Characteristics of the nocturnal desaturation waveform pattern of SpO2 in COPD patients: an observational study

Respiratory Research

Table 1 Patients’ characteristics

	All N = 153	Desaturation + N = 128	Desaturation-N = 25	P value
Male/female	136/17	116/12	20/5	0.158
Age, years	72 [68–76]	71 [68–75]	73 [70.5–77.5]	0.063
BMI	22.7 [20.6–24.4]	22.7 [20.6–24.5]	22.6 [20.3–24.2]	0.542
Daytime SpO₂, %	97 [96–98]	97 [96–98]	98 [96.3–98]	0.111
Smoking history, pack-years	50 [40–75]	50 [40–76.5]	45 [33.1–60]	0.115
Severity (Gold grade 1, 2, 3, 4)	27, 80, 38, 4 unknown 4	23, 68, 30, 3 unknown 4	4, 12, 8, 1	0.649
%FVC, %	89.7 [78.7–99.5]	90.1 [77.8–100.1]	85.8 [80.7–99.1]	0.932
%FEV₁, %	59.8 [49.2–66.0]	62.4 [49.4–76.9]	63.3 [43.8–76]	0.576
FEV₁/FVC, %	62.4 [47.9–76.7]	60.2 [50–66.1]	53.4 [40.5–63.3]	0.080
PM-AHI	15.2 [8.4–25.0]	17.2 [10.4–28.5]	6.6 [3.9–9.1]	< 0.0001*
CT90, %	1.48 [0.10–7.92]	2.7 [0.44–9.8]	0.03 [0–0.11]	< 0.0001*
Lowest SpO₂, %	85 [79–89]	84 [78–87]	90 [88–91]	< 0.0001*

The data are presented as median [interquartile range]. *P < 0.05
PM-AHI, CT90% and Lowest SpO₂ were obtained from a pulse oximeter performed during night
BMI body mass index, FVC forced vital capacity, FEV₁ forced expiratory volume in 1 s, PM-AHI apnoea-hypopnea index from portable monitor, CT90 cumulative percentage time at SpO₂ below 90%

ISSN: 1465-993X