Bariatric Surgery, Weight Loss Linked To 60% Lower Risk Of Severe Covid-19
It’s not a replacement for vaccination against Covid-19. And it’s certainly not for everyone. But if you qualify for bariatric surgery, could such weight-loss surgery reduce your risk of suffering worse Covid-19 outcomes?
Well, a study recently published in JAMA Surgery looked at what happened to over 11,000 patients at the Cleveland Clinic Health System (CCHS) through the first year of the Covid-19 coronavirus pandemic.
A quarter of these patients had previously undergone bariatric surgery well before the start of the pandemic, and three quarters had not. And those who had had the surgery were about 60% less likely to have suffered a severe Covid-19 coronavirus infection.
Ali Aminian, MD, the first author of the study and Professor of Surgery and Director of the Bariatric and Metabolic Institute at the Cleveland Clinic, tweeted out some key results from the study:
As you can see in the tweet, Aminian used the word “impressive.” It’s a word that experienced researchers and medical doctors don’t tend to use lightly.
For example, if a physician tells you that you have put an impressive amount of moisturizer on your face, you may have overdone it.
When it comes to Covid-19 outcomes, a 60% difference could qualify as “impressive.” So let’s take a closer look at the study that Aminian conducted along with Chao Tu, MS, Alex Milinovich, Kathy E. Wolski, MPH, Michael W. Kattan, PhD, and Steven E. Nissen, MD, from the Cleveland Clinic.
This study focused on a cohort of patients who had undergone bariatric surgery sometime between January 1, 2004, and December 31, 2017, and a matching set of control patients who had not had such surgery.
The original cohort had 20,212 patients with 5053 in the surgery group and 15,159 in the control group. Of those in the surgery group, 3348 had a Roux-en-Y gastric bypass and 1705 a sleeve gastrectomy.
The Roux-en-Y gastric bypass and sleeve gastrectomy are two common types of bariatric surgery, which is an umbrella term for different types of surgery that can help address obesity and facilitate weight loss.
The following video from the American Society for Metabolic and Bariatric Surgery (ASMBS) presents an overview of bariatric surgery:
The patients ranged from 35 to 57 years of age with the median age being 46 years old. A little over three-quarters (77.6%) of the patients were female. Their body mass index (BMI) at enrollment into the study ranged from 41 to 51, with a median of 45.
By March 1, 2020, those who had gotten bariatric surgery seemed to be fairing significantly better than the control group, at least when it came to several key outcome measures.
The bariatric surgery group had lost on average 18.6% more body weight than those in the control group. Additionally, a smaller percentage of patients in the surgery group had died (4.7% vs. 9.4% in control group).
The lengths of patient follow-up had ranged from 3.8 to 9.0 years with a median of 6.1 years.
So Aminian and his colleagues wanted to see what happened to this cohort from March 1, 2020, to March 1, 2021.
The starting date, March 1, 2020 was ten days before the World Health Organization (WHO) had declared the Covid-19 coronavirus outbreak officially a pandemic.
By this date, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was already actively spreading in the U.S., as evidenced by the fact that toilet paper was being hoarded as if it were cryptocurrency.
At this point, 11,809 patients remained available in the cohort with 2,958 in the surgery group and 8851 in the control group.
During the ensuing year, 9.1% of those in the bariatric surgery group ended up testing positive for the SARS-CoV-2 at some point. This was a bit higher but not significantly different from the 8.7% that ended up testing positive in the control group.
However, those who had undergone bariatric surgery were 0.51 as likely to have been hospitalized, 0.37 as likely to have required supplemental oxygen, and 0.40 as likely to have had a severe SARS-CoV-2 infection, compared to the control group. These were, dare we say, rather impressive numbers.
Do these numbers prove that bariatric surgery was solely responsible for preventing worse Covid-19 outcomes? No. Such observational cohort studies can only show associations or correlations rather than demonstrate cause and effect relationships.
The surgery and control groups could have been different in other ways besides whether they underwent bariatric surgery. The study didn’t really measure face mask use, vaccination rates, and adherence to other Covid-19 precautions such as social distancing.
It didn’t determine how much contact with doctors and the health care system patients in each group had. It also didn’t look closer at other factors that may affect Covid-19 risk such as living situations and types of occupations.
Plus, bariatric surgery is not for everyone. It’s not like getting a facial. The ASMBS has very clear guidelines for who may qualify:
Keep in mind that for bariatric surgery to be successful, it’s hard work. You’ve got to maintain the appropriate diet and exercise problem afterwards.
So the bariatric surgery group could have been a very motivated group of patients who were interested in improving their health in general.
Nevertheless, 43%, 63%, and 60% differences were still impressive. The magnitude of the differences suggested that there was something more going on than just random differences between the surgery and control groups.
Moreover, this study’s findings were in line with findings from previous studies that have shown associations between obesity and more severe Covid-19.
As I’ve covered for Forbes previously, there are multiple potential reasons for these observed associations. After all, obesity is a darn complex disease, affecting multiple systems in your body.
For example, those with obesity may be more restricted in their ability to expand their lungs while inhaling.
They may have some immune system impairment and disruptions in their metabolism and body function in different ways. Calling obesity a simple problem would be akin to calling the TV series Game of Thrones a rom-com. It’s a complex problem that merits more attention.
“This study clearly demonstrated that obesity is a ‘modifiable’ risk factor for Covid-19,” Aminian explained.
“Since the pandemic started almost two years ago, multiple studies have shown that two main risk factors for poor Covid-19 outcomes are advanced age and obesity.
Age is not a modifiable risk factor. But based on the findings of this study, we can conclude that obesity is a modifiable risk factor.”
Indeed, it would be difficult to modify your age no matter how often you say, “that’s dope,” or dress like a high schooler.
A real age modification would require something like that time machine used by Professor Hulk on Ant-Man in the movie Avengers: End Game.
There are ways of tackling obesity, though, including bariatric surgery when appropriate. However, don’t forget that obesity is a complex systems problem that requires more multiple, coordinated systems approaches that extend across different aspects of society.
“Considering worldwide prevalence of obesity, findings of this study can have significant public health implications in the current pandemic and future infectious outbreaks,” Aminian mentioned. “If we help patients to lose weight, we can reverse many health consequences of obesity.”
Of course, this doesn’t mean that the Covid-19 coronavirus will only be a problem for those with obesity as some people like Rep. Marjorie Taylor Greene (R-Georgia) have suggested. Although humans may discriminate based on body weight, the SARS-CoV-2 doesn’t seem to do so in the same manner.
The virus has already shown that it can infect and cause problems in a wide range of people. You just have to have lungs, a respiratory tract, and a nose or mouth. If you have none of those, you either are a ficus plant or should see a doctor immediately.
Bruce Y. Lee / forbes