| First author [ref.] | Patients | Methods | OSA | Results |
| Singh [225] | 190 NAFLD patients | AST/ALT, liver biopsy, modified Berlin Questionnaire | 46% of the sample reported symptoms of OSA | No difference in liver damage between patients with and without OSA |
| Jouët [237] | 62 morbidly obese (54 females) | AST/ALT, liver biopsy | OSA in 84.7% of the sample | Male sex and OSA increased the risk for increased AST/ALT NASH and fibrosis not different between OSA and non-OSA |
| Kallwitz [234] | 85 morbidly obese (61 females) | AST/ALT, liver biopsy | AHI ≥15 in 51% of the sample | Increased ALT in OSA patients; OSA tended to be associated with progressive liver disease |
| Mishra [235] | 101 morbidly obese | AST/ALT, liver biopsy | OSA in 83.5% of NASH positive and 72.7% of NASH negative patients (ns) | Higher liver enzymes and OSA severity in NASH positive compared to NASH negative patients |
| Campos [236] | 200 morbidly obese (168 females) | Liver biopsy | OSA diagnosed in 13.5% of the sample | OSA increased the risk of NASH (OR 4.0, 95% CI 1.3–12.2) |
| Polotsky [233] | 90 morbidly obese (75 females) | AST/ALT, liver biopsy | RDI >5 in 81.1% of the sample; RDI 15±29 | NASH in patients with severe O2 desaturation during sleep |
| Daltro [238] | 40 morbidly obese (26 females) | AST/ALT, liver biopsy | AHI >5 in 80% of the sample; median AHI 11 (6–30) | No significant association between OSA and liver enzymes or NASH |
| Tanné [239] | 163 suspected OSA | AST/ALT, liver biopsy | Moderate to severe OSA in 79% of the sample | Liver enzymes associated with BMI and OSA (OR 5.9, 95% CI 1.2–29.2) NASH more severe in patients with AHI >50, but insulin resistance was a stronger factor |
| Tatsumi [240] | 83 OSA, 41 controls | Serum type III pro-collagen (latent NASH), CT liver/spleen ratio | Mean AHI 32.5 | Non-obese patients (mean BMI 25.6 kg·m−2) Correlation between serum type III pro-collagen (marker of fibrosis) and O2 desaturation during sleep Hepatic steatosis unaffected by OSA |
| Norman [241] | 109 OSA | AST/ALT | Mean AHI 53 | AST/ALT correlated with nocturnal hypoxaemia |
| Chin [242] | 40 obese OSA | AST/ALT | Mean AHI 57 | Increase in AST/ALT from evening to morning in untreated patients, blunted by acute and prolonged CPAP treatment |
| Kohler [243] | 94 OSA | AST/ALT | Mean ODI 42.4 | Randomised controlled trial Decrease in AST after both therapeutic and subtherapeutic CPAP |
| Kheirandish-Gozal [244] | 518 snoring children, 142 overweight/obese | AST/ALT | OSA in 66.2% of the sample | Increased liver enzymes (>40 U·L−1) in obese OSA children, associated with insulin resistance and hyperlipidaemia Improvement after treatment |
| Verhulst [245] | 75 children and adolescents | AST/ALT | OSA in 44% of the sample | Increased liver enzymes associated with RDI and hypoxaemia during sleep |
NAFLD: non-alcoholic fatty liver disease; AST: aspartate aminotransferase; ALT: alanine aminotransferase; NASH: non-alcoholic statohepatitis; ns: nonsignificant; RDI: respiratory disturbance index; AHI: apnoea/hypopnoea index; BMI: body mass index; CT: computed tomography; CPAP: continuous positive airway pressure; ODI: oxygen desaturation index.