A possible association between dysphonia and sleep duration: A cross-sectional study based on the Korean National Health and nutrition examination surveys from 2010 to 2012

Background Sleep is important in terms of good general health and appropriate sleep duration has been linked to quality-of-life. Dysphonia may impair communication and social relationships, and is thus also closely related to quality-of-life. No large-scale, cross-sectional epidemiological study of a sample representative of the population of an entire country has yet assessed the possible existence of a relationship between sleep duration and dysphonia. Methods We investigated a possible association between subjective voice problems and self-reported sleep duration in South Korean subjects using 2010-2012 data from the Korean National Health and Nutrition Examination Survey (KNHANES). Cross-sectional data on 17,806 adults (7,578 males and 10,228 females) over the age of 19 years who completed the KNHANES were analyzed. All participants reported voice problems (if present) and their daily average sleep duration using a self-reporting questionnaire. Sleep duration was classified into five categories as follows: <= 5, 6, 7, 8, and >= 9 h/day. Results The overall prevalence of dysphonia was 6.8%; 5.7% in males and 7.7% in females. The prevalence for dysphonia by sleep duration exhibited a U-shape, with the lowest point being at sleep duration of 7-8h. After adjustment for covariates (age, sex, smoking status, alcohol consumption, regular exercise, low income, high-level education), a sleep duration of <= 5 h (OR = 1.454; 95% CI, 1.153-1.832) and a sleep duration of >= 9 h (OR = 1.365; 95% CI, 1.017-1.832) were significantly associated with dysphonia, compared to a sleep duration of 7 h. In terms of gender, males who slept for >= 9 h were at a 2-fold (OR = 2.028; 95% CI, 1.22-3.35) higher odds for dysphonia (p < 0.05) compared to those who slept for 7 h. A sleep duration <= 5 h was associated with a 1.6-fold (OR = 1.574; 95% CI, 1.203-2.247) higher odds of dysphonia >= 3 weeks in duration (long-term dysphonia). Conclusions This is the first study to show that both short and long sleep duration were significantly associated with the development of dysphonia. The association between sleep duration and dysphonia was more marked in males than females. A sleep duration <= 5 h had a significant impact on the prevalence of long-term dysphonia.