Poor sleep not only makes you grouchy. New research indicates it can also make you more susceptible to inflammation after having a stressful conversation with your spouse.

“We know that sleep is important for our health, in part because people with sleep problems also tend to have worse health and more chronic illnesses. We also have learned from sleep deprivation experiments that being deprived of a night’s sleep can have pervasive effects on people’s behavior, health, and general ability to function. But do a few nights of slightly shorter sleep in daily life also have detectable effects?” the study’s corresponding author, Stephanie J. Wilson of the Ohio State University College of Medicine, told PsyPost.

“We also know that the quality of our close relationships can impact our physical health. Marital conflict in particular has potent effects on inflammation. Bringing these two pieces together led us to question how recent sleep is related to inflammation in couples—whether one partner’s sleep would increase the other’s inflammation, whether less sleep exacerbates the response to conflict, and how marital behavior and emotion regulation are involved.”

The study was published online February 16, 2017 in the peer-reviewed journal Psychoneuroendocrinology.

Wilson and her research team recruited 43 married couples for their study. (The average length of marriage was 11.5 years.) The couples went to a lab where they participated in a 10- to 20-minute interview about one or more marital problems they were experiencing. The couples provided blood samples before and after this discussion, which were tested for biomarkers of inflammation.

The researchers found evidence that lack of sleep increased inflammatory reactivity to marital conflict. Husbands and wives who slept less over the last 48 hours experienced greater inflammatory responses after discussing their marital problems compared to those who slept more. Couples also behaved more negatively and less positively when both the husband and wife had slept less.

“You may not start the day with higher levels of inflammation simply because you slept a bit less in the last few nights. However, those few nights of shorter sleep may mean greater increases in inflammation after a stressful encounter, like marital conflict, than if you had slept longer,” Wilson explained to PsyPost.

Previous research had found that poor sleep quality could provoke hostility between romantic partners. The new study suggests that poor sleep has physiological consequences for couples as well.

“These are two experiences quite common in everyday life — having a few nights sparse on sleep, and getting into a spat with a loved one,” Wilson said. “Together, they may spell trouble for health over months or years. On the other hand, our study also found that couples who were able to use healthy emotion regulation strategies during disagreement were protected from higher inflammation related to sleeping less in recent days.”

Some of the emotion regulation strategies included expressing one’s feelings, taking the perspective of one’s partner, and focusing on problem-solving.

“It is important to note that couples came into the laboratory to discuss a disagreement—this was part of the study’s design,” Wilson said. “Prior studies indicate that sleep problems do translate to increased conflict in couples’ daily lives, and disagreements can be as nasty in the lab as they are elsewhere. Tensions and disagreements are the most common stressors in daily life, but it would be interesting to see whether this pattern holds for other kinds of stressors—like work-related pressures and worries.”

“We are grateful to our research participants for giving us a glimpse into their lives, and giving us an opportunity to learn about how stress and relationships affect health,” she added. “The next time you see a study you are eligible for, please consider participating!”

The study, “Shortened sleep fuels inflammatory responses to marital conflict: Emotion regulation matters“, was also co-authored by Lisa M. Jaremka, Christopher P. Fagundes, Rebecca Andridge, Juan Peng, William B. Malarkey, Diane Habash, Martha A. Belury, and Janice K. Kiecolt-Glaser.