| Intervention | Comparison/control | Duration months | Subjects n | Baseline OSA | Outcomes | Additional metabolic benefits reported | |||||
| Diagnostic procedure | Severity | Weight loss intervention | Weight loss control | p-value | |||||||
| Diet + CPAP | |||||||||||
| Ballester [71] | Conservative treatment + CPAP | Conservative treatment only | 3 | 105 | Partially attended night-time respiratory recording | Severe (AHI 56±20) | -1.1 kg | -3.1 kg | <0.001 | Nil | |
| Conservative treatment: sleep hygiene and weight loss programme, home diet prescribed by dietician | |||||||||||
| Monasterio [73] | Conservative measures + CPAP | Conservative measures only | 6 | 125 | PSG | Moderate (AHI 20±6) | +0.1 kg 6 months | -2.7 kg 6 months | <0.001 | Nonsignificant improvement in blood pressure in both control and CPAP group | |
| Conservative measures: weight loss programme following a home diet, avoidance of sedatives and alcohol consumption, avoidance of supine position during sleep and adequate hours of sleep | |||||||||||
| Kajaste [72] | Weight reduction strategy + CPAP (individualised CBT + dietary counselling) | Weight reduction strategy + CPAP (CBT + dietary counselling) | 24 | 31 males | PSG | Moderate (AHI 20±6) | -19.1 kg 6 months | -19.2 kg 6 months | >0.05 | Nil | |
| Intensive Lifestyle Intervention (ILI) | |||||||||||
| Foster [74] | ILI: group weight loss programme based on low calorie diet and physical activity prescription of 175 min·week−1 of moderate, developed specifically for obese T2DM patients | Three group diabetes support education sessions focused on diet, physical activity and social support | 12 | 264 | Unattended PSG | Moderate (AHI 23.2±16.5, ODI 19.4±4.9) | 10.8 kg post-1-year intervention | 0.6 kg post-1-year intervention | <000.1 | Significant improvement in waist and neck circumference and HBA1c (p<0.001) | |
| Tuomilehto [75] | Lifestyle intervention: individual tailored counselling and weight reduction programme with emphasis placed on diet, exercise and modification of lifestyle, focusing on eating behaviour | One dietary and exercise counselling session | 12 | 71 | Embletta | Mild (AHI 9.65±12) | 10.7 kg post-1-year intervention | 2.4 kg post-1-year intervention | <0.001 | Significantly improved waist circumference (p<0.001) | |
| Lifestyle Intervention | |||||||||||
| Kemppainen [76] | Lifestyle intervention: individual tailored counselling and weight reduction programme with emphasis on diet, exercise and lifestyle modification (focusing on eating behaviour) | One dietary and exercise counselling session | 3 | 52 | Embletta | Mild (AHI 10.1±6.3) | BMI 5.4 kg·m−2 3 months | BMI 0.49 kg·m−2 3 months | <0.05 | Nil | |
| Papandreou [77] | ILI: individualised weight reduction programme based on a low calorie Mediterranean diet and physical activity prescription of at least 30 min·day−1, developed specifically for obese OSA patients who underwent CPAP treatment | Individualised weight reduction programme based on a low calorie prudent diet and physical activity prescription of at least 30 min·day−1, developed specifically for obese OSA patients who underwent CPAP treatment | 6 | 21 | PSG | Severe (AHI 46.2±32.7) | Weight -8.9 kg Waist circumference -8.7 cm Body fat -4.3% | Weight -7.2 kg Waist circumference 5.7 cm Body fat -2.6% | 0.162 0.013 0.032 | Nil | |
| Kline [78] | ILI: group exercise training based on 150 min per week of moderate intensity aerobic activity followed by resistance training twice per week | Stretching exercises | 3 | 43 | PSG | Moderate (AHI 28.3±5.6) | Body fat -1.1% | Body fat -0.2% | <0.01 | Significant AHI reduction in exercise group and ODI | |
| Ackel-D'Elia [79] | ILI: 2-month supervised aerobic exercise three times per week + CPAP therapy | CPAP therapy only | 2 | 32 males | PSG | Moderate (AHI >15) | No significant difference in weight parameters between groups | >0.05 | Subjective sleepiness improved in exercise | ||
| Other | |||||||||||
| Sengul [80] | Exercise training programme (breathing and aerobic exercise) | No treatment | 6 | 20 males | PSG | Moderate (AHI 16.5±5.94) | No significant changes in weight parameters between groups | > 0.05 | Nil | ||
| Stradling [81] | Dietary advice and Arm 1: hypnotherapy type 1 (emphasis on ego strengthening centred on stress reduction) versus Arm 2: hypnotherapy type 2 (emphasis on ego strengthening centred on altering attitudes to food using the Spiegal and Spiegal approach) | Dietary advice on two occasions only | 18 | 46 | Not stated | Not assessed | 3 months no significant difference between groups, 18 months follow-up hypnotherapy + stress reduction mean weight loss 3.8 kg compared to baseline. | <0.02 | Nil | ||
| Johansson [82] | Weight loss programme (very low energy diet using a standard 2.3 MJ per day liquid energy intake protocol Cambridge diet) | Usual diet | 2.25 | 63 males | Two consecutive unattended sleep studies using a 6-channel ambulatory polyography equipment | Severe whole group 37±15 AHI | 18.7 kg weight loss | 1.1 kg weight loss | <0.001 | Nil | |
CPAP: continuous positive airway pressure; AHI: apnoea/hyponoea index; PSG: polysomnography; CBT: cognitive behavioural therapy; T2DM: type 2 diabetes mellitus; ODI: oxygen desaturation index; BMI: body mass index.