40% of Americans have a body mass index (BMI) of 30 or more, suggesting that they are obese . Although scientists agree that factors other than BMI may more accurately describe obesity–such as waist circumference, waist-hip ratio, and total body fat–it is undeniable that a large amount of the US population suffers from obesity . Unfortunately, obesity is associated with a higher risk of several health concerns, including diabetes, cardiovascular disease, and complications with anesthesia . Some of these concerns are lesser known but essential for medical practitioners to be aware of when treating their patients.
Because obesity is associated with several comorbidities, anesthesiologists must be aware of these conditions when sedating obese patients . For instance, there is a negative correlation between obesity and respiratory function; many obese patients have low lung volumes, decreased airway compliances, and diaphragmatic restriction (caused by visceral fat) . Additionally, obesity also puts patients at a higher risk of cardiovascular– and obstructive sleep apnea-associated complications [2, 3]. Other studies have found that obesity is independently associated with poorer anesthesia outcomes . It is crucial that anesthesiologists be consulted preoperatively and that a multidisciplinary team plan any major surgeries for obese patients .
The correlation between obesity and the development of various cancers has also been widely studied. According to a comprehensive 2007 study, obesity is associated with higher incidences of a variety of cancers, including endometrial, kidney, pancreatic, postmenopausal breast, colorectal, and esophageal cancer . Another more recent form of cancer linked to obesity is thyroid cancer: researchers have found that patients with higher BMIs have larger tumors and greater rates of multifocality . Unfortunately, obese people with cancer experience much more difficult recoveries and lower chances of survival . The mechanisms guiding these correlations are not entirely understood, making this a crucial topic to address considering the growing rate of global obesity.
Most recently, the link between obesity and COVID-19 has been a subject of much discussion. In the past, obese people have been at greater risk of complications from infectious diseases than non-obese populations and less receptive to vaccines . This is due to the greater amount of adipose fat that obese people carry . Excess adipose fat can result in chronic inflammation, which diminishes the efficacy of the specialized inflammation triggered by the immune system and/or vaccines in response to an infection . Adipose fat can also serve as a reservoir for viruses . These observations may help explain the greater rates of COVID-19 infection, hospitalization, and death experienced by obese patients . Even when a vaccine is developed for the novel coronavirus, obese patients will require specialized attention, given these immune inhibitions.
Ultimately, obesity can result in a variety of health difficulties: cardiovascular problems, respiratory issues, cancers, and infectious diseases. Especially during the pandemic, medical professionals must work to closely monitor their obese patients, both in and out of surgery, to promote the best possible outcomes.
 S. Varney, “America’s Obesity Epidemic Threatens Effectiveness of Any COVID Vaccine,” KHN, August 6, 2020. [Online]. Available: https://khn.org/news/americas-obesity-epidemic-threatens-effectiveness-of-any-covid-vaccine/
 S. Sharma and L. Arora, “Anesthesia for the Morbidly Obese Patient,” Anesthesiology Clinics, vol. 38, no. 1, p. 197-212, March 2020. [Online]. Available: https://doi.org/10.1016/j.anclin.2019.10.008
 A. De Jong et al., “How can I manage anaesthesia in obese patients?,“ Anaesthesia Critical Care & Pain Medicine, vol. 39, no. 2, p. 229-238, April 2020. [Online]. Available: https://doi.org/10.1016/j.accpm.2019.12.009
 S. K. Park, H.K. Yoon, and W. H. Kim, “Obesity and spinal anesthesia outcomes,” Anesthesiology Clinics, vol. 33, no. 6, p. 704, December 2019. [Online]. Available: https://doi.org/10.1007/s00540-019-02685-7
 M. Patlak and S. J. Nass, The Role of Obesity in Cancer Survival and Recurrence, 1st ed. Washington, D.C., USA: The National Academies Press, 2012, ch. 1, p. 1-4.
 S. Zhao et al., “Association of obesity with the clinicopathological features of thyroid cancer in a large, operative population: A retrospective case-control study.,” Medicine, vol. 98, no. 50, p. e18213, July 2020. [Online]. Available: https://doi.org/10.1097/MD.0000000000018213
 J. V. V. de Siqueira et al., “Impact of obesity on hospitalizations and mortality, due to COVID-19: A systematic review,” Obesity Research & Clinical Practice, vol. 14, no. 5, p. 398-403, July 2020. [Online]. Available: https://doi.org/10.1016/j.orcp.2020.07.005
 M. Banerjee et al., “Obesity and COVID-19: A Fatal Alliance,” Indian Journal of Clinical Biochemistry, vol. 35, no. 4, p. 410-417, July 2020. [Online]. Available: https://doi.org/10.1007/s12291-020-00909-2