Tag: 1/11/22

Diverticular Disease Linked to Cancers outside the Gastrointestinal System

Anatomy of the gut
Source: Pixabay CC0

In a large-scale study of cancer among 75 000 patients with a diagnosis of diverticular disease and colorectal histopathology, researchers have reported an elevated cancer risk in patients with diverticular disease. Their findings were published in the Journal of the National Cancer Institute.

The data comes from the ESPRESSO cohort, which covers all histopathology reports from Sweden’s 28 pathology departments. Through linkage with the Swedish national patient register, researchers identified patients with diverticular disease. Diverticular disease can present through gastrointestinal bleeding, but also through diverticulitis when patients may have fever, nausea and abdominal pain. Previous research has focused on colorectal cancer development in diverticular disease but less has been know about cancer development elsewhere. The researchers found a 33% increased risk of overall cancer in Swedish patients with diverticular disease.

“This is the first nationwide cohort study to demonstrate that diverticular disease is associated with an increased, long-term risk of overall cancer”, says first-author Wenjie Ma from Massachusetts General Hospital. “Diverticular disease is associated with an increased risk of specific cancers, including liver cancer and lung cancer.”

She also adds that “Given the high prevalence of diverticular disease, our results highlight the need for awareness for cancer, not only for colorectal cancer, in patients with diverticular disease.”

Patients with diverticular disease had significantly increased overall cancer incidence (24.5 vs 18.1 cancer cases per 1000 person-years). After adjusting for covariates, these rates corresponded to 1 extra cancer case in 16 individuals with diverticular disease followed for ten years.

“There has been a lot of research on extraintestinal cancer in other bowel disorders such as inflammatory bowel disease (IBD) and celiac disease, but less is known about diverticular disease”, says senior author Jonas F Ludvigsson, professor at Karolinska Institutet.

“These data suggest that patients with diverticular disease are at increased risk of other cancers than colorectal cancer, but it should also be emphasized that the absolute risk for cancer was moderate”, adds Ludvigsson. “I hope other researchers are inspired by our findings and explore the biological mechanisms underlying the association between diverticular disease and cancer”, he concludes.

Source: Karolinska Institutet

Apaxiban Has Lowest Gastrointestinal Bleeding Risk of Common DOACs

https://www.pexels.com/photo/a-close-up-shot-of-bags-of-blood-4531306/
Photo by Charlie-Helen Robinson on Pexels

A large-scale comparison of direct oral anticoagulants (DOACs), published in Annals of Internal Medicine, one of the two most common direct oral anticoagulants (DOACs), apixaban, has the lowest risk of gastrointestinal bleeding, with similar performance on stroke prevention and other side effects.

DOACs are used to prevent strokes for people with atrial fibrillation, a condition affecting over 33 million people worldwide. They have recently become gained popularity over warfarin, the previous standard treatment, as they do not require as much follow-up monitoring (which was particularly valuable during the COVID pandemic) and have less risk of side-effects.

For the new study, University College London researchers compared the efficacy and risk of side effects for the four most common DOACs. They reviewed data from more than 500 000 new DOAC users in the UK, France, Germany and the US, including 281 320 apixaban users, 61 008 dabigatran users, 12 722 edoxaban users, and 172 176 rivaroxaban users.

They found that all four drugs were comparable on outcomes for ischemic stroke, brain bleeds and all-cause mortality, while they did identify a difference in risk of gastrointestinal bleeding, which is one of the most common and concerning side effects of DOACs.

The study revealed that apixaban stood out as having lower risk of gastrointestinal bleeding, with 19-28% lower risks when compared directly to each of the other three DOACs.

The researchers found that their findings held true when looking at data only from those aged over 80, and those with chronic kidney disease, two groups that are often underrepresented in clinical trials.

Dr Wallis Lau (UCL School of Pharmacy), who jointly led the work along with her colleague Professor Ian Wong, said: “Direct oral anticoagulants have been prescribed with increasing frequency worldwide in recent years, but evidence comparing them directly has been limited. Our results indicate that apixaban may be preferable to other blood thinners because of the lower rate of gastrointestinal bleeding and similar rates of stroke, a finding that we hope will be supported by randomised controlled trials.

“As with all medications, potential risks and benefits can differ between people, so considering the full spectrum of outcomes and side effects will still be necessary for each individual patient.

Source: University College London

Nose Picking Opens up a Pathway for Dementia-linked Bacteria

Photo by Ketut Subiyanto

In mice, researchers have shown that Chlamydia pneumoniae can travel through the olfactory nerve in the nose and into the brain, where it creates markers that are a tell-tale sign of Alzheimer’s disease. Damage from nose picking can make infection easier for C. pneumoniae.

The Griffith University study, published in the journal Scientific Reports, showed that C. pneumoniae used the nerve extending between the nasal cavity and the brain as an invasion path to invade the central nervous system. The cells in the brain then responded by depositing amyloid beta protein which is a hallmark of Alzheimer’s disease.

Professor James St John, Head of the Clem Jones Centre for Neurobiology and Stem Cell Research, is a co-author of the world first research.

“We’re the first to show that Chlamydia pneumoniae can go directly up the nose and into the brain where it can set off pathologies that look like Alzheimer’s disease,” Professor St John said. “We saw this happen in a mouse model, and the evidence is potentially scary for humans as well.”

The olfactory nerve in the nose is directly exposed to air and offers a short pathway to the brain, one which bypasses the blood-brain barrier. It’s a route that viruses and bacteria have sniffed out as an easy one into the brain.

The team at the Centre is already planning the next phase of research and aim to prove the same pathway exists in humans.

“We need to do this study in humans and confirm whether the same pathway operates in the same way. It’s research that has been proposed by many people, but not yet completed. What we do know is that these same bacteria are present in humans, but we haven’t worked out how they get there.”

There are some simple steps to look after the lining of your nose that Professor St John suggests people can take now if they want to lower their risk of potentially developing late-onset Alzheimer’s disease.

“Picking your nose and plucking the hairs from your nose are not a good idea”,” he said.

“We don’t want to damage the inside of our nose and picking and plucking can do that. If you damage the lining of the nose, you can increase how many bacteria can go up into your brain.”

Smell tests may also have potential as detectors for Alzheimer’s and dementia says Professor St John, as loss of sense of smell is an early indicator of Alzheimer’s disease. He suggests smell tests from when a person turns 60 years old could be beneficial as an early detector.

“Once you get over 65 years old, your risk factor goes right up, but we’re looking at other causes as well, because it’s not just age—it is environmental exposure as well. And we think that bacteria and viruses are critical.”

Source: Griffith University

Study Reveals How Shingles Elevates the Risk of Stroke

MRI images of the brain
Photo by Anna Shvets on Pexels

Scientists investigating why people who have had shingles have an increased stroke risk now believe the answer lies within, exosomes, lipid vesicles called that shuttle proteins and genetic information between cells. Their study, published The Journal of Infectious Diseases, details the mechanisms behind the link between shingles and strokes.

“Most people know about the painful rash associated with shingles, but they may not know that the risk of stroke is elevated for a year after infection,” said the study’s lead author Andrew Bubak, PhD, assistant research professor in the Department of Neurology at the University of Colorado School of Medicine. “Importantly, the rash is often completely healed and individuals feel normal but nonetheless are walking around with this significant elevation in stroke risk.”

Herpes zoster (HZ) or shingles is caused by the varicella zoster virus which causes chicken pox. The virus lingers in the ganglionic neurons and can reactivate, causing excruciating pain. But researchers have found that shingles can also increase the risk of stroke especially for those under age 40 where the shingles vaccine is not typically recommended.

The risk is greatest in people with the rashes on their faces, perhaps due to the proximity to the brain.

To better understand how this works, Bubak and his team began looking more closely at exosomes.

“Exosomes carry pathogenic cargo that can cause thrombosis and inflammation distant from site of actual infection,” Bubak said. “That could ultimately lead to a stroke in patients.”

Researchers collected plasma samples from 13 patients with shingles and 10 without. The samples were taken at time of infection and at 3-month follow-ups for a subset of patients and exosomes were extracted from the plasma.

The researchers found prothrombotic exosomes which could cause blood clots in those with the infection. They also discovered proinflammatory exosomes that also pose risks for stroke at the 3-month follow-up.

Bubak said the findings suggest that in a subset of people with shingles, the virus may not return to latency or the circulating exosomes that induce a prolonged prothrombotic state may persist even after therapy is done and the rash is gone. He said using antiviral agents longer with the addition of antiplatelet and anti-inflammatory agents could help.

“As well as initiatives to increase HZ vaccine uptake to decrease stroke risk, particularly in individuals with known preexisting stroke risk factors,” said Bubak. “If these findings are confirmed with a larger longitudinal study, then this could change clinical practice.”

Most physicians are unaware of the connection between shingles (which has an effective vaccine) and stroke.

“But it’s really important and so easily mitigated,” Bubak said. “Send them home with antiplatelet agents.”

Source: University of Colorado Anschutz Medical Campus