Scientists have found that people with diabetes who sleep poorly have higher insulin resistance, and a harder time controlling the disease.

The result suggests that poor sleep may contribute to worse outcomes in people with diabetes.

"Poor sleep quality in people with diabetes was associated with worse control of their blood glucose levels," said Kristen Knutson, assistant professor of medicine and lead author of the study.

"People who have a hard time controlling their blood glucose levels have a greater risk of complications. They have a reduced quality of life. And, they have a reduced life expectancy," said Knutson.

For the study, the researchers monitored the sleep of 40 people with diabetes for six nights.

The subjects wore activity monitors on their wrists at night, which measure their wrist movements throughout the night.

Poor sleep, or insomnia, was determined by both poor sleep quality based on the activity monitors and the subject telling the researchers that they often had a hard time falling asleep or woke up during the night.

Among the diabetics, poor sleepers had 23% higher blood glucose levels in the morning, and 48% higher blood insulin levels.

Using these numbers to estimate a person's insulin resistance, the researchers found that poor sleepers with diabetes had 82% higher insulin resistance than normal sleepers with diabetes.

The findings were published in the June issue of Diabetes Care.

Psychologists found that people who watched an eight minute clip from a scary movie suffered more symptoms associated with post traumatic stress if they were left handed than if they were right handed.

When asked to recall events from the film clip, taken from near the tense climax of thriller Silence of the Lambs, left handed volunteers gave more fragmented accounts filled with more repetition than their right handed counterparts.

This effect is common in people suffering from Post Traumatic Stress Disorder.

The scientists now believe their results could provide new insights into how people develop post traumatic stress and the way the brain deals with fear.

Dr Carolyn Choudhary, who led the research at Queen Margaret University in Edinburgh, said: "The prevalence of post traumatic stress disorder is almost double in left handers compared to right handers.

"We used a portion of film from Silence of the Lambs that we know elicits fear, so we could check the recalled account against the film. People who were left handed showed significantly more fragmentation in their memories and more repetition.

"It seems that after experiencing a fearful event, even on film, people who are left handed had subtle behaviours that were like people suffering from post traumatic stress disorder."

Silence of the Lambs, starring Anthony Hopkins as serial killer Hannibal Lector and Jodie Foster as FBI agent Clarice Starling, is widely regarded as one of the most tense thrillers ever made.

Participants who were left handed showed more signs of symptoms found in patients suffering from post traumatic stress disorder after watching the eight minute clip from the movie.

Dr Choudhary, who will present her findings at the annual conference of the British Psychology Society this week, added: "The mistakes they made were subtle errors in verbal recall.

"It appears these are tied to the way the brain makes memories during fearful experiences.

"It is apparent the two sides of the brain have different roles in PTSD and the right hand-side of the brain seems to be involved in fear. In people who are left handed, the right hand side of their brain is dominant, so it may have something to do with that.

"We need to do more experiments to understand what exactly is going on here."