A new study has linked sleepless nights to a heightened stroke risk, with those under the age of 40 advised to be the most wary of insomnia symptoms.

Indeed, sufferers of insomnia were 54 percent more likely to be hospitalized as a result of a stroke, with the 18 - 35 age group the most vulnerable - around eight times more likely than non-insomniacs of the same age. The study was conducted over four years by a group of Taiwanese researchers, who parsed data from 85,000 health records to reach their findings.

Of that, 21,000 people were self-reported insomniacs, while the remaining 64,000 formed the control group that the theories were posited against. While the risk was higher among insomniacs aged 18 - 25, the role of insomnia significantly diminished after the age of 35. And, despite strokes occurring most frequently in those aged 65 and over for reasons not associated with insomnia, researchers noted at a large chunk - around 10 to 15 percent - of strokes occur in people aged 45 and under. Generally, the more severe the insomnia (for example, lengthy sleepness nights as opposed to intermittent tossing and turning), the higher the risk of stroke was.

The researchers are still unsure why insomnia leads to an increased stroke risk, though the condition has previously been linked to a range of cardiovascular risk factors such as higher blood pressure, unpredictable blood sugar, and systemic inflammation.

"We feel strongly that individuals with chronic insomnia, particularly younger persons, see their physician to have stroke risk factors assessed and, when indicated, treated appropriately," said the study's lead author, Dr. Ya-Wen Hsu. "Our findings also highlight the clinical importance of screening for insomnia at younger ages. Treating insomnia is also very important, whether by medication or cognitive therapy."

The study was published in Stroke.