BACKGROUND: Recent studies have demonstrated that human preadipocyte fibroblastsin orbital connective tissues from patients with Graves' ophthalmopathy differentiate into cells resemblingadipocytes and acquire expression of leptin and functional thyroid stimulating hormone receptors. Thesefinding imply that leptin may play a role in the pathogenesis of Graves' ophthalmopathy. However, littleis known about plasma leptin concentration in patients with Graves' disease with or without ophthalmopathy.
MATERIAL AND METHODS: To investigate this relationship; 28 patients with active Graves' ophthalmopathy(19 female and 9 male, mean age: 32.7+/-10.5 years, mean BMI: 24.8+/-3.7 kg/m2) and 10 patients withoutophthalmopathy (6 female and 4 male, mean age: 24.6+/-5.6, mean BMI: 23.02+/-2.4 kg/m2) all with untreatedGraves' disease were included in the study at first diagnosis in our endocrinology out-patient clinic.Sex-, BMI- and age-matched twenty healthy subjects (13 female, 7 male, mean age: 31.9+/-10.0, mean BMI:24.2+/-3.0 kg/m2) were selected as a control group. Plasma leptin levels were measured by a RIA methodwith a sensitivity of 0.5 ng/ml.
RESULTS: Results showed any significant differences neither betweenpatients and controls (7.97+/-5.2 ng/ml vs. 7.83+/-3.7 ng/ml) nor between patients with or without Graves'ophthalmopathy (8.29+/-5.0 ng/ml vs. 7.06+/-5.8 ng/ml) (both P>0.05). Moreover, no correlation was foundbetween plasma leptin levels and ophthalmopathy index score, or proptosis.
CONCLUSIONS: Although effectsof local leptin production in the orbit cannot be excluded, our data suggest that circulating plasmaleptin does not have a significant direct influence on ophthalmopathy index score or pathophysiologyof Graves' ophthalmopathy.

Keywords: Graves, Leptin