The association between body mass index and severe biliary infections: a multivariate analysis.
BACKGROUND
Obesity has been associated with worse infectious disease outcomes. It is a risk factor for cholesterol gallstones, but little is known about associations between body mass index (BMI) and biliary infections. We studied this using factors associated with biliary infections.


METHODS
A total of 427 patients with gallstones were studied. Gallstones, bile, and blood (as applicable) were cultured. Illness severity was classified as follows: none (no infection or inflammation), systemic inflammatory response syndrome (fever, leukocytosis), severe (abscess, cholangitis, empyema), or multi-organ dysfunction syndrome (bacteremia, hypotension, organ failure). Associations between BMI and biliary bacteria, bacteremia, gallstone type, and illness severity were examined using bivariate and multivariate analysis.


RESULTS
BMI inversely correlated with pigment stones, biliary bacteria, bacteremia, and increased illness severity on bivariate and multivariate analysis.


CONCLUSIONS
Obesity correlated with less severe biliary infections. BMI inversely correlated with pigment stones and biliary bacteria; multivariate analysis showed an independent correlation between lower BMI and illness severity. Most patients with severe biliary infections had a normal BMI, suggesting that obesity may be protective in biliary infections. This study examined the correlation between BMI and biliary infection severity.
Department of Surgery, University of California San Francisco, San Francisco, CA 94121, USA. lygia.stewart@med.va.gov
Lygia
L
Stewart
J McLeod
JM
Griffiss
Gary A
GA
Jarvis
Lawrence W
LW
Way
D000038:Abscess / Q000209:etiology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000209:etiology; D001646:Bile / Q000382:microbiology; D001660:Biliary Tract Diseases / Q000209:etiology* / Q000382:microbiology; D015992:Body Mass Index; D015331:Cohort Studies; D004653:Empyema / Q000209:etiology*; D005260:Female; D042882:Gallstones / Q000737:chemistry / Q000209:etiology / Q000382:microbiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000209:etiology*; D015999:Multivariate Analysis; D009765:Obesity / Q000150:complications; D012720:Severity of Illness Index; D018746:Systemic Inflammatory Response Syndrome / Q000209:etiology*; D055815:Young Adult