Sleep problems, such as difficulty falling asleep and staying asleep, double the risk of prostate cancer in men, according to new research.

The study was conducted by a team at the University of Iceland in Reykjavik and was published in the journal Cancer Epidemiology, Biomarkers & Prevention.

Lara G. Sigurdardóttir, M.D., a researcher at the University of Iceland, said:

“Sleep problems are very common in modern society and can have adverse health consequences. Women with sleep disruption have consistently been reported to be at an increased risk for breast cancer, but less is known about the potential role of sleep problems in prostate cancer.”

Past research has produced contradicting results for a link between sleep disruption from working night shifts and prostate cancer risk.

Therefore, Sigurdardóttir and her team set out to examine the effect sleep might have on prostate cancer risk. They observed 2,102 men from the prospective Age, Gene/Environment Susceptibility-Reykjavik study – which consisted of a population-based cohort of 2,425 males between the ages of 67 and 96.

At the start of the investigation, the subjects were asked to answer four questions regarding sleep disruptions:

  • whether they took medicine to sleep
  • whether they had difficulty falling asleep
  • whether they woke up during the night with difficulty going back to sleep
  • whether they woke up early in the morning with a hard time going back to sleep

Among the subjects examined, 8.7 reported severe sleep problems and 5.7% reported very severe sleep problems. At the start of the study, none of the volunteers had prostate cancer.

The subjects were followed for five years – during this time, 6.4% received a prostate cancer diagnosis.

After adjusting for age, the experts discovered that with reported severity of difficulty falling and staying asleep, the risk of prostate cancer elevated proportionately, from 1.6-fold to 2.1-fold, compared to men with no problems sleeping.

Additionally, the scientists found that the link was stronger for advanced prostate cancer compared to overall prostate cancer – with more than a three times higher likelihood for advanced prostate cancer linked to “very severe” sleep problems.

In order to rule out the possibility that the sleep problems were due to undiagnosed cancer or an enlarged prostate, the investigators re-examined the data after leaving out men with symptoms of sleep disturbance that may be a sign of nocturia – waking up to urinate.

The results remained the same, according to the team. However, it is necessary to confirm these findings in larger studies with longer observation times, Sigurdardóttir pointed out.

Sigurdardóttir concluded:

“Prostate cancer is one of the leading public health concerns for men and sleep problems are quite common. If our results are confirmed with further studies, sleep may become a potential target for intervention to reduce the risk for prostate cancer.”

A recent study demonstrated that early baldness is significantly associated with an increased risk of prostate cancer.

Written by Sarah Glynn