The Rise of Metabolic Syndrome: A Cause for Concern

DESPITE CONSIDERABLE technological achievements, the law of unintended consequences still holds sway over human endeavors. Take hunger as an example. For millennia, hunger was the bane of rulers across the globe. Until recently, every society struggled to provide enough sustenance for its people, and at the end of the day, most human beings went to bed hungry. Malnutrition brought with it a host of medical issues, including rickets, stunted growth, anemia, etc., and physicians were well-accustomed to treating them.But by the late 1700s, the Industrial Revolution brought forth new planting and harvesting machines that allowed farmers to grow more food on the same acreage. Over the ensuing decades, better understanding of irrigation and crop rotation also contributed to increasing yields, as did selective crossbreeding of crops. The arrival of rail and steamships coupled with modern refrigeration allowed for the development of vast new distribution networks that could bring food from the farm to cities quickly. Automated canning factories and the development of quick-freezing methods combined with the earlier developments ensured most Americans (and soon, others around the world) had access to more food than their parents and grandparents could ever have imagined. Moreover, it was more varied and more affordable than had been enjoyed by royalty a century earlier.

All these advances greatly reduced the incidence of mass starvation across the globe. But as the law of unintended consequences kicked in, two developments arose out of the sudden, unexpected bounty of cheap, available foodstuffs:

1) The newly efficient agricultural sector needed far fewer farm workers to harvest the additional food, leading to a mass exodus from the countryside and into cities (a process still occurring in parts of India, China and Africa). And, these new city dwellers found themselves with jobs that were far less physically strenuous than the farmwork in which their parents and grandparents had engaged. Plus, the advent of radio and television also led to many people’s leisure hours being spent sitting passively.

2) Cheap, available food led to a dramatic rise in the average daily caloric intake of most people. It turned out that when food was plentiful and affordable, people consumed more than their bodies needed.

This combination of too much food and too little physical activity has led to what is an unprecedented outbreak of diseases formerly associated with wealth: obesity, cardiovascular disease and type 2 diabetes. Today, these conditions affect people from all demographics in the West. In fact, the poor are more likely to suffer from some of these than are the wealthy.

Metabolic syndrome is one condition associated with overnutrition and a sedentary lifestyle, another unexpected development from the successful effort to reduce mass starvation. And it is affecting more people than ever before — more than a third of all U.S. adults.¹

What Is Metabolic Syndrome?

Metabolic syndrome is the name given to a collection of risk factors that heighten the chance of developing heart disease, stroke and/or type 2 diabetes.² The National Institutes for Health lists these risk factors as (Figure 1):³

• A large waistline (35 inches or greater for women, 40 inches or greater for men)

• A high triglyceride level

• A low HDL cholesterol level

• High blood pressure

• High fasting blood sugar

Having three or more of these indicators generally leads to a diagnosis of metabolic syndrome.

What is now referred to as metabolic syndrome was first described in 1966 by French physician Jean-Pierre Camus, although he referred to it as a “metabolic trisyndrome.”⁴ Twenty-two years later, Gerald Reaven, MD, referred to this cluster of factors as “Syndrome X” in a talk at the American Diabetes Association national meeting,⁵ which led to a flurry of interest in this condition. Studies and papers about it accelerated as researchers realized this was a growing problem associated with the abundance of food and a growing amount of highly processed foods heavy in sugars in the average diet.

At one time, metabolic syndrome was considered the same condition known as insulin resistance, which occurs when the body’s cells don’t react normally to insulin, preventing glucose from being absorbed into cells.⁶ However, while there remains a high correlation between metabolic syndrome and insulin resistance, they are generally now viewed as two distinct albeit related conditions.⁷

As the name metabolic syndrome indicates, researchers believe this collection of risk factors is likely caused by an underlying “abnormal carbohydrate and lipid metabolism.”⁸

Causes of Metabolic Syndrome

While researchers are fairly certain obesity and low activity levels are the cause of metabolic syndrome, the specific triggers that cause the body’s metabolism to change are not fully understood.⁷ And, while some people who suffer from obesity never develop metabolic syndrome, not all people who have metabolic syndrome are obese.

In addition to obesity and a sedentary lifestyle, other significant risk factors are age and genetics. The risk of developing metabolic syndrome increases as people age, and those with a family history of diabetes seem more likely to develop it.

Smoking, high alcohol intake and high levels of stress also seem to have a correlative relationship.⁷ Other possible contributing factors include sleep apnea, gallstones and ovarian cysts.³

Health Risks Associated with Metabolic Syndrome

Individuals with metabolic syndrome are already suffering damage to their cardiovascular system, as well as their ability to process nutrients at the cellular level. Hence, they are at elevated risk for developing full-blown heart disease and type 2 diabetes.

Recent research suggests the long-term systemic inflammation caused by obesity is the driving factor in developing metabolic syndrome,⁹ with patients having a high correlation for high-sensitivity C-reactive protein, a marker for systemic inflammation. Other inflammation markers found in higher-than-normal levels in patients diagnosed with metabolic syndrome include tumor necrosis factor-alpha, interleukin (IL)-6 , IL-18 and oxidation of LDL.⁸

In fact, the serious bodily damage caused by metabolic syndrome has led the American Heart Association to predict it will soon eclipse smoking as the main cause of heart disease.⁷

Prevalence of Metabolic Syndrome

A major study conducted a decade ago found the incidence of metabolic syndrome among adults in the United States increased from 25.3 percent in 1994 to 34.2 percent in 2012.¹⁰ The researchers noted the correlation between the increase in the percentage of adults with metabolic syndrome and the percentage of adults who are overweight or obese, which now tops two-thirds of the population in the United States. (Even in Kazakhstan, which is not yet as developed as the United States, more than 20 percent of the population was obese as of 2017.¹¹)

Among the clinically obese, 61.6 percent suffer from metabolic syndrome, according to one recent study. But even 8.6 percent of American adults at a healthy weight had metabolic syndrome.¹²

More troubling than the increase in the percentage of adults developing metabolic syndrome, though, are recent signs that children are also now suffering the effects of a high-fat, nutrient-poor diet combined with a lack of physical activity. A 2017 study in Chile found 18 percent of children had early onset obesity, and half of those remained obese into their teens and had a high-risk factor for metabolic syndrome.¹³

Considering the troubling worldwide numbers, it is easy to see why the American Heart Association has labeled metabolic syndrome as the greatest future threat to cardiovascular health in the United States.

Metabolic Syndrome and Expected Life Span

While metabolic syndrome obviously increases the chances of developing life-threatening conditions such as arteriosclerosis or suffering a stroke, research indicates that charting a clear mortality risk from the diagnosis remains fuzzy. Numerous studies have shown patients with metabolic syndrome have a higher mortality rate than those without it, but nearly all of these studies caution against trying to determine a quantitative value.¹⁴ In fact, researchers pointed out that other underlying conditions also contribute to mortality and trying to assign mortality rates to what are overlapping conditions is impossible.

Best Practices

The reality is while there are genetic factors at work in triggering metabolic syndrome, it is largely driven by behavior. The most effective way to reverse a diagnosis is weight loss and an increase in physical activity. When these are both achieved, even at modest levels, blood pressure generally improves, and weight loss also lowers the systemic inflammation associated with obesity. However, changing behavior in human beings is one of the most challenging tasks (and attempting to do so undoubtedly contributes significant stress to the professional lives of physicians).

Controlling blood pressure with medication will not reverse a diagnosis of metabolic syndrome, but it will significantly reduce the risk of cardiovascular damage. Controlling triglyceride levels and cholesterol are also effective methods of lowering the long-term health risks of metabolic syndrome.

One recent study recommended a treatment blending lifestyle changes with proven medications to lower risks while pursuing longer-term improvements. According to the researchers, “While therapeutic lifestyle changes (TLCs) should be strongly recommended, clinicians should not let the perfect be the enemy of the possible. Evidence-based doses of statins, aspirin and angiotensin-converting enzyme inhibitors, or angiotensin II receptor blockers, should be prescribed as adjuncts, not alternatives, to TLCs.”¹⁵

Looking Ahead

Humans spent millions of years honing the skills necessary to find enough food to sustain another day. So, adjusting to the influx of an overabundance of food is likely to take some time to adjust to. Individuals are programmed by nature to seek out high-calorie foods, and overcoming that innate drive that allowed our ancestors to survive is difficult for most. This explains why recent studies show the prevalence of metabolic syndrome continues to rise. And, as more nations raise the standard of living for their people, metabolic syndrome will undoubtedly increase in those societies as well.

While new treatments and medications to assist with control of symptoms or assisting with weight loss will undoubtedly come to market, it is unlikely there will ever be a magic pill that allows people to simply undo the effects of poor eating habits. Consequently, for the foreseeable future, the only effective treatment for metabolic syndrome will consist of working with patients to establish healthy eating and exercise regimens, augmented with medications to regulate blood pressure, triglycerides and cholesterol.

As one of the greatest public health crises of the next generation, it is a challenge that will likely be met in clinical settings rather than in research laboratories.