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Monthly Archives: November 2021

The Omicron Variant

On Thanksgiving, reports emerged that a new concerning variant of Covid was identified in southern Africa. Later named Omicron by the World Health Organization, the variant has since been identified in several locations around the world, including England, Israel, Italy, Netherlands, and Hong Kong. It has not yet been detected in the U.S., but this may be because America doesn’t as frequently test for specific variants of Covid compared to some other countries. According to many experts, there’s a good chance it’s already here.

So why is this variant especially concerning? First, there is evidence that it may be more transmissible than previous versions of the coronavirus. One important data point in this regard is the variant’s rapid rate of spread in South Africa. But it will take more data collection over time to confirm if Omicron is genuinely more contagious. A second concern is that our current vaccines may be less effective at protecting us against the Omicron variant. This is based on mutations in the genes that code for the spike protein the vaccines neutralize. If Omicron’s spike protein is different previous variants, our current vaccines might bind to it less effectively and thus be less successful at preventing the virus from entering our cells. Experts think it’s unlikely Omicron will completely evade or escape our current vaccines. According to reports from vaccine manufacturers we should know how well current vaccines work against Omicron in around 2 weeks.

There is no solid evidence at this point on the question of whether Omicron causes a different severity of disease compared to other Covid variants.  

Even if the vaccines are less effective against Omicron, it’s not like we’re back to square one. First, again, there is good reason to believe our current vaccines they will still offer some measure of protection against Omicron. Indeed, booster doses of the current vaccines can, at least for a time, elicit such sky-high levels of antibody that they can broadly withstand a mutated virus, even if the antibodies aren’t targeting the specific viral proteins as well. So that’s more reason to get a booster ASAP if you haven’t already.

It’s also important to remember we now have knowledge we didn’t have when the pandemic began. We know transmission is very low risk outdoors. We know masks, of which we have abundant supply, work. We know improving ventilation through opening windows and using air filtration devices lowers transmission indoors.

We also have tools we didn’t have when at the outset of the pandemic. We have home tests to know if we’re contagious with Covid before we gather with family and friends. We know how to more effectively treat Covid in the hospital with meds like dexamethasone and tocilizumab. For outpatient therapy, even if current monoclonal antibodies don’t work against this new variant, inhaled steroids and fluvoxamine will still help, along with the antiviral medicines from Pfizer and Merck when they become available in likely the next 1-2 months. If Omicron is resistant to our currently available monoclonal antibodies, they would likely be able to be updated to target this new variant. Most importantly, the mRNA platform for creating vaccines is versatile, allowing updated vaccines that target the Omicron variant to be created and available in a much shorter time than it took to create the current vaccines. I have read reliable experts estimate that, if necessary, vaccines updated for Omicron could available in the spring. One exciting possibility being researched is a vaccine that would protect against all possible variants of SARS-CoV-2. 

So what should you do now? Get vaccinated if you haven’t already. Get your booster 6 months after your second shot of Pfizer or Moderna or 2 months after your first shot of J&J. Wear a mask in indoor crowded spaces, especially if you don’t know if people around you are vaccinated or symptomatic. If gathering around a person more vulnerable to a bad case of Covid, such as the immunocompromised or elderly, consider having everybody take a home Covid test beforehand to help rule out an asymptomatic infection.  

The emergence of the Omicron variant shows why we need to vaccinate the entire world. If a virus is circulating at high levels anywhere, this increases the chance a more challenging variant will occur. And in our connected world, a dangerous variant is likely to travel around the globe quickly.  We’re all in this together.

 
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Posted by on November 29, 2021 in Uncategorized

 

Is a Blood Test that Screens for 50 cancers Ready for Prime Time?

One of my chief tasks as a primary care physician is preventing illness. Today we can thankfully prevent or at least postpone some of the most common causes of premature death and disability. By identifying and controlling risk factors such as high blood pressure and high cholesterol, we can largely prevent heart attacks and strokes. By controlling diabetes, we can prevent the most common cause of kidney disease. Through vaccines we can lower the risk of suffering hospitalization and death from infectious diseases like flu, covid, and bacterial pneumonia. We can screen for colon, prostate, breast, lung, and cervical cancer and thereby often provide curative treatment. But there are still many conditions we cannot screen for and prevent. These include several cancers such as pancreatic, bladder, kidney, bile duct, and thyroid.

Enter a blood test called Galleri that screens for 50 types of cancer. It does so by looking for cell-free DNA (cfDNA) that cells shed into the bloodstream. Galleri uses genetic sequencing technology to scan for changes in cfDNA that come from cancer cells. In a study of people already diagnosed with cancer, Galleri accurately detected cancer in 51.5% of people. It predicted the location of the tumor 89% of the time. 

Since this study was published this June 2021, I’ve been intrigued by the potential benefits of Galleri and had several patients ask about it. But further analysis shows it isn’t ready for widespread use. One limitation is that the test only found cancer in 16.8% of the patients with stage I cancer. It was much better at finding cancer at later stages in which treatment options are limited. In addition, I question the value of screening the general population for many of the cancers it seeks to detect. Some of the cancers it screens for are very rare. These include cancers of the small intestine, ampulla of vater, and adrenal gland. For some of the other cancers in the panel, including cancers of the cervix, colon, prostate, and breast, we already have screening tests. Other cancers included in the screening occur almost exclusively in people with certain behaviors or risk factors. For instance, mesothelioma usually presents in people with a large amount of exposure to asbestos. Galleri includes leukemia as one of the cancers it detects. But, if present, leukemia shows up on a complete blood cell count (CBC) that is part of an annual physical. Galleri screens for testicular cancer and yet in the population in which Galleri is seeking an indication—50 years and older—testicular cancer is very rare. 80% of cases occur in men between 20-34 years old. I could go on, but you get the point. The bottom line is that many of the cancers Galleri screens for are quite rare and it’s not very good at detecting them at an early enough stage to effectively impact treatment. 

Nonetheless, the technology is promising. There is clearly a need for screening tests for pancreatic, ovarian, kidney, and lung cancer (in non-smokers). Right now these malignancies are often detected at too late a stage to allow for curative treatment. I’d encourage researchers to focus on more sensitively identifying these more common cancers. Ongoing studies will shed further light on Galleri’s strengths and limitations. Over time, I think it’s likely innovations will enable Galleri and other similar screening tests to detect cancers at an earlier stage. When that occurs,  hopefully in the not too distant future, such testing will be a valuable preventative tool.

 
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Posted by on November 22, 2021 in Uncategorized

 

Protecting Your Mind as You Age: Part II

In an earlier post I discussed exercise and sleep as important strategies for protecting our mind as we age. This week, I’ll discuss some other steps we can take to lower our risk of dementia.

Control blood pressure

Hypertension is when we have persistently elevated blood pressure. A growing body of research shows hypertension increases the risk of dementia. Blood pressure is the amount of pressure in our body’s arteries at a given time. Arteries are blood vessels that take oxygen and other nutrients to our body’s tissues, including our brain. The top number, systolic blood pressure, is the pressure when the left side of heart is contracting. The bottom number, diastolic blood pressure, is the pressure when the left side of the heart is relaxing. When blood pressure is persistently elevated, it damages the arteries. Think of a hose that you always filled with a massive amount of water pressure. Over time, the lining of the hose would wear out. The same thing happens with arteries in hypertension. When arteries are damaged they become less effective at supplying tissues including the brain. Parts of the brain die when they don’t get the oxygen and other nutrients they need. This is what we call mini-strokes and stroke. 

For many health conditions, we develop symptoms that tell us we have a problem. Not so with hypertension. That’s why it’s known as the silent killer. The only way to know it’s present is to measure your blood pressure. Fortunately, that’s relatively easy to do. Buy a home blood pressure cuff. I recommend the brand Omron and using a cuff that takes measurements at the arm rather than the wrist. When you measure blood pressure, have your feet flat on the ground. Place your arm at chest level, resting it on a desk of table. And wait a few minutes to check the pressure to give yourself time to relax. It’s the average that matters. Enter the readings into app like BP Companion that calculates the average of your readings. Check at least once daily for at around two weeks to get a sufficient sample size. An average above 135 systolic or 85 diastolic is when it’s worth contacting your doctor to discuss if a medicine might be needed. For people with vascular conditions like coronary artery disease, chronic kidney disease, or cerebrovascular disease, we aim for an average less than 130/80. 

While there are several inexpensive, well-tolerated medicines to lower blood pressure, a number of behavioral steps are also effective at doing so. Regular exercise lowers blood pressure. So does a diet low in salt and sugar and high in fruits and vegetables. Taking time to relax and manage stress if helpful. As is getting enough sleep every night. 

Eat Mostly Plants

Multiple studies show a Mediterranean-style diet lowers the risk of developing dementia. It consists of olive oil, nuts, fish, whole grains, fruits, and vegetables. Minimize cheese, sweets, red meats, fried food, and processed foods like white pasta, white rice, white breads, crackers, and chips. A large study over 10 years of a Mediterranean diet called the MIND diet found impressive benefits. People who followed the diet the least had the fastest rate of cognitive decline. People who most followed the diet had a 53% reduction in the risk of developing Alzheimer’s. This makes sense since a healthy diet lowers the risk of conditions like diabetes and hypertension that are harmful to the brain. 

Avoid excessive alcohol

There are long-term risks to brain health from excessive alcohol intake. Current recommendations are for men not to exceed 2 alcohol drinks daily and for women not to exceed one alcohol drink daily. 

Keep Your Mind Active

The idea of “use it or lose it” applies to the brain as much as the rest of your body. When you maintain social connections and participate in stimulating activities you build what is called cognitive reserve. It gives you a buffer or a back-up if your brain is injured by an accident or a disease like Alzheimer’s. Autopsy studies show that different brains of people with the same pathological findings can exhibit very different behaviors when they were alive. One person with signs of Alzheimer’s in their brain may have displayed signs of advanced dementia, requiring continuous caregiving. While another person with identical findings in their brain tissues may have shown no signs of cognitive impairment. The difference in such cases seems to be the cognitive reserve that was present. People who “built up their brain” with regular engagement could afford to lose a bit of it and still effectively function. So how do we create cognitive reserve? Maintain demands on your brain that keep it thinking, strategizing, and solving problems. Focus on activities that are enjoyable, but demand effort. Examples of doing so are learning a new language, musical instrument, or game. Activities that involve other people are especially helpful due to the cognitive demands and benefits of social interaction. 

Prioritize Relationships

Research shows people with few social connections have higher stress hormones, disrupted sleep patterns, altered immune systems, and increased inflammation. The psychiatrist and researchers Dr Robert Waldinger reports that “being in securely attached relationship to another person” is protective for the brain. Waldinger further reports that “one of the key ingredients was that people in relationships where they really feel they can count on the other person in times of need had their memories stay sharper longer.”  

Treat Hearing Loss

There is evidence that hearing loss increases the risk of dementia and that treating it with hearing aids lowers the risk. Theories for these findings are that hearing loss ups social isolation and that there is harm to the brain from receiving less information from the world. In contrast to wearing glasses, there is a stigma to wearing hearing aids. It’s seen as a sign somebody is old. Fortunately, many hearing aids are now designed in a way that makes them hard to notice. 

I hope this summary how to protect your age as you age has been helpful. If you’re interested in digging deeper, Dr Sanjay Gupta’s book Keep Sharp is excellent. I also recommend AARP’s website The Global Council on Brain Health https://www.aarp.org/health/brain-health/global-council-on-brain-health/

 
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Posted by on November 8, 2021 in Uncategorized

 
 
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