Leptin, the product of the ob gene, is secreted mainly by adipocytes. It regulates body weight by suppressing food intake and increasing energy expenditure. It is well known that hyperthyroidism changes the body weight and appetite, however its possible influence on leptin levels remains controversial. The aim of this study was to assess the effects of hyperthyroidism on leptin levels in women. Twenty-one newly diagnosed patients with hyperthyroidism and twenty-four healthy women who were age, sex and body mass index matched, were participated in this study. Serum leptin levels were measured by specific radioimmunoassay. The mean leptin level in the hyperthyroid patient group was lower (18.62 ± 14.37 ng/ml) than in the control group (38.91±19.82 ng/ml; P<0.0001). Serum leptin levels correlated with body mass index in the hyperthyroidism and control groups (r:0.65, P<0.01; r:0.47, P<0.05 respectively). In conclusion, leptin levels are decreased in hyperthyroid patients.
Keywords: Leptin, hyperthyroidism, women