Year: 2015
Type: editorial
Abstract: Infections, both community-acquired and nosocomial, are a major source of morbidity and mortality in patients with cirrhosis.1 The overall 3- and 12-month mortality in cirrhotic patients with infections is 30.3% and 63%, respectively, and is 4-times higher as compared to patients without infections. Hence, there is great impetus to identify factors, which may modify infection risk in patients with cirrhosis. In a recent issue of the Journal, Sundaram et al., used the Nationwide Inpatient Sample to study whether obesity may be an independent risk factor for infection in patients with cirrhosis.2 They observed that among 115 465 patients hospitalised with cirrhosis, 12.5% were classified as obese. About one-third of patients had a diagnosis of infection, with significantly higher prevalence in patients with class III obesity [body mass index (BMI), ≥40 kg/m2) (44.0%), followed by class I/II obesity (BMI 30.0–39.9 kg/m2) (38.9%), followed by nonobese adults (31.9%). Obese patients had a higher prevalence of urinary tract infections, bacteraemia and skin/soft tissue infections, whereas a lower prevalence of spontaneous bacterial peritonitis, as compared to nonobese patients. On multivariable-adjusted analysis after controlling for risk factors associated with infection, patients with cirrhosis who had class III obesity and class I/II obesity were associated higher risk of infection as compared to nonobese patients with cirrhosis, respectively. While there are inherent limitations of using an administrative database (risk of misclassification of exposure and outcome, lack of access to patient level data and more granular risk factors of infection), these findings may have important implications. With an estimated 1.9 billion adults worldwide being overweight, of which 600 million are obese, the prevalence of overweight and obesity has reached epidemic proportions.3 Obesity is an independent risk factor for nonalcoholic fatty liver disease, and also portends worse prognosis in patients with other chronic liver diseases.4 Obesity along with other factors such as alcohol use and/or smoking may even have a synergistic effect in worsening liver-related outcomes such as mortality and hepatocellular carcinoma.5-7 In the general population, obesity has been associated with an increased risk of both bacterial and viral infections, at several body sites, and nosocomial and surgical site infections.8 Obese patients are also more likely to get more severe infections than their nonobese counterparts, and carry poorer prognosis with higher risk of resistance to treatment.9 This increased infection risk is probably attributable to metabolically active visceral fat, as opposed to subcutaneous fat. Adipocytokines, in particular leptin, activates polymorphonuclear neutrophils, exerts proliferative and anti-apoptotic activities on T lymphocytes, affects cytokine production, regulates the activation of monocytes/macrophages, and contributes to wound healing.10 The increased risk of skin and soft tissue infections, however, may be related to impaired blood supply in adults with subcutaneous adiposity. Clinicians should be cognizant of this association between obesity and infection risk in cirrhosis. Prospective studies are warranted to better understand pathophysiology, risk stratification as well as outcomes in this cohort. This offers further impetus to tackle to growing obesity epidemic in liver diseases. Declaration of personal and funding interests: None.
DOI: 10.1111/apt.13463
Institution: University of California San Diego
Language: English
Subfield: Hepatology
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2219591005