The relationship between sleep disturbance and health status in patients with COPD

Figures & data

Table 1 Patient demographics

Variables	ISI<8	8≤ISI<15	ISI≥15	p-value
Number (%)	144 (75.0)	34 (17.7)	14 (7.3)
Age, years, median (IQR)	74.00 (68.00, 78.00)	71.00 (62.50, 76.00)	74.00 (63.50, 78.25)	0.258
Female, n (%)	3 (2.1)	2 (5.9)	1 (7.1)	0.191
BMI, kg/m^2, mean (SD)	23.20 (3.23)	23.50 (3.63)	24.36 (4.23)	0.453
Comorbidities, n (%)*
Diabetes mellitus	31 (21.5)	12 (35.3)	5 (35.7)	0.165
Hypertension	75 (52.1)	21 (61.8)	5 (35.7)	0.237
Tuberculosis history	43 (29.9)	9 (26.5)	3 (21.4)	0.790
Chronic renal disease	2 (1.4)	1 (2.9)	2 (14.3)	0.032
Liver disease	4 (2.8)	1 (2.9)	1 (7.1)	0.422
Heart disease	32 (22.2)	7 (20.6)	4 (28.6)	0.908
Cerebrovascular disease	6 (4.2)	2 (5.9)	0 (0.0)	0.811
History of malignancy	5 (3.5)	0 (0.0)	0 (0.0)	0.717
Dyslipidemia	33 (22.9)	8 (23.5)	4 (28.6)	0.954
Osteoporosis	24 (16.7)	4 (11.8)	3 (21.4)	0.702
Gastritis	19 (13.2)	4 (11.8)	2 (14.3)	1.000
Benign prostate hyperplasia	39 (27.1)	8 (23.5)	5 (35.7)	0.689
Alcohol intake, n (%)	64 (44.8)	8 (24.2)	5 (35.7)	0.091
Smoking pack-years, median (IQR)	40.00 (25.00, 52.00)	37.50 (26.88, 50.00)	45.50 (38.75, 53.25)	0.408
Maintenance drugs, n (%)*
LAMA inhaler	116 (81.1)	26 (76.5)	13 (92.9)	0.421
ICS/LABA inhaler	69 (48.6)	22 (64.7)	8 (57.1)	0.222
LABA inhaler	16 (11.5)	2 (6.1)	2 (14.3)	0.593
Theophyllines	55 (38.2)	16 (47.1)	7 (50.0)	0.521
Oral beta agonist	12 (8.3)	2 (5.9)	2 (14.3)	0.594
Insomnia drugs, n (%)*	11 (7.6)	4 (11.8)	3 (21.4)	0.161
Benzodiazepine	8 (5.6)	3 (8.8)	0 (0.0)	0.531
Zolpidem	1 (0.7)	2 (5.9)	3 (21.4)	0.001
Other drugs	4 (2.8)	1 (2.9)	0 (0.0)	1.000
Chronic bronchitis, n (%)	49 (36.0)	20 (60.6)	7 (50.0)	0.028
Number of COPD exacerbations	0.00 (0.00, 1.00)	0.00 (0.00, 1.00)	2.00 (1.00, 3.00)	0.001
in the past year, median (IQR)
Pulmonary function tests
FVC, % predicted, mean (SD)	94.32 (17.61)	91.94 (23.22)	92.57 (16.25)	0.817
FEV1, % predicted, mean (SD)	71.75 (18.36)	72.68 (23.18)	67.43 (17.10)	0.679
FEV1/FVC, %, median (IQR)	52.00 (43.00, 61.00)	56.50 (45.00, 64.00)	49.50 (43.75, 57.25)	0.305
DLCO, % predicted, mean (SD)	14.42 (4.79)	14.80 (5.75)	13.09 (4.94)	0.555

Note:

* Multiple responses possible.

Abbreviations: BMI, body mass index; DLCO, diffusion capacity of the lung for carbon monoxide; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; ICS, inhaled corticosteroid; IQR, interquartile range; ISI, insomnia severity index; LABA, long-acting β2-agonist; LAMA, long-acting muscarinic antagonist.

Figure 1 CAT scores according to insomnia severity.

Note: Jonckheere–Terpstra test was done.
Abbreviations: CAT, COPD assessment test; ISI, insomnia severity index.

Figure 2 Frequency of insomnia according to CAT scores.

Abbreviations: CAT, COPD assessment test; ISI, insomnia severity index.

Table 2 Variables associated with insomnia in COPD

Variables	Univariate analysis			Multivariate analysis
	Odds ratio	95% CI	p-value	Odds ratio	95% CI	p-value
Age (years)	0.97	0.93–1.01	0.089	0.96	0.92–1.02	0.128
BMI	1.05	0.95–1.16	0.328
Diabetes mellitus	2.00	0.98–4.08	0.057	2.03	0.85–4.84	0.112
Hypertension	1.09	0.57–2.09	0.802
Chronic renal disease	4.73	0.77–29.22	0.094	2.22	0.24–20.22	0.480
Heart disease	1.04	0.48–2.27	0.920
Cerebrovascular disease	1.00	0.20–5.13	1.00
Benign prostate hyperplasia	1.00	0.48–2.09	1.00
Smoking pack-year	1.01	0.99–1.02	0.564
CAT total score	1.25	1.15–1.35	<0.001	1.23	1.13–1.34	<0.001
LAMA inhaler	1.01	0.44–2.33	0.984
ICS/LABA inhaler	1.76	0.90–3.45	0.097	0.86	0.37–1.98	0.718
LABA inhaler	0.72	0.23–2.26	0.567
Theophyllines	1.49	0.77–2.88	0.236
Oral beta agonist	1.00	0.31–3.26	1.00
FVC, % predicted	0.99	0.98–1.01	0.477
FEV1, % predicted	1.00	0.98–1.02	0.849
FEV1/FVC	1.01	0.98–1.04	0.570
DLCO	1.00	0.93–1.06	0.876
Chronic bronchitis	2.40	1.22–4.71	0.011	0.99	0.43–2.29	0.989
Number of COPD exacerbations in the past year	1.36	1.04–1.78	0.025	1.03	0.72–1.48	0.861

Abbreviations: BMI, body mass index; CAT, COPD assessment test; DLCO, diffusion capacity of the lung for carbon monoxide; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; ICS, inhaled corticosteroid; LABA, long-acting β2-agonist; LAMA, long-acting muscarinic antagonist.

Figure 3 ROC curve for insomnia versus CAT score.

Abbreviations: CAT, COPD assessment test; ROC, receiver operating characteristic.