Does snoring intensity correlate with the severity of obstructive sleep apnea?

Study Objectives: It is commonly believed that louder snoring is associated with more severe obstructive sleep apnea (OSA). We evaluated the association between snoring intensity and the severity of OSA to better understand this clinical correlation. We also investigated the relationships between body mass index (BMI), neck size, sleep stage, and body position with the intensity of snoring. Methods: Overnight polysomnography, including objective measurement of snoring intensity, in 1643 habitual snorers referred for evaluation of sleep apnea. Results: Sixty-five percent of patients were male; the cohort had a mean age of 48.7 ± 13.7 y and BMI of 30.9 ± 8.8 kg/m². The mean apnea-hypopnea index (AHI) was 28.2 ± 26. The severity of OSA was graded as no OSA (AHI < 5), mild (AHI 5 to 15), moderate (AHI 15 to 30), severe (AHI 30 to 50), and very severe OSA (AHI > 50). Snoring intensity increased progressively across all 5 categories of AHI frequency and ranged from 46.3 ± 3.6 db in patients with AHI < 5 to 60.5 ± 6.4 db in those with AHI > 50. Furthermore, there was a positive correlation between the intensity of snoring and the AHI (r = 0.66, p < 0.01). Conclusions: The intensity of snoring increases as OSA becomes more severe.