Non-surgical weight loss reduces AHI by 11.10 in adults with obstructive sleep apnoea

BACKGROUND: Obstructive sleep apnoea (OSA) is a prevalent disorder closely linked to obesity. While weight loss is a recommended strategy to target its root cause, evidence on the efficacy and sustainability of non-surgical interventions remains unclear. This meta-analysis aimed to systematically evaluate their effects on OSA severity and cardiometabolic outcomes, and to explore sources of heterogeneity. METHODS: This meta-analysis of randomized controlled trials was conducted PRISMA guidelines (PROSPERO: CRD420250641507). We searched PubMed, EMBASE, Cochrane Library, and Web of Science for trials assessing non-surgical weight loss interventions in adults with OSA. The primary outcome was the Apnea-Hypopnea Index (AHI); secondary outcomes included anthropometric and blood pressure measures. Data were synthesized using random-effects models, with heterogeneity explored via pre-specified subgroup analyses (by follow-up duration and type 2 diabetes status). Risk of bias and evidence certainty (GRADE) were assessed. RESULTS: Eighteen studies involving 2242 participants were included. Non-surgical weight loss interventions significantly reduced AHI (MD = -11.10; p < 0.0001). Significant improvements were observed in all secondary outcomes: body weight (MD = -6.53), body mass index (MD = -2.40), waist circumference (MD = -5.13), neck circumference (MD = -0.97), systolic blood pressure (MD = -6.51), and diastolic blood pressure (MD = -3.26) (all p < 0.01). Evidence for benefits was most robust in the short to mid-term. Heterogeneity was high (I >90%) for most outcomes. The overall certainty of evidence was rated as very low. CONCLUSION: Non-surgical weight loss constitutes a viable short-to-midterm strategy for improving OSA severity and cardiometabolic health. It should be integrated as a foundational component of initial management, with emphasis on long-term weight maintenance. High-quality research with extended follow-up is needed to confirm the durability of benefits.