Psychomotor Performance in Patients with Obstructive Sleep Apnea Syndrome

Figures & data

Table 1 Demographic Characteristics of Patients with Obstructive Sleep Apnea and Control Participants

	OSA (n=103)	Controls (n=103)
Age (years)	57.14±11.31	57.04±12.44
Height (m)	1.81±0.07	1.79±0.08
Weight (kg)	101.83±16.50	94.67±15.05
BMI (kg/m^2)	30.96±4.58	29.80±5.07
ESS	8.65±4.50	5.20±2.69
AHI (events/hour)	45.02±19.09	NA
ODI	38.15±22.82	NA
Average saturation	92.23%±3.96%	NA
Time spent in SpO2<90% (minutes)	89:49±98:10	NA

Note: Data is expressed as mean±standard deviation.

Abbreviations: OSA, obstructive sleep apnea; BMI, body mass index; ESS, Epworth Sleepiness Scale score; AHI, apnea hypopnea index; ODI, oxygen desaturation index.

Table 2 Frequency of Comorbid Disease in OSA Patients and Controls

Comorbid Diagnosis	OSA	Controls	P^a
Depression	2% (2)	1.9% (2)	0.968
Psychosis	1% (1)	1% (1)	0.978
Hypertension	33.01% (34)	22.22% (22)	0.087
DM II	10.7% (11)	5.1% (5)	0.139
Coronary heart disease	10.7% (11)	8.1% (8)	0.527
Arthritis	1% (1)	2% (2)	0.538
Thyroid disease	2.9% (3)	2.0% (2)	0.683

Notes: Data are presented as percentage (N). ^aP-value calculated for the χ² test.

Abbreviations: OSA, obstructive sleep apnea; DM, diabetes mellitus.

Table 3 Frequency of Prescription Medication in OSA Patients and Controls

Prescription Drugs	OSA	Controls	P^a
Antihypertensive medication	33% (34)	19.2% (19)	0.026^b
Antidepressants	2% (2)	1.9% (2)	0.968
Antipsychotics	1% (1)	1% (1)	0.978
Heart disease medication	16.5% (17)	10.1% (10)	0.181
DM II medication	10.7% (11)	4% (4)	0.072
Thyroid medication	2.9% (3)	2% (2)	0.683
PPI	4.9% (5)	4% (4)	0.779
Gout medication (Allopurinol)	7.65 (6)	7.35 (9)	0.783

Notes: Data are presented as percentage (N). ^aP-value calculated for the χ² test; ^bP<0.05.

Abbreviations: OSA, obstructive sleep apnea; DM, diabetes mellitus; PPI, proton-pump inhibitors.

Table 4 Psychomotor Test Performance of Patients with Obstructive Sleep Apnea and Control Participants

	OSA (n=103)	Controls (n=103)	P
Arithmetics
MinT (s)	3.03±0.9	2.62±0.6	<0.001^c
MedT (s)	4.68±1.5	4.11±1.2	0.006^b
TTST (s)	183.7±62.1	166.7±56.2	0.054
SB (s)	38.7±23.3	34.6±16.6	0.176
EB (s)	38.8±19.3	33.3±14.1	0.028^a
TB (s)	77.5±40.0	68.3±30.4	0.083
Visual Stimulus
MinT (s)	0.49±0.1	0.46±0.1	0.089
MedT (s)	0.66±0.1	0.62±0.1	0.013^a
TTST (s)	41.1±7.8	38.6±6.6	0.013^a
SB (s)	6.7±2.2	6.0±2.1	0.02^a
EB (s)	5.2±1.8	4.5±1.3	0.003^b
TB (s)	11.9±3.7	10.4±2.7	0.001^c
Limbs Coordination
MinT (s)	0.69±0.2	0.61±0.1	0.007^b
MedT (s)	1.2±0.5	1.0±0.3	0.070
TTST (s)	63.8±34.6	52.9±21.2	0.016^a
SB (s)	14.7±13.4	11.8±8.0	0.096
EB (s)	25.1±17.9	20.3±11.1	0.038^a
TB (s)	39.8±29.0	32.7±19.2	0.066

Notes: Data is expressed as mean±standard deviation. Significance of t-test indicated as: ^aP<0.05, ^bP<0.01, ^cP<0.001.

Abbreviations: OSA, obstructive sleep apnea; MinT, minimum single task solving time; MedT, median single task solving time; TTST, total test solving time; SB, start ballast; EB, end ballast; TB, total ballast.

Table 5 Pearson Correlation Coefficients Between Psychomotor Tests Results and Severity of Apnea Expressed as AHI in Patients with Obstructive Sleep Apnea

	r	P
Arithmetics
MinT	0.076	0.448
MedT	0.044	0.664
TTST	0.038	0.704
SB	0.009	0.928
EB	−0.004	0.968
TB	0.003	0.976
Visual Stimulus
MinT	0.195	0.049^a
MedT	0.213	0.031^a
TTST	0.256	0.011^a
SB	0.140	0.160
EB	0.113	0.259
TB	0.140	0.162
Limbs Coordination
MinT	0.140	0.162
MedT	0.110	0.272
TTST	0.086	0.388
SB	0.012	0.905
EB	0.096	0.337
TB	0.065	0.518

Notes: Pearson correlation coefficients calculated. Statistical significance of the correlation coefficient indicated as ^aP<0.05.

Abbreviations: MinT, minimum single task solving time; MedT, median single task solving time; TTST, total test solving time; SB, start ballast; EB, end ballast; TB, total ballast; AHI, apnea hypopnea index.

Figure 1 Correlation between speed of perception to visual stimulus and AHI index of patients with OSA.

Notes: The scatter plot represents the association of a total test solving time needed to perform the perception to visual stimulus test and the severity of apnea expressed as AHI (r=0.256; P=0.011).

Abbreviations: CRD 311, test of speed of perception to visual stimulus; AHI, apnea hypopnea index; TTST, total test solving time.

Table 6 Regression Analysis of Obesity, Age, Daytime Sleepiness and Severity of Apnea Indicators in the Prediction of Psychomotor Test Performance Among Patients with Obstructive Sleep Apnea

	OSA				Controls
	R^2	P	β	P	R^2	P	β	P
Arithmetics
BMI	0.378	<0.001^a	0.091	0.326	0.56	<0.001^a	0.02	0.791
Age			0.613	<0.001^a			0.751	<0.001^a
ESS			−0.073	0.39			0.013	0.862
AHI			0.08	0.372	-
Visual Stimulus
BMI	0.378	<0.001^a	0.152	0.104	0.633	<0.001^a	0.054	0.401
Age			0.589	<0.001^a			0.796	<0.001^a
ESS			−0.107	0.211			<0.001	0.999
AHI			0.158	0.079	-
Limbs Coordination
BMI	0.401	<0.001^a	−0.001	0.988	0.525	<0.001^a	0.005	0.956
Age			0.599	<0.001^a			0.733	<0.001^a
ESS			−0.178	0.035			0.065	0.436
AHI			0.129	0.143	-

Notes: R² is calculated as multiple regression coefficient, β values indicate predictive contribution of each factor in the regression model. Statistical significance of the regression model and predictors is indicated as: ^aP<0.001.

Abbreviations: OSA, obstructive sleep apnea; BMI, Body Mass Index; ESS, Epworth sleepiness scale; AHI, Apnea Hypopnea Index.

Figure 2 Total and minimal psychomotor reaction time of obstructive sleep apnea patients (n=103) and controls (n=103), divided at age groups.

Notes: Average minimum solving time of a single task and total test solving time for all three psychomotor tests (test of speed of perception to visual stimulus, test of speed of solving simple arithmetic operations, test of psychomotor limbs coordination) of patients with OSA (n=103) and control (n=103) subjects, divided at age groups. Solid lines are showing the reference range of test results in healthy subjects, dotted lines are showing the average test results for patients with OSA and dashed lines are showing the average test results for control subjects. Asterisk (*) indicates a significant difference with P<0.05 among OSA patients and controls of a single age group in a specific chronometric measure following t-test for independent samples.

Abbreviations: TTST, total test solving time; MinT, minimum solving time of a single task.

Table 7 Psychomotor Changes in Moderate and Severe OSA Patients Compared to Controls

	Severe OSA(n=83)	Moderate OSA(n=20)	Controls(n=103)	P
Arithmetics
MinT (s)	2.9 (2.5–3.6)^c	2.6 (2.3–2.9)	2.7 (2.0–3.1)	<0.001
MedT (s)	4.4 (3.8–5.6)^c	3.8 (3.3–4.4)	4 (3.0–4.7)	0.001
TTST (s)	172.1 (150.2–222.1)^b	140.7 (132.0–175.5)	158.4 (115.0–196.8)	0.007
SB (s)	36.1 (26.1–42.9)^a	24.9 (17.7–45.3)	30.7 (23.3–41.1)	0.035
EB (s)	38.7 (28.2–43)^a	28.2 (22.8–37.8)	31.3 (21.9–41.7)	0.028
TB (s)	70.8 (57.3–88.5)^a	57.6 (45.1–74.7)	63.2 (45.1–82.1)	0.016
Visual Stimulus
MinT (s)	0.5 (0.4–0.6)^a	0.4 (0.4–0.4)	0.5 (0.4–0.5)	0.002
MedT (s)	0.7 (0.6–0.7)^b	0.6 (0.5–0.6)	0.6 (0.5–0.7)	<0.001
TTST (s)	41.5 (36.7–45.9)^b	36.2 (32.6–39.5)	37.6 (33.6–42.6)	<0.001
SB (s)	6.6 (5.3–8.3)^a	5.9 (5.2–7.0)	5.9 (4.6–7.0)	0.052
EB (s)	5.0 (3.9–6.1)^a	4.5 (4.0–5.4)	4.4 (3.5–5.5)	0.038
TB (s)	11.6 (9.4–13.7)^b	10.4 (9.7–12.8)	10.1 (8.3–12.4)	0.014
Limbs Coordination
MinT (s)	0.7 (0.6–0.8)^b	0.6 (0.5–0.7)	0.6 (0.5–0.7)	0.009
MedT (s)	1.1 (0.9–1.4)^a	0.9 (0.8–1.0)	1.0 (0.8–1.2)	0.008
TTST (s)	55.2 (44.1–74.3)^b	46.2 (37.2–57.7)	46.4 (38.6–64.2)	0.007
SB (s)	10.9 (8.5–17.5)^a	8.3 (7.3–14.1)	8.6 (5.8–14.9)	0.073
EB (s)	21.8 (14.8–32.8)^a	15.5 (10.7–22.6)	19.0 (11.9–25.7)	0.013
TB (s)	33.4 (23.7–46.4)^a	24.4 (18.1–35.8)	25.8 (18.9–45.6)	0.028

Notes: Data is expressed as median (interquartile range). Significance of Kruskal–Wallis H nonparametric analysis of variance is noted in the P-value column. Significance of Mann Whitney U-test between three groups is indicated as: ^aP<0.05, ^bP<0.01, ^cP<0.001 if a group is significantly different from controls.

Abbreviations: OSA, obstructive sleep apnea; MinT, minimum single task solving time, MedT, median single task solving time; TTST, total test solving time; SB, start ballast; EB, end ballast; TB, total ballast.