Relationship between Charlson Comorbidity Index and Obstructive Sleep Apnea severity indicators in a Tunisian cohort

Obstructive sleep apnea (OSA) is a recognized cardiovascular risk factor, associated with increased morbidity and mortality. Charlson comorbidity index (CCI) is widely used to measure comorbidities in chronic conditions.

This study aimed to evaluate the CCI as a potential screening tool for severe OSA by assessing its association with OSA severity predictors.

A retrospective study was conducted at a pneumology department, including OSA patients. The CCI was assessed and its median CCI calculated. Patients were divided to two groups: Group1 including patients with CCI greater than or equal to the median, and group2 below the median.

Median CCI was 3±1.6. Statistical analysis showed a significant association between a CCI greater than or equal to 3 and age (63 vs 47 years; p<0.001), Stop Bang score (5 vs 4; p=0.003), diastolic blood pressure (80 vs 70 mmHg; p=0.023), glycemia (7 vs 5 mmol/l; p=0.0001), arterial oxygen pressure (82 vs 86 mmHg; p=0.009), desaturation index (32 vs 28/h; p=0.022), minimal nocturnal pulse oxygen saturation (76 vs 78%; p=0.005), and nocturnal pulse oxygen saturation below 90% (17 vs 13%; p=0.02). No significant association was noted between the CCI and Epworth score, Pichot score, body mass index, apnea hypopnea index, mean duration of hypopnea or apnea, and mean nocturnal oxygen saturation. The CCI demonstrated sensitivity of 66% and specificity of 49% at a cutoff of 2.5 (AUC = 0.6, p<0.001).

The CCI showed a significant but modest ability to identify severe OSA, with variable associations across OSA severity predictors.