London: Smokers are more likely to doze off for less than six hours a day and have a `disturbed` sleep compared to non-smokers, a new study has claimed.
Researchers from Charite Berlin medical school in Germany found that of nearly 1,100 smokers surveyed, 17 per cent got fewer than six hours of sleep each night and 28 per cent reported `disturbed` sleep quality.
That compared with rates of 7 per cent and 19 per cent respectively among more than 1,200 non-smokers who were also surveyed, the Daily Mail reported.
"This study demonstrates for the first time an elevated prevalence of sleep disturbance in smokers compared with non-smokers in a population without lifetime history of psychiatric disorders even after controlling for potentially relevant risk factors," lead researcher Stefan Cohrs, said.
The findings cannot prove that smoking directly impairs sleep, since smokers may have other habits that could affect their shut-eye such as staying up late to watch TV or getting little exercise, he said.
However, there is also reason to believe the stimulating effects of nicotine may be to blame, Cohrs said.
The researchers used a questionnaire that gauges sleep quality.
Overall, more than one-quarter of smokers had a score than landed them in the category of `disturbed` sleep, meaning they had a high probability of insomnia.
The study appeared in the journal Addiction Biology.