Impressive lipid changes following hypolipidaemic drug administration can unveil subclinical hyperthyroidism.

It is well known that thyroid hormones modulate lipoprotein metabolism. Thus, the presence of clinical or subclinical hyperthyroidism may influence lipid parameters of dyslipidaemic patients and the efficacy of hypolipidaemic therapy. Here we present a patient with mixed hyperlipidaemia whose impressive improvement of his lipid profile following ciprofibrate administration pointed towards the diagnosis of asymptomatic underlying subclinical hyperthyroidism.