)
TLCSB, L	5.5 (4.9–6.2)	5.8 (5.1–7.1)	5.0 (4.4–5.9)^†	4.6 (4.1–5.3)^*††	3.9 (3.3–4.7)^***†††‡‡‡
TLCSB, %p	91 (85–97)	97 (93–103)*	85 (75–90)^*†††	79 (65–84)^***†††	68 (60–77)^***†††‡‡‡
FRCSB, L	2.5 (2.1–2.7)	3.0 (2.8–3.2)**	2.5 (2.1–2.8)^†	2.1 (1.6–2.9)^†	2.4 (1.8–2.9)^†††‡‡‡
FRCSB, %p	75 (67–87)	93 (81–104)**	76 (66–91)^††	71 (56–80)^††	69 (61–102)^†††‡‡‡
Difference between BP and SB
RV %pBP−SB	28 (19–40)	33 (23–40)	43 (29–62)^*†	95 (80–129)^***†††‡‡‡	149 (119–192)^***†††‡‡‡##
TLC %pBP−SB	14 (11–18)	14 (11–18)	18 (13–27)*	35 (30–49)^***†††‡‡‡	57 (39–70)^***†††‡‡‡#

∗Significant difference compared to healthy smokers, †significant difference compared to GOLD1, ‡significant difference compared to GOLD2, #significant difference compared to GOLD3, one symbol flagging P < 0.05, two symbols flagging P < 0.01 and three symbols flagging P < 0.001. All data are presented as median (interquartile range).