Biomarkers to Improve Diagnosis and Monitoring of Obstructive Sleep Apnea Syndrome: Current Status and Future Perspectives

Table 1

Studies assessing inflammatory biomarkers in obstructive sleep apnea syndrome.

Study	Biomarkers	Comparison groups	Comments
Sahlman et al. [20]	CRP; TNF-α; IL-6	84 mild OSAS patients versus 40 non-OSAS controls	CRP and TNF-α, but not IL-6, levels were higher in the OSAS group. CRP levels increased with the increase of AHI
Shamsuzzaman et al. [21]	CRP	22 OSAS patients versus 20 non-OSAS controls	CRP levels were higher in OSAS group and were independently associated with OSAS severity
Hayashi et al. [22]	CRP	60 OSAS patients versus 30 non-OSAS controls	CRP levels were higher in the OSAS group and increased with OSAS severity. Repetitive hypoxaemia correlated with CRP levels
Steiropoulos et al. [23]	CRP; TNF-α; IL-6; Fibrinogen	38 OSAS patients versus 23 non-OSAS controls	TNF-α levels were higher in OSAS patients and were correlated with neck circumference, AHI, and ODI.; No differences in CRP, IL-6, and fibrinogen levels were recorded between groups
Guven et al. [24]	CRP	47 OSAS patients versus 29 non-OSAS controls	CRP levels were higher in the OSAS group and were positively correlated with BMI and AHI
Hall et al. [25]	CRP	161 OSAS patients versus 61 controls	CRP levels were higher in the OSAS group and were associated with AHI
Yokoe et al. [26]	CRP; IL-6	30 OSAS patients versus 14 non-OSAS obese controls	CRP and IL-6 levels were higher in patients with OSAS. CRP levels were influenced by severity of OSAS and BMI. IL-6 levels were influenced by nocturnal hypoxia and BMI
Guilleminault et al. [31]	CRP	146 OSAS patients versus 39 UARS patients versus 54 non-OSAS controls	CRP levels did not differ among groups. BMI was associated with increased CRP values
Ryan et al. [32]	CRP	35 mild-to-moderate OSAS patients versus 31 severe OSAS patients versus 14 obese severe OSAS patients versus 30 non-OSAS controls	CRP levels were higher in the obese severe OSAS group than in the other groups. BMI was an independent predictor for CRP levels
Vgontzas et al. [35]	TNF-α; IL-6	14 OSAS patients versus 11 obese non-OSAS controls versus 12 normal weight controls	TNF-α and IL-6 values were highest in the OSAS group and lowest in the lean controls. Their values for obese controls were between those of the other groups
Minoguchi et al. [36]	TNF-α	24 mild and moderate-to-severe OSAS patients versus 15 obese non-OSAS controls versus 12 healthy subjects	TNF-α levels were higher in patients with moderate-to-severe OSAS than in patients with mild OSAS, obese control subjects, or healthy subjects. The duration of hypoxia was independently associated with production of TNF-α by monocytes
Kanbay et al. [37]	TNF-α	106 OSAS patients versus 32 non-OSAS controls	TNF-α levels were increased in OSAS group, positively correlated with SaO2 <90% and BMI and negatively with adiponectin levels
Liu et al. [38]	TNF-α; IL-6	22 OSAS patients versus 16 non-OSAS controls	TNF-α and IL-6 levels were higher in OSAS group and were correlated with percentage of time of apneas and hypopneas and with percentage of time spending at SaO2 <90%
Ciftci et al. [39]	TNF-α; IL-6	43 obese OSAS patients versus 22 BMI matched non-OSAS controls	TNF-α and IL-6 levels were higher in OSAS group and were correlated with AHI but not with BMI
Ciccone et al. [40]	CRP; TNF-α; IL-6	26 mild OSAS versus 54 moderate-to-severe OSAS versus 40 controls	CRP, TNF-α, and IL-6 levels were higher in moderate/severe OSAS than in other groups
Imagawa et al. [43]	TNF-α; IL-6	110 severe OSAS patients versus 45 non-OSAS controls	TNF- and IL-6 levels did not differ between groups. BMI was correlated with the severity of the AHI
Guasti et al. [44]	TNF-α; IL-8	16 OSAS patients versus 11 non-OSAS controls	Resting and stimulated TNF-α and IL-8 release, as well as serum levels, were similar in the two groups
Ohga et al. [48]	IL-8; ICAM-1	20 OSAS patients versus 10 non-OSAS controls	IL-8 and ICAM-1 levels were higher in OSAS patients and were correlated with apnea index and desaturation magnitude
Alzoghaibi [50]	IL-8	25 severe OSAS patients versus 17 non-OSAS controls	IL-8 levels were higher in OSAS group
Cofta et al. [61]	CRP; E-selectin; L-selectin; P-selectin	60 OSAS patients versus 20 non-OSAS controls	CRP and selectins levels progressively increased with increasing severity of OSAS
Testelmans et al. [62]	CRP; TNF-α; IL-8; IL-6; ICAM-1	15 non-OSAS controls versus 12 patients with cardiovascular disease versus 15 OSAS patients with cardiovascular disease versus 15 non-obese OSAS patients versus 15 obese OSAS patients	CRP, TNF-α, IL-8, IL-6, and ICAM-1 levels were higher in patients with acute cardiovascular events and OSAS and were associated with AHI
Ursavas et al. [64]	ICAM-1; VCAM-1	39 moderate-to-severe OSAS patients versus 34 non-OSAS controls	ICAM-1 and VCAM-1 levels were increased in the OSAS group. ICAM-1 levels were correlated with AHI
Ohga et al. [65]	ICAM-1; VCAM-1; L-selectin	7 OSAS patients versus 6 non-OSAS controls	ICAM-1, VCAM-1, and L-selectin levels were increased in OSAS group before sleep compared with controls. Only ICAM-1 and L-selectin levels were increased after sleep
Basoglu et al. [74]	CRP; Fibrinogen	36 obese OSAS patients versus 34 obese non-OSAS controls	CRP and fibrinogen levels were higher in obese OSAS patients
Shamsuzzaman et al. [76]	Fibrinogen	10 mild OSAS patients versus 26 severe OSAS patients versus 18 non-OSAS controls	Fibrinogen levels were elevated in patients with severe OSAS compared with other groups