In a study published in the Journal of Pain Research, Chinese researchers investigated the relationship between sleep quality and the prevalence of pain.
In 2011, it was globally estimated that one-fifth of the general population suffered from pain, and one-tenth of the population received a diagnosis of chronic pain, annually. Studies have found that poor sleep may increase the risk of experiencing pain. Poor sleep has also been associated with a higher likelihood of experiencing lower back pain, fibromyalgia (in women), headaches and chronic widespread pain. Additionally, there is experimental data to support the theory that poor sleep or sleep deprivation may result in a reduced pain threshold or may, itself, be the cause of pain.
Most laboratory-based pain research has focused on pain sensitivity or acute pain tolerance, while epidemiological studies have primarily focused on the link between poor sleep quality and the risk of experiencing pain, not its effects on pain intensity. Few studies have investigated the association between sleep quality and pain intensity within the general population.
Chinese researchers recently performed a cross-sectional survey to shed light on sleep quality in a sample of rural Chinese adults and its association with prevalence of pain. They also examined the influence of sleep quality, associated psychosocial variables, and health status on pain intensity among the general population in everyday settings. They published their results in the Journal of Pain Research.
Assessing sleep quality and pain intensity in Liuyang City
The study took place in Liuyang City in Hunan Province in south-central China. They selected two of the 33 rural towns in Liuyang for the study. Then, they selected two villages from each town and randomly selected two blocks from each village, giving a total of eight samples.
All residents who had lived in the selected blocks for more than six months before the study were recruited as participants. They recruited a total of 2052 adults and collected data from November 1, 2010, to August 31, 2011. Each eligible family in the blocks received a home visit from one of three interviewing teams. Eligible participants in the household were invited to complete a series of questionnaires, which participants completed in one visit.
The questionnaires collected information on pain intensity and sleep quality in the preceding four weeks. They also collected health status information, assessing physical, mental, and social health. Physical health refers to physical mobility, daily physical activities, and organ function. Mental health denotes the individual’s level of happiness and perceived cognitive function. Social health refers to social contacts and networks, such as one’s communication level with family members or the availability of a support network when needed.
They also measured depressive symptoms, perceived stress, and self-efficacy, which measured an individual’s perceived ability to face difficulties. Lastly, researchers collected sociodemographic information on gender, age, education, income and religion.
Decreased sleep quality may increase pain intensity
The survey results revealed that 38.55% of the general population sample in rural China reported having high-quality sleep, while 4.78% reported having poor sleep. The four-week prevalence of pain reported by the group having high-quality sleep was 52.72%, while the group that experienced poor sleep had a prevalence of pain at 85.71%. From this, the authors concluded that decreased sleep quality is associated with an increase in the prevalence of pain intensity in the general population. In this case, it was a population of Chinese adults residing in rural areas. They also found evidence for strong associations between sleep quality and physical and mental health, as well as, depressive symptoms, which have also been identified in previous studies.
The authors identify several study limitations. The first limitation was the cross-sectional design, which does not allow for the identification of the direction of cause and effect between sleep and pain; additional longitudinal studies are needed to clarify any causal relationship. Second, the use of a single visual analog scale to measure sleep quality does not provide detailed information for a deeper exploration of the dimensions of sleep quality. Finally, the sample population consisted of adults from rural China, meaning the results may not generalized globally.
Improving sleep quality may be an effective way of mitigating pain intensity
More needs to be done to raise awareness of the importance of improving sleep quality for the prevention and management of pain. Together with the findings from previous studies, these findings suggest that improvements to sleep quality may be an effective way of mitigating pain intensity in the general population.
The use of therapies, such as breathing techniques in preparation for sleep or the use of slow to moderate exercise before sleep may be useful and practical for use in the general population. Alternatively, providing education on sleep hygiene to promote a healthy sleep-wake cycle may prove beneficial.
Written by Sara Alvarado BSc, MPH
Reference: Liu, X., Xiao, S., Zhou, L., Hu, M., Zhou, W., Liu, H. (2018). Sleep quality and covariates as predictors of pain intensity among the general population in rural China. Journal of Pain Research (11), 857-866. DOI: 10.2147/JPR.S156731