Review
Obesity and infection

https://doi.org/10.1016/S1473-3099(06)70523-0Get rights and content

Summary

Obesity increases morbidity and mortality through its multiple effects on nearly every human system. However, the various aspects of the association between obesity and infection have not been reviewed. Thus, we reviewed the relevant literature focusing on clinical aspects of this association. Obesity has a clear but not yet precisely defined effect on the immune response through a variety of immune mediators, which leads to susceptibility to infections. Data on the incidence and outcome of specific infections, especially community-acquired infections, in obese people are so far limited. The available data suggest that obese people are more likely than people of normal weight to develop infections of various types including postoperative infections and other nosocomial infections, as well to develop serious complications of common infections. Large prospective studies are required to further define the burden of infectious morbidity and mortality conferred by obesity.

Introduction

The US National Institutes of Health and the WHO classify people regarding their body weight according to the body mass index (BMI), calculated as body weight (in kg) divided by the body height (in m) squared. Overweight, obese, and morbidly obese people are those with a BMI 25–30 kg/m2, 30–40 kg/m2, and greater than 40 kg/m2, respectively. Normal weight and underweight people are those with BMI 20–25 kg/m2 and less than 20 kg/m2, respectively. Obesity, through various well-described pathophysiological interactions, increases the risk of cardiovascular and other diseases, compromises the quality of life, and increases overall mortality.1, 2 However, the various aspects of the association between obesity and infection have not been reviewed.

We review the available evidence regarding the various aspects of the association between obesity and infection, including obesity-related mechanisms that lead to predisposition to infections, the epidemiology of nosocomial and community-acquired infections in the obese population, and special issues related to the management of infections in the obese patient. We briefly review infections that are the result of procedures for the management of obesity. In addition, we mention the evidence for the reverse association between obesity and infection—namely, the possibility that infectious agents may have an aetiological role in obesity, an idea known as “infectobesity”.

Section snippets

Mechanisms that predispose obese patients to infection

It has been recently recognised that the adipose tissue participates actively in inflammation and immunity, producing and releasing a variety of proinflammatory and anti-inflammatory factors, including the well-studied adipokines leptin and adiponectin, as well as cytokines and chemokines.3 Adiponectin is potently immunosuppressive,4 while leptin activates polymorphonuclear neutrophils,5 exerts proliferative and anti-apoptotic activities on T lymphocytes, affects cytokine production, regulates

Nosocomial infections

The incidence of nosocomial infections in overweight and obese patients is increased compared with normal weight patients. Routine medical care of obese patients in everyday practice may present certain difficulties. In some instances usual diagnostic and treatment procedures must be modified. For example, some computed tomography equipment cannot accommodate obese patients above a certain weight limit. Routine care of non-ambulatory morbidly obese patients (eg, lifting and bathing) requires

Infections in critically ill patients

Obese and morbidly obese patients in the intensive care unit setting are reported to have higher mortality compared with normal weight patients.80, 81 A matched cohort study compared 170 mechanically ventilated patients with BMI over 30 kg/m2 with 170 normal weight mechanically ventilated patients. The obese patients had increased intensive care unit mortality (OR 2·1, 95% CI 1·2–3·6), explained by a higher risk of complications (OR 4·0, 95% CI 1·4–11·8), including sepsis, ventilator-associated

Obesity and HIV infection

Only a few studies have addressed the association of baseline obesity with the natural progression of HIV infection, the response to antiretroviral treatment, and other outcomes in HIV-infected patients. The effects of obesity on immune function, disease progression, and mortality were evaluated longitudinally in 125 HIV-1-seropositive drug users and 148 HIV-1-seronegative controls followed at a community clinic from 1992 to 1996, before administration of highly active antiretroviral therapy

Infections following procedures for the management of obesity

Several procedures have been used in obese patients for the management of obesity itself and for the restoration of the accompanying cosmetic deformities. These procedures are sometimes complicated by infections caused by common or rare microorganisms.

Liposuction is a common cosmetic procedure. Infectious complications following liposuction have occasionally been reported and include subcutaneous abscesses, herpes zoster virus infection, necrotising fasciitis, and wound infection caused by

Management of infection in obese patients

Despite the growing prevalence of obesity worldwide, there are no well-established guidelines about the management of infections in obese patients, including specific recommendations regarding adjustment of dosage of therapy with antimicrobial agents, when necessary.

Several variables related to body weight have been used in pharmacokinetic studies in obese individuals, including body weight, lean body weight, ideal body weight, body surface area, BMI, fat-free mass, percent ideal body weight,

Obesity of infectious origin

Obesity of infectious origin is a concept that has been studied in animal models during the past two decades. Seven different pathogens (canine distemper virus, Rous-associated virus 7, Borna disease virus, scrapie agent, SMAM-1 avian adenovirus, and human adenoviruses Ad36 and Ad37) have been reported to cause obesity in animal models.119, 120 Canine distemper virus, a morbillivirus closely related to the human measles virus, was the first reported obesity-promoting virus, inducing

Conclusions

Although obesity is a well-known risk factor for several morbid conditions, its relation to infection has not been adequately studied. The available evidence suggests that infections of several organs and systems are more common in obese people than those of normal weight. However, the literature is so far lacking large epidemiological studies that could verify obvious or expected associations between obesity and infection and reject biased assumptions. In addition, it should be noted that

Search strategy and selection criteria

We searched PubMed to identify English language articles on the association between obesity and infection. Relevant articles published between 1975 and 2005 were sought using the term “obesity” in combination with other terms including “immune system”, “cellular immunity”, “humoral immunity”, “sepsis”, “white blood cell”, “cytokine”, “chemotaxis”, or “transplantation”, as well as “obesity” in combination with various specific organ and system infections. To expand our search strategy, we

References (129)

  • RW Vaughan et al.

    Part I: cardiopulmonary consequences of morbid obesity

    Life Sci

    (1980)
  • P Marik et al.

    The obese patient in the ICU

    Chest

    (1998)
  • W Jedrychowski et al.

    Predisposition to acute respiratory infections among overweight preadolescent children: an epidemiologic study in Poland

    Public Health

    (1998)
  • A Monto et al.

    Steatosis in chronic hepatitis C: relative contributions of obesity, diabetes mellitus, and alcohol

    Hepatology

    (2002)
  • V Ortiz et al.

    Contribution of obesity to hepatitis C-related fibrosis progression

    Am J Gastroenterol

    (2002)
  • J Massard et al.

    Natural history and predictors of disease severity in chronic hepatitis C

    J Hepatol

    (2006)
  • JS Torgerson et al.

    Gallstones, gallbladder disease, and pancreatitis: cross-sectional and 2-year data from the Swedish Obese Subjects (SOS) and SOS reference studies

    Am J Gastroenterol

    (2003)
  • J Suazo-Barahona et al.

    Obesity: a risk factor for severe acute biliary and alcoholic pancreatitis

    Am J Gastroenterol

    (1998)
  • JJ Snyder et al.

    Body size and outcomes on peritoneal dialysis in the United States

    Kidney Int

    (2003)
  • DE Slade et al.

    Hidradenitis suppurativa: pathogenesis and management

    Br J Plast Surg

    (2003)
  • A El-Solh et al.

    Morbid obesity in the medical ICU

    Chest

    (2001)
  • RJ Knight et al.

    Risk factors for intra-abdominal infection after pancreas transplantation

    Am J Surg

    (2000)
  • A Humar et al.

    The impact of donor obesity on outcomes after cadaver pancreas transplants

    Am J Transplant

    (2004)
  • J Rogers et al.

    Influence of mild obesity on outcome of simultaneous pancreas and kidney transplantation

    J Gastrointest Surg

    (2003)
  • FX Pi-Sunyer

    The medical risks of obesity

    Obes Surg

    (2002)
  • EE Calle et al.

    Body-mass index and mortality in a prospective cohort of U.S. adults

    N Engl J Med

    (1999)
  • H Zarkesh-Esfahani et al.

    Leptin indirectly activates human neutrophils via induction of TNF-alpha

    J Immunol

    (2004)
  • G Fantuzzi et al.

    Leptin in the regulation of immunity, inflammation, and hematopoiesis

    J Leukoc Biol

    (2000)
  • M Ozata et al.

    Human leptin deficiency caused by a missense mutation: multiple endocrine defects, decreased sympathetic tone, and immune system dysfunction indicate new targets for leptin action, greater central than peripheral resistance to the effects of leptin, and spontaneous correction of leptin of leptin-mediated defects

    J Clin Endocrinol Metab

    (1999)
  • R Faggioni et al.

    Leptin regulation of the immune response and the immunodeficiency of malnutrition

    FASEB J

    (2001)
  • S Ikejima et al.

    Impairment of host resistance to Listeria monocytogenes infection in liver of db/db and ob/ob mice

    Diabetes

    (2005)
  • P Mancuso et al.

    Leptin-deficient mice exhibit impaired host defense in Gram-negative pneumonia

    J Immunol

    (2002)
  • MC Blanc et al.

    Arginine and glutamine availability and macrophage functions in the obese insulin-resistant Zucker rat

    J Cell Physiol

    (2005)
  • V Vachharajani et al.

    Obesity exacerbates sepsis-induced inflammation and microvascular dysfunction in mouse brain

    Microcirculation

    (2005)
  • BJ Plotkin et al.

    Immune responsiveness in a rat model for type II diabetes (Zucker rat, fa/fa): susceptibility to Candida albicans infection and leucocyte function

    J Med Microbiol

    (1996)
  • O Lamas et al.

    Obesity and immunocompetence

    Eur J Clin Nutr

    (2002)
  • C Winkelman et al.

    Obese ICU patients: resource utilization and outcomes

    Clin Nurs Res

    (2005)
  • PS Choban et al.

    Increased incidence of nosocomial infections in obese surgical patients

    Am Surg

    (1995)
  • Z Canturk et al.

    Nosocomial infections and obesity in surgical patients

    Obes Res

    (2003)
  • E Fleischmann et al.

    Tissue oxygenation in obese and non-obese patients during laparoscopy

    Obes Surg

    (2005)
  • LA Herwaldt et al.

    Preoperative risk factors for nasal carriage of Staphylococcus aureus

    Infect Control Hosp Epidemiol

    (2004)
  • M Lofgren et al.

    Postoperative infections and antibiotic prophylaxis for hysterectomy in Sweden: a study by the Swedish National Register for Gynecologic Surgery

    Acta Obstet Gynecol Scand

    (2004)
  • MA Olsen et al.

    Risk factors for surgical site infection in spinal surgery

    J Neurosurg

    (2003)
  • C Wimmer et al.

    Predisposing factors for infection in spine surgery: a survey of 850 spinal procedures

    J Spinal Disord

    (1998)
  • DE Lilienfeld et al.

    Obesity and diabetes as risk factors for postoperative wound infections after cardiac surgery

    Am J Infect Control

    (1988)
  • EV Potapov et al.

    Impact of body mass index on outcome in patients after coronary artery bypass grafting with and without valve surgery

    Eur Heart J

    (2003)
  • G Harrington et al.

    Surgical-site infection rates and risk factor analysis in coronary artery bypass graft surgery

    Infect Control Hosp Epidemiol

    (2004)
  • MS Al-Zahrani et al.

    Obesity and periodontal disease in young, middle-aged, and older adults

    J Periodontol

    (2003)
  • N Wood et al.

    Comparison of body composition and periodontal disease using nutritional assessment techniques: Third National Health and Nutrition Examination Survey (NHANES III)

    J Clin Periodontol

    (2003)
  • B Willershausen et al.

    Relationship between high weight and caries frequency in German elementary school children

    Eur J Med Res

    (2004)
  • Cited by (677)

    View all citing articles on Scopus
    View full text