Cancer tissue-freezing approach may help more breast cancer patients in lower income countries

A new reusable device created by the Johns Hopkins University can help women with breast cancer in lower income countries by using carbon dioxide, a widely available and affordable gas, to power a cancer tissue-freezing probe instead of industry-standard argon.

A study detailing the tool's success in animals was published this month in PLOS One.

"Innovation in cancer care doesn't always mean you have to create an entirely new treatment, sometimes it means radically innovating on proven therapies such that they're redesigned to be accessible to the majority of the world's population," says Bailey Surtees, a recent Johns Hopkins University biomedical engineering graduate and the study's first author.

"This project is a remarkable example of success from the Biomedical Engineering Design Program," says Nicholas Durr, an Assistant Professor of Biomedical Engineering at Johns Hopkins and the study's senior author. "This team of undergraduates has been so successful because they created a practical solution for the problem after really understanding the constraints that needed to be met to be impactful."

The largest cause of cancer-related mortality for women across the globe, breast cancer disproportionately affects women in lower-income countries due to lack of treatment. While the survival rate for women in the United States is greater than 90%, they are significantly lower at 64%, 46% and 12% in Saudi Arabia, Uganda and The Gambia, respectively.

"Instead of saying 'She has breast cancer," the locals we met while conducting focus groups for our research said 'She has death,' because breast cancer is often considered an automatic death sentence in these communities," adds Surtees.

In lower-income countries, the main barriers to treating breast cancer are inadequate treatment options -- with surgery, chemotherapy and radiation being impractical or too expensive -- and long travel times to regional hospitals where efficient treatment is available. Even if a woman is able to travel to a hospital for treatment, she may not be seen and recovery times will keep her out of work for an additional few weeks.

Killing cancerous tissue with cold, or cryoablation, is preferable to surgically removing tumors in these countries because it eliminates the need for a sterile operating room and anesthesia, thus making it possible to local clinics to perform the procedure. It's also minimally invasive, thereby reducing complications such as pain, bleeding and extended recovery time.

Current cryoablation technologies, however, are too expensive, with a single treatment costing upwards of $10,000, and are dependent on argon gas, which typically isn't available in lower-income countries, to form the tissue-killing ice crystals.

With these barriers in mind, the student-led research team, named Kubanda (which means "cold" in Zulu), wanted to create a tissue-freezing tool that uses carbon dioxide, which is already widely available in most rural areas thanks to the popularity of carbonated drinks.

The research team tested their tool in three experiments to ensure it could remain cold enough in conditions similar to the human breast and successfully kill tumor tissue.

In the first experiment, the team used the tool on jars of ultrasound gel, which thermodynamically mimics human breast tissue, to determine whether it could successfully reach standard freezing temperatures killing tissue and form consistent iceballs. In all trials, the device formed large enough iceballs and reached temperatures below -40 degrees Celsius, which meets standard freezing temperatures for tissue death for similar devices in the United States.

For the second experiment, the team treated 9 rats with 10 mammary tumors. Afterwards, they looked at the tissue under a microscope and confirmed that the tool successfully killed 85% or more tissue for all tumors.

Finally, the team tested the tool's ability to reach temperatures cold enough for tissue destruction in the normal liver of a pig, which has a temperature similar to a human breast. The device was successfully able to stay cold enough during the entire experiment to kill the target tissue.

"When we started the project, experts in the area told us it was impossible to ablate meaningful tissue volumes with carbon dioxide. This mindset may have come from both the momentum of the field and also from not thinking about the importance of driving down the cost of this treatment," says Durr.

While the results are promising, the device still requires additional experiments before it's ready for commercial use. Mainly, the research team's next steps are to ensure it can consistently kill cancer tissue under the same heat conditions as human breast tissue.

In the near future, the team hopes to continue testing their device for human use, and expand its use to pets.

Other authors on this paper include Sean Young, Yixin Hu, Guannan Wang, Evelyn McChesney, Grace Kuroki, Pascal Acree, Serena Thomas, Tara Blair, Shivam Rastogi, Dara L. Kraitchman, Clifford Weiss, Saraswati Sukumar and Susan C. Harvey, all of Johns Hopkins.

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Ancient Saharan seaway shows how Earth's climate and creatures can undergo extreme change

A new paper to be published in the Bulletin of the American Museum of Natural History integrates 20 years of research by a diverse scientific team and describes the ancient Trans-Saharan Seaway of Africa that existed 50 to 100 million years ago in the region of the current Sahara Desert. Led by Maureen O'Leary, Professor of Anatomical Sciences at the Renaissance School of Medicine at Stony Brook University, the paper is a comprehensive synthesis and contains the first reconstructions of extinct aquatic species in their habitats along the seaway and places in context massive climate and sea level changes that can occur on Earth.

The region now holding the Sahara Desert was once under water, in striking contrast to the present-day arid environment. This dramatic difference in climate over time is recorded in the rock and fossil record of West Africa during a time range that extends through the Cretaceous-Paleogene (KPg) boundary. West Africa was bisected by a shallow saltwater body that poured onto continental crust during a time of high global sea level. The Bulletin paper involves an assessment and continued analysis of three expeditions led by Professor O'Leary (1999, 2003, and 2008) within rock exposures in the Sahara Desert in Mali, and subsequently the laboratory work of the fossil finds in the region.

"Fossils found on the expeditions indicate that the sea supported some of the largest sea snakes and catfish that ever lived, extinct fishes that were giants compared to their modern day relatives, mollusk-crushing fishes, tropical invertebrates, long-snouted crocodilians, early mammals and mangrove forests," explained Professor O'Leary, who is also a Research Associate in the Division of Paleontology, American Museum of Natural History. "Because the seaway changed in size and geography frequently, we propose that it may have resulted in 'islands of water' that stimulated species gigantism."

The paper contains the first reconstructions of ancient relatives of elephants and large apex predators such as sharks, crocodilians and sea snakes.

"With our analysis and new technologies, such as a computer-aided map of the seaway, our work is an important step toward increasing our understanding of the KPg boundary event, the time of non-avian dinosaur extinction," said Professor O'Leary.

She and colleagues point out that the paper places in context climate and sea level changes that can occur on Earth.

For example, scientists currently predict that global warming will result in the sea rising two meters by the end of the 21st century. The study in the Bulletin describes how, in the Late Cretaceous, the time under study, sea level rise far exceeded that which is predicted by human-induced climate change. In the Late Cretaceous sea level was 300m higher than present -- 40 percent of current land was under water, which is very different from today. This information underscores the dynamic nature of Earth.

Professor O'Leary explained that scientists do not have detailed stratigraphic terrestrial/near shore sections with fossils on every continent to examine exactly how the KPg boundary unfolded globally. There is only one good nearshore or terrestrial section with vertebrate fossils in the western United States. The expeditions in Mali, she added, created a new section, which is imperfect, missing some of the earliest Paleogene yet contributes to a better understanding of global events 50 to 100 million years ago.

The expeditions spanning 20 years involved Professor O'Leary and numerous colleagues internationally to excavate the fossils and conduct the research. The collaborative research team consists of paleontologists and geologists from the United States, Australia and Mali.

"Few paleontologists had worked the region, given its remoteness and scorching 125 degree F temperatures. The shifting sand dunes made it difficult to find rocky outcrops, and worse still, a flash rain storm flooded the roadways making navigation nearly impossible," said Leif Tapanila, PhD, Professor of Geosciences at Idaho State University and a co-author of the paper. "These expeditions could not have succeeded without the experience of local Malian drivers and guides, and I was amazed by the quality and diversity of marine fossils we found in the Sahara Desert."

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Oceans are the ‘lungs of the Earth’

The United Nations calls oceans as the “lungs of the Earth” as they generate most of the oxygen we breathe. Oceans produce oxygen through marine plants, such as phytoplankton, kelp and algal planktons. These plants produce oxygen as a byproduct of photosynthesis.

Containing 97 percent of the world’s water, oceans are home to millions of marine species that provide humans with at least a sixth of the animal protein they eat, as well as ingredients for our medicines.

But benefits from oceans go beyond air, food and water. Oceans cover 70 percent of the world’s surface, and transport heat from the equator to the poles, regulating our climate and weather patterns. They absorb carbon dioxide from the atmosphere and reduce climate-change impacts. 

Aside from these life-supporting products and services, oceans provide wondrous recreational areas and limitless inspiration to millions of people. Clearly, oceans play an essential role for life on earth.

Asean oceans: among the world’s richest marine ecosystems

The 10 Asean member-states—Brunei Darussalam, Cambodia, Lao PDR, Indonesia, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam—house a third of the world’s coral reefs, mangrove and seagrass areas.

According to Dr. Theresa Mundita S. Lim, executive director of Asean Centre for Biodiversity (ACB), nine out of 10 Asean countries are endowed with extensive coastlines, and all 10 Asean member-states have a total of 173,000 kilometers of shorelines.

Indonesia and the Philippines are recognized as among those having the most coral reef areas in the world. Indonesia, Malaysia and the Philippines are three of the six countries bordering the Coral Triangle, which is home to 75 percent of the world’s reef-building corals.

Overall, the Asean region hosts a third of the world’s coastal and marine habitats, which include coral reefs, mangroves, estuaries, sandy and rocky beaches, seagrass and seaweed beds, and other soft bottom communities.

These habitats and their resident species provide various forms of ecosystem services, such as breeding, nursing and feeding grounds for marine plants and animals, as well as resources important to livelihoods of coastal communities. 

Lim enumerated the regulatory ecosystem services derived from marine and coastal ecosystems: carbon sequestration and storage in mangrove tree trunks and roots, seagrass, seaweeds, and other algae; climate regulation; sediment protection; and shoreline retention to buffer coastal areas from storm surges.

According to the Asean Biodiversity Outlook 2, a publication of the ACB, coastal habitats maintain nutrient cycles and provide media for the exchange of genetic materials. These habitats provide cultural services in the form of recreation and tourism, education, research and places of worship.

There are various estimates of the monetary value of coastal habitats in the region. Coral reefs generate and may constitute a significant percentage of national economies, where such habitats occur in large scale, and where industries—such as coral reef-related tourism, fisheries, live fish aquarium, and shell craft industries thrive.

Coral reef-related tourism relies on water and habitat quality, the type and quality of services offered, and accessibility factors. The Asean Biodiversity Outlook 2 reported that potential annual economic value of coral reefs in the Asean region arising from fisheries, shoreline protection, tourism, recreation, and aesthetic values is estimated at $12.7 billion.

Clearly, resources from the oceans of the Asean region not only provide life-sustaining and economic benefits for some 650 Asean residents but also contribute to global sustainable development.

Behind the richness are the threats

Behind the richness of Asean’s oceans are the threats. The integrity of the world’s oceans, including in the Asean region, is threatened by marine debris and other forms of pollution; overfishing and use of destructive fishing practices; and coral bleaching, as well as other impacts from climate change. 

According to the Asean’s Population Reference Bureau, close to 500 million people will be living in or near coastal and marine areas in the Asean region by 2050.

Indonesia and the Philippines were identified by the Reefs at Risk Revisited Report as two countries that have tens of millions of coastal people living within 30 kilometers of reefs.

Considering that the Asean is one of the fastest-growing economies in the world, its nearshore ecosystems have become more vulnerable to habitat change from overexploitation, sedimentation, pollution, coastal development, ineffective governance, and collateral damage from coastal tourism and climate change.

Plastic: Oceans’ enemy No. 1

Human activities present the biggest threat to oceans as more than 80 percent of marine pollution comes from land-based activities and wastes, specifically plastics.

A surge in single-use plastics has led to a global environmental catastrophe. The UN has reported that 13 million tons of plastic leak into the oceans every year, killing 100,000 marine animals annually, among other damages.

While most plastics are expected to remain intact for decades or centuries after use, those that do erode end up as microplastics, consumed by fish and other marine wildlife, quickly making their way into the global food chain.

In a presentation during the celebration of the International Day for Biodiversity held in Bangkok, Thailand, on May 2, Dr. Suchana Chavanich, a faculty member of the Department of Marine Science, Faculty of Science, Chulalongkorn University, Thailand, said that 39 percent of plastic wastes go to open ocean waters; 33.7 percent settle in coastline and sea floor; 26.8 percent remain in coastal ocean waters; and 0.5 percent float on the waters.

Chavanich reported that a study conducted by the Chulalongkorn University found microplastics in 93 percent of bottled water.

Another threat to marine life is illegal, unreported and unregulated (IUU) fishing.

According to a European Union report, the estimated global value of IUU fishing is around $11 billion to $22 billion per year. Between 11 million tons and 26 million tons of fish are caught illegally a year, accounting for at least 15 percent of the world’s catches. IUU unsustainably affects the world’s fish stocks.

Asean nations unite to protect the oceans

The 10 Asean member-states, supported by the Asean Centre for Biodiversity, recognize that protecting the Asean region’s oceans has a global significance, as benefits go beyond the borders of Southeast Asia.

Thus, they are working together to ensure that the region’s marine and coastal biodiversity and ecosystems are conserved, protected and sustainably used.

During the Special Asean Ministerial Meeting on Marine Debris held on March 5 in Bangkok, Thailand, the ministers responsible for natural resources, environment and marine affairs affirmed the Asean’s commitment to conserve the region’s marine environment and strengthen regional cooperation in addressing marine debris issues.

The ministers expressed their full support to advance partnerships for sustainability, as well as to promote synergy within the framework of Asean partnership, in particular to combat marine debris in the region.

During the 34th Asean Summit held in Bangkok, Thailand, on June 22, the heads of the 10 Asean member-states adopted the Bangkok Declaration on Combating Marine Debris, reiterating the commitment of the 10 Asean member-states in protecting and conserving the region’s rich marine resources.

The Bangkok Declaration called for collaborative actions to prevent and significantly reduce marine debris, particularly from land-based activities; recommended an integrated land-to-sea approach to prevent and reduce marine debris; and called for the strengthening of national laws and regulations, as well as enhancing regional and international cooperation, including on relevant policy dialogue and information sharing.

The declaration also promoted mainstreaming of biodiversity and ecosystem conservation as it called for coordination among Asean sectoral bodies to effectively address the multidimensional and far-reaching negative effects, as well as sources of marine debris pollution; and encouraged private-sector engagement and investment in preventing and reducing marine debris, including partnerships between public and private sector through various mechanisms and incentives.

The Bangkok Declaration called for the strengthening of research capacity and application of scientific knowledge to combat marine debris; accelerating advocacy and actions to increase public awareness and participation; and enhancing education for behavioral change toward preventing and reducing marine debris.

Marine debris is a transboundary issue that requires integrated regional cooperation. Without immediate action, marine debris pollution would negatively impact marine biodiversity, environment, health, society and economy. Marine debris threatens the health and cleanliness of oceans and their resources which are key to the sustenance and livelihood of hundreds of millions of people, including Asean residents.

Protecting and conserving oceans: a shared responsibility

Lim said saving our oceans is not the sole turf of governments, marine scientists, conservationists and environmentalists. She recommends the following actions that individuals can take to protect and conserve the world’s rich marine heritage:

  • Learn about the wealth of diverse and beautiful ocean creatures and habitats, how our daily actions affect them, and how we are all interconnected.
  • Mind our carbon footprint and reduce energy use.
  • Buy sustainably sourced seafoods.
  • Properly dispose wastes, especially hazardous materials.
  • Use fewer plastics or reusable ones and dispose them properly.
  • Join coastal cleanup activities.
  • Plant native species of mangrove trees.
  • Report illegal activities that are harmful to marine life.
  • Support organizations working to protect our oceans.
  • Influence change in our homes, schools and communities.

“Conservation is a shared responsibility. By working together, we can protect our shared oceans. Let us keep in mind that oceans are our life,” Lim said.

Gigantic ‘potentially hazardous asteroid’ due to speed past Earth this week

A huge asteroid three times as long as a football field is set to speed by Earth on Thursday. The “potentially hazardous asteroid” is projected to whizz by our planet at over 25,400 mph (40,800 kph).

Asteroid ‘2008 KV2’ is estimated to measure 1,082 feet (330 meters) across and will be just 4.2 million miles (6.7 million kilometers) from Earth when it flies by. 

The gigantic space rock is considered a Near Earth Object (NEO) and the center at NASA’s Jet Propulsion Laboratory (JPL) for studying such close encounters considers 2008 KV2 to be a “potentially hazardous asteroid” because of its size and its relative proximity to our planet, passing within 0.045 astronomical units (AU) of Earth. One AU is about the distance between the Earth and the Sun. 

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As indicated in its name, the asteroid was first discovered in 2008 and scientists began to calculate how often to expect it to come near our planet. It orbits the Sun, like Earth, but doesn’t always get so close. It’s expected to pass Earth again in 2021.

How trees affect the weather

Nature, said Ralph Waldo Emerson, is no spendthrift. Unfortunately, he was wrong.

New research led by University of Utah biologists William Anderegg, Anna Trugman and David Bowling find that some plants and trees are prolific spendthrifts in drought conditions -- "spending" precious soil water to cool themselves and, in the process, making droughts more intense. The findings are published in Proceedings of the National Academy of Sciences.

"We show that the actual physiology of the plants matters," Anderegg says. "How trees take up, transport and evaporate water can influence societally important extreme events, like severe droughts, that can affect people and cities."

Functional traits

Anderegg studies how tree traits affect how well forests can handle hot and dry conditions. Some plants and trees, he's found, possess an internal plumbing system that slows down the movement of water, helping the plants to minimize water loss when it's hot and dry. But other plants have a system more suited for transporting large quantities of water vapor into the air -- larger openings on leaves, more capacity to move water within the organism. Anderegg's past work has looked at how those traits determine how well trees and forests can weather droughts. But this study asks a different question: How do those traits affect the drought itself?

"We've known for a long time that plants can affect the atmosphere and can affect weather," Anderegg says. Plants and forests draw water out of the soil and exhale it into the atmosphere, affecting the balance of water and heat at our planet's surface, which fundamentally controls the weather. In some cases, like in the Amazon rainforest, all of that water vapor can jumpstart precipitation. Even deforestation can affect downwind weather by leaving regions drier than before.

Anderegg and his colleagues used information from 40 sites around the world, in sites ranging from Canada to Australia. At each site, instruments collected data on the flows of heat, water and carbon in and out of the air, as well as what tree species were prevalent around the instrumentation. Comparing that data with a database of tree traits allowed the researchers to draw conclusions about what traits were correlated with more droughts becoming more intense.

Two traits stuck out: maximum leaf gas exchange rate and water transport. The first trait is the rate at which leaves can pump water vapor into the air. The second describes how much water the tree can move to the leaves. The results showed that in cool regions, plants and trees slowed down their water use in response to declining soil moisture. But in hot climates, some plants and trees with high water transport and leaf gas exchange rates cranked up the AC, so to speak, when the soil got dry, losing more and more water in an effort to carry out photosynthesis and stay cool while depleting the soil moisture that was left.

"You end up getting to these conditions that are hotter and drier much faster with those plants than with other plants," Anderegg says.

More drought to come

It's true that hot and dry regions tend to have more plants and trees that are adapted to dry conditions. But regardless of the climate some species with water-intensive traits, such as oaks in a Mediterranean climate, can still exacerbate a drought.

Anderegg says that understanding the relationship between a tree's traits and drought conditions helps climate scientists and local leaders to plan for future drought effects on communities.

"Failing to account for this key physiology of plants would give us less accurate predictions for what climate change is going to mean for drought in a lot of regions," he says.

Drought is always on Anderegg's mind, even during the recent wet spring. "Just because we're having a good water year in the U.S. and in Utah this year doesn't get us off the hook," he says. "We need to remember that we're going to see a lot more droughts in the future."

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Yogurt may help to lower pre-cancerous bowel growth risk in men

Eating two or more weekly servings of yogurt may help to lower the risk of developing the abnormal growths (adenomas) which precede the development of bowel cancer -- at least in men -- finds research published online in the journal Gut.

The observed associations were strongest for adenomas that are highly likely to become cancerous, and for those located in the colon rather than in the rectum, the findings indicate.

Previously published research has suggested that eating a lot of yogurt might lower the risk of bowel cancer by changing the type and volume of bacteria in the gut (microbiome).

But it's not been clear whether yogurt intake might also be associated with a lower risk of pre-cancerous growths, known as adenomas.

The researchers therefore looked at the diets and subsequent development of different types of adenoma among 32,606 men who were part of the Health Professionals Follow Up Study and 55,743 women who were part of the Nurses Health Study.

All the study participants had had a lower bowel endoscopy -- a procedure that enables a clinician to view the inside of the gut -- between 1986 and 2012. And every four years, they provided detailed information on lifestyle and diet, including how much yogurt they ate.

During the study period, 5811 adenomas developed in the men and 8116 in the women.

Compared with men who didn't eat yogurt, those who ate two or more servings a week were 19% less likely to develop a conventional adenoma.

This lower risk was even greater (26%) for adenomas that were highly likely to become cancerous, and for those located in the colon rather than in the rectum.

While no obvious association was seen for men with a potentially more dangerous type of adenoma (serrated), a trend towards reduced risk was seen for those measuring 1 or more cm, which is considered to be large.

No such associations between yogurt intake and the development of adenomas were evident among the women.

This is an observational study, and as such, can't establish cause. Further research would be needed to confirm the findings and uncover the biology involved, emphasise the researchers.

But the large number of people studied and the regular updates on diet and lifestyle factors add heft to the findings, they suggest.

By way of a possible explanation for what they found, the researchers point out that Lactobacillus bulgaricus and Streptococcus thermophilus, two bacteria commonly found in live yogurt, may lower the number of cancer causing chemicals in the gut.

And the stronger link seen for adenomas growing in the colon may partly be due to the lower acidity (pH) in this part of the gut, making it a more hospitable environment for these bacteria, they add.

Alternatively, yogurt may have anti-inflammatory properties and may reduce the 'leakiness' of the gut as adenomas are associated with increased gut permeability, they suggest.

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Good physical fitness in middle age linked to lower chronic lung disease risk

Good heart and lung (cardiorespiratory) fitness in middle age is associated with a lower long term risk of chronic lung disease (COPD), suggests Danish research published online in the journal Thorax.

Physical activity that boosts fitness should be encouraged "to delay development, progression and death from COPD," conclude the researchers.

COPD, short for chronic obstructive pulmonary disease, is an umbrella term for respiratory conditions that narrow the airways, such as bronchitis and emphysema. Smoking is the main risk factor for COPD, which the World Health Organization ranks as the fourth most frequent cause of death worldwide.

Studies have suggested that a high level of physical activity and/or leisure time exercise is associated with a reduced risk of COPD, and that physical inactivity may speed up its progression.

To explore this further, the researchers tracked the respiratory health of 4,730 healthy middle-aged men from the Copenhagen Male Study, who were recruited from 14 large workplaces in Copenhagen between 1970 and 1971. Their average age was 49.

Those with a previous diagnosis of COPD, asthma, or with symptoms of chronic bronchitis were excluded. Participants were monitored for up to 46 years to January 2016.

All participants provided information on smoking, alcohol intake, physical activity levels, educational attainment, occupation, and medical history.

Height, weight, and resting blood pressure were measured, and cardiorespiratory fitness (CRF) was calculated as low, normal, or high, using a VO2 max test -- a measure of the body's ability to use oxygen during exercise. National registers were used to identify cases of COPD and death from COPD.

Compared with low CRF, the estimated risk of COPD diagnosis was 21% lower in men with normal CRF and 31% lower in men with high CRF.

Similarly, compared with low CRF, the estimated risk of death from COPD was 35% lower in men with normal CRF and 62% lower in men with high CRF.

High CRF in middle age was also associated with a delay to both diagnosis of, and death from, COPD by 1.5 to 2 years.

The results were largely unchanged after excluding those who were diagnosed with COPD or who died during the first 10 years of monitoring, suggesting that the findings withstand scrutiny, say the researchers.

This is an observational study, and as such, can't establish cause. And it's possible that participants with high levels of CRF were more resilient to underlying COPD, delaying time to diagnosis, say the researchers.

But their results are in line with those of previous studies and provide further insight into the association between cardiorespiratory fitness and the long-term risk of COPD over an exceptionally long monitoring period.

And while the processes that link CRF with the development and progression of COPD aren't clear, the researchers nevertheless speculate that inflammation, linked to physical inactivity, may have a key role.

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Three public health interventions could prevent 94 million premature deaths

Increasing severity of sleep-disordered breathing and sleep disruption are associated with epigenetic age acceleration, according to preliminary results of a new study.

Results show that each standard deviation increase in the apnea-hypopnea index, a measure of sleep-disordered breathing severity, was associated with the equivalent of 215 days of biological age acceleration. Similarly, each standard deviation increase in the arousal index, a measure of sleep disruption, was associated with the equivalent of 321 days of age acceleration.

"People's biological age might not be the same as their chronological age," said lead author Xiaoyu Li, Sc.D., a postdoctoral research fellow in the Division of Sleep and Circadian Disorders in the Department of Medicine at Brigham and Women's Hospital and the Department of Social and Behavioral Sciences at the Harvard T.H. Chan School of Public Health in Boston, Massachusetts. "Individuals whose biological age is higher than their chronological age exhibit age acceleration or fast aging. In our study, we found that more severe sleep-disordered breathing is associated with epigenetic age acceleration. Our data provide biological evidence supporting adverse physiological and health effects of untreated sleep-disordered breathing."

Sleep-disordered breathing, such as obstructive sleep apnea, is characterized by abnormalities of respiration during sleep. Episodes often result in reductions in blood oxygen saturation and are usually terminated by brief arousals from sleep. Nearly 30 million adults in the U.S. have obstructive sleep apnea. Common warning signs include snoring and excessive daytime sleepiness.

According to the authors, epigenetic age acceleration is a DNA methylation-based marker of fast biological aging, and it is associated with modifiable lifestyle factors. Although sleep-disordered breathing is associated with multiple age-related health disorders, its relationship with epigenetic aging has not been well studied.

The study involved 622 adults with a mean age of 69 years; 53.2% were women. Participants were measured for blood DNA methylation, and their sleep was evaluated at home by polysomnography. Age acceleration measures were calculated as residuals from the regression of each epigenetic age on chronological age. The association of each sleep-disordered breathing trait with age acceleration was estimated using linear regression, controlling for socio-demographics, health behaviors, body mass index, and study site.

Another surprising finding was that the associations were stronger in women than in men, suggesting that women may be particularly vulnerable to the adverse effects of sleep-disordered breathing.

"While women are often considered to be at lower risk for health outcomes related to sleep-disordered breathing, our findings suggest increased biological susceptibility," said Li.

The authors suggested that future work should study whether treatment reduces epigenetic age acceleration among people who have sleep-disordered breathing.

"Since sleep-disordered breathing is not only common and treatable, but often undiagnosed and under-treated, our data highlight the potential for sleep-disordered breathing treatment to improve age-related chronic conditions and longevity," said Li. "Because epigenetic changes are reversible, epigenetic age estimators may be useful for identifying and validating anti-aging interventions."

The research abstract was published recently in an online supplement of the journal Sleep and will be presented Wednesday, June 12, in San Antonio at SLEEP 2019, the 33rd annual meeting of the Associated Professional Sleep Societies LLC (APSS), which is a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.

The study was supported by funding from the National Heart, Lung, and Blood Institute of the National Institutes of Health.

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