Obesity: A comorbidity-acquired immunodeficiency syndrome (CAIDS)

Abstract

Accumulating data emphasize a strong link between obesity and the severity of coronavirus disease-2019 (COVID-19), including mortality. Obesity interferes with several components of the immune system including lymphoid tissue’s integrity, leukocytes’ development and function, complement system’s activation, and the coordination of innate and adaptive immune responses. Overall, obesity results in a less efficient immune response to infectious agents. Severe acute respiratory syndrome coronavirus 2 exploits this weakened immune system in people with obesity to precipitate COVID-19, and in some cases death. It is therefore the author’s recommendation that obesity should be viewed as another form of acquired immunodeficiency syndrome and be treated with the appropriate seriousness. Unlike the previously described acquired immunodeficiency syndrome (AIDS) that is caused by the Human Immunodeficiency Virus (HIV), obesity is a comorbidity-acquired immunodeficiency syndrome. People with AIDS do not die from HIV, but may die from opportunistic pathogens such as Mycobacterium tuberculosis. However, AIDS is ascribed its due importance in the course of deterioration of the patient. Similarly, obesity should be acknowledged further as a risk factor for mortality from COVID-19. Obesity is a modifiable condition and even in people with a strong genetic predisposition, lifestyle modifications can reverse obesity, and even moderate weight loss can improve the inflammatory milieu. Strong public health actions are warranted to promote lifestyle measures to reduce the burden from overweight and obesity that currently affect more than one-third of the global population, with projections alarming this may reach 55-80% within the next thirty years.

Graphical Abstract

PLAIN LANGUAGE SUMMARY

Accumulating data emphasize a strong link between obesity and the severity of coronavirus disease-2019 (COVID-19), including mortality. Obesity interferes with several components of the immune system, reducing the body’s capacity for defence against infectious agents, such as viruses and bacteria. Severe acute respiratory syndrome coronavirus 2 takes advantage of this weakened defence in people with obesity to precipitate COVID-19, and in some cases death. It is therefore the author’s recommendation that obesity should be viewed as another form of acquired immunodeficiency syndrome and be treated with the appropriate seriousness. Unlike the previously described acquired immunodeficiency syndrome (AIDS) that is caused by the Human Immunodeficiency Virus (HIV), obesity is a comorbidity-acquired immunodeficiency syndrome. People with AIDS do not die from HIV, but may die from opportunistic pathogens such as Mycobacterium tuberculosis. However, AIDS is ascribed its due importance in the course of deterioration of the patient. Similarly, obesity should be acknowledged further as a risk factor for mortality from COVID-19. Obesity is a modifiable condition and even in people with a strong genetic predisposition, lifestyle modifications can reverse obesity. Strong public health actions are warranted to promote lifestyle measures to reduce the burden from overweight and obesity that currently affect more than one-third of the global population, with projections alarming this may reach 55-80% within the next thirty years.

Keywords:

• Acquired immunodeficiency syndrome
• AIDS
• CAIDS
• cause of death
• comorbidity-acquired immunodeficiency syndrome
• COVID-19
• epidemiology
• HIV
• human immunodeficiency virus
• immune system
• immunity
• morbidity
• mortality
• obesity
• SARS-CoV-2

Acknowledgments

Dr Siopis kindly thanks Dr Robert Finlayson (HIV and Sexual Health Physician, Conjoint Senior Lecturer, The Kirby Institute, University of New South Wales, Sydney, Australia) and Dr Alice Ma (Interventional and Vascular Neurologist, Royal North Shore Hospital, Sydney, Australia) for their discussions and editing suggestions.

Authors’ contributions

George Siopis conceived the idea for the manuscript, reviewed the literature, coined the term “comorbidity-acquired immunodeficiency syndrome (CAIDS)”, conceived the idea of and proposed the mechanism for death due to obesity and its comorbidities (e.g. diabetes) combined with COVID-19, in alignment with the AIDS-opportunistic pathogen mechanism of death, and wrote the manuscript.

Declarations

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Conflicts of interest/competing interests

The author declares no conflicts of interest.

Additional information

Funding

The author declares no receipt of funding for the preparation of this manuscript. George Siopis is a recipient of the Executive Dean Health Research Fellowship from Deakin University.