Late Chronotype Is Associated With Dizziness and Postural Instability.
OBJECTIVES Sleep has been reported to be associated with dizziness. However, its relationship with chronotype, a behavioral manifestation of circadian rhythms reflecting individual variation in sleep-activity timing, has not been widely investigated. This study aimed to examine the association between chronotype and dizziness and its related symptom profiles. METHODS From the eighth Korea National Health and Nutrition Examination Survey (2021), 3766 participants with information on demographics, underlying diseases, dizziness, and sleep pattern were included after excluding 19 individuals with outlier sleep debt-corrected midpoint of sleep on work-free days (MSFsc) values. Then the subjects were classified into early sleep (MSFsc ≤ 01:00), intermediate sleep (01:00 < MSFsc < 04:30), and late sleep groups (MSFsc ≥ 04:30). RESULTS In the multivariable analysis, the late sleep group had significantly higher prevalence of recurrent dizziness (aOR = 1.480, 95% CI = 1.139-1.922, p = 0.003), postural instability (aOR = 2.354, 95% CI = 1.039-5.332, p = 0.040), and chronic dizziness (aOR = 2.300, 95% CI = 1.449-3.651, p < 0.001) than the intermediate sleep group. Furthermore, the late sleep group exhibited higher prevalence of recurrent dizziness (aOR = 1.464, 95% CI = 1.039-2.062, p = 0.030) and chronic dizziness (aOR = 2.100, 95% CI = 1.173-3.758, p = 0.012) compared with the early sleep group. CONCLUSION Late sleep was significantly associated with dizziness, particularly recurrent dizziness, chronic dizziness, and postural instability, suggesting a potential link with persistent dizziness. Further studies are needed to clarify causality and therapeutic implications. LEVEL OF EVIDENCE: 3