Roundtable Discussion: COVID-19 and Obesity—Implications and Integrative Management

Alternative and Complementary TherapiesVol. 27, No. 2 Free AccessRoundtable Discussion: COVID-19 and Obesity—Implications and Integrative ManagementModerator: Jane Hart, Participants: David L. Katz, Robert F. Kushner, Beth Frates, and Donald D. HensrudModerator: Jane HartSearch for more papers by this author, Participants: David L. KatzDavid L. Katz, MD, MPH, FACPM, FACP, FACLM, is the founding director (1998–2019) of the Prevention Research Center at Yale University/Griffin Hospital, Derby, Connecticut, USA, the president of True Health Initiative, Tulsa, Oklahoma, USA, and the CEO of Diet ID, Detroit, Michigan, USA.Search for more papers by this author, Robert F. KushnerRobert F. Kushner, MD, MS, is a professor in the departments of medicine and medical education at Northwestern University Feinberg School of Medicine, and the director of the Center for Lifestyle Medicine at Northwestern Medicine, Chicago, Illinois, USA.Search for more papers by this author, Beth FratesBeth Frates, MD, FACLM, DipABLM, is a lifestyle medicine specialist and health and wellness coach at Wellness Synergy, LLC, and an assistant professor at Harvard Medical School, Boston, Massachusetts, USA.Search for more papers by this author, and Donald D. HensrudDonald D. Hensrud, MD, MPH, is an associate professor of preventive medicine and nutrition, division of general internal medicine, at Mayo Clinic College of Medicine, and medical director of the Mayo Clinic Healthy Living Program, Rochester, Minnesota, USA.Search for more papers by this authorPublished Online:12 Apr 2021https://doi.org/10.1089/act.2021.29318.dlkAboutSectionsPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookXLinked InRedditEmail Dr. Hart: Research suggests significantly increased risks of both hospitalization and death if a person who is obese develops COVID-19. What is our current understanding about degrees of obesity and the risk of developing COVID-19? What seems to be the mechanisms behind the risk?David L. Katz, MD: Famously, the dose makes the poison—and while Paracelsus was speaking of toxins and literal poisons, the same thinking pertains to cardiometabolic liability. Of course degree of obesity matters, just as the damage done to blood vessels by hypertension varies with magnitude, the propagation of atherosclerosis by hyperlipidemia varies with its severity, and so on. Stage 2 obesity (i.e., body mass index [BMI] >35) and in particular stage 3 obesity (i.e., BMI >40) stand out as leading indicators of adverse COVID-19 outcomes in young people, notably those under age 40. Greater degrees of obesity mean not only more and larger adipocytes, but more influence on circulating hormones and cytokines that influence immune response. A principal mechanism by which obesity compounds COVID-19 is immune dysfunction and inflammatory responses that are both exaggerated and ineffectual.There is another purely mechanical means by which relatively severe obesity exacerbates COVID-19. Early in the pandemic, the importance of positioning to improve oxygenation was discerned. I witnessed this first hand during a brief stint as a frontline volunteer in New York City. I also observed firsthand how much more difficult such frequent repositioning was—for patient and medical staff alike—when the patient had severe obesity. In addition, severe obesity is a long-established risk factor for respiratory ailments in general because of potential constraints on normal lung excursions and tidal volume.I hasten to note that while we may "blame" obesity for some element of COVID-19 risk, we may NOT blame victims of obesity for suffering the condition. Obesity is a "social" disease if a disease at all, mediated by an obesogenic environment and culture, and much propagated by social disparities that are, in turn, independent risk factors for adverse COVID-19 outcomes.Robert F. Kushner, MD: Shortly after COVID-19 reached the United States it became apparent that obesity was a risk factor for severe illness, prompting the Centers for Disease Control and Prevention (CDC) to include obesity (BMI ≥30 kg/m2) on its list of at-risk underlying medical conditions. Over the past year, multiple studies from small single-site medical centers to large retrospective analyses of health care systems have consistently shown a significant association between BMI and increased risk for admission to the intensive care unit (ICU), need for invasive mechanical ventilation, and death. The increased risk is particularly noted among those with moderate to severe obesity, males and younger age (approximately <60 years). A recent pooled analysis showed that individuals with obesity were 74% more likely to be admitted to the ICU and experienced a 48% increased risk for death.1Exploring the underlying mechanisms that underlie this risk among individuals with obesity has been an intense topic of inquiry; 1439 articles on obesity and COVID-19 were published in PubMed in 2020. Predisposing factors include metabolic dysfunction (insulin resistance, prothrombotic, and vasoconstrictive states), chronic state of low-grade inflammation (increased adipokines and cytokines), immune impairment (Treg suppression), comorbidities (diabetes, hypertension, and obstructive sleep apnea), and challenges of hospital management (intubation, proning, transportation, and imaging).Beth Frates, MD: Affirming and adding to the other comments, the CDC identified 12 conditions that put adults at higher risk for severe illness from the virus that causes COVID-19. As mentioned, two of these conditions are obesity (defined as BMI >30 but <40 kg/m2) and severe obesity (defined as BMI >40 kg/m2).2 In addition, there is some evidence that even being in the overweight BMI category (BMI 25–30 kg/m2) increases the risk of COVID-19 by 44%.3One way to explore the association between obesity and COVID-19 is to examine the mechanistic changes in obesity and its physical changes.1 Mechanistic changes include metabolic dysfunction, immune impairment, and adipose inflammation as outlined in the article by Popkin et al. titled, "Individuals with obesity and COVID-19: A global perspective on the epidemiology and biological relationships."1 For metabolic dysfunction in obesity, there is an increase in insulin and leptin, a decrease in adiponectin, and an increase in hypoxia and lipotoxicity. With regard to immune impairment, there is an imbalance of T helper cells altering the ratio of Th2 and Th1, a decrease in Tregs' (regulatory T cells) ability to suppress and clear immune cell-mediated inflammation after infection, and a decrease in specialized pro-resolving mediators, which are specialized pro-resolving lipid mediators that work to resolve inflammation. Adipose inflammation involves the alteration of a number of cytokines, including an increase in interleukin-6, C-reactive protein (CRP), granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor-α and interferon-δ. With obesity, there is an increase in Th1 cells, macrophages, and cytotoxic T lymphocytes.As mentioned, there are physical changes that accompany obesity and impact a person's ability to fight the infection with the coronavirus. Visceral adiposity is one such change. In addition, excessive tissue around the neck measured in collar size often accompanies obesity and is a risk factor for obstructive sleep apnea. People with abdominal obesity also have lower lung capacity and an increased risk of other respiratory problems that increase the risk of hypoventilation-associated pneumonia. There is an association with decreased physical activity and obesity, and less exercise leads to lower cardiorespiratory fitness levels, which translates to less efficient delivery of oxygen to tissues throughout the body. This may also be a factor in the increased risk and increased severity of illness with COVID-19 in patients with obesity. It is important to mention that many people who are obese feel stigmatized by society and health care providers. This may result in patients with obesity delaying health care visits.Dr. Hart: Are there other important associations linked specifically to obesity and COVID-19 risk such as comorbidities, age, or gender that contribute? Or are all people who are obese carrying the same risk?Dr. Katz: This is a very important question. Not all obesity is created equal—simply on the basis of severity. But there are other important distinctions, too. We have long referred to a division in anthropometrics between gynoid or "pear" and android or "apple" pattern obesity. The sex-based distinction is common, but of course not perfectly reliable. In general, though, premenopausal women are more prone to store excess body fat in the lower extremities while men and postmenopausal women are more apt to store extra fat around the middle. Genetic and ethnic distinctions are relevant here as well, so the tale is not limited to sex. Whatever the underlying predispositions, the accumulation of fat around the middle is much more strongly linked to visceral fat accumulation, insulin resistance, the stigmata of the "metabolic syndrome," and type 2 diabetes than is lower extremity fat. Ultimately, it is the type (distribution) as well as degree of obesity that determines the metabolic contribution to COVID-19, while degree alone may have more to do with the mechanical contribution.Dr. Kushner: Most of the databases used to explore the association between obesity and COVID-19 complications have access to only demographic variables that are routinely captured in an electronic medical record, such as height, weight, age, gender, and race/ethnicity. From these data, we have learned that individuals with moderate to severe obesity that are male, younger, and belong to minority groups have an increased risk for complications. Hypotheses are now emerging to explain these associations. As Dr. Katz stated, males are more likely to have an increased abdominal fat distribution (android phenotype), which is associated with increased visceral and ectopic fat, lipotoxicity (increased adipokines and cytokines), and impaired diaphragmatic excursion, leading to reduced functional residual capacity and hypoxia.The heightened risk among disadvantaged populations places a spotlight on social determinants of health as an underlying contributor of risk, particularly the role of food deserts, the built environment, financial insecurity, and limited access to health care. Clearly, defining obesity by a single anthropometric measurement (BMI) is insufficient since BMI alone does not directly measure body fat, or distinguish body fat distribution, assess fitness, or assess an individuals' health status.Dr. Frates: As I stated before, obesity and severe obesity are 2 of the 12 risk factors identified as risk factors for COVID-19 by the CDC; however, it is important to point out that 3 of the other risk factors are highly correlated with obesity, including type 2 diabetes, heart disease, and cancer. People with more than one risk factor for COVID-19 are at increased risk for infection and serious illness. For example, with diabetes, the body has a disrupted immune response with reduced cytokine production, impaired phagocytosis, and dysfunction of immune cells. As noted earlier, people with obesity have mechanistic and physical changes that put them at risk for infection and subsequent severe problems due to COVID-19.4 People with obesity and diabetes have chronic low-level inflammation. This state could aggravate the inflammatory response to coronavirus infection, putting patients at increased risk for the cytokine storm that leads to pneumonia, acute respiratory distress syndrome, and ultimately multiple organ failure, which can occur in severe COVID-19 cases.5People with heart disease and obesity are at increased risk for severe disease as well. A healthy heart allows for optimal oxygen and nutrient delivery to all cells in the body. When the heart is not functioning properly, the delivery system is compromised, which can lead to worse oxygenation and greater physiologic dysfunction with COVID-19. With a fever, the body responds with a rapid heart rate, which can put strain on a heart muscle often already riddled with disease. In addition, pneumonia lowers oxygen saturation, which puts increased stress on the heart.6People with cancer are also at increased risk for morbidity and mortality. Research has demonstrated that cancer patients have significantly lower platelet levels and higher D-dimer levels, C-reactive protein levels, and prothrombin time, which makes them vulnerable to severe sequelae with COVID-19.7 Combining cancer with the mechanistic dysfunction and physiologic changes that accompany obesity puts patients at increased risk with respect to coronavirus infection.As mentioned, with respect to gender, data reveal that more men are dying of COVID-19 than women. Reasons for this gender difference may be attributed to differences in biology such as carrying adipose tissue in the abdominal region, pre-existing conditions, and the reluctance to seek health care.8 In addition, there is research supporting the fact that women are more likely to believe that COVID-19 is a serious health problem, more likely to agree with restraining public policy measures, and also more likely to comply with the policies.8Socioeconomic status plays a role in COVID-19 risk and severity of illness.9 People who live in areas that are densely populated and in households with members sharing bedrooms and other tight spaces are more likely to contract and spread the virus. Jobs that do not lend themselves to working from home such as bus drivers, grocery store clerks, and warehouse workers put people at risk for the virus day to day. Access to health care is another factor that comes into play with this disparity. People living in poverty may experience multiple barriers to visiting the doctor or going to the hospital. All of this can contribute to risk and severity of COVID-19.There is evidence that people who are black, Hispanic, and Asian are at increased risk of COVID-19.10,11 The reasons for this disparity are multifactorial and need further research.Donald D. Hensrud, MD: The bottom line is that obesity increases the risk of type 2 diabetes mellitus, hypertension, pulmonary disease, and cardiovascular disease and other conditions, all of which independently increase the risk, severity, and mortality of COVID-19 through various mechanisms. Insulin resistance, a hallmark of type 2 diabetes and present in many cases of obesity, is a key factor in increasing the inflammatory response. Regarding age, severe obesity appears to be the most important risk factor for severe disease in younger people. In contrast, prior bariatric surgery for obesity appears to be associated with decreased risk.Dr. Hart: What are some of the most promising integrative medicine interventions that clinicians should be aware of for addressing obesity and COVID-19? What is the role of nutritional medicine?Dr. Katz: There is much in the realm of nutritional medicine to help mitigate the ills of COVID-19 in no small measure because overall dietary pattern is the leading determinant of chronic disease risk in the United States and much of the modern world. A balanced high-quality plant-predominant diet is vital to immune function in various ways, and is also vital to the prevention or amelioration of leading COVID-19 risk factors such as diabetes, hypertension, and cardiovascular disease. Isolated nutrients of special interest include vitamin D, zinc, antioxidant families (i.e., carotenoids, flavonoids) and omega-3 fatty acids. Probiotics are another potential mediator of balanced immune responses. I would recommend with the most confidence, supplements of vitamin D and zinc as a type of preventive medicine insurance—likely to help a bit, unlikely to harm—with a dedicated focus on optimizing overall diet quality.But when it comes to obesity per se, the list is quickly truncated. Obesity really is a matter of energy balance, and as we have all heard—weight can be lost even on a junk food diet if energy intake is restricted. Thus, an enlightened integrated approach to managing weight for the sake of attenuating COVID-19 risk would extend well beyond weight to overall considerations of diet quality and nutritional status, and the ways these reverberate through every aspect of metabolic health.Dr. Kushner: Lifestyle counseling is foundational to obesity care, particularly during the COVID-19 pandemic. In addition to emphasizing consumption of a nutritionally balanced calorie-controlled diet as Dr. Katz mentioned, and engaging in ample physical activity and reducing sedentary time, increased attention needs to be directed toward using adaptive coping skills. COVID-19 has brought an unprecedented increase of stress for most people due to loss of "normalcy" of our lives, financial insecurity, and social isolation. The impact of stress on physical and mental health has been defined by the terms allostasis, allostatic state, and allostatic load. Allostatic load reflects the cumulative effects of experiences of daily life and the resulting health damaging behaviors, including poor sleep, social isolation, lack of exercise, and unhealthy diet—all manifestations of living during the COVID-19 pandemic. Mind–body therapies, such as yoga, meditation, mindfulness, guided imagery, t'ai chi, and mindfulness-based stress reduction, can be particularly useful to recommend to patients.Dr. Frates: Unfortunately, but not surprisingly, there is evidence that people are gaining weight during the pandemic mostly related to a change in lifestyle that includes staying home, sitting more, moving less, eating more along with increased stress levels, decreased social connection, decreased sleeping time, and increased alcohol consumption. All of these factors are powerful lifestyle factors. The six pillars of lifestyle medicine outlined by the American College of Lifestyle Medicine (ACLM) include routine exercise, a healthy diet, stress sleeping to a social and or alcohol consumption promising for obesity during this pandemic is the of lifestyle medicine interventions to help patients these patients for and and research in the six pillars as well as to the for The is to and the social created during the the patients to all of the lifestyle medicine pillars are important to for who is working to weight, a can help people the need in The pandemic has these because are and there are no or of patients physical activity that at home and for is one way to people with obesity to a healthy change during this pandemic. patients to a food eating pattern people to on and feel as well as on nutrients that can help them immune systems such as eating for the vitamin and with zinc, which are for immune include and help themselves by eating and with vitamin D, to help the immune system and help fight is a of vitamin D as well. to levels of and leptin, which can help with weight of sleep is associated with increased consumption the day in the of and alcohol not only to the but the and to can also lead to stress mindfulness-based stress reduction, meditation, and can help lower levels of and with also stress and which is more now during the pandemic. interventions can some social for patients.Dr. loss during an COVID-19 infection is not likely to be loss developing a COVID-19 infection be weight loss some of the metabolic of obesity. large of weight loss in a of may have a on immune mentioned, obesity is associated with immune status is important for optimal immune function and an response to inflammation and infection, including There are many nutrients that are in these in the including zinc, omega-3 fatty and D, and of are but evidence from them is very limited at the present As in other areas of medicine, we often with on potential and In it is important to with the do no it may that with may be such as vitamin and as both are associated with increased of the current evidence to COVID-19 on which need to be with For example, blood levels of zinc have been to be lower in patients with COVID-19. zinc is to and blood levels of and zinc are lower in patients with severe illness as of the metabolic response to inflammation and Thus, zinc levels identified in many studies may not zinc which suggests with zinc is less likely to be even in the of blood from are to from an showed no from vitamin zinc on of in the vitamin D some D is relatively in various with of people blood levels, on the for In addition, vitamin D levels are lower in obese and decrease with blood of vitamin D have been associated with COVID-19 infection, disease severity, and mortality. D is a key of the system that is an point of the virus into cells and is also in immune studies have that vitamin D the risk of COVID-19 infection and it has been that a large of from COVID-19 are due to vitamin D The risk of vitamin D is at D is often for the general particularly if blood levels have been For all these data from are it would not be to vitamin D for obese and to or with COVID-19. The dose has not been a vitamin D blood of is often a Hart: What is being done in the integrative and lifestyle medicine to specifically obesity during this Katz: Not The pandemic is an experience for all and were there to be a weight and health it would the of many including As a is the of and are less apt to be a the pandemic and less prone to a difference at The data we have weight, on has Dr. during the pandemic, so we are to it is not Kushner: In the United the Health to overweight and obesity in of the COVID-19 pandemic. The weight loss is to eating and a more change that has in the United States is the of which increased since when the Centers for & for is more for patients and the financial and of to the medical For increases of care, and allows for more of With and counseling can be and it is if this be in people with Frates: We need more specifically addressing obesity during this pandemic. that lifestyle medicine are articles for to which are by most of the public and health lifestyle medicine are using social such as and to spread about the importance of exercise, nutrition, sleep, stress reduction, social connection, and alcohol or patients is during the pandemic, mostly with are to work with patients on the six one at a on a for It was for people to weight COVID-19, and has more for many people during this pandemic. people are working at home and may be less low-level physical with when were working the home, and many fitness centers have Regarding diet, people may be around food more while working at home and increase intake through People who do not much may be increasing intake by more food or health problems have increased during COVID-19, and many mental health are related to increased some physical activity have to people in fitness is an but is not to many people and not to increase physical people have the ability to for a on a and people should activity when working at at have been demonstrated to increase and many people have a or during this a to healthy at home can help weight and be an food does not have to be in to healthy dietary such as the diet, may decrease the risk of COVID-19 and improve COVID-19 in while many people were eating less healthy and gaining weight, greater to a diet and lower BMI was in of the people have used this as an to the behaviors, and weight even more health and health care can help in this by education and on addressing these challenges and weight a approach to be Hart: can we disparities in terms of of obesity and access to nutritional medicine, and healthy Katz: to obesity from disparities of and There is no for so a But clinicians can be in the of change by clear and and as for There are to with eating well, from to food to medicine live of the relevant is to the so the role is to and role a dose of we