We’re learning more each day.

Every day, we’re learning more about how COVID-19 spreads and its impact on communities around the world. In the United States, at the time this post was written, we’re only at the beginning of what will likely be a months-long period of social distancing and travel restrictions.

However, the outbreak of this virus started back in November/December in China, which means that there’s been some opportunity for research on the characteristics of COVID-19, including symptoms, modes of transmission, and risk factors. This research is helping inform treatment and care, providing healthcare workers around the world with much-needed information on typical and atypical clinical symptoms.

One of the most written-about features of this disease is how it impacts those with underlying health issues and chronic diseases, such as diabetes, heart disease, hypertension, and obesity. While there are certainly outliers for who is affected by the disease, research demonstrates that in addition to increased age, the risk for becoming critically ill from COVID-19 increases with the presence of chronic disease.

The impact of chronic disease on health and healthcare under normal circumstances.

Six in ten adults in the United States have one chronic disease, and four in ten adults have two or more. Heart disease, cancer, and diabetes are the current leading causes of death in the United States and are responsible for $3.5 trillion in healthcare costs.

Chronic disease had been putting strain on patients and healthcare systems around the world well before the threat of a pandemic. People with multimorbidity – the presence of two or more chronic conditions – are more likely to utilize healthcare resources, and the care they receive is often much more complex and expensive.

Chronic disease, once thought of as a given for older people, has become much more prevalent in younger populations. About 20% of U.S. adolescents age 12–19 are obese, and as many as one in four have a chronic condition, like diabetes and asthma. Undesirable lifestyle behaviors, such as being sedentary and eating a poor diet, have contributed to earlier onset of chronic disease. In addition, tobacco use is prevalent in adolescents, and most recently, the use of vaporizers has brought nation- and worldwide attention to the health implications of such use. The younger people develop chronic disease, the longer they’ll need costly healthcare.

The impact of chronic disease on health and healthcare when afflicted with COVID-19.

COVID-19 affects the respiratory system, with typical clinical symptoms of fever, cough, fatigue, and shortness of breath. While it is thought that the majority of people who contract the disease only show mild symptoms, COVID-19 can cause pneumonia, which may require hospitalization for oxygen supplementation in addition to being put on a ventilator to support respiratory function.

Because of the rapid pace at which the virus has spread, hospitals have become inundated with COVID-19 patients and are putting stress on an already stressed healthcare system that still needs to address normal day-to-day emergencies. Furthermore, the patients being admitted to the hospital require the most care in the intensive care unit (ICU) and are often older and have underlying conditions.

There have been some common threads between the research studies to learn more about the risk factors for becoming critically ill from COVID-19; most notably chronic disease but also others, which we’ll explore here. Note: Because this is being written at a time when information is evolving, this research is also likely to evolve. We won’t have a full, clear picture until this pandemic reaches its conclusion and beyond.

Risk Factor #1: Age

Among 44,000 confirmed cases admitted to the hospital in China, approximately 80% of patients were age 30–69. Of those patients, approximately 20% were considered critically ill enough to be admitted to the ICU, with the average age being 61. For those over 80 years of age, the case fatality rate was almost double that of those age 60–69. Among 191 patients admitted to two hospitals in China, the average age of admission was 56 years.

In the United States, one of the first clusters emerged from a nursing facility in Washington State. While the sample size was smaller and the median age was skewed higher due to where the outbreak occurred, it’s still helpful to understand the progression of disease in a certain age demographic. Of 21 cases admitted to the ICU, the average age was 70 years (range: 43 to 92 years), and the mortality rate was 67%.

Risk Factor #2: Sex

The majority of patients who became critically ill and died due to COVID-19 were men, and men were 50% more likely to die after contracting the disease. Researchers are drawing inferences from the lifestyle behavior of men as compared to women to determine why the mortality rate is so much higher. Men tend to consume more alcohol and smoke more often in countries such as China, Italy, and South Korea, which also means they’re more likely to have developed chronic diseases, such as heart disease, lung disease, and other respiratory conditions that are further aggravated by a virus.

Some factors may be biological rather than lifestyle-related. For example, women’s immune systems are better at fighting viral infections, including the enhanced ability to remember past infections and fight them appropriately. It’s also been hypothesized that estrogen, the dominant hormone in women, can also help mount better immune responses.

Risk Factor #3: Comorbidities and multimorbidity

Of those 44,000 confirmed cases admitted to the hospital in China, case fatality rates increased dramatically for those with comorbidities – the presence of one or more chronic conditions – such as cardiovascular disease, diabetes, hypertension, and cancer. Of the cohort in Washington state, 86% had comorbidities.

In an article published in The Lancet, the most distinctive comorbidities associated with death due to COVID-19 complications were cardiovascular disease and diabetes. Researchers found that coronaviruses in particular like to bind to target cells found in the lungs, intestines, kidneys, and blood vessels called angiotensin-converting enzyme 2 (ACE2), which helps control cardiovascular function. Patients with diabetes as well as cardiovascular disease are treated with ACE inhibitors, which further exacerbates the virus’s expression in patients with these conditions.

In general, the recommendations put forth by the CDC are aligned with these risk factors, but that doesn’t mean that younger people aren’t at risk for becoming critically ill from COVID-19. There’s been some speculation as to whether vaping tobacco products is putting the younger population at risk for becoming more ill from COVID-19, but there’s not enough research at this time to point to solid evidence. However, smoking cigarettes has been proven to contribute to lung disease and thus puts one at higher risk.

Chronic disease prevention is key to protecting your health.

Engaging in healthy lifestyle behaviors – eating a balanced diet, exercising, taking care of one’s mental health, not smoking, not drinking in excess – is incredibly important for maintaining health and preventing chronic disease. Not only will you physically feel your best and save on healthcare costs, but you’ll also be able to show up for your community every day and especially during times of crisis.

Well before this difficult situation began, we’ve been helping people around the world learn how to transform their health so they could lead vibrant, fulfilled lives. We focus on understanding how to nourish yourself with primary food – your relationships, environment, physical activity, career – which are ever important as we practice social distancing and learn how to make our virtual connections just as meaningful.

We also emphasize bio-individuality, the concept that what works for one person might not work for another. There’s no one-size-fits-all approach to health, and our deep understanding of that through a holistic health education empowers our students and graduates to guide themselves and their clients to better health. Now more than ever, understanding your unique needs – from food to self-care and beyond – is crucial as you navigate your new normal.

Disease prevention encompasses all these areas of wellness. The choices we make every day build upon one another to create health in the long-term and can help protect us from critical illness during a pandemic.