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Cranky coupledom?

Why sleepless nights can lead to worse fights

Not sleeping can affect your relationship — and your health.

A study found that couples who argue after sleeping fewer than seven hours the night before have higher levels of inflammation in their blood than normal, according to researchers at The Ohio State University Wexner Medical Center’s Institute for Behavioral Medicine Research.

The stress-related inflammation is associated with higher risk of cardiovascular disease, diabetes, arthritis and other diseases.

We sat down with Stephanie Wilson, lead researcher on the study, and Janice Kiecolt-Glaser, senior author and director of the institute, to discover how inflammation also contributes to stress in a relationship.

What prompted this study?

“We know sleep problems are also linked with inflammation and many of the same chronic illnesses. So we were interested to see how sleep related to inflammation among married couples, and whether one partner’s sleep affected the other’s inflammation,” Wilson said.

The research team recruited 43 couples who completed two study visits. Each time, the couples provided blood samples and reported how many hours they had slept the previous two nights.

Then researchers had the couples try to resolve a topic that sparks conflict in their marriage. Blood samples were taken again following the discussion.

What did you find?

“We found that people who slept less in the past few nights didn’t wake up with higher inflammation, but they had a greater inflammatory response to the conflict. So that tells us less sleep increased vulnerability to a stressor,” Wilson said.

If both partners got less than seven hours of sleep the previous two nights, the couple was more likely to argue or become hostile. 

For every hour of sleep lost, the researchers noted that levels of two known inflammatory markers rose 6 percent.

Did “fighting dirty” make things worse?

Couples who used unhealthy tactics in their disagreement had an even greater inflammatory response — about a 10 percent increase with each hour of less sleep.

“Any increase (in inflammatory response) isn’t good, but a protracted increase that isn’t being addressed is where it can become a problem,” Wilson said.

“What’s concerning is both a lack of sleep and marital conflict are common in daily life. So, the fact that people are experiencing both of these together sort of introduces a risk that we didn’t pinpoint before.”

About half of the study couples had slept less than the recommended seven hours in recent nights.

What happens when one partner gets more sleep?

If one partner was well-rested, they tended to neutralize the disagreement that might be stirred by the sleep-deprived partner, Kiecolt-Glaser said.

But when both were tired, it was a different story.

“Couples were more hostile to each other only if both had slept less than the recommended seven hours. If one partner was well rested, there was a protective effect.”

And couples often sleep together. So one can disrupt the other’s rest?

“Part of the issue in a marriage is that sleep patterns often track together. If one person is restless, or has chronic problems, that can impact the other’s sleep,” Kiecolt-Glaser said.

“If these problems persist over time, you can get this nasty reverberation within the couple. None of us feels that good when we don’t have enough sleep.”

How do couples avoid putting a strain on their marriage and their health?

“What we worry about in a study like this is having relatively modest changes in inflammation — but persistent over time,” Kiecolt-Glaser said.

She adds that failing to resolve conflict over time is risky.

“That would be one of the ways where, with continual disagreements, we could really see a heightening of inflammation,” she said.  “We would tell people that it’s important to find good ways to process the relationship and resolve conflict — and get some sleep.”