Circulating leptin levels in juvenile idiopathic arthritis: a marker of nutritional status?
BACKGROUND
Weight loss is common in juvenile idiopathic arthritis (JIA) and has been positively correlated with an increase in the production of proinflammatory cytokines.


OBJECTIVE
To assess if plasma leptin is a mediator of cytokine dependent decreased food intake during inflammatory diseases and if it is increased in JIA.


METHODS
Leptin levels were determined in 31 patients with polyarticular disease and in 37 with oligoarticular disease; 32 healthy children served as controls.


RESULTS
Patients had significantly reduced body mass index (BMI) compared with controls (17.3 (3) v 19.1 (3) kg/m(2); p<0.005). Leptin was significantly lower in patients than controls (8.1 (4.8) v 10.7 (7.3) ng/ml; p = 0.036), but leptin/BMI values were similar. Absolute (8.2 (4.8) v 8 (4.9); p>0.05) and normalised (0.45 (0.24) v 0.47 (0.24); p>0.05) leptin levels were not significantly different between patients with active and inactive disease and between patients with oligoarticular and polyarticular arthritis (7.8 (4.4) v 8.6 (5.3); p>0.05 and 0.45 (0.23) v 0.48 (0.26); p>0.05, respectively).


CONCLUSIONS
Leptin production per unit of fat mass is similar in patients and controls. The hypothesis that high levels of proinflammatory cytokines that characterise JIA might induce an increase of adipocytes leptin production is not supported by the results. Leptin may be a marker of nutritional status of JIA.
Perfetto
F
F
Department of Internal Medicine, Rheumatology Unit, University of Florence, 50139 Florence, Italy. perfetto@unifi.it
Tarquini
R
R
Simonini
G
G
Bindi
G
G
Mancuso
F
F
Guiducci
S
S
Matucci-Cerinic
M
M
Falcini
F
F
D017667:Adipocytes / Q000378:metabolism; D000293:Adolescent; D000886:Anthropometry; D001171:Arthritis, Juvenile / Q000097:blood* / Q000473:pathology; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002648:Child; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D009752:Nutritional Status
D015415:Biomarkers; D020738:Leptin