THYROID-DYSFUNCTION IS NOT ASSOCIATED WITH ALTERATIONS IN SERUM LEPTIN LEVELS

To determine if serum leptin levels are affected by thyroid dysfunctio n, we measured its concentration in serum samples from 25 euthyroid co ntrols and 25 subjects each with hypothyroidism and thyrotoxicosis col lected over a 3-month period. Mean leptin levels in the euthyroid (24. 1 +/- 8.3 mu g/L), hypothyroid (22.7 +/- 7.0 mu g/L) and thyrotoxic (2 3.3 +/- 4.3 mu g/L) groups were not significantly different. Data were available to express leptin in terms of body mass index (BMI) in 11 e uthyroid,and 6 untreated hypothyroid and thyrotoxic individuals. There was a significant positive correlation between BMI and leptin level ( r=0.60, p=.0002) for this subgroup, irrespective of their thyroid stat us. These data suggest that leptin levels are not affected by thyroid dysfunction.