Interleukin-6 and human immunodeficiency virus load, but not plasma leptin concentration, predict anorexia and wasting in adults with pulmonary tuberculosis in Malawi.
BACKGROUND
Wasting is a prominent feature of tuberculosis and may be more severe among individuals with HIV coinfection. It is likely that several biological mechanisms, including the anorexia of infection, are contributing to wasting.


OBJECTIVE
The purpose of this study was to determine whether leptin concentrations, in relation to the inflammatory cytokine response and level of HIV infection, are contributing to loss of appetite and wasting in adults with pulmonary tuberculosis and HIV infection.


METHODS
We characterized plasma leptin concentrations in relationship with self-reported loss of appetite, body mass index, fat mass (FM), IL-6, and HIV load in a cross-sectional study of 500 adults who presented with pulmonary tuberculosis in Zomba, Malawi.


RESULTS
Plasma leptin concentrations, associated with FM, significantly decreased by increasing tertile of plasma HIV load (P = 0.0001). Leptin concentrations were inversely associated with plasma IL-6 concentrations after adjusting for sex, age, FM, and HIV load. Plasma leptin concentrations were associated with neither loss of appetite nor wasting. Inflammation, reflected by increased IL-6 concentrations, was associated with loss of appetite (odds ratio, 3.41; 95% confidence interval, 1.91-6.09), when adjusted for sex, age, FM, leptin concentrations, and HIV load. A high plasma HIV load was associated with severe wasting, defined as body mass index less than 16.0 kg/m2 (odds ratio, 2.14; 95% confidence interval, 1.09-4.19) when adjusted for sex, age, IL-6, FM, and leptin concentrations.


CONCLUSIONS
This study suggests that the anorexia and wasting seem primarily determined by the level of inflammation and the level of HIV infection in patients with tuberculosis and HIV coinfection.
van Lettow
Monique
M
Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA. mvlettow@imailbox.com
van der Meer
Jos W M
JW
West
Clive E
CE
van Crevel
Reinout
R
Semba
Richard D
RD
D000328:Adult; D000855:Anorexia / Q000097:blood / Q000209:etiology / Q000276:immunology*; D001066:Appetite; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D019247:HIV Wasting Syndrome / Q000097:blood / Q000150:complications / Q000276:immunology*; D006801:Humans; D015850:Interleukin-6 / Q000097:blood / Q000276:immunology*; D020738:Leptin / Q000097:blood*; D008295:Malawi; D008297:Male; D011237:Predictive Value of Tests; D014397:Tuberculosis, Pulmonary / Q000150:complications*; D019562:Viral Load
D015415:Biomarkers; D015850:Interleukin-6; D020738:Leptin