Leptin concentration and the Zn/Cu ratio in plasma in women with thyroid disorder

We investigated the possible correlation between the leptin concentration and the Zn/Cu ratio in the plasma of women with thyroid disorder. Forty women with hypothyroidism (n=20) or hypothyroidism (n=20) and 20 euthyroid controls were recruited. The results showed that the women with thyroid disorder (hypothyroidism or hyperthyroidism) had higher plasma leptin concentrations than the normal controls (p<0.05). Moreover, the plasma leptin concentration had no correlation with plasma thyroid hormone levels in the separate groups, nor among all the participants considered together. A strong correlation (p<0.005) between leptin and adiposity was only observed in euthyroid women. Plasma values of Zn and Cu and the Zn/Cu ratio were not markedly different among women with altered thyroid status. However, a weak correlation (r=0.28, p=0.032) between leptin and the Zn/Cu ratio was found from the pooled data of all participants and retained after adjustment for adiposity. We suggest that there may exist an interaction between the plasma leptin level and thyroid hormone-induced abnormality for selected minerals.