The Association between Sleep Duration and Self-Rated Health in the Korean General Population

Abstract

Study Objectives: Sleep duration is recognized as one of the most common issues in modern society. Self-rated health is a commonly used subjective health measure based on a single question asking individuals to rate their general health on a four-or fi ve-point scale. However, few studies have examined the relationship between sleep duration and self-rated health. Here, we examined the association between sleep duration and poor self-rated health, using a large representative sample of the general Korean adult population. Design: We conducted a cross-sectional study of 15,252 participants in the Korea National Health and Nutrition Examination Survey IV (2007)(2008)(2009)) who were aged 19 years and older. Sleep duration was categorized as ≤ 5, 6, 7, 8, or ≥ 9 hours. The main outcome of interest was poor self-rated health (n = 3,705, 19.7%). Multiple logistic regression analysis was performed to examine the association between sleep duration and self-rated health. Results: We found both short (≤ 5 h) and long (≥ 9 h) sleep duration to be associated with poor self-rated health independent of sociodemographic, health risk, and health status variables. Compared with 7-h sleep duration, the multivariate odds of poor self-rated health were 1.358 times higher (95% CI 1.167-1.580) with short sleep duration and 1.322 times higher (95% CI 1.091-1.601) with long sleep duration. This association persisted in subgroup analyses of gender, body mass index, and age by gender. Conclusions:In a large representative sample of the Korean general adult population, compared with sleep duration of 7 hours, we found a positive association between short and long sleep duration and poor self-rated health in Korean adults. Furthermore, the association between sleep duration and poor self-rated health was consistently present in subgroups divided by gender, age, and BMI. Keywords: Sleep, sleep duration, self-rated health, gender, age, body mass index (BMI), KNHANES Citation: Kim JH; Kim KR; Cho KH; Yoo KB; Kwon JA; Park EC. The association between sleep duration and self-rated health in the Korean general population.

Association between Sleep Duration and Self-Reported Health Status: Findings from the Bhutan's Gross National Happiness Study

“…For instance, cross-sectional studies from Korea, United States and Australia revealed that only 8%, 9%, and 17% of surveyed population slept ≥ 9 h, respectively. [29][30][31] In addition, Bhutan's average sleep time of 8.5 h is high when compared to other nationally representative studies from Finland (7.5 h), Austria (7 h), Korea (6.7 h), and United States (7.2 h). 19,[41][42][43] The high proportion of long sleepers in Bhutan could be because the majority of the respondents were from the rural areas without formal education.…”

“…From this 24-h recall period, the sleep duration was recorded as continuous variable in minutes and converted into hours with one decimal place, then they were categorized into ≤ 6 h, 7 h, 8 h, 9 h, 10 h, and ≥ 11 h. These categories were consistent with previous studies on sleep and self-reported health status. 1 Seven hours is used as a reference category because the majority of the studies have used 7 h as the reference category 14,29,31,38 and 7 to 8 h sleep is also reportedly associated with the lowest risk of morbidity and mortality. 4,14,39 Other Main Covariates Sociodemographic factors like age, gender, household income and household size were included in the analysis.…”

“…8 Furthermore, some studies have indicated that sleep duration was associated with poor self-reported health status, but they were mostly conducted in developed countries and the results were not consistent. For example, large nationally represented studies from Korea (≥ 19 y), 29 Australia (45-74 y) 30 and United States (≥ 18 y) 31 found that both short (≤ 5 h, ≤ 6 h, and ≤ 6 h, respectively) and long (≥ 9 h, ≥ 9 h, and ≥ 8 h, respectively) sleep durations were associated with poor self-reported health status. Conversely, a study conducted among elderly population (> 60 y) in Lima, Peru and a large multi-country study among university students aged 17-30 y found that only short sleep duration (< 6 h and < 7 h, respectively) was associated with poor self-reported health status 32,33 ; whereas Jean-Louis et al found no association between sleep duration and the health-related quality-of-life score in a small sample size (273…”

Relationship of Sleep Duration with Sociodemographic Characteristics, Lifestyle, Mental Health, and Chronic Diseases in a Large Chinese Adult Population

“…The association between sleep duration and chronic medical diseases and multi-morbidity was found in this study, which is broadly consistent with results in the literature. 10,28,30,36,43 The adjusted odds ratio of short sleep increased in patients with multimorbidity compared to those with a single chronic disease. The high rate of serious medical conditions, such as hypertension, diabetes, ischemic heart disease and chronic obstructive pulmonary disease, found in short sleepers could partly account for the commonly reported association between mortality and short sleep.…”

The Association between Short or Long Sleep Times and Quality of Life (QOL): Results of the Korea National Health and Nutrition Examination Survey (KNHANES IV–V)

“…Equivalized household income was used by dividing the household monthly income by the square root of household size 30 and grouped into four household income quartiles. Education level was categorized into four groups: elementary school or lower, middle school, high school, and college or higher.…”