Table 1.
Description of included studies
| Study | Country | N (Pre/Post CPAP) | Assay | Age (Pre/Post CPAP) | CPAP time/CPAP set | NOS | AHI (Pre/Post CPAP) | BMI (Pre/Post CPAP) |
|---|---|---|---|---|---|---|---|---|
| Muller et al., 2003 [20] | Germany | 10/25 | commercial chemiluminescent immunoassay | 49/49 | 30 days/NA | 6 | 40.9 ± 23.9/42.2 ± 24.4 | 28.2 ± 3.8/30.8 ± 5.1 |
| Li et al., 2014 [24] | China | 15 | chemiluminescent immunoassay | 10.8 (6.6–13.3)/ 11.1 (7.4–14.8) | 12 weeks/NA | 7 | 19.5 (9.6–33.3)/0.8 (0.5–1.5) | 1.20(− 0.18–1.91)/1.40(0.17–1.83) |
| Chang et al., 2017 [25] | Australia | 28 | immunoassay | 48 ± 12 | 8-week/sham CPAP: 0.5 cmH2O, treatment pressure: 90th centile pressure | 7 | 40.26 ± 27.4/6.97 ± 11.3 | 31.95 ± 4.22 |
| Craig et al., 2015 [27] | UK | 158/158 | immunoassay | 57.2 ± 6.5/57.6 ± 7.2 | 6-month/given on an individual basis | 8 | NA | 31.8 ± 4.9/31.9 ± 5.5 |
| Maeder et al., 2009 A [22] | Switzerland | 40 | chemiluminescent immunoassay | 50 ± 9 | 7.9-month/NA | 7 | 37 (20–65) | 30.3 ± 4.5 |
| Maeder et al., 2009 B [22] | Switzerland | 16 | chemiluminescent immunoassay | 49 ± 8 | 8-month/NA | 7 | 17 (11–26) | 30.6 ± 5.6/30.1 ± 5.1 |
| Maeder et al., 2009 C [22] | Switzerland | 24 | chemiluminescent immunoassay | 51 ± 10 | 7-month/NA | 7 | 54 (40–74) | 30.0 ± 3.7/30.0 ± 3.7 |
| Miyazaki et al., 2015 [26] | Japan | 32 | immunoassay | NA | 3–6 month/NA | 8 | 45.3 ± 13.6/2.5 ± 3.7 | NA |
| Randerath et al., 2012 A [23] | Germany | 36/34 | immunoassay | NA | 3-month/4–30 cmH2O | 6 | 10.8 ± 11.3/16.5 ± 17.3 | NA |
| Randerath et al., 2012 B [23] | Germany | 36/34 | immunoassay | NA | 12-month/4–30 cmH2O | 6 | 11.1 ± 11.6/17 ± 17.9 | NA |
| Strehmel et al., 2016 [28] | Germany | 21 | immunoassay | 61 ± 11 | NA/NA | 7 | 53 ± 21 | 35 ± 7 |
NA not given, Maeder et al.: Group A means all, Group b AHI < 30 h and Group c means AHI ≥ 30 h; Randerath et al.: Group A means follow up 3 months and Group B means follow up 12 months