COVID-19, Our Metabolism & Our Orthopaedic Health

Jeffreybergmd.comI noticed a strange phenomenon throughout the summer and into the fall and winter of 2020 during the COVID-19 Pandemic. My clinic usually deals with traumatic and nontraumatic orthopaedic problems. However, during much of 2020, there was a significant reduction in the number of injured patients. Due to the shutdown of nonessential industries, schools, and sports leagues, this was somewhat predictable. What was less anticipated was that the number of patients with nontraumatic pain sources did not similarly diminish but instead seemed to increase. 

Why? Well, perhaps the cause is not so surprising. 

Early surgical procedures, and in particular, early orthopaedic surgeries, mainly focused on the treatment of injuries. The earliest treatment methods were very mechanical. The primary treatment techniques were bone setting and splinting or casting when the broken bone was manageable, and amputation, when the break was uncontrollable, didn’t heal or infection set in. Orthopaedics dealt with very objective medical issues and usually required very physical means to address the problems. Bone broke – We fix it – Think manual force, hammer, saw, drills, and plaster. 

Even as orthopedic technology advanced and more sophisticated procedures such as joint replacement and arthroscopy became commonplace, mechanical explanations for most orthopaedic issues persisted. Mechanical tendon irritation from adjacent bones was believed responsible for rotator cuff tears and other tendon problems. Arthritis was solely “wear and tear.” 

Then things changed…

Orthopaedists and other scientists started to delve into the particulars. Just as the micro-universe studied by quantum physics better explains previously unanswerable physics dilemmas, human biology seemed to explain previously misunderstood orthopaedic issues. As a result, scientists identified cellular sources and solutions for many of our orthopaedic problems. 

So how does this relate to increased orthopaedic pain during the COVID pandemic?

As Orthopaedists started to identify the biological root causes for many orthopaedic ailments, we noted that our tendon and joint problems and pain are often related to our metabolism. And sometimes, our metabolism isn’t optimal. 

There is a process called Metabolic Syndrome (MetS). Those with this disorder have at least three of the following five medical conditions: central obesity – an enlarged belly, high blood pressure, high blood sugar, elevated serum triglycerides, and low high-density lipoprotein (HDL) – the good cholesterol. About 1/4 to 1/3 of the US population are estimated to fit this criterion. And so in the US, at least, Metabolic Syndrome is a common issue…and a big problem. 

What makes MetS such a big problem? MetS is associated with insulin resistance, type II diabetes, and even pre-diabetes, heart disease, strokes, and Alzheimer’s disease. In addition, and most important for this post, it has been more recently determined that Met(S) is also associated with many orthopaedic joint and tendon problems like rotator cuff tears and arthritis. 

What causes it? 

The significant risk factors are diet, primarily high sugar-containing refined foods, low activity or sedentary behavior, disrupted sleep, mood disorders, and excessive alcohol intake. Sound like anyone you know during the 2020 shutdown? Genetics and older age are also contributing factors. 

What is going on?

What exactly is responsible for the multitude of problems that MetS causes is unclear, but some hypotheses exist. 

To better understand how MetS can cause us problems, it is essential to understand the basis for our present metabolism. In this regard, we have not evolved much from early humans. Our metabolism system developed to convert our food into stored energy and then to optimize our energy utilization during times of stress or conserve that energy during food shortages.

In early times, food was scarce, and obtaining it required a considerable portion of our stored energy. The amount of energy we took in was in relative equilibrium with the amount of energy we expended. Not so true today. In modern times, particularly in Western culture, food and calories are abundant, whereas physical activity is much less common. Further compounding this is that the food we consume often has low nutritional value, leading us to consume even more food and utilize even less energy to digest it. This imbalance between our consumption and need has led to an excess in nutrient (calorie) storage.

Why does this matter?

As a result of an increase in nutrient storage, a reduction in energy expenditure due to a more sedentary lifestyle, and an increase in consumption of processed foods, humans are now developing obesity, muscle loss, and greater exposure to inflammatory substances abundant in our everyday foods. This leads to a vicious cycle of more significant tissue damage, impaired tissue repair, and reduced tissue protection, resulting in even more significant tissue damage, pain, further reduced activity, and more substantial weight gain. 

How? 

There are several factors critical to this process: 

1. Sarcopenic Obesity

Sarcopenic obesity is the loss of significant muscle mass in association with an increase in substantial body fat. I have discussed the dangers of sarcopenia (age-related loss of muscle mass) in a prior post. Sarcopenic obesity is even more problematic since it is more closely associated with MetS than either sarcopenia or obesity alone. Sarcopenic obesity results in a reduction in activity-generated muscle loading. The diminished muscle loading arises from increased body weight in conjunction with further muscle function loss due to fat deposition within the muscle.  

2.  Impaired Tissue Repair

Normal tissue cells are continually going through a process of damage and repair. This process is true for muscle, bone, tendon, and even to some degree, cartilage. Inflammatory cells mediate this process. MetS and obesity, in particular, impair this process by maintaining a chronic low level of inflammation and an inappropriate elevation of various inflammatory factors, as well as an alteration of the environment in which they exist.  

Increased glucose levels are especially problematic in this regard. Elevated glucose and its breakdown products are particularly inflammatory. Excessive glucose directly and adversely affects the cells responsible for tissue repair and leads to overall weakening and low biological tissue properties. Which then results in worse tissue function, making these tissues susceptible to further damage. Additionally, elevated glucose levels can lead to insulin resistance and other metabolic disturbances that promote a feedback loop that amplifies this process’s ill effects. 

3. Altered Cellular Environment and Tissue Function

MetS directly impairs other cellular functions as well. For instance, when we intake glucose, our body must break it down for storage and utilization. These byproducts, such as advanced glycation end products (or AGEs), can interfere directly with tissue healing and function. As function declines, activities become more challenging and often lessen, leading to progressive disuse and subsequent tissue wasting, reduced overall function, obesity, and promoting MetS even more.

And so?…

These tissue changes not only lead to progressive tissue damage but increased tissue pain as well. This has tremendous implications for orthopaedic patients in general and those patients seen during the COVID pandemic specifically. There are several particular areas in which these symptoms manifest.

Arthritis

Arthritis describes the degeneration of a joint. In those with MetS, arthritis is not only more common in weight-bearing joints, such as the hip and knee, but also non-weight-bearing joints, such as the hand. Therefore, the effect of MetS is not just an increase of forces on the joint due to greater body weight. But it appears that it also is a result of cellular alterations and chronic low-grade inflammation, as discussed above. 

Not only does MetS appear to speed up the progression of arthritis, but it also is associated with an increase in arthritic pain irrespective of the degree of arthritis.

Both of these, increased arthritis progression and increased arthritic pain, ultimately lead to worsening overall function that further promotes MetS and deteriorating overall health. 

Tendon Pain and Degeneration 

Tendons connect our muscles to our bones. They are critical in enabling our muscles to move our bones. As a result of performing this essential function, our tendons can sustain degenerative micro-trauma and, on rare occasions, abrupt macro-trauma. Either way, for our pain to resolve and our function to improve, this tendon damage must heal. 

MetS makes tendons more vulnerable to injury, directly damaging tendons from cellular changes and the increased loads from greater body weight. MetS also disrupts injured tendons’ healing capacity. As a result, tendon issues (degeneration and tears), such as tennis elbow, Achilles tendonitis, and rotator cuff tendonitis and tears, are more common among those who have MetS. Furthermore, at least in the case of rotator cuff tears, the tears in those with MetS are more significant. Finally, although not a tendon issue per se, frozen shoulder appears to be more common in those with MetS, as well. 

 Surgical Outcomes

Complications, including even unexpected death, following surgery in patients with MetS are more common than in those without MetS. These complications are more frequent following orthopaedic surgeries as well as general, cardiac, vascular, cancer, liver, and trauma surgeries. As a result, these patients often also have significantly longer, and more complicated postoperative hospital stays. 

For instance, those with MetS undergoing joint replacements have a greater frequency of infections, blood clots, and cardiovascular complications. Those who have spinal surgery also are at a greater risk for cardiac complications. They develop pneumonia and other lung complications more frequently as well. 

The greater incidence of perioperative complications in these patients is not entirely unexpected. They are generally less healthy, often having diabetes, heart disease, and obesity. However, surgical results in patients with MetS, even without perioperative complications, are inferior to those without MetS. 

In those undergoing joint replacements, the postoperative function is worse, and persistent pain is more common

Similar inferior results occur in those with MetS following rotator cuff repairs. The ultimate function is lower, and the rotator cuff’s failure to heal is near twice those of healthier patients.

Even those with MetS who undergo carpal tunnel surgery experience a worse postsurgical course as they have a slower return of their function. 

What to do?

Like most things, the wise choice is to listen to your mother. :). I make light of it, but most of us know what to do. Metabolic Syndrome is primarily caused by our lifestyle and therefore, the cure is mostly influenced by us and our behavior. Developing a plan is the easy part. It’s implementing the solution that is not so easy. Although an orthopaedist can help you with the downstream issues that manifest due to Met(S), you are the key to preventing and halting these issues from developing or progressing. 

Once again, listen to your mother: Eat better and eat less, exercise more, lose weight, get more sleep, drink less alcohol, stop smoking, and reduce your stress. Nothing changes quickly, but if you do these things, there is a real chance that not only will you be healthier and perhaps live longer, but you may have a lot fewer aches and pains along the way. 

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