Abstract
BACKGROUND: Multimorbidity (≥2 chronic diseases) is common among older adults and is linked to increased disability and mortality. Sleep disordered breathing (SDB) is underdiagnosed and has been associated with several chronic diseases. However, little is known about the specific patterns of comorbidity in the elderly. This study investigated the association between SDB and multimorbidity patterns in individuals aged ≥65 years and assessed the impact of SDB on all-cause mortality. METHODS: This registry-based case-control study utilised the Danish National Patient Registries from 2002 to 2019. Individuals aged ≥65 years diagnosed with SDB were identified and matched 1:4 with controls based on age, sex, cohabitation status and region of residence. Comorbidities were categorised using eight World Health Organization (WHO) disease chapters, and 22 specific chronic diseases were assessed within 7 years prior to SDB diagnosis. Conditional logistic regression estimated odds ratios (ORs) for comorbidities; Cox hazard regression models evaluated mortality risk. RESULTS: A total of 21 555 patients with SDB were matched to 86 212 controls. Patients with SDB had significantly higher odds of multimorbidity (OR 2.99, p<0.01), with increased prevalence across all eight WHO disease groups. The highest ORs were found in the cardiovascular (OR 2.52, p<0.01) and metabolic disease categories (OR 2.52, p<0.01). SDB was associated with elevated all-cause mortality (hazard ratio 1.09, p<0.01). CONCLUSION: SDB in older adults is associated with multimorbidity and increased mortality, highlighting the need for increased recognition and coordinated treatment of SDB in elderly patients with multiple chronic conditions.