Israeli scientists have discovered that sleep apnoea, an exhausting sleep disorder that causes heavy snoring, can actually prolong life.
Studies conducted in the past have shown that sleep apnoea increases the risk of high blood pressure, heart attack and stroke.
The latest study, presented at European Sleep Research Society's conference in Glasgow last month, suggests that some sufferers live longer than those who do not have the condition.
The new finding also indicates that doctors may be causing more harm to some patients than good by treating them for the disorder.
The study followed 611 patients aged 65 and over for more than four years.
According to the researchers, patients with moderate sleep apnoea were less likely to die over the course of the study than those who did not have the condition.
By the end of the four years, three times as many people without sleep apnoea died as had the condition.
Mortality rates among patients with light and severe sleep apnoea were the same as the general population, the study showed.
Peretz Lavie, who carried out the research at the Lloyd Rigler Sleep Apnoea Research Laboratory in Haifa, Israel, called the findings "astonishing".
"We know that sleep apnoea does reduce life expectancy for people under the age of 50, so to find that it could actually prolong life for elderly patients was quite a shock," the Telegraph quoted him as saying.