While some of these relationships were strong when looking at everyone as a group, not everyone with sleep problems has abnormalities in their spinal fluid.
Lack of proper sleep may predict the risk of developing Alzheimer's disease in people who are otherwise healthy, researchers claim. Such tangles and plaques - the hallmarks of Alzheimer's - are present in the brains of patients with the disease.
Alzheimer's disease is the change in tau protein that results in the breakdown of microtubules in brain cells. "There is now no cure, but studies like this give us hope that research will deliver better treatments for people with Alzheimer's disease".
A few studies in cognitively normal people and one in mice have shown a connection between chronic sleep disruption and the development of amyloid plaques. Although it's not clear why poor sleep is associated with the disease, the team hypothesize that the brain does a lot of its cleaning during sleep, The New York Times reported.
This is because they had either a parent with the disease or being a carrier of a gene that increases the risk for Alzheimer's disease called apolipoprotein E (APOE).
Jay-Z's '4:44' Tidal exclusive has already gone platinum
It's unclear how the album reached platinum certification so quickly despite it being a Tidal exclusive. What did help, though, was when 160 iHeartRadio stations streamed "4:44" for its 35-minute length.
Barbara Bendlin, coauthor of the study and a researcher from Wisconsin Alzheimer's Disease Research Center, said their findings align with the theory that worse sleep quality may contribute to the buildup of Alzheimer's disease proteins in the brain.
"Our study looked not only for amyloid but for other biological markers in the spinal fluid as well".
Tangles are created by damaged tau, a protein responsible for cell stability and structure.
The solid evidence is still lacking to confirm whether sleep problems affect the development of the disease or Alzheimer itself is causing the sleep disorders.
They're not sure what might explain the discrepancy, but they point out that they did not actually test participants for sleep apnea; they only asked people if they had it. "Sleep-disordered breathing often goes undetected by patients, and subjective reports are not reliable", they wrote.
India vs China: Five claims Chinese media is making about Sikkim standoff
India, meanwhile, says 38,000 square kilometers (15,000 square miles) of the Aksai Chin plateau belongs to it. There was no mention of a bilateral meeting with Chinese President Xi Jinping as was being speculated.
"It's important to identify modifiable risk factors for Alzheimer's given that estimates suggest that delaying the onset of Alzheimer's disease in people by a mere five years could reduce the number of cases we see in the next 30 years by 5.7 million and save US$367 billion (AU$480 billion) in health care spending. Amyloid structures can form in many different ways, so it has been unclear how close these lab versions resembled those in human disease", commented Scheres.
Future studies may require people to attend sleep laboratories so their bedtime habits can be monitored, according to the researchers.
Finding out what causes Alzheimer's could be critical to stopping the disease as early as possible, before irreversible damage has been done.
The study published in the journal Nature takes these imaging efforts one step further.
Wimbledon leaves injured players rule in place for time being
So they play, even if they know they are not at 100%. "It's unfortunate that it happened today like this". Alexandr Dolgopolov, a former world No13, owns one of the more unconventional games on a tennis court.