Abstract
The relationship between serum cholesterol, thyrotropin, thyroxine and triiodothyronine was investigated in 456 male patients with suspected hypothyroidism. The correlation between serum cholesterol and serum thyroxine (r = 0·0572) and between serum cholesterol and serum triiodothyronine (r = 0·1136) were not significant but the correlation between serum cholesterol and TSH (r = 0·0376) was significant (P< 0·001). The mean serum cholesterol was only significantly increased in the patient groups with a serum TSH greater than 20 mU/L. In 26 patients treated for hypothyroidism with thyroxine replacement there was a significant correlation between the decrease in serum cholesterol and the decrease in serum TSH (r = 0·5334, P<0·01) but there was poor correlation between the decrease in cholesterol and either the increase in serum triiodothyronine or the increase in serum thyroxine.