The study included 145 couples in which one partner had knee osteoarthritis that caused moderate to intense pain. The participants recorded their levels of pain, sleep quality and levels of feeling rested or refreshed in the morning over 22 consecutive nights.
When patients reported higher levels of knee pain at the end of the day, their spouses slept poorly that night and felt less refreshed in the morning. Spouses who awoke with symptoms of depression and bad mood were more likely to have poor sleep quality and less refreshing sleep.
Couples with the closest marriage bonds had the strongest association between patient pain levels and the spouse's ability to get a good night's sleep, according to the study in the September issue of the journal Pain.
"Sleep is a critical health behavior, and individuals whose sleep is affected by their partner's pain are at risk for physical and psychiatric problems," lead investigator Lynn Martire, of Penn State University, said in a journal news release. "Spouses whose sleep is compromised may also be less able to respond empathically to patients' symptoms and need for support."
Many patients with knee pain have trouble getting comfortable in bed and staying asleep, and their restlessness can disturb their partner's sleep, the researchers explained.
"Compromised sleep caused by exposure to a loved one's suffering may be one pathway to spousal caregivers' increased risk for health problems, including cardiovascular disease," Martire said.
"Our findings suggest that assessing the extent to which partners are closely involved in each other's lives would help to identify spouses who are especially at risk for being affected by patient symptoms and in need of strategies for maintaining their own health and well-being," she added.
The American Academy of Orthopaedic Surgeons has more about knee osteoarthritis.