Insomniacs, who were experiencing chronic pain, showed increased sensitivity to pain. Pain sensitivity was also linked to the amount of time it took to get to sleep.
Borge Sivertsen of the Norwegian Institute of Public Health in Bergen said that the need to improve sleep among chronic pain patients and vice versa, is evident.
Researchers measured pain sensitivity in more than 10,000 adults, who were participants in the Tromso Study, an ongoing public health study in Norway that began in 1974. Out of all of the participants, 10.5 percent had what the researchers considered an insomnia disorder, Live Science reported.
The participants were asked to place their hands in cold water for a set period of time. People who removed their hands early show a decreased tolerance to pain.
The results showed that 42 percent of patients who had insomnia took their hands out of the water before the 106 seconds were up, while only 31 percent of all participants lasted the stipulated period.
This increased sensitivity to pain was greater in those with severe insomnia. The patients with both severe insomnia and chronic pain were more likely to take their hands out of the water earlier than participants who had none of the conditions.
The authors said that future research should look into not only clinical implications, but also the role of neurotransmitters in the co-occurrence of sleep disorder and pain.
The study was published in the journal Pain.