OSA is more common in men – but it’s often more dangerous in women

Sleep apnoea, which causes pauses in people’s breathing during the night, is usually associated with snoring middle-aged men. But women experience it, too, and may suffer from poorer heart health than men, according to a recent study in the journal Circulation.

sleep disorder, insomnia. young blonde woman lying on the bed awake

Snoring is one of the most common signs of sleep apnoea.

“The sleep apnoea seems to have a stronger influence on women than men,” says Dr. Amil Shah, an author of the paper and an assistant professor of medicine at Harvard Medical School.

Shah and his colleagues looked at 752 men and 893 women, with an average age of 62.5. At the beginning of the study, none of the participants had experienced any sort of cardiac problems. Then the researchers looked at the same people about 14 years later to see if anyone had experienced coronary disease, heart failure, and cardiovascular disease.

Both men and women who had obstructive sleep apnoea had higher troponin T levels – a marker in the blood that indicates heart injury – and larger, thicker hearts, and heart failure. But when the researchers checked for other diseases, such as diabetes and hypertension, only the women experienced high troponin T levels, heart failure, and thicker hearts.

“This finding implies that sleep apnoea potentially has a much more serious independent effect in women than men,” says Shah. “It is important to look for sleep apnoea, and it is important to treat it as early as possible.”

However the study provides real evidence that women need to take their sleep seriously, especially after menopause when women’s rate of sleep apnoea increases.

Good undisturbed sleep is critical, and just last month, a survey by the University of Leeds found that 25 per cent of people get less than five hours’ sleep a night. It noted a distinct mismatch between how much sleep people intended to get – and what they actually got.

A run of poor sleep can have a potentially profound effect on the internal workings of the human body. The activity of hundreds of genes was altered when people’s sleep was cut to less than six hours a day for a week, and the results helped explain how poor sleep damaged health.

Heart disease, diabetes, obesity and poor brain function have all been linked to substandard sleep due to such things as snoring and sleep apnoea, but what lack of sleep did to alter health was still unknown.

So researchers at the University of Surrey analysed the blood from people after they had had plenty of sleep, up to 10 hours each night for a week, and compared the results with samples after a week of fewer than six hours a night.  They found that more than 700 genes were altered by the shift. Each contains the instructions for building a protein, so those that became more active produced more proteins – changing the chemistry of the body.

Prof Colin Smith, from the University of Surrey, said in a BBC interview: “There was quite a dramatic change in activity in many different kinds of genes.”

Areas such as the immune system and how the body responds to damage and stress were affected. A different study has also shown that women who worked long years of night shift work had double the risk of breast cancer compared with those who had never worked night shifts.

Health-wise, some of the major effects of sleep loss are:

  • You will be more likely to get colds and viruses
  • You become tired and irritable, and lose your sense of humour
  • You’ll yawn more and speaking can be slurred
  • Any aches and pains will seem worse
  • You’re more easily affected by alcohol
  • You will be probably eat more than usual and weight gain adds to the problem as it increases your likelihood to snore
  • Memory can be affected with early onset of Alzheimer’s
  • Daytime drowsiness is common and dangerous if driving

Scientists from Oxford, Cambridge, Harvard, Manchester, Leeds and Surrey Universities have all warned that cutting sleep is leading to “serious health problems” and they say people and governments need to take the problem seriously, including treating snoring and sleep apnoea as early as possible.

John Redfern