Prospective observation on the association of snoring with subclinical changes in carotid atherosclerosis over four years

Objective: Although there is a growing interest in the independent effect of snoring on carotid atherosclerosis, few studies have observed the relationship between snoring and change in carotid atherosclerosis prospectively. Therefore, the present study aimed to prospectively examine the association of snoring with subclinical changes in carotid atherosclerosis during a four-year period. Methods: Participants in an ongoing prospective cohort study (n= 3129) were enrolled. Subclinical changes in carotid atherosclerosis were assessed using: (i) mean and maximum intima-media thickness (IMT) on both common carotid arteries; (ii) prevalence of elevated IMT (maximum IMT ≥1.0. mm); and (iii) presence of plaque. Measurement was performed using B-mode ultrasonogram at baseline and after two and four years. Subjects were classified into three groups, based on self-reported snoring frequency at baseline: habitual, occasional, and non-snorer. Results: After adjustment for conventional cardiovascular risk factors and self-reported witnessed sleep apnea, the present study found significant cross-sectional differences in mean and maximum IMT between female snorers and non-snorers at baseline only. The changes in IMTs and presence of plaque over four years, however, did not differ by three groups, with different snoring frequency in both genders. Conclusions: Snoring did not accelerate subclinical change in carotid atherosclerosis during a four-year follow-up, although baseline difference in IMT between snorers and non-snorers was significant in women, independent of witnessed sleep apnea. Additional longer-term studies with objective assessment of snoring are needed.