Hypoxic burden, systemic inflammation and respiratory muscle dysfunction in obstructive sleep apnoea: a multicentre cross-sectional study
Year: 2026
Type: article
Study design: Observational Study
Abstract: Background Obstructive sleep apnoea (OSA) is characterised by intermittent hypoxaemia and systemic inflammation. Hypoxic burden has emerged as a physiologically relevant marker of disease severity, but its relationship with inflammatory biomarkers and respiratory muscle strength remains unclear.Methods In this multicentre cross-sectional study, 137 adults with suspected OSA from tertiary care centres in Lahore, Pakistan underwent overnight attended polysomnography using standardised protocols. Hypoxic burden was quantified as the cumulative area under the oxygen desaturation curve across sleep. Fasting blood samples were analysed for C reactive protein (CRP), interleukin-6, tumour necrosis factor-alpha, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio using standard laboratory methods. Respiratory muscle strength was assessed using maximal inspiratory and expiratory pressures. Clinical, anthropometric and questionnaire-based data were also collected. Multivariable linear regression models were used to examine factors independently associated with hypoxic burden and systemic inflammation after adjustment for potential confounders.Results OSA severity was associated with increases in age, body mass index (BMI), blood pressure, hypoxic burden and inflammatory biomarkers, alongside reductions in respiratory muscle strength (all p<0.05). Hypoxic burden demonstrated the strongest association with disease severity (η²=0.73, p=0.001). In multivariable analysis, higher BMI (β=1.35, p=0.002), older age (β=0.25, p=0.024), higher Epworth Sleepiness Scale score (β=0.50, p=0.015) and lower inspiratory muscle strength (β=−0.68, p=0.007) were independently associated with greater hypoxic burden (adjusted R²=0.47). Systemic inflammation (CRP) was independently associated with higher BMI (β=0.28, p=0.003), greater hypoxic burden (β=0.045, p=0.004) and lower inspiratory muscle strength (β=−0.10, p=0.009) (adjusted R²=0.58). Inflammatory markers increased progressively, while maximal inspiratory pressure and maximal expiratory pressure declined across OSA severity.Conclusions Hypoxic burden was independently associated with disease severity and systemic inflammation in OSA, while reduced respiratory muscle strength was independently associated with greater hypoxaemia and systemic inflammation.
Source: BMJ Open Respiratory Research
Institutions: University of Lahore, Islamic Azad University, Isfahan
Language: English
Subfield: Physiology (medical)
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,085
OpenAlex ID: W7223663720