Mood, sleepiness, and weight gain after three years on CPAP therapy for sleep apnoea

Figures & data

Table 1. Variables at baseline and differences between CPAP users and non-users

	CPAP-users n = 76		Non-users n = 73		p-value
Gender
Male (n, %)	32	42	33	45
Female (n, %)	44	58	40	55
	Median	Range	Median	Range
Age	54	28–76	53	29–84	0.500
BMI (kg/m^2)	34.7	23.3–56.5	28.2	21.5–55.2	<0.001
AHI (#/h)	21	2.8–91.6	8.7	0.3–69.9	<0.001
ODI4 (#/h)	13.7	1.5–120.4	3.8	0–60.2	<0.001
DEPS (0–30)	10	0–24	6	0–21	0.011
ESS (0–20)	10	0–22	9	1–22	0.572
PSQI (0–21)	7	3–17	6	0–19	0.060
STAI (8–80)	35	21–63	32.5	35–56	0.054
Fruit VAS (0–100)	77	0–100	81.5	1–100	0.783
Protein VAS (0–100)	77	0–100	67.5	0–100	0.420
Dairy products VAS (0–100)	68	0–100	60	1–100	0.783
Salty VAS (0–100)	26.5	0–100	23	0–100	0.286
Sweet VAS (0–100)	40	0–100	53	0–100	0.286
High-carbohydrate products VAS (0–100)	57	0–100	23	0–100	0.906
Vegetables VAS (0–100)	62	0–100	68	0–100	0.683
Thirst VAS (0–100)	25	0–100	15	0–97	0.032
Satiety VAS (0–100)	73	0–100	77.5	10–100	0.082
Hunger VAS (0–100)	6	0–100	4	0–72	0.304
Nausea VAS (0–100)	5	0–73	5	0–65	0.812
Appetite VAS (0–100)	8	0–100	7	0–69	0.310
Food quantity (VAS 0–100)	13.5	0–99	10	0–100	0.422
Exercise habits (0–7)	4	1–7	4	1–7	0.412
Exercise duration (0–7)	3	1–4	2	1–4	0.712

Values are presented as number and %, or median (range). BMI body mass index, AHI apnea-hypopnea index, ODI₄ Oxygen desaturation index with the desaturation of 4% or more, DEPS depression scale, ESS Epworth sleepiness scale, PSQI Pittsburg Sleep Quality Index, STAI State-Trait Anxiety Inventory, VAS Visual Analogue Scale (millimeters).

Figure 1. Formation of patient groups. From the original baseline cohort (n = 223), 74 patients did not participate in follow-up study three years later, when patients were divided into two groups (CPAP users or non-users). CPAP users had used CPAP device regularly over four hours per day for three years, and those who discontinued therapy before the three-year follow-up point, were treated as non-users, leaving 76 CPAP users and 73 non-users to final analysis

Table 2. Change of variables during the 3-year follow-up and differences between CPAP-users and non-users

	CPAP-users n = 76 M 42%, F 58%		Non-users n = 73 M 45%, F 55%
	Median	Range	Median	Range	p-value
BMI (kg/m^2)	0.5	−6.7–7.5	0.3	−13.4–6.5	0.674
Hours of use (#/day)	0	−5.8–3.3	–	–	N/A-
Pressure (cmH2O)	1	−1–6	–	–	N/A-
DEPS (0–30)	−3	−20–9	0	−11–21	0.002
ESS (0–20)	−3.5	−14–8	−2	−10–8	0.031
PSQI (0–21)	−1	−8–7	0	−11–10	<0.001
STAI (8–80)	−3	−19–15	1	−12–25	<0.001
Fruit VAS (0–100)	1.5	47–88	0	−95–57	0.255
Protein VAS (0–100)	−9	−85–40	−1	−59–96	0.077
Dairy products VAS (0–100)	8	−79–90	0	−78–93	0.312
Salty VAS (0–100)	−3	−92–63	0	−85–88	0.063
Sweet VAS (0–100)	−1	−72–98	0	−96–82	0.910
High-carbohydrate products VAS (0–100)	1	−66–99	−3.5	−128–101	0.137
Vegetables VAS (0–100)	9	−21–94	1	−43–89	0.090
Thirst VAS (0–100)	0	−98–91	7.5	−65–100	0.026
Satiety VAS (0–100)	−38	−100–97	−41.5	−100–33	0.280
Hunger VAS (0–100)	3	−72–99	8.5	−41–100	0.112
Nausea VAS (0–100)	−1	−71–89	0	−45–64	0.112
Appetite VAS (0–100)	5.5	−56–99	10	−59–98	0.387
Food quantity (VAS 0–100)	4	−11–68	13	−71–95	0.154
Exercise habits (0–7)	0	−5–3	0	−3–4	0.230
Exercise duration (0–7)	0	−3–2	0	−2–2	0.484

Values are median (range: change from the baseline scores), BMI body mass index, DEPS depression scale, ESS Epworth sleepiness scale, PSQI Pittsburg Sleep Quality Index, STAI State-Trait Anxiety Inventory (score), VAS Visual Analogue Scale (millimeters).

Table 3. Correlations between the change in BMI and variables at the 3-year follow-up

	CPAP-users n = 76 M 42%, F 58%		Non-users n = 73 M 45%, F 55%
	r	p-value	r	p-value
Hours of use (#/day)	0.283	0.015	N/A	N/A
CPAP pressure (cmH2O)	−0.040	0.737	N/A	N/A
DEPS (0–30)	0.247	0.069	0.152	0.207
ESS (0–20)	0.037	0.788	0.006	0.958
PSQI (0–21)	0.019	0.888	0.007	0.952
STAI (8–80)	−0.08	0.587	−0.028	0.823
Fruit VAS (0–100)	−0.040	0.775	0.073	0.544
Protein VAS (0–100)	0.043	0.754	0.054	0.652
Dairy products VAS (0–100)	−0.240	0.078	0.251	0.036
Salty VAS (0–100)	−0.026	0.852	0.066	0.585
Sweet VAS (0–100)	−0.339	0.011	0.119	0.324
High-carbohydrate products VAS (0–100)	−0.156	0.254	0.206	0.085
Vegetables VAS (0–100)	−0.079	0.569	0.179	0.136
Thirst VAS (0–100)	0.214	0.116	0.021	0.865
Satiety VAS (0–100)	0.043	0.758	−0.062	0.610
Hunger VAS (0–100)	0.035	0.797	−0.003	0.983
Nausea VAS (0–100)	0.189	0.168	0.046	0.703
Appetite VAS (0–100)	−0.016	0.908	−0.032	0.793
Food quantity VAS (0–100)	−0.063	0.649	−0.046	0.701
Exercise habits (0–7)	−0.144	0.313	−0.138	0.248
Exercise duration (0–7)	0.019	0.898	0.020	0.868

DEPS depression scale, ESS Epworth sleepiness scale, PSQI Pittsburg Sleep Quality Index, STAI State-Trait Anxiety Inventory, VAS Visual Analogue Scale (millimeters).

Table 4. Regression analysis of subgroups and significant factors that effect on weight gain

	Baseline BMI			Baseline DEPS
	β	CI 95%	p-value	β	CI 95%	p-value
All	0.84	0.71–0.98	<.001	0.167	0.03–0.33	0.017
CPAP users (n = 76)	0.83	0.69–0.99	<.001	0.20	0.05–0.38	0.01
Men (n = 32)	0.94	0.55–0.92	<.001	0.11	−0.16–0.38	0.40
Women (n = 44)	0.94	0.77–1.3	<.001	0.26	0.07–0.47	0.01
Non-users (n = 73)	0.90	0.77–0.95	<.001	0.16	0.04–0.28	0.09
Men (n = 33)	0.88	0.65–0.95	<.001	0.30	0.08–0.53	0.01
Women (n = 40)	0.98	0.88–1.1	<.001	0.05	−0.1–0.1	0.93

BMI Body mass index, DEPS Depression scale.