Marriage may improve your sleep, and better sleep may improve your marriage, two new studies suggest.

Women who are married or who have stable partners appear to sleep better than women who have never married or lost a partner, according to research from an eight-year study presented at the US Associated Professional Sleep Societies’ annual meeting.

They also found that marital happiness lowers the risk of sleep problems, while marital strife heightens the risk.

Although married women overall slept more soundly than unmarried women, the researchers, from the University of Pittsburgh School of Medicine, did identify a “newlywed” effect. Women who were single at the start of the study but gained a partner, had more restless sleep than women who were already married.

The researchers speculated that newly married women were less adjusted to sleeping with their partner than those who had been married longer.

The study included 360 middle-aged African-American, Caucasian and Chinese-American women who had taken part in the Study of Women’s Health Across the Nation.

The researchers used in-home sleep studies, activity monitors to track sleep-wake patterns and relationship histories to look at the effect stable marriages, unstable marriages and marital transitions, such as a divorce, had on sleep.

Another small study of 29 couples found that on a daily basis, the quality of a couple’s relationship and the quality of their sleep are closely linked.

In that study, from the University of Arizona, 29 heterosexual couples who shared a bed and did not have children completed sleep and relationship diaries for a week. The results showed that when men get better sleep, they are more likely to feel positive about their relationship the next day. And for women, problems in the relationship were strongly associated with poor sleep.

Brant Hasler, a clinical psychology doctoral candidate at the University of Arizona, said the data, although preliminary, suggest that couples experience a “vicious cycle” where sleep affects their relationship and the relationship then affects the subsequent night’s sleep. “Sleep research has focused nearly entirely on the individual and this research underscores the importance of considering the effects of, and consequences on, the bed partner,” he said. “These effects are particularly notable, given that sleep is increasingly sacrificed in the modern world. The research provides preliminary evidence that our sleep not only influences our own psychological and physical health, but can also impact our dear ones.”

Data from both studies suggest that sleep and relationship happiness are closely linked.

Sleeping with a snorer

After writing about the link between marriage and better sleep, I heard from several skeptical readers who were the long-suffering bed partners of snorers. “I’m happily married, but never get a good night’s sleep because of the noise!” wrote Lisa.

“My husband snores louder than a lawnmower, and I kick him harder than Beckham with a soccer ball,” Caroline wrote. “We both slept much better when single.”

It’s true that sleeping with a snorer can take a toll on your health. People who sleep next to snorers report high levels of fatigue and sleepiness and may even be at higher risk for hearing loss. Often, snoring is due to sleep apnea, which is characterised by episodes of interrupted breathing during sleep, which leads to regular night-time awakenings linked with a number of health problems.

But studies show that the person with sleep apnea is not the only one waking up. When the apnea is accompanied by loud snorts and snoring, the bed partner may wake up as often during the night as the person with the actual sleep disorder. One study from the Mayo Clinic in Rochester, Minnesota, found that spouses of snorers woke up, at least partially, an average of 21 times an hour, nearly as often as the 27 times the snorers were awakened by their apnea episodes.

In a 2005 study from Finland of 37 male snorers and their wives, half the women reported being disturbed by snoring every night.

In a 2003 study published in Chest, doctors from the Mayo Clinic in Scottsdale, Arizona, tracked the spouses of 54 patients with sleep apnea. Once the sleep apnea and snoring were treated, the spouses’ quality-of-life scores surged more than those who received the actual treatment. And treating apnea also improved sleepiness scores among the spouses by 20 per cent.

Second-hand snoring also may take a toll on hearing. In a pilot study of just four snorers in Kingston, Ontario, all the patients had slept next to a snorer for at least 15 years. The study showed the bed partners had significant noise-induced hearing loss in the one ear that was most exposed to the snoring.

Solutions are difficult.

One study found that earplugs can be a simple and effective treatment, but for some, especially parents of young children, these are not a practical option.

To find out if second-hand snoring is taking a toll on your health, doctors suggest taking a “sleep vacation” from your partner by moving into another room to determine if your sleep, mood and daytime alertness improves. The test may help convince your partner that his or her snoring is more than just an amusing annoyance and a real medical issue that is affecting the health of both you and your relationship.