As the quality of our sleep worsens as we get older, our overall quality of life suffers too. But age-related poor sleep quality may be reversible, according to new research in the journal Plos Biology. The German and British scientists behind the new findings speculate that new drug treatments could be developed based on their research.
To understand how sleep declines with age, the international team from the Max Planck Institute for Biology of Ageing and University College London studied the role of biological factors known to be important in ageing in the fruit fly Drosophila melanogaster.
“Drosophila’s sleep has many features in common with that of humans, including the decline in quality,” explains study author Dr. Luke Tain. “Like humans, flies sleep at night and are active during the day. We can observe when and how long flies sleep. We can also determine their sleep quality by measuring how often they wake. This allows us to study the effects of specific substances or other sleep-influencing factors such as age and genetic disposition.”
The scientists found that insulin-like growth factor (IGF) and target of rapamycin (TOR)proteins were related to specific patterns of sleep and activity in the flies. Flies with reduced IGF signaling slept more at night and were more active during the day. Interestingly, sleep and day activity were found to have separate mechanisms, with IGF signaling being responsible for day activity and night sleep being determined by TOR.
The scientists were surprised to find that sleep quality improved when the flies were given acute doses of rapamycin, a TOR inhibitor. Furthermore, improvements in sleep were even seen in the older flies suggesting that age-related sleep problems could be reversible. More research will be necessary to understand these processes and whether the research is translatable to humans.
The research comes at a time when governments across the globe are becoming increasingly concerned over the burden of ageing populations. Around 50 percent of people over 65 have a sleep disorder, raising the hope for millions that improved sleep quality may be just around the corner. “Given the high evolutionarily conservation of IIS and TOR function, our result implicates potential therapeutic targets to improve sleep quality in humans. This would be our longer-term goal,” Tain said.